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Sample records for acrylonitrile butadiene styrene

  1. Survey of volatile substances in kitchen utensils made from acrylonitrile-butadiene-styrene and acrylonitrile-styrene resin in Japan.

    PubMed

    Abe, Yutaka; Yamaguchi, Miku; Mutsuga, Motoh; Kawamura, Yoko; Akiyama, Hiroshi

    2014-05-01

    Residual levels of 14 volatile substances, including 1,3-butadiene, acrylonitrile, benzene, ethylbenzene, and styrene, in 30 kitchen utensils made from acrylonitrile-butadiene-styrene resin (ABS) and acrylonitrile-styrene resin (AS) such as slicers, picks, cups, and lunch boxes in Japan were simultaneously determined using headspace gas chromatography/mass spectroscopy (HS-GC/MS). The maximum residual levels in the ABS and AS samples were found to be 2000 and 2800 μg/g of styrene, respectively. The residual levels of 1,3-butadiene ranged from 0.06 to 1.7 μg/g in ABS, and three of 15 ABS samples exceeded the regulatory limit for this compound as established by the European Union (EU). The residual levels of acrylonitrile ranged from 0.15 to 20 μg/g in ABS and from 19 to 180 μg/g in AS. The levels of this substance in seven ABS and six AS samples exceeded the limit set by the U.S. Food and Drug Administration (FDA). Furthermore, the levels of acrylonitrile in three AS samples exceeded the voluntary standard established by Japanese industries. These results clearly indicate that the residual levels of some volatile compounds are still high in ABS and AS kitchen utensils and further observations are needed.

  2. Reactive processing of recycled polycarbonate/acrylonitrile butadiene styrene.

    PubMed

    Jung, Woo-Hyuk; Choi, Yeon-Sil; Moon, Jung-Min; Tortorrela, Nathan; Beatty, Charles L; Lee, Jang-Oo

    2009-04-01

    Cellular phone housings were ground to make original particulates using a knife mill. Foams and adhesives with a lighter density than water were removed from ground mixtures using a sink-float process in water; ground metals, button rubbers, and wires were separated from desired materials by using a sink float process in salt All housing materials, consisting of seven thermoplastics included in cellular phone housings, showed better tensile properties than pure housing materials made of polycarbonate/acrylonitrile butadiene styrene, but they only had about half of the impact strength. In contrast, the low impact strength for all housing materials was improved by adding 25 wt % polyethylene elastomer and/or 2.4 wt % ground epoxy circuit boards for batch mixing. Impact strengths, tensile strengths, and the energy absorption ability of all housing materials were improved by adding 5.4wt% glycidyl methacrylate for twin screw extrusion.

  3. Dynamic Evolution of Acrylonitrile Butadiene Styrene (ABS) Subjected to High Strain Rate Compressive Loads

    DTIC Science & Technology

    2013-01-01

    Salisbury, M. Worswick, D. Lloyd, M. Finn, High strain rate tensile testing of automotive aluminum alloy sheet, International Journal of Impact...selected aluminum alloys, Materials Science and Engineering: A, Volume 278, Issues 1–2, 15 February 2000, Pages 225-235 [6] A.G. Odeshi, S. Al-ameeri...mechanical behavior of the of 3D-printed Acrylonitrile Butadiene Styrene material to assess potential strain rate dependency. The mechanical

  4. Characterisation of recycled acrylonitrile-butadiene-styrene and high-impact polystyrene from waste computer equipment in Brazil.

    PubMed

    Hirayama, Denise; Saron, Clodoaldo

    2015-06-01

    Polymeric materials constitute a considerable fraction of waste computer equipment and polymers acrylonitrile-butadiene-styrene and high-impact polystyrene are the main thermoplastic polymeric components found in waste computer equipment. Identification, separation and characterisation of additives present in acrylonitrile-butadiene-styrene and high-impact polystyrene are fundamental procedures to mechanical recycling of these polymers. The aim of this study was to evaluate the methods for identification of acrylonitrile-butadiene-styrene and high-impact polystyrene from waste computer equipment in Brazil, as well as their potential for mechanical recycling. The imprecise utilisation of symbols for identification of the polymers and the presence of additives containing toxic elements in determinate computer devices are some of the difficulties found for recycling of acrylonitrile-butadiene-styrene and high-impact polystyrene from waste computer equipment. However, the considerable performance of mechanical properties of the recycled acrylonitrile-butadiene-styrene and high-impact polystyrene when compared with the virgin materials confirms the potential for mechanical recycling of these polymers.

  5. Preparing cellulose nanocrystal/acrylonitrile-butadiene-styrene nanocomposites using the master-batch method.

    PubMed

    Ma, Libo; Zhang, Yang; Meng, Yujie; Anusonti-Inthra, Phuriwat; Wang, Siqun

    2015-07-10

    The master-batch method provides a simple way to apply cellulose nanocrystal (CNC) as reinforcement in a hydrophobic matrix. The two-stage process includes making high-CNC content (70 wt%) master batch pellets, then mixing acrylonitrile-butadiene-styrene (ABS) and maleic anhydride grafted polyethylene with the master batch pellets to prepare the ABS/CNC nanocomposite in extruder. SEM image indicates that self-assembled CNC nanosheets disperse evenly throughout the polymer matrix. The improved mechanical properties shown in tensile and DMA tests reveal that the CNC combines well with the ABS. TGA results show that the thermal degradation temperature of CNC in the master batch increases because of the protection of the ABS coating. This approach not only improves the dispersion ability and the thermal stability of CNC, but it is also applicable to use with other hydrophobic thermoplastics in industrial scale production.

  6. Design and testing of digitally manufactured paraffin Acrylonitrile-butadiene-styrene hybrid rocket motors

    NASA Astrophysics Data System (ADS)

    McCulley, Jonathan M.

    This research investigates the application of additive manufacturing techniques for fabricating hybrid rocket fuel grains composed of porous Acrylonitrile-butadiene-styrene impregnated with paraffin wax. The digitally manufactured ABS substrate provides mechanical support for the paraffin fuel material and serves as an additional fuel component. The embedded paraffin provides an enhanced fuel regression rate while having no detrimental effect on the thermodynamic burn properties of the fuel grain. Multiple fuel grains with various ABS-to-Paraffin mass ratios were fabricated and burned with nitrous oxide. Analytical predictions for end-to-end motor performance and fuel regression are compared against static test results. Baseline fuel grain regression calculations use an enthalpy balance energy analysis with the material and thermodynamic properties based on the mean paraffin/ABS mass fractions within the fuel grain. In support of these analytical comparisons, a novel method for propagating the fuel port burn surface was developed. In this modeling approach the fuel cross section grid is modeled as an image with white pixels representing the fuel and black pixels representing empty or burned grid cells.

  7. Acrylonitrile Butadiene Styrene (ABS) plastic based low cost tissue equivalent phantom for verification dosimetry in IMRT.

    PubMed

    Kumar, Rajesh; Sharma, S D; Deshpande, Sudesh; Ghadi, Yogesh; Shaiju, V S; Amols, H I; Mayya, Y S

    2009-12-17

    A novel IMRT phantom was designed and fabricated using Acrylonitrile Butadiene Styrene (ABS) plastic. Physical properties of ABS plastic related to radiation interaction and dosimetry were compared with commonly available phantom materials for dose measurements in radiotherapy. The ABS IMRT phantom has provisions to hold various types of detectors such as ion chambers, radiographic/radiochromic films, TLDs, MOSFETs, and gel dosimeters. The measurements related to pre-treatment dose verification in IMRT of carcinoma prostate were carried out using ABS and Scanditronics-Wellhoffer RW3 IMRT phantoms for five different cases. Point dose data were acquired using ionization chamber and TLD discs while Gafchromic EBT and radiographic EDR2 films were used for generating 2-D dose distributions. Treatment planning system (TPS) calculated and measured doses in ABS plastic and RW3 IMRT phantom were in agreement within +/-2%. The dose values at a point in a given patient acquired using ABS and RW3 phantoms were found comparable within 1%. Fluence maps and dose distributions of these patients generated by TPS and measured in ABS IMRT phantom were also found comparable both numerically and spatially. This study indicates that ABS plastic IMRT phantom is a tissue equivalent phantom and dosimetrically it is similar to solid/plastic water IMRT phantoms. Though this material is demonstrated for IMRT dose verification but it can be used as a tissue equivalent phantom material for other dosimetry purposes in radiotherapy.

  8. Method for the separation of high impact polystyrene (HIPS) and acrylonitrile butadiene styrene (ABS) plastics

    DOEpatents

    Jody, Bassam J.; Arman, Bayram; Karvelas, Dimitrios E.; Pomykala, Jr., Joseph A.; Daniels, Edward J.

    1997-01-01

    An improved method is provided for separating acrylonitrile butadiene styrene (ABS) and high impact polystyrene (HIPS) plastics from each other. The ABS and HIPS plastics are shredded to provide a selected particle size. The shredded particles of the ABS and HIPS plastics are applied to a solution having a solution density in a predefined range between 1.055 gm/cm.sup.3 and 1.07 gm/cm.sup.3, a predefined surface tension in a range between 22 dynes/cm to 40 dynes/cm and a pH in the range of 1.77 and 2.05. In accordance with a feature of the invention, the novel method is provided for separating ABS and HIPS, two solid thermoplastics which have similar densities by selectively modifying the effective density of the HIPS using a binary solution with the appropriate properties, such as pH, density and surface tension, such as a solution of acetic acid and water or a quaternary solution having the appropriate density, surface tension, and pH.

  9. Fabrication of Acrylonitrile-Butadiene-Styrene Nanostructures with Anodic Alumina Oxide Templates, Characterization and Biofilm Development Test for Staphylococcus epidermidis.

    PubMed

    Desrousseaux, Camille; Cueff, Régis; Aumeran, Claire; Garrait, Ghislain; Mailhot-Jensen, Bénédicte; Traoré, Ousmane; Sautou, Valérie

    2015-01-01

    Medical devices can be contaminated by microbial biofilm which causes nosocomial infections. One of the strategies for the prevention of such microbial adhesion is to modify the biomaterials by creating micro or nanofeatures on their surface. This study aimed (1) to nanostructure acrylonitrile-butadiene-styrene (ABS), a polymer composing connectors in perfusion devices, using Anodic Alumina Oxide templates, and to control the reproducibility of this process; (2) to characterize the physico-chemical properties of the nanostructured surfaces such as wettability using captive-bubble contact angle measurement technique; (3) to test the impact of nanostructures on Staphylococcus epidermidis biofilm development. Fabrication of Anodic Alumina Oxide molds was realized by double anodization in oxalic acid. This process was reproducible. The obtained molds present hexagonally arranged 50 nm diameter pores, with a 100 nm interpore distance and a length of 100 nm. Acrylonitrile-butadiene-styrene nanostructures were successfully prepared using a polymer solution and two melt wetting methods. For all methods, the nanopicots were obtained but inside each sample their length was different. One method was selected essentially for industrial purposes and for better reproducibility results. The flat ABS surface presents a slightly hydrophilic character, which remains roughly unchanged after nanostructuration, the increasing apparent wettability observed in that case being explained by roughness effects. Also, the nanostructuration of the polymer surface does not induce any significant effect on Staphylococcus epidermidis adhesion.

  10. Fabrication of Acrylonitrile-Butadiene-Styrene Nanostructures with Anodic Alumina Oxide Templates, Characterization and Biofilm Development Test for Staphylococcus epidermidis

    PubMed Central

    Desrousseaux, Camille; Cueff, Régis; Aumeran, Claire; Garrait, Ghislain; Mailhot-Jensen, Bénédicte; Traoré, Ousmane; Sautou, Valérie

    2015-01-01

    Medical devices can be contaminated by microbial biofilm which causes nosocomial infections. One of the strategies for the prevention of such microbial adhesion is to modify the biomaterials by creating micro or nanofeatures on their surface. This study aimed (1) to nanostructure acrylonitrile-butadiene-styrene (ABS), a polymer composing connectors in perfusion devices, using Anodic Alumina Oxide templates, and to control the reproducibility of this process; (2) to characterize the physico-chemical properties of the nanostructured surfaces such as wettability using captive-bubble contact angle measurement technique; (3) to test the impact of nanostructures on Staphylococcus epidermidis biofilm development. Fabrication of Anodic Alumina Oxide molds was realized by double anodization in oxalic acid. This process was reproducible. The obtained molds present hexagonally arranged 50 nm diameter pores, with a 100 nm interpore distance and a length of 100 nm. Acrylonitrile-butadiene-styrene nanostructures were successfully prepared using a polymer solution and two melt wetting methods. For all methods, the nanopicots were obtained but inside each sample their length was different. One method was selected essentially for industrial purposes and for better reproducibility results. The flat ABS surface presents a slightly hydrophilic character, which remains roughly unchanged after nanostructuration, the increasing apparent wettability observed in that case being explained by roughness effects. Also, the nanostructuration of the polymer surface does not induce any significant effect on Staphylococcus epidermidis adhesion. PMID:26284922

  11. 21 CFR 177.1050 - Acrylonitrile/styrene copoly-mer modified with butadiene/styrene elastomer.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... Determination of Polymer Extracted from Borex ® 210 Resin Pellets,” which is incorporated by reference. Copies... ADDITIVES: POLYMERS Substances for Use as Basic Components of Single and Repeated Use Food Contact Surfaces... butadiene/styrene elastomer consists of a blend of: (1) 82-88 parts by weight of a matrix copolymer...

  12. 21 CFR 177.1050 - Acrylonitrile/styrene copoly-mer modified with butadiene/styrene elastomer.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... Determination of Polymer Extracted from Borex ® 210 Resin Pellets,” which is incorporated by reference. Copies... ADDITIVES: POLYMERS Substances for Use as Basic Components of Single and Repeated Use Food Contact Surfaces... butadiene/styrene elastomer consists of a blend of: (1) 82-88 parts by weight of a matrix copolymer...

  13. Effect of reactive compatibilization on the morphology and physical properties of bisphenol-A-polycarbonate/acrylonitrile-butadiene-styrene blends

    NASA Astrophysics Data System (ADS)

    Wildes, Gregg Stephen

    1998-11-01

    An amine functional styrene-acrylonitrile (SAN-amine) polymer is proposed as a reactive compatibilizer for bisphenol-A-polycarbonate/acrylonitrile-butadiene-styrene (PC/ABS) blends. This polymer is miscible with the styrene/acrylonitrile (SAN) copolymer matrix of ABS materials, and the pendant secondary amine groups react with PC at the carbonate linkage to form a SAN-g-PC copolymer. The graft copolymer molecules reside at the PC/ABS interface and provide improved morphological stability at elevated temperatures by suppressing phase coalescence. The synthesis of this reactive compatibilizer and its reaction with carbonate moieties is described. Characterization of this reaction was done by NMR and GPC using model secondary amine and carbonate containing compounds. A technique was developed for the quantitative measurement of the kinetics of dispersed phase particle coalescence in these blends; the morphology was examined using TEM. While uncompatibilized PC/SAN blends showed an increase in particle size from approximately 1 mum to 2 mum (depending on PC viscosity) in less than five minutes at 270sp°C; compatibilized blends containing as little as 1% SAN-amine exhibited no change in morphology after 20 minutes. The effects of dispersed phase concentration, viscosity ratio and interfacial compatibilization using the SAN-amine compatibilizer on the process induced morphology of PC/SAN blends were also examined. Dispersed phase particle size increased significantly with SAN concentration and, although the morphology of uncompatibilized PC/SAN blends mixed in a Brabender mixer, single and twin screw extruders were quite similar, the twin screw extruder produced significantly finer morphologies in blends containing SAN-amine. The average particle size for blends compatibilized with the SAN-amine polymer was approximately half that of uncompatibilized blends and was relatively independent of viscosity ratio and dispersed phase composition. The fracture of thin (3.18 mm

  14. Separation of polycarbonate and acrylonitrile-butadiene-styrene waste plastics by froth flotation combined with ammonia pretreatment.

    PubMed

    Wang, Chong-Qing; Wang, Hui; Liu, Qun; Fu, Jian-Gang; Liu, You-Nian

    2014-12-01

    The objective of this research is flotation separation of polycarbonate (PC) and acrylonitrile-butadiene-styrene (ABS) waste plastics combined with ammonia pretreatment. The PC and ABS plastics show similar hydrophobicity, and ammonia treatment changes selectively floatability of PC plastic while ABS is insensitive to ammonia treatment. The contact angle measurement indicates the dropping of flotation recovery of PC is ascribed to a decline of contact angle. X-ray photoelectron spectroscopy demonstrates reactions occur on PC surface, which makes PC surface more hydrophilic. Separation of PC and ABS waste plastics was conducted based on the flotation behavior of single plastic. At different temperatures, PC and ABS mixtures were separated efficiently through froth flotation with ammonia pretreatment for different time (13 min at 23 °C, 18 min at 18 °C and 30 min at 23 °C). For both PC and ABS, the purity and recovery is more than 95.31% and 95.35%, respectively; the purity of PC and ABS is up to 99.72% and 99.23%, respectively. PC and ABS mixtures with different particle sizes were separated effectively, implying that ammonia treatment possesses superior applicability.

  15. Reclamation of post-consumer plastics for development of polycarbonate and acrylonitrile butadiene styrene based nanocomposites with nanoclay

    NASA Astrophysics Data System (ADS)

    Zicans, Janis; Meri, Remo Merijs; Ivanova, Tatjana; Berzina, Rita; Saldabola, Ruuta; Maksimov, Robert

    2016-05-01

    Suitability of recycled acrylonitrile-butadiene-styrene (R-ABS) and recycled polycarbonate (R-PC) for the development of polymer matrix nanocomposites with organically modified nanoclay (OMMT) is evaluated in comparison to virgin polymers (V-ABS and V-PC) based systems. The influence of OMMT content on the structure as well as calorimetric, mechanical and thermal properties of virgin and recycled polymers containing systems is revealed. Increase in stiffness and strength of virgin and recycled polymers based systems is observed along with rising nanoclay content. However, it is observed that reinforcing efficiency of clays on the R-ABS containing systems is reduced to certain extent in comparison to those, based on virgin polymers. It is shown, that in the presence of OMMT approximation of glass transition temperatures of both polymeric components is observed, which can testify about certain improvement of compatibility between PC and ABS. Increment of the modulus of elasticity and yield strength of the nanocomposites is associated with anisodiametric shape of OMMT, as well as with intercalation of polymer within the interlaminar space of the clay nanoparticles. It is also demonstrated that addition of nanoclay improves thermogravimetric behavior of the investigated compositions. Consequently, it is suggested that nanoclays can be used as promising functional additives and replace halogenated flame-retardants, without reducing mechanical properties of the composites.

  16. 21 CFR 177.1030 - Acrylonitrile/butadiene/styrene/methyl methacrylate copolymer.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    .../styrene/methyl methacrylate copolymer consists of: (1) 73 to 79 parts by weight of a matrix polymer... composition range as the matrix polymer. (b) Adjuvants. The copolymer identified in paragraph (a) of this...: POLYMERS Substances for Use as Basic Components of Single and Repeated Use Food Contact Surfaces §...

  17. 21 CFR 177.1030 - Acrylonitrile/butadiene/styrene/methyl methacrylate copolymer.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    .../styrene/methyl methacrylate copolymer consists of: (1) 73 to 79 parts by weight of a matrix polymer... composition range as the matrix polymer. (b) Adjuvants. The copolymer identified in paragraph (a) of this... HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) INDIRECT FOOD ADDITIVES:...

  18. 21 CFR 177.1030 - Acrylonitrile/butadiene/styrene/methyl methacrylate copolymer.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    .../styrene/methyl methacrylate copolymer consists of: (1) 73 to 79 parts by weight of a matrix polymer... composition range as the matrix polymer. (b) Adjuvants. The copolymer identified in paragraph (a) of this...: POLYMERS Substances for Use as Basic Components of Single and Repeated Use Food Contact Surfaces §...

  19. 21 CFR 177.1030 - Acrylonitrile/butadiene/styrene/methyl methacrylate copolymer.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    .../styrene/methyl methacrylate copolymer consists of: (1) 73 to 79 parts by weight of a matrix polymer... composition range as the matrix polymer. (b) Adjuvants. The copolymer identified in paragraph (a) of this...: POLYMERS Substances for Use as Basic Components of Single and Repeated Use Food Contact Surfaces §...

  20. 21 CFR 177.1050 - Acrylonitrile/styrene copoly-mer modified with butadiene/styrene elastomer.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... chapter as Type VI-B under conditions for use E, F, or G described in table 2 of § 176.170(c) of this.... (e) Accelerated extraction end test. The modified copolymer shall yield acrylonitrile monomer not in... room temperature. A sample of the extracting solvent is then withdrawn and analyzed for...

  1. 21 CFR 177.1050 - Acrylonitrile/styrene copoly-mer modified with butadiene/styrene elastomer.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... chapter as Type VI-B under conditions for use E, F, or G described in table 2 of § 176.170(c) of this.... (e) Accelerated extraction end test. The modified copolymer shall yield acrylonitrile monomer not in... room temperature. A sample of the extracting solvent is then withdrawn and analyzed for...

  2. Spatial distribution of stabilizer-derived nitroxide radicals during thermal degradation of poly(acrylonitrile-butadiene-styrene) copolymers: a unified picture from pulsed ELDOR and ESR imaging.

    PubMed

    Jeschke, Gunnar; Schlick, Shulamith

    2006-09-21

    Double Electron-Electron Resonance (DEER) provides information on the spatial distribution of radicals on the length scale of a few nanometres, while Electron Spin Resonance Imaging (ESRI) provides information on a length scale of millimetres with a resolution of about 100 micrometres. Despite the gap between these length scales, results from the two techniques are found to complement and support each other in the characterization of the identity and distribution of nitroxide radicals derived from the Hindered Amine Stabilizer (HAS) Tinuvin 770 in poly(acrylonitrile-butadiene-styrene) (ABS) copolymers. DEER measurements demonstrate that there is no significant formation of biradicals from the bifunctional HAS, and provide the distributions of local radical concentrations. These distributions are poorly resolved for model-free analysis of the DEER data by the Tikhonov regularization; the resolution was significantly improved by utilizing information obtained by ESRI. DEER data can be fitted with only one adjustable parameter, namely the average radical concentration, if 1D and 2D spectral--spatial ESRI results on both the spatial distribution of nitroxides and their distribution between the acrylonitrile--styrene-rich (SAN) and butadiene-rich (B) microphases are considered.

  3. 21 CFR 177.1020 - Acrylonitrile/butadiene/sty-rene co-polymer.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Acrylonitrile/butadiene/sty-rene co-polymer. 177... SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) INDIRECT FOOD ADDITIVES: POLYMERS Substances.../butadiene/sty-rene co-polymer. Acrylonitrile/butadiene/styrene copolymer identified in this section may...

  4. 21 CFR 177.1020 - Acrylonitrile/butadiene/sty-rene co-polymer.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Acrylonitrile/butadiene/sty-rene co-polymer. 177... SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) INDIRECT FOOD ADDITIVES: POLYMERS Substances.../butadiene/sty-rene co-polymer. Acrylonitrile/butadiene/styrene copolymer identified in this section may...

  5. 21 CFR 177.1020 - Acrylonitrile/butadiene/sty-rene co-polymer.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Acrylonitrile/butadiene/sty-rene co-polymer. 177... SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) INDIRECT FOOD ADDITIVES: POLYMERS Substances.../butadiene/sty-rene co-polymer. Acrylonitrile/butadiene/styrene copolymer identified in this section may...

  6. 21 CFR 177.1020 - Acrylonitrile/butadiene/sty-rene co-polymer.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Acrylonitrile/butadiene/sty-rene co-polymer. 177... SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) INDIRECT FOOD ADDITIVES: POLYMERS Substances.../butadiene/sty-rene co-polymer. Acrylonitrile/butadiene/styrene copolymer identified in this section may...

  7. Synchrotron-based FTIR microspectroscopy for the mapping of photo-oxidation and additives in acrylonitrile-butadiene-styrene model samples and historical objects.

    PubMed

    Saviello, Daniela; Pouyet, Emeline; Toniolo, Lucia; Cotte, Marine; Nevin, Austin

    2014-09-16

    Synchrotron-based Fourier transform infrared micro-spectroscopy (SR-μFTIR) was used to map photo-oxidative degradation of acrylonitrile-butadiene-styrene (ABS) and to investigate the presence and the migration of additives in historical samples from important Italian design objects. High resolution (3×3 μm(2)) molecular maps were obtained by FTIR microspectroscopy in transmission mode, using a new method for the preparation of polymer thin sections. The depth of photo-oxidation in samples was evaluated and accompanied by the formation of ketones, aldehydes, esters, and unsaturated carbonyl compounds. This study demonstrates selective surface oxidation and a probable passivation of material against further degradation. In polymer fragments from design objects made of ABS from the 1960s, UV-stabilizers were detected and mapped, and microscopic inclusions of proteinaceous material were identified and mapped for the first time.

  8. Three-dimensional Printed Acrylonitrile Butadiene Styrene Framework Coated with Cu-BTC Metal-organic Frameworks for the Removal of Methylene Blue

    PubMed Central

    Wang, Zongyuan; Wang, Jiajun; Li, Minyue; Sun, Kaihang; Liu, Chang-jun

    2014-01-01

    Three-dimensional (3D) printing was applied for the fabrication of acrylonitrile butadiene styrene (ABS) framework. Functionalization of the ABS framework was then performed by coating of porous Cu-BTC (BTC = benzene tricarboxylic acid) metal-organic frameworks on it using a step-by-step in-situ growth. The size of the Cu-BTC particles on ABS was ranged from 200 nm to 900 nm. The Cu-BTC/ABS framework can take up most of the space of the tubular reactor that makes the adsorption effective with no need of stirring. Methylene blue (MB) can be readily removed from aqueous solution by this Cu-BTC/ABS framework. The MB removal efficiency for solutions with concentrations of 10 and 5 mg/L was 93.3% and 98.3%, respectively, within 10 min. After MB adsorption, the Cu-BTC/ABS composite can easily be recovered without the need for centrifugation or filtration and the composite is reusable. In addition the ABS framework can be recovered for subsequent reuse. A significant advantage of 3D-printed frameworks is that different frameworks can be easily fabricated to meet the needs of different applications. This is a promising strategy to synthesize new frameworks using MOFs and polymers to develop materials for applications beyond adsorption. PMID:25089616

  9. Co-recycling of acrylonitrile-butadiene-styrene waste plastic and nonmetal particles from waste printed circuit boards to manufacture reproduction composites.

    PubMed

    Sun, Zhixing; Shen, Zhigang; Zhang, Xiaojing; Ma, Shulin

    2015-01-01

    This study investigated the feasibility of using acrylonitrile-butadiene-styrene (ABS) waste plastic and nonmetal particles from waste printed circuit boards (WPCB) to manufacture reproduction composites (RC), with the aim of co-recycling these two waste resources. The composites were prepared in a twin-crew extruder and investigated by means of mechanical testing, in situ flexural observation, thermogravimatric analysis, and dimensional stability evaluation. The results showed that the presence of nonmetal particles significantly improved the mechanical properties and the physical performance of the RC. A loading of 30 wt% nonmetal particles could achieve a flexural strength of 72.6 MPa, a flexural modulus of 3.57 GPa, and an impact strength of 15.5 kJ/m2. Moreover, it was found that the application of maleic anhydride-grafted ABS as compatilizer could effectively promote the interfacial adhesion between the ABS plastic and the nonmetal particles. This research provides a novel method to reuse waste ABS and WPCB nonmetals for manufacturing high value-added product, which represents a promising way for waste recycling and resolving the environmental problem.

  10. Process Window for Direct Recycling of Acrylonitrile-Butadiene-Styrene and High-Impact Polystyrene from Electrical and Electronic Equipment Waste.

    PubMed

    Vazquez, Yamila V; Barbosa, Silvia E

    2017-01-01

    The aim of this paper is to assess recycling process window of ABS (Acrylonitrile-Butadiene-Styrene) and HIPS (High impact Polystyrene) from WEEE (waste from electrical and electronic equipment) through a final properties/structure screening study on their blends. Main motivation is to evaluate which amount of one plastic WEEE can be included into the other at least keeping their properties. In this sense, a wider margin of error during sorting could be admitted to obtain recycling materials with similar technological application of recycled ABS and HIPS by themselves. Results are discussed in terms of final blend structure, focusing in the interaction, within blends, of copolymers phases and fillers presents in WEEE. The comparative analysis of mechanical performance and morphology of HIPS/ABS blends indicates that the addition of 50wt% HIPS to ABS even improves 50% the elongation at break maintaining the strength. On the opposite, HIPS maintains its properties with 20wt% of ABS added. This study allows enlarging composition process window of recycling plastic WEEE for similar applications. This could be a sustainable way to improve benefit of e-scrap with low costs and easy processability. In consequence, social interest in the recycling of this kind of plastic scrap could be encourage from either ecological or economical points of view.

  11. Three-dimensional Printed Acrylonitrile Butadiene Styrene Framework Coated with Cu-BTC Metal-organic Frameworks for the Removal of Methylene Blue

    NASA Astrophysics Data System (ADS)

    Wang, Zongyuan; Wang, Jiajun; Li, Minyue; Sun, Kaihang; Liu, Chang-Jun

    2014-08-01

    Three-dimensional (3D) printing was applied for the fabrication of acrylonitrile butadiene styrene (ABS) framework. Functionalization of the ABS framework was then performed by coating of porous Cu-BTC (BTC = benzene tricarboxylic acid) metal-organic frameworks on it using a step-by-step in-situ growth. The size of the Cu-BTC particles on ABS was ranged from 200 nm to 900 nm. The Cu-BTC/ABS framework can take up most of the space of the tubular reactor that makes the adsorption effective with no need of stirring. Methylene blue (MB) can be readily removed from aqueous solution by this Cu-BTC/ABS framework. The MB removal efficiency for solutions with concentrations of 10 and 5 mg/L was 93.3% and 98.3%, respectively, within 10 min. After MB adsorption, the Cu-BTC/ABS composite can easily be recovered without the need for centrifugation or filtration and the composite is reusable. In addition the ABS framework can be recovered for subsequent reuse. A significant advantage of 3D-printed frameworks is that different frameworks can be easily fabricated to meet the needs of different applications. This is a promising strategy to synthesize new frameworks using MOFs and polymers to develop materials for applications beyond adsorption.

  12. Surface hydrophilic modification of acrylonitrile-butadiene-styrene terpolymer by poly(ethylene glycol-co-1,4-cyclohexanedimethanol terephthalate): Preparation, characterization, and properties studies

    NASA Astrophysics Data System (ADS)

    Chen, Tingting; Zhang, Jun

    2016-12-01

    Surface hydrophilic modified acrylonitrile-butadiene-styrene (ABS) terpolymer was prepared by melt blending with poly(ethylene glycol-co-1,4-cyclohexanedimethanol terephthalate) (PETG) random copolymer as the modifier. Attenuated total reflectance-Fourier transform-infrared spectroscopy (ATR-FTIR) and X-ray photoelectron spectroscopy (XPS) were used for surface analysis. Through the contact angle measurement, the relationship between surface properties of the ABS/PETG blends and PETG content was investigated. Scanning electron microscope (SEM) and dynamical mechanical thermal analysis (DMTA) were used to characterize interface morphology and compatibility of the blends. The effect of PETG content on the mechanical and rheological properties was examined. The ATR-FTIR and XPS analysis suggested that the hydrophilic groups were enriched on the surface with increasing PETG content in the blend. The decrease of the water contact angle and the increase of the polarity for the blends with increasing PETG content indicated that the hydrophilic property of the blends was enhanced with increasing PETG content. The ABS/PETG blends were partially miscible. And the blends with ≤50 wt% PETG had better compatibility than the blends with above 50 wt% PETG. It was clear that below 50 wt% PETG, the PETG phase was dispersed in spherical form and the ABS phase was continuous. Above 50 wt% PETG, the PETG phase became continuous and the ABS phase was dispersed in irregular form. Moreover, the tensile strength and flexural strength of the blends were enhanced with increasing PETG content. The flexural modulus almost remained constant. And the impact strength was decreased when the content of PETG was increasing.

  13. Comparison of sodium naphthenate and air-ionization corona discharge as surface treatments for the ethylene-tetrafluoroethylene polymer (ETFE) to improve adhesion between ETFE and acrylonitrile-butadiene-styrene polymer (ABS) in the presence of a cyanoacrylate adhesive (CAA)

    NASA Astrophysics Data System (ADS)

    Lucía Johanning-Solís, Ana; Stradi-Granados, Benito A.

    2014-09-01

    This study compares two ethylene-tetrafluoroethylene (ETFE) surface activation treatments, namely chemical attack with a solution of sodium naphthenate and plasma erosion via air-ionization corona discharge in order to improve the adhesive properties of the ETFE. An experimental design was prepared for both treatments in order to assess the effect of the treatment characteristics on the tensile load needed to break the bond between the ETFE and the acrylonitrile-butadiene-styrene polymer (ABS) formed with a cyanoacrylate adhesive (CAA) applied between them. The reason for the selection of this problem is that both polymers are frequently used in the biomedical industry for their properties, and they need to be joined firmly in biomedical devices, and the cyanoacrylate adhesive is the adhesive traditionally used for fluoropolymers, in this case the ETFE, and the same CAA has also shown good adhesion with ABS. However, the strength of the bond for the triplet ETFE-CAA-ABS has not been reported and the improvement of the strength of the bond with surface treatments is not found in scholarly journals for modern medical devices such as stents and snares. Both treatments were compared based on the aforementioned design of experiments. The case where ETFE receives no surface treatment serves as the reference. The results indicated that the three factors evaluated (initial drying of the material, temperature of the chemical bath, and immersion time), and their interactions have no significant effect over the tensile load at failure (tensile strength) of the adhesive bond being evaluated. For the air-ionization corona discharge treatment, two factors were evaluated: discharge exposition time and air pressure. The results obtained from this experimental design indicate that there is no significant difference between the levels of the factors evaluated. These results were unexpected as the ranges used were representative of the maximum ranges permissible in manufacturing

  14. 21 CFR 177.1020 - Acrylonitrile/butadiene/sty-rene co-polymer.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Acrylonitrile/butadiene/sty-rene co-polymer. 177... SERVICES (CONTINUED) INDIRECT FOOD ADDITIVES: POLYMERS Substances for Use as Basic Components of Single and Repeated Use Food Contact Surfaces § 177.1020 Acrylonitrile/butadiene/sty-rene co-polymer....

  15. Heterogeneity in styrene-butadiene latex films.

    PubMed

    Santos, Juliane P; Corpart, Pascale; Wong, Kenneth; Galembeck, Fernando

    2004-11-23

    Low-Tg styrene-butadiene (SB) latex films were investigated by noncontact atomic force microscopy and scanning electric potential microscopy, revealing a number of different morphologies and electric potential patterns across films cast from the same SB latex dispersions under the same conditions. Surface leveling and charge dispersion throughout the films are, thus, restrained even at temperatures above Tg and the minimum film-formation temperature. An unprecedented electric pattern is observed, in which the particle cores are more positive than the contacting particle outer layers. Different packing patterns, including cubic and hexagonal arrays, coexist in neighboring areas. Zonal centrifugation of the SB latex in sucrose density gradient shows that particles cover a broad range of densities. Thus, film surface heterogeneity is at least partly due to particle heterogeneity. Fractal dimensions of topographic profiles are lower than those of the electric potential profiles, showing that charge mobility is much more restrained than polymer chain motion at the film surface and that it imposes a limit to the charged chain-ends motion.

  16. Characterization and development of new hydrogenated acrylonitrile-butadiene rubber blends

    NASA Astrophysics Data System (ADS)

    Severe, Geralda

    Characteristics were determined for hydrogenated acrylonitrile-butadiene rubber (HNBR), which is a copolymer of butadiene and acrylonitrile made from hydrogenation of the diene segment in acrylonitrile rubber. There was close attention given to the glass transition behavior of HNBR and its tendency to crystallize in the quiescent and in stretching state. The glass transition behavior in HNBR was similar to that of other ethylene copolymers such as for example ethylene vinyl-acetate etc. The crystallinity in HNBR at high acrylonitrile content was due to alternating sequence of acrylonitrile and hydrogenated trans-1,4 butadiene rubber. Furthermore, the structure of HNBR does not have any effect on it rheological properties at the temperature investigated. HNBR exhibits a zero shear viscosity. It is common knowledge that most polymers are immiscible. However, over the years scientists have found numerous miscible polymers. On that basis we investigated miscibility between HNBR with ethylenic copolymers, chlorinated polymers, diene polymers, and hydrogenated acrylonitrile-butadiene rubber. HNBR is miscible with high chlorine content chlorinated polymers like chlorinated polyethylene (42% Cl), chlorosulfonated polyethylene (43% Cl), PVC and CPVC. We have also developed dynamically vulcanized blends of HNBR with polychloroprene, epoxydized natural rubber, chlorobutyl, and carboxylated acrylonitrile-butadiene copolymer. Most of the blends at 75/25 composition have promising properties.

  17. 21 CFR 177.1040 - Acrylonitrile/styrene copoly-mer.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... Styrene Monomers-Gas Chromatographic Internal Standard Method”; “Infrared Spectrophotometric Determination... methods for determination of residual acrylonitrile monomer content, maximum extractable fraction, number... Weights of Acrylonitrile/Styrene Copolymers,” and “Analytical Method for 10% Solution Viscosity of...

  18. 21 CFR 177.1040 - Acrylonitrile/styrene copoly-mer.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... Styrene Monomers-Gas Chromatographic Internal Standard Method”; “Infrared Spectrophotometric Determination... methods for determination of residual acrylonitrile monomer content, maximum extractable fraction, number... Weights of Acrylonitrile/Styrene Copolymers,” and “Analytical Method for 10% Solution Viscosity of...

  19. 21 CFR 177.1040 - Acrylonitrile/styrene copoly-mer.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... Styrene Monomers-Gas Chromatographic Internal Standard Method”; “Infrared Spectrophotometric Determination... methods for determination of residual acrylonitrile monomer content, maximum extractable fraction, number... Weights of Acrylonitrile/Styrene Copolymers,” and “Analytical Method for 10% Solution Viscosity of...

  20. 21 CFR 177.1040 - Acrylonitrile/styrene copoly-mer.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... Styrene Monomers-Gas Chromatographic Internal Standard Method”; “Infrared Spectrophotometric Determination... methods for determination of residual acrylonitrile monomer content, maximum extractable fraction, number... Weights of Acrylonitrile/Styrene Copolymers,” and “Analytical Method for 10% Solution Viscosity of...

  1. Recycling of Chrome Tanned Leather Dust in Acrylonitrile Butadiene Rubber

    NASA Astrophysics Data System (ADS)

    El-Sabbagh, Salwa H.; Mohamed, Ola A.

    2010-06-01

    Concerns on environmental waste problem caused by chrome tanned leather wastes in huge amount have caused an increasing interest in developing this wastes in many composite formation. This leather dust was used as filler in acrylonitrile butadiene rubber (NBR) before treatment and after treatment with ammonia solution and sod. formate. Different formulations of NBR/ leather dust (untreated-treated with ammonia solution—treated with sod. formate) composites are prepared. The formed composite exhibit a considerable improvement in some of their properties such as rheometric characteristics especially with composites loaded with treated leather dust. Tensile strength, modulus at 100% elongation, hardness and youngs modulus were improved then by further loading start to be steady or decrease. Cross linking density in toluene were increased by incorporation of leather dust treated or untreated resulting in decreases in equilibrium swelling. Distinct increase in the ageing coefficient of both treated and untreated leather with drop in NBR vulcanizates without leather dust. Addition of leather dust treated or untreated exhibit better thermal stability.

  2. Styrene-butadiene rubber/halloysite nanotubes composites modified by epoxidized natural rubber.

    PubMed

    Jia, Zhixin; Luo, Yuanfang; Yang, Shuyan; Du, Mingliang; Guo, Baochun; Jia, Demin

    2011-12-01

    The reinforcement effects of halloysite nanotubes on styrene-butadiene rubber and the modification effect of epoxidized natural rubber on styrene-butadiene rubber/halloysite nanotubes composites were studied. The structure, morphology and properties of styrene-butadiene rubber/halloysite nanotubes composites before and after the incorporation of epoxidized natural rubber were investigated. The results indicated that epoxidized natural rubber can promote the dispersion and orientation of halloysite nanotubes in styrene-butadiene rubber matrix at nanoscale and strengthen interfacial combination between halloysite nanotubes and styrene-butadiene rubber by the formation of covalent bonds and hydrogen bonds between epoxidized natural rubber and halloysite nanotubes. Consequently epoxidized natural rubber can improve the mechanical properties of the vulcanizates of styrene-butadiene rubber/halloysite nanotubes composites. Besides epoxidized natural rubber can decrease the rolling resistance of the vulcanizates and increase the wet grip property of the vulcanizates.

  3. 40 CFR 63.500 - Back-end process provisions-carbon disulfide limitations for styrene butadiene rubber by emulsion...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... disulfide limitations for styrene butadiene rubber by emulsion processes. 63.500 Section 63.500 Protection... limitations for styrene butadiene rubber by emulsion processes. (a) Owners or operators of sources subject to this subpart producing styrene butadiene rubber using an emulsion process shall operate the...

  4. 40 CFR 63.500 - Back-end process provisions-carbon disulfide limitations for styrene butadiene rubber by emulsion...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... disulfide limitations for styrene butadiene rubber by emulsion processes. 63.500 Section 63.500 Protection... limitations for styrene butadiene rubber by emulsion processes. (a) Owners or operators of sources subject to this subpart producing styrene butadiene rubber using an emulsion process shall operate the...

  5. 40 CFR 63.500 - Back-end process provisions-carbon disulfide limitations for styrene butadiene rubber by emulsion...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... disulfide limitations for styrene butadiene rubber by emulsion processes. 63.500 Section 63.500 Protection... limitations for styrene butadiene rubber by emulsion processes. (a) Owners or operators of sources subject to this subpart producing styrene butadiene rubber using an emulsion process shall operate the...

  6. 40 CFR 63.500 - Back-end process provisions-carbon disulfide limitations for styrene butadiene rubber by emulsion...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... disulfide limitations for styrene butadiene rubber by emulsion processes. 63.500 Section 63.500 Protection... limitations for styrene butadiene rubber by emulsion processes. (a) Owners or operators of sources subject to this subpart producing styrene butadiene rubber using an emulsion process shall operate the...

  7. 21 CFR 181.32 - Acrylonitrile copolymers and resins.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... with polyvinyl chloride resins—for use only on paper and paperboard in contact with meats and lard. (ii... fruits, vegetables, and fish. (iii) Acrylonitrile/butadiene/styrene copolymer—no restrictions....

  8. 21 CFR 181.32 - Acrylonitrile copolymers and resins.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... with polyvinyl chloride resins—for use only on paper and paperboard in contact with meats and lard. (ii... fruits, vegetables, and fish. (iii) Acrylonitrile/butadiene/styrene copolymer—no restrictions....

  9. Durability of styrene-butadiene latex modified concrete

    SciTech Connect

    Shaker, F.A.; El-Dieb, A.S.; Reda, M.M.

    1997-05-01

    The durability of reinforced concrete structures represents a major concern to many investigators. The use of latex modified concrete (LMC) in construction has urged researchers to review and investigate its different properties. This study is part of a comprehensive investigation carried on the use of polymers in concrete. The main objective of this study to investigate and evaluate the main durability aspects of Styrene-Butadiene latex modified concrete (LMC) compared to those of conventional concrete. Also, the main microstructural characteristics of LMC were studied using a Scanning Electron Microscope (SEM). The SEM investigation of the LMC showed major differences in its microstructure compared to that of the conventional concrete. The LMC proved to be superior in its durability compared to the durability of conventional concrete especially its water tightness (measured by water penetration, absorption, and sorptivity tests), abrasion, corrosion, and sulphate resistance.

  10. Styrene production, use, and human exposure.

    PubMed

    Miller, R R; Newhook, R; Poole, A

    1994-01-01

    Styrene is an extremely important commodity chemical used extensively in the manufacture of numerous polymers and copolymers, including polystyrene, acrylonitrile-butadiene-styrene (ABS), styrene-acrylonitrile (SAN), styrene-butadiene latex, and styrene-butadiene rubber. Styrene is a component of cigarette smoke and automobile exhaust, and it may occur naturally at low levels in various types of foods. The highest potential human exposures to styrene occur in occupational settings, particularly those involving the production of large glass-reinforced polyester products such as boats, which require manual lay-up and spray-up operations. Substantially lower occupational exposures occur in styrene monomer and polymer production facilities. The general public is exposed to very low concentrations of styrene in ambient air, indoor air, food, and drinking water.

  11. Preparation and characterization of zinc sulphide nanocomposites based on acrylonitrile butadiene rubber

    NASA Astrophysics Data System (ADS)

    Ramesan, M. T.; Nihmath, A.; Francis, Joseph

    2013-06-01

    Rubber composite based on acrylonitrile butadiene rubber (NBR) reinforced with nano zinc sulphide (ZnS) have been prepared via vulcanization process and characterized by several techniques. Processing characteristics such as scorch time, optimum cure time decreases with increase in concentration of nano filler in acrylonitrile butadiene rubber. Mechanical properties such as tensile and tear strength increases with increase in concentration of nano filler up to 7 phr of loading thereafter the value decreases, whereas hardness, and flame resistance increases with the dosage of fillers. These enhanced properties are due to the homogenous dispersion of nano fillers in NBR matrix, which is evidenced from the structure that evaluated using X-ray diffraction (XRD) and scanning electron microscopy (SEM).

  12. Effects of Soy Protein Nanoparticle Aggregate Size on the Viscoelastic Properties of Styrene-Butadiene Composites

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soy protein nanoparticle aggregates were prepared by alkaline hydrolysis of soy protein isolate (SPI). Light scattering measurements indicated a narrow size distribution of SPI aggregates. Nanocomposites were formed by mixing hydrolyzed SPI (HSPI) nanoparticle aggregates with styrene-butadiene (SB...

  13. Determination of styrene-butadiene rubber composition by attenuated total internal reflection infrared spectroscopy

    NASA Astrophysics Data System (ADS)

    Orlov, A. S.; Kiselev, S. A.; Kiseleva, E. A.; Budeeva, A. V.; Mashukov, V. I.

    2013-03-01

    A rapid method for determining the composition of styrene-butadiene rubber using attenuated total internal reflection infrared spectroscopy was proposed. PMR and 13C NMR spectroscopy and infrared transmission spectroscopy were used as absolute techniques for determining the compositions of calibration samples. It was shown that the method was applicable to a wide range of styrene-butadiene rubbers, did not require additional sample preparation, and was easily reproducible.

  14. Butadiene production process overview.

    PubMed

    White, Wm Claude

    2007-03-20

    Over 95% of butadiene is produced as a by-product of ethylene production from steam crackers. The crude C4 stream isolated from the steam cracking process is fed to butadiene extraction units, where butadiene is separated from the other C4s by extractive distillation. The amount of crude C4s produced in steam cracking is dependent on the composition of the feed to the cracking unit. Heavier feeds, such as naphtha, yield higher amounts of C4s and butadiene than do lighter feeds. Crackers using light feeds typically produce low quantities of C4s and do not have butadiene extraction units. Overall butadiene capacity is determined by ethylene cracker operating rates, the type of feed being cracked, and availability of butadiene extraction capacity. Global butadiene capacity is approximately 10.5 million metric tons, and global production is approximately 9 million metric tons [Chemical Marketing Associates, Inc. (CMAI), 2005 World Butadiene Analysis, Chemical Marketing Associates, Inc. (CMAI), 2005]. Crude C4s are traded globally, with the United States being the only significant net importer. Finished butadiene is also traded globally, with the largest exporters being Canada, Western Europe, Saudi Arabia and Korea. The largest net importers are Mexico, the United States and China. The global demand for butadiene is approximately 9 million metric tons [Chemical Marketing Associates, Inc. (CMAI), 2005 World Butadiene Analysis, Chemical Marketing Associates, Inc. (CMAI), 2005]. Production of styrene-butadiene rubber and polybutadiene rubber accounts for about 54% of global butadiene demand, with tire production being the single most important end use of butadiene synthetic rubbers. Other major butadiene derivatives are acrylonitrile-butadiene-styrene (ABS) and styrene butadiene latex (about 24% of demand combined).

  15. Mechanical properties of products of thermocatalytic and radiolytic styrene - acrylonitrile copolymerization

    SciTech Connect

    Gadalla, A.M.; Derini, M.A.E.

    1983-12-01

    The mechanical properties of styrene (S)-acrylonitrile (AN) mixtures, ranging from 20 to 80 wt % S, polymerized by thermocatalytic and radiolytic techniques were studied. Maximum compressive and tensile strength was obtained for the mixture containing 60 wt % styrene. The hardness increased with styrene concentration up to 40 wt % and then remained nearly constant. Radiolytic copolymerization gave stronger copolymers than thermal copolymerization since irradiation enhances crosslinking. For the same composition, as the dose increases, the strength increases to a maximum and then decreases due to competing rates of crosslinking and degradation. 5 figures.

  16. Alteration of Acrylonitrile-Methylacrylate-Butadiene Terpolymer by Nocardia rhodochrous and Penicillium notatum†

    PubMed Central

    Antoine, A. D.; Dean, A. V.; Gilbert, S. G.

    1980-01-01

    [14C]Barex-210, a terpolymer of acrylonitrile, methylacrylate, and butadiene, was tested for bioconversion. Powdered samples of polymer, each specifically 14C labeled at different carbon atoms of the polymer, were incubated with either Nocardia rhodochrous or Penicillium notatum in an enriched growth medium for various periods of time. After 6 months of incubation, the 14C-labeled polymer was transformed from a high-molecular-weight material completely soluble in dimethyl formamide (DMF) into both a lower-molecular-weight form still soluble in DMF and a second form that was no longer soluble in DMF. The amount of 14C-labeled carbon atoms converted into DMF-insoluble material was 8% of the backbone carbon-carbon atoms and 12% of the side-chain nitrile and acrylate atoms from the acrylonitrile-methylacrylate copolymer and 60% of the elastomer (acrylonitrile-butadiene copolymer) atoms. Metabolism of the polymer was not established from measurements of metabolic 14CO2. Evolution of 14CO2 amounted to only 0.3, 0.6, 1.8, and 3.3% of these four fractions, respectively. Although the transformation of high-molecular-weight polymer into DMF-insoluble material was rapid in the early stages of microbial growth, the accompanying CO2 evolution was much slower. Further evidence of polymer alteration was indicated by the infrared spectrum of the insoluble material, which showed a disappearance of the nitrile and methylacrylate peaks. PMID:16345541

  17. Radiation-induced crosslinking of poly(styrene-butadiene-styrene) block copolymers and their sulfonation

    NASA Astrophysics Data System (ADS)

    Lee, Sun-Young; Song, Ju-Myung; Sohn, Joon-Yong; Shul, Yong-Gun; Shin, Junhwa

    2013-12-01

    Several crosslinked poly(styrene-butadiene-styrene) (c-SBS) block copolymer films were prepared using a gamma ray or electron beam with various irradiation doses and the prepared c-SBS film was then subjected to sulfonation using a chlorosulfonic acid (CSA) solution to introduce a sulfonic acid group. To estimate the degree of crosslinking, the gel fractions and FT-IR spectra of the c-SBS films were used and the results indicate that the degree of crosslinking is increased with an increase in the radiation dose. The surface morphology and mechanical property of the c-SBS films were observed using SEM and UTM instruments, respectively. The sulfonated c-SBS films were investigated by measuring the ion exchange capacity (IEC) and by observing the cross-sectional distribution patterns of sulfonic acid group using an SEM-EDX instrument. The IEC and SEM-EDX studies indicate that the sulfonated c-SBS membranes can be successfully prepared through the radiation crosslinking of the SBS film and the subsequent sulfonation with a diluted CSA solution.

  18. Analysis of styrene-butadiene-styrene polymer modified bitumen using fluorescent microscopy and conventional test methods.

    PubMed

    Sengoz, Burak; Isikyakar, Giray

    2008-01-31

    This paper presents a laboratory study of modified bitumen containing styrene-butadiene-styrene (SBS) copolymer. Polymer modified bitumen (PMB) samples have been produced by mixing a 50/70 penetration grade unmodified (base) bitumen with SBS Kraton D1101 copolymer at five different polymer contents. The fundamental characteristics of the SBS PMB samples have been determined using conventional methods. The morphology of the samples as well as the percent area (%) distribution of SBS polymers throughout the base bitumen have been characterized and determined by means of fluorescence microscopy and Qwin Plus image analysis program, respectively. The mechanical properties of the hot-mix asphalt (HMA) containing SBS PMBs have also been analyzed and compared with HMA incorporating base bitumen. The effect of polymer addition on the short and long term aging characteristics of HMA have been evaluated by indirect tensile strength (ITS) test. The results indicated that polymer modification improved the conventional properties (penetration, softening point, etc.) and the mechanical properties (Marshall, ITS, etc.) of the base bitumen. It was also concluded that at low polymer contents, the samples revealed the existence of dispersed polymer particles in a continuous bitumen phase, whereas at high polymer contents a continuous polymer phase has been observed. Moreover, it was found out that the polymer addition minimizes the short and long term aging of HMA.

  19. Application of Lignin as Antioxidant in Styrene Butadiene Rubber Composite

    NASA Astrophysics Data System (ADS)

    Liu, Shusheng; Cheng, Xiansu

    2010-11-01

    Lignin isolated from enzymatic hydrolyzed cornstalks (EHL) is a renewable natural polymer, and rubber is one of the most important polymer materials. The application of EHL in rubber industry is of great significance. The influence of EHL and antioxidant RD on the vulcanizing characteristics, thermal oxidative aging stability under free condition, and water extraction resistance of styrene-butadiene rubber (SBR) were investigated. The effect of EHL/antioxidant D composite antioxidant on the thermal oxidative ageing of SBR was also evaluated. Results showed that the protection of SBR from thermal oxidative aging by EHL/antioxidant D composite antioxidant was superior to that of antioxidant D. This is because EHL molecules have hindered phenol group and have excellent auxiliary antioxidant role with antioxidant D. Moreover, the influence of EHL on the vulcanizing characteristics of SBR compounds was better than that of antioxidant RD, and EHL can reduce the cure rate and increase the optimum cure time. It is because that the EHL molecules have hindered phenol group and methoxy group, which can form a special structure to capture free radical and terminate the chain reaction. The retained tensile strength of SBR compounds with EHL was similar to that of the samples with antioxidant RD, while the retained elongation at break of SBR compounds with EHL was higher than that of the samples with antioxidant RD. In addition, the SBR compounds with EHL have a good water extraction resistance property, which was similar to the samples with antioxidant RD. This is because EHL have large molecular weight, good stability and low solubility in water. In conclusion, due to the low price, abundant resources, non-toxic and pollution-free, etc., EHL will have broad application prospect.

  20. Quantitative analysis of styrene butadiene copolymers using S-SIMS and LA-FTICRMS

    NASA Astrophysics Data System (ADS)

    Ruch, D.; Boes, C.; Zimmer, R.; Muller, J. F.; Migeon, H.-N.

    2003-01-01

    Styrene butadiene copolymers (SBR) have been analyzed by static secondary ion mass spectrometry (S-SIMS) and laser ablation Fourier transform ion cyclotron resonance mass spectrometry (LA-FTICRMS) to obtain quantitative information based on specific peaks knowing that the complication of this system is that there are no characteristic SIMS peaks unique to each styrene and butadiene monomer. So, to overcome this problem, a silver deposition has been applied into polystyrene (PS), butadiene rubber (BR) and SBR. By this way, new secondary ions are detected in particular silver cationized butadiene and styrene monomers at m/ z 161/163 and 211/213, respectively. The LA-FTICRMS experiments do not require pre-treatment. At high laser power density, UV photons (193, 266 and 355 nm) allow to detect directly the styrene and butadiene ions at m/ z 104 and 54, respectively. Using these SIMS and LA-FTICRMS peaks, it is possible to obtain quantitative results. However, the silver coating in the SIMS experiment seems to have a great influence on the obtention of quantitative information. For LA-FTICRMS experiments, the best results seem to be obtained at the 355 nm wavelength.

  1. Birchwood biochar as partial carbon black replacement in styrene-butadiene rubber composites

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Birchwood feedstock was used to make slow pyrolysis biochar that contained 89% carbon and < 2% ash. This biochar was blended with carbon black as filler for styrene-butadiene rubber. Composites made from blended fillers of 25/75 biochar/carbon black were equivalent to or superior to their 100% carbo...

  2. Experimental study on behaviors of dielectric elastomer based on acrylonitrile butadiene rubber

    NASA Astrophysics Data System (ADS)

    An, Kuangjun; Chuc, Nguyen Huu; Kwon, Hyeok Yong; Phuc, Vuong Hong; Koo, Jachoon; Lee, Youngkwan; Nam, Jaedo; Choi, Hyouk Ryeol

    2010-04-01

    Previously, the dielectric elastomer based on Acrylonitrile Butadiene Rubber (NBR), called synthetic elastomer has been reported by our group. It has the advantages that its characteristics can be modified according to the requirements of performances, and thus, it is applicable to a wide variety of applications. In this paper, we address the effects of additives and vulcanization conditions on the overall performance of synthetic elastomer. In the present work, factors to have effects on the performances are extracted, e.g additives such as dioctyl phthalate (DOP), barium titanium dioxide (BaTiO3) and vulcanization conditions such as dicumyl peroxide (DCP), cross-linking times. Also, it is described how the performances can be optimized by using DOE (Design of Experiments) technique and experimental results are analyzed by ANOVA (Analysis of variance).

  3. Chitosan/polyanion surface modification of styrene-butadiene-styrene block copolymer membrane for wound dressing.

    PubMed

    Yang, Jen Ming; Yang, Jhe-Hao; Huang, Huei Tsz

    2014-01-01

    The surface of styrene-butadiene-styrene block copolymer (SBS) membrane is modified with tri-steps in this study. At first, two step modified SBS membrane (MSBS) was prepared with epoxidation and ring opening reaction with maleated ionomer. Then chitosan was used as the polycation electrolyte and sodium alginate, poly(γ-glutamic acid) (PGA) and poly(aspartic acid) (PAsp) were selected as polyanion electrolytes to deposit on the surfaces of MSBS membrane by the layer-by-layer self-assembly (LbL) deposition technique to get three [chitosan/polyanion] LbL modified SBS membranes, ([CS/Alg], [CS/PGA] and [CS/PAsp]). From the quantitative XPS analysis and water contact angle measurement, it is found that the order of wettability and the content of functional group percentages of COO(-) and OCN on the three [CS/polyanion] systems are [CS/Alg]>[CS/PGA]>[CS/PAsp]. Performances of water vapor transmission rates, fibronectin adsorption, antibacterial assessment and 3T3 fibroblast cell growth on [CS/Alg], [CS/PGA] and [CS/PAsp] membranes were also evaluated. With the evaluation of water vapor transmission rate, these [CS/Alg], [CS/PGA] and [CS/PAsp] membranes are sterile semipermeable with water evaporation at about 82±8g/day·m(2). It is found that the amount of fibronectin adsorption on the three [CS/polyanion] systems is significantly determined by the sum of the functional group of COO(-) and OCN on the surfaces of [CS/Alg], [CS/PGA] and [CS/PAsp] systems. The results are inverse with the sum of the functional group of COO(-) and OCN on the three [CS/polyanion]. From the cytotoxicity test and cell adhesion and proliferation assay of 3T3 fibroblasts on the three [CS/polyanion] systems, it revealed that the cells not only remained viable but they also proliferated on the surfaces of [CS/Alg], [CS/PGA] and [CS/PAsp]. The bactericidal activity was found on [CS/Alg], [CS/PGA] and [CS/PAsp]. The transport of bacterial through these [CS/polyanion] membranes was also conducted

  4. Radiation-induced vulcanisation of natural rubber latex in presence of styrene-butadiene rubber latex

    NASA Astrophysics Data System (ADS)

    Chaudhari, C. V.; Bhardwaj, Y. K.; Patil, N. D.; Dubey, K. A.; Kumar, Virendra; Sabharwal, S.

    2005-04-01

    Radiation vulcanisation of natural rubber latex in presence of styrene butadiene rubber latex (SBRL) has been investigated. The cast films were characterised for their swelling properties, tensile strength and thermal stability as a function of radiation dose as well as SBRL content. The gel content, tensile strength and thermal stability of the copolymer films were found to increase with increasing the SBRL content in the feed solution and radiation dose.

  5. Polybutadiene and Styrene-Butadiene rubbers for high-dose dosimetry

    SciTech Connect

    Oliveira, Lucas N.; Vieira, Silvio L.; Schimidt, Fernando; Antonio, Patricia L.; Caldas, Linda V.E.

    2015-07-01

    Polybutadiene and Styrene-Butadiene are synthetical rubbers used widely for pneumatic tires manufacturing. In this research, the dosimeter characteristics of those rubbers were studied for application in high-dose dosimetry. The rubber samples were irradiated with doses of 10 Gy up to 10 kGy, using a {sup 60}Co Gamma Cell-220 system (dose rate of 1.089 kGy/h) and their readings were taken on a Fourier Transform Infrared Spectroscopy-FTIR system (model Frontier/Perkin Elmer). The ratios of two absorbance peaks were taken for each kind of rubber spectrum, Polybutadiene (1306/1130 cm{sup -1}) and Styrene-Butadiene (1449/1306 cm{sup -1}). The ratio calculated was used as the response to the irradiation, and is not uniform across the sample. From the results, it can be concluded for both rubbers: a) the dose-response curves may be useful for high-dose dosimetry (greater than 250 Gy); b) their response for reproducibility presented standard deviations lower than 2.5%; c) the relative sensitivity was higher for Styrene-Butadiene (1.86 kGy{sup -1}) than for Polybutadiene (1.81 kGy{sup -1}), d) for doses of 10 kGy to 200 kGy, there was no variation in the dosimetric response. Both types of rubber samples showed usefulness as high-dose dosimeters. (authors)

  6. Flame retardant brominated styrene-based polymers. II. Synthesis, characterization and application of dibromostyrene, styrene and butadiene terpolymers

    SciTech Connect

    Wang, J.L.; Favstritsky, N.A.

    1993-12-31

    Brominated styrene-based polymers having surprisingly good physical properties in combination with flame retardancy are prepared from terpolymers of dibromostyrene, styrene and butadiene. Polymerization compositions were determined by bromine contents (% Br) of the polymers by Schoeninger Combustion Method and {sup 1}H NMR integration. Weight losses (% loss) were measured at 20{degrees}C/min by Thermogravimetric Analysis (TGA). Molecular weights were measured by GPC based on a standard molecular weight (MW) of polystyrene (PS)> Flammability of the latex products when used in textile backcoatings was testing by Motor Vehicle Safety Standard 302 (MVSS-302) flammability test. As latexes were used as non-woven binders, flammability was tested by exposure to a 4 in high, 1950{degrees}F propane flame from a Fisher Burner. When latexes were employed for carpet backing, flammability was tested by DOC. FF-1-70 (pill test) flammability tests.

  7. Estimation of the Surface Properties of Styrene-Acrylonitrile Random Copolymers from Contact Angle Measurements.

    PubMed

    Adão; Saramago; Fernandes

    1999-09-01

    The surface free energy per unit area of a solid, gamma(S), is a fundamental property of materials and determines their surface and interfacial behavior in processes like wetting and adhesion. In this study the gamma(S) of a series of styrene-acrylonitrile random copolymers is evaluated. Three different approaches are used to determine the components in which the surface free energy can be decomposed. Using the geometric and the harmonic mean approach, the dispersive, gamma(d), and polar, gamma(p), components of the solid surface free energy were determined and compared to the Lifshitz-van der Waals, gamma(LW), and acid-base, gamma(AB), components using the approach developed by C. J. van Oss et al. (1987, Adv. Colloid Interface Sci. 28, 35). The acid-base approach was also used to evaluate the work of adhesion of the test liquids: water, glycerol, and thiodiglycol. It was found that the contact angles of these liquids follow closely the predictions of Cassie equation. The evaluation of the surface free energy components on one hand and the relative magnitude of the work of adhesion components on the other hand, suggest that below 50% of acrylonitrile the polystyrene repeating units are preferentially at the surface. Above 50% of acrylonitrile the segregation of the low-energy homopolymer at the surface decreases. Copyright 1999 Academic Press.

  8. An investigation on chloroprene-compatibilized acrylonitrile butadiene rubber/high density polyethylene blends.

    PubMed

    Ahmed, Khalil

    2015-11-01

    Blends of acrylonitrile butadiene rubber/high density polyethylene (NBR/HDPE) compatibilized by Chloroprene rubber (CR) were prepared. A fixed quantity of industrial waste such as marble waste (MW, 40 phr) was also included. The effect of the blend ratio and CR on cure characteristics, mechanical and swelling properties of MW-filled NBR/HDPE blends was investigated. The results showed that the MW-filled NBR/HDPE blends revealed an increase in tensile strength, tear, modulus, hardness and cross-link density for increasing weight ratio of HDPE. The minimum torque (M L) and maximum torque (M H) of blends increased with increasing weight ratio of HDPE while scorch time (ts2) cure time (tc90), compression set and abrasion loss of blends decreased with increasing weight ratio of HDPE. The blends also showed a continuous reduction in elongation at break as well as swelling coefficient with increasing HDPE amount in blends. MW filled blends based on CR provided the most encouraging balance values of overall properties.

  9. The physical and degradation properties of starch-graft-acrylonitrile/carboxylated nitrile butadiene rubber latex films.

    PubMed

    Misman, M A; Azura, A R; Hamid, Z A A

    2015-09-05

    Starch-graft-acrylonitrile (ANS) is compounded with carboxylated nitrile butadiene rubber (XNBR) latex. The control XNBR and the ANS/XNBR latex films were prepared through a coagulant dipping process. The films were subjected to ageing and soil burial procedures. For the biodegradation experiment, the surface of the film was assessed after the 2nd, 4th and 8th week of soil burial. The ANS, XNBR, and ANS/XNBR colloidal stability were determined with a Malvern Zetasizer. For the dipped latex films, the mechanical, morphological and thermal properties were analyzed. The addition of ANS into the XNBR latex increased the stability of the colloidal dispersions, decreased the latex film tensile strength, but increased the elongation at break due to the bipolar interaction of the ANS and XNBR particles. The ANS/XNBR latex films aged faster than the control films while the morphological analysis showed the existence of a starch crystal region and the formation of microbial colonies on the surfaces of the films. Based on the TGA-DTA curves, a higher ΔT was observed for the ANS/XNBR latex films signifying high thermal energy needed for the film to thermally degrade.

  10. An investigation on chloroprene-compatibilized acrylonitrile butadiene rubber/high density polyethylene blends

    PubMed Central

    Ahmed, Khalil

    2014-01-01

    Blends of acrylonitrile butadiene rubber/high density polyethylene (NBR/HDPE) compatibilized by Chloroprene rubber (CR) were prepared. A fixed quantity of industrial waste such as marble waste (MW, 40 phr) was also included. The effect of the blend ratio and CR on cure characteristics, mechanical and swelling properties of MW-filled NBR/HDPE blends was investigated. The results showed that the MW-filled NBR/HDPE blends revealed an increase in tensile strength, tear, modulus, hardness and cross-link density for increasing weight ratio of HDPE. The minimum torque (ML) and maximum torque (MH) of blends increased with increasing weight ratio of HDPE while scorch time (ts2) cure time (tc90), compression set and abrasion loss of blends decreased with increasing weight ratio of HDPE. The blends also showed a continuous reduction in elongation at break as well as swelling coefficient with increasing HDPE amount in blends. MW filled blends based on CR provided the most encouraging balance values of overall properties. PMID:26644917

  11. Review of the toxicology of styrene.

    PubMed

    Bond, J A

    1989-01-01

    Styrene is used in the production of plastics and resins, which include polystyrene resins, acrylonitrile-butadiene-styrene resins, styrene-acrylonitrile resins, styrene-butadiene copolymer resins, styrene-butadiene rubber, and unsaturated polyester resins. In 1985, styrene ranked in the top ten of synthetic organic chemicals produced in the U.S. This review focuses on various aspects of styrene toxicology including acute and chronic toxicity, carcinogenicity, genotoxicity, pharmacokinetics, effects on hepatic and extrahepatic xenobiotic-metabolizing enzymes, pharmacokinetic modeling, and covalent interactions with macromolecules. There appear to be many similarities between the toxicity and metabolism of styrene in rodents and humans. Needed areas of future research on styrene include studies on the molecular dosimetry of styrene in terms of both hemoglobin and DNA adducts. The results of such research should improve our ability to assess the relationship between exposure to styrene and surrogate measures of "effective dose", thereby improving our ability to estimate the effects of low-level human exposures.

  12. Perinatal toxicity and carcinogenicity studies of styrene-acrylonitrile trimer, a ground water contaminant.

    PubMed

    Behl, Mamta; Elmore, Susan A; Malarkey, David E; Hejtmancik, Milton R; Gerken, Diane K; Chhabra, Rajendra S

    2013-12-06

    Styrene acrylonitrile (SAN) trimer is a by-product in the production of acrylonitrile styrene plastics. Following a report of a childhood cancer cluster in the Toms River section of Dover Township, New Jersey, SAN Trimer was identified as one of the groundwater contaminants at Reich Farm Superfund site in the township. The contaminants from the Reich Farm site's ground water plume impacted two wells at the Parkway well field. The National Toxicology Program (NTP) studied the toxicity and carcinogenicity of SAN Trimer in rats exposed during their perinatal developmental period and adulthood. The chronic toxicity and carcinogenicity studies in F344/N rats were preceded by 7- and 18-week perinatal toxicity studies to determine the exposure concentrations for the 2-year studies. Subsequently, Fisher 344 pregnant dams were exposed to SAN Trimer containing diet at 400, 800, or 1600ppm concentrations during gestation, nursing and weaning periods of offspring followed by two year of adult exposures to both male and female pups. There was no statistically significant evidence of carcinogenic activity following SAN-Trimer exposure; however, rare neoplasms in the brain and spinal cord were observed in males and to lesser extent in female rats. These incidences were considered within the range of historical background in the animal model used in the current studies. Therefore, the presence of a few rarely occurring CNS tumors in the treated groups were not judged to be associated with the SAN Trimer exposure. The major finding was a dose-related peripheral neuropathy associated with the sciatic nerves in females and spinal nerve roots in males and females thereby suggesting that SAN Trimer is potentially a nervous system toxicant.

  13. Perinatal Toxicity and Carcinogenicity Studies of StyreneAcrylonitrile Trimer, A Ground Water Contaminant

    PubMed Central

    Behl, Mamta; Elmore, Susan A.; Malarkey, David E.; Hejtmancik, Milton R.; Gerken, Diane K.; Chhabra, Rajendra S.

    2015-01-01

    Styrene Acrylonitrile (SAN) Trimer is a by-product in the production of acrylonitrile styrene plastics. Following a report of a childhood cancer cluster in the Toms River section of Dover Township, New Jersey, SAN Trimer was identified as one of the groundwater contaminants at Reich Farm Superfund site in the township. The contaminants from the Reich Farm site’s ground water plume impacted two wells at the Parkway well field. The National Toxicology Program (NTP) studied the toxicity and carcinogenicity of SAN Trimer in rats exposed during their perinatal developmental period and adulthood. The chronic toxicity and carcinogenicity studies in F344/N rats were preceded by 7- and 18-week perinatal toxicity studies to determine the exposure concentrations for the 2-year studies. Subsequently, Fisher 344 pregnant dams were exposed to SAN Trimer containing diet at 400, 800, or 1600 ppm concentrations during gestation, nursing and weaning periods of offspring followed by two year of adult exposures to both male and female pups. There was no statistically significant evidence of carcinogenic activity following SAN-Trimer exposure; however, rare neoplasms in the brain and spinal cord were observed in males and to lesser extent in female rats. These incidences were considered within the range of historical background in the animal model used in the current studies. Therefore, the presence of a few rarely occurring CNS tumors in the treated groups were not judged to be associated with the SAN Trimer exposure. The major finding was a dose-related peripheral neuropathy associated with the sciatic nerves in females and spinal nerve roots in males and females thereby suggesting that SAN trimer is potentially a nervous system toxicant. PMID:24060431

  14. Styrene-butadiene-styrene copolymer compatibilized carbon black/polypropylene/polystyrene composites with tunable morphology, electrical conduction and rheological stabilities.

    PubMed

    Song, Yihu; Xu, Chunfeng; Zheng, Qiang

    2014-04-21

    We report a facile kinetic strategy in combination with styrene-butadiene-styrene (SBS) copolymer compatibilizers for preparing carbon black (CB) filled immiscible polypropylene (PP)/polystyrene (PS) (1/1) blends with finely tuned morphologies and show the important role of location and migration of CB nanoparticles in determining the electrical conductivity and rheological behaviour of the composites. A novel method of mixing a SBS/CB (5/3) masterbatch with the polymers allowed producing composites with CB aggregates dispersed partially in the unfavorable PP phase and partially in the PP side of the interface to exhibit diverse phase connectivity and electrical conductivity depending on the compounding sequences. A cocontinuous morphology with CB enrichment along the interface was formed in the composite prepared by mixing the SBS/CB masterbatch with the premixed PP/PS blend, giving rise to a highest electrical conductivity and dynamic moduli at low frequencies. On the other hand, mixing the masterbatch with one and then with another polymer yielded droplet (PS)-in-matrix (filled PP) composites. The composites underwent phase coalescence and CB redistribution accompanied by marked dynamic electrical conduction and modulus percolations as a function of time during thermal annealing at 180 °C. The composites with the initial droplet-in-matrix morphology progressed anomalously into the cocontinuous morphology, reflecting a common mechanism being fairly nonspecific for understanding the processing of filled multicomponent composites with tailored performances of general concern.

  15. Effect of Wheat Flour Pre-cooking on the Composite Modulus of Wheat Flour and Carboxylated Styrene-Butadiene Latex

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Commercial wheat flours with two different concentrations of insoluble protein were used as fillers to reinforce styrene-butadiene latex composites and their viscoelastic properties were examined. Both wheat flours were also cooked at 55, 70, or 95 deg C for one hour in an aqueous dispersion prior ...

  16. On the form of the strain energy function for a family of SBR materials. [Styrene-Butadiene Rubber

    NASA Technical Reports Server (NTRS)

    Arenz, R. J.

    1977-01-01

    Styrene-butadiene materials with varying crosslink densities are analyzed through use of a strain energy function of the type introduced by Valanis and Landel (1967). A form of the strain energy function derived from strip biaxial tests proves to be accurate when checked against uniaxial and other biaxial test results.

  17. Effect of strain rate on mechanical properties of melt-processed soy flour composite filler and styrene-butadiene blends

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Polymer composites were prepared by melt-mixing polymer and soy flour composite fillers in an internal mixer. Soy flour composite fillers were prepared by blending aqueous dispersion of soy flour with styrene-butadiene rubber latex, dried, and cryogenically ground into powders. Upon crosslinking, th...

  18. Evaluating corn starch and corn stover biochar as renewable filler in carboxylated styrene-butadiene rubber composites

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Corn starch, corn flour, and corn stover biochar were evaluated as potential renewable substitutes for carbon black as filler in rubber composites using carboxylated styrene-butadiene as the rubber matrix. Previous work has shown that starch-based fillers have very good reinforcement properties at t...

  19. Acrylonitrile

    Integrated Risk Information System (IRIS)

    Acrylonitrile ; CASRN 107 - 13 - 1 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic Eff

  20. Fracture morphologies of carbon-black-loaded SBR (styrene-butadiene rubber) subjected to low-cycle, high-stress fatigue. [Styrene-butadiene rubber

    SciTech Connect

    Goldberg, A.; Lesuer, D.R.; Patt, J.

    1988-02-01

    Experimental results, together with an analytical model, related to the loss in tensile strength of styrene-butadiene rubber (SBR) loaded with carbon black (CB) that had been subjected to low-cycle, high-stress fatigue tests were presented in a prior paper. The drop in tensile strength relative to that of a virgin sample was considered to be a measure of damage induced during the fatigue test. The present paper is a continuation of this study dealing with the morphological interpretations of the fractured surfaces, whereby the cyclic-tearing behavior, resulting in the damage, is related to the test and material parameters. It was found that failure is almost always initiated in the bulk of a sample at a material flaw. The size and definition of a flaw increase with an increase in carbon-black loading. Initiation flaw sites are enveloped by fan-shaped or penny-shaped regions which develop during cycling. The size and morphology of a fatigue-tear region appears to be independent of the fatigue load or the extent of the damage (strength loss). By contrast, either an increase in cycling load or an increase in damage at constant load increases the definition of the fatigue-region morphology for all formulations of carbon-black. On the finest scale, the morphology can be described in terms of tearing of individual groups of rubber strands, collapsing to form a cell-like structure. 18 refs., 13 figs.

  1. High-Energy-Density Poly(styrene-co-acrylonitrile) Thin Films

    NASA Astrophysics Data System (ADS)

    Wen, Fei; Xu, Zhuo; Xia, Weimin; Ye, Hongjun; Wei, Xiaoyong; Zhang, Zhicheng

    2013-12-01

    The dielectric response of poly(styrene-co-acrylonitrile) (PSAN) thin films fabricated by a solution casting process was investigated in this work. Linear dielectric behavior was obtained in PSAN films under an electric field at frequencies from 100 Hz to 1 MHz and temperature of -50°C to 100°C. The polymer films exhibited an intermediate dielectric permittivity of 4 and low dielectric loss (tan δ) of 0.027. Under 400 MV/m, the energy density of the PSAN films was 6.8 J/cm3, which is three times higher than that of biaxially oriented polypropylene (BOPP) (about 1.6 J/cm3). However, their charge-discharge efficiency (about 90%) was rather close to that of BOPP. The calculated effective dielectric permittivity of the PSAN films under high electric field was as high as 9, which may be attributed to the improved displacement of the cyanide groups (-CN) polarized at high electric fields. These high-performance features make PSAN attractive for high-energy-density capacitor applications.

  2. Radiation crosslinking of styrene-butadiene rubber containing waste tire rubber and polyfunctional monomers

    NASA Astrophysics Data System (ADS)

    Yasin, Tariq; Khan, Sara; Shafiq, Muhammad; Gill, Rohama

    2015-01-01

    The objective of this study was to investigate the influence of polyfunctional monomers (PFMs) and absorbed dose on the final characteristics of styrene-butadiene rubber (SBR) mixed with waste tire rubber (WTR). A series of SBR/WTR blends were prepared by varying the ratios of WTR in the presence of PFMs, namely trimethylolpropane trimethacrylate (TMPTMA) and trimethylolpropane triacrylate (TMPTA) and crosslinked using gamma rays. The physicochemical characteristics of the prepared blends were investigated. It was observed that tensile strength, hardness and gel content of the blends increased with absorbed dose while the blends containing TMPTA showed higher tensile strength, gel content and thermal stability as compared to the blends containing TMPTMA. Higher thermal stability was observed in the blends which were crosslinked by radiation as compared to the blends crosslinked by sulfur. These blends exhibited higher rate of swelling in organic solvents, whereas negligible swelling was observed in acidic and basic environment.

  3. Experimental thermal transport evolution of silane activated nano-clay reinforced styrene butadiene elastomeric nanocomposites

    NASA Astrophysics Data System (ADS)

    Iqbal, S. S.; Iqbal, N.; Jamil, T.; Bashir, A.; Shahid, M.

    2016-08-01

    In this study, silane activated nanoclay was reinforced in styrene butadiene rubber (SBR) to enhance the thermal resistance/stability and mechanical properties of SBR. silane activated nanoclay with variant concentrations was impregnated in the rubber matrix to fabricate polymer nanocomposites under control processing conditions. Experimental thermal transport, thermal oxidation, phase transition study, and mechanical properties of the nanocomposite specimens were carried out. Thermal insulation, thermal stability, and heat flow response were remarkably enhanced with the addition of nanokaolinite in the polymer matrix. Phase transition temperatures, their corresponding enthalpies, tensile strength, elastic modulus, elongation at break and hardness of the rubber composites were positively influenced with the filler incorporation into the host matrix. The Even dispersion of nanoreinforcements, morphological and compositional analyses of the thermal transport tested specimens were performed using scanning electron microscopy and energy dispersive spectroscopy, respectively.

  4. Morphological and mechanical properties of styrene butadiene rubber/nano copper nanocomposites

    NASA Astrophysics Data System (ADS)

    Harandi, Maryam Hadizadeh; Alimoradi, Fakhrodin; Rowshan, Gholamhussein; Faghihi, Morteza; Keivani, Maryam; Abadyan, Mohamadreza

    In this research, rubber based nanocomposites with presence of nanoparticle has been studied. Styrene butadiene rubber (SBR)/nanocopper (NC) composites were prepared using two-roll mill method. Transmission electron microscope (TEM) and scanning electron microscope (SEM) images showed proper dispersion of NC in the SBR matrix without substantial agglomeration of nanoparticles. To evaluate the curing properties of nanocomposite samples, swelling and cure rheometric tests were conducted. Moreover, the rheological studies were carried out over a range of shear rates. The effect of NC particles was examined on the thermal behavior of the SBR using thermal gravimetric analysis (TGA). Furthermore, tensile tests were employed to investigate the capability of nanoparticles to enhance mechanical behavior of the compounds. The results showed enhancement in tensile properties with incorporation of NC to SBR matrix. Moreover, addition of NC increased shear viscosity and curing time of SBR composites.

  5. Effect of concentration of polyfunctional monomers on physical properties of acrylonitrile butadiene rubber under electron-beam irradiation

    NASA Astrophysics Data System (ADS)

    Yasin, Tariq; Ahmed, Shamshad; Ahmed, Munir; Yoshii, Fumio

    2005-06-01

    An investigation has been undertaken to find out the effect of concentration of different polyfunctional monomers (PFMs) on the physical properties of the acrylonitrile-butadiene rubber (NBR) crosslinked by electron beam (EB). The PFMs used were diethylene glycol dimethacrylate, trimethylol propane trimethacrylate and trimethylol propane triacrylate. The physical properties of EB-irradiated NBR sheets were evaluated by measuring the tensile strength, elongation percent at break, hardness and gel fraction. The results showed a remarkable increase in tensile strength, hardness and gel fraction as the concentration of PFMs was increased from 1 part per hundred (phr) to 5 phr in the NBR samples whereas elongation percent decreased in a steady manner. The improvement in physical properties of radiation crosslinked NBR in the presence of PFMs may be attributed to its increased crosslinking density as observed by the corresponding increase in gel content.

  6. Screening-level risk assessment for styrene-acrylonitrile (SAN) trimer detected in soil and groundwater.

    PubMed

    Kirman, C R; Gargas, M L; Collins, J J; Rowlands, J C

    2012-01-01

    A screening-level risk assessment was conducted for styrene-acrylonitrile (SAN) Trimer detected at the Reich Farm Superfund site in Toms River, NJ. Consistent with a screening-level approach, on-site and off-site exposure scenarios were evaluated using assumptions that are expected to overestimate actual exposures and hazards at the site. Environmental sampling data collected for soil and groundwater were used to estimate exposure point concentrations. Several exposure scenarios were evaluated to assess potential on-site and off-site exposures, using parameter values for exposures to soil (oral, inhalation of particulates, and dermal contact) and groundwater (oral, dermal contact) to reflect central tendency exposure (CTE) and reasonable maximum exposure (RME) conditions. Three reference dose (RfD) values were derived for SAN Trimer for short-term, subchronic, and chronic exposures, based upon its effects on the liver in exposed rats. Benchmark (BMD) methods were used to assess the relationship between exposure and response, and to characterize appropriate points of departure (POD) for each RfD. An uncertainty factor of 300 was applied to each POD to yield RfD values of 0.1, 0.04, and 0.03 mg/kg-d for short-term, subchronic, and chronic exposures, respectively. Because a chronic cancer bioassay for SAN Trimer in rats (NTP 2011a) does not provide evidence of carcinogenicity, a cancer risk assessment is not appropriate for this chemical. Potential health hazards to human health were assessed using a hazard index (HI) approach, which considers the ratio of exposure dose (i.e., average daily dose, mg/kg-d) to toxicity dose (RfD, mg/kg-d) for each scenario. All CTE and RME HI values are well below 1 (where the average daily dose is equivalent to the RfD), indicating that there is no concern for potential noncancer effects in exposed populations even under the conservative assumptions of this screening-level assessment.

  7. Fast and robust method for the determination of microstructure and composition in butadiene, styrene-butadiene, and isoprene rubber by near-infrared spectroscopy.

    PubMed

    Vilmin, Franck; Dussap, Claude; Coste, Nathalie

    2006-06-01

    In the tire industry, synthetic styrene-butadiene rubber (SBR), butadiene rubber (BR), and isoprene rubber (IR) elastomers are essential for conferring to the product its properties of grip and rolling resistance. Their physical properties depend on their chemical composition, i. e., their microstructure and styrene content, which must be accurately controlled. This paper describes a fast, robust, and highly reproducible near-infrared analytical method for the quantitative determination of the microstructure and styrene content. The quantitative models are calculated with the help of pure spectral profiles estimated from a partial least squares (PLS) regression, using (13)C nuclear magnetic resonance (NMR) as the reference method. This versatile approach allows the models to be applied over a large range of compositions, from a single BR to an SBR-IR blend. The resulting quantitative predictions are independent of the sample path length. As a consequence, the sample preparation is solvent free and simplified with a very fast (five minutes) hot filming step of a bulk polymer piece. No precise thickness control is required. Thus, the operator effect becomes negligible and the method is easily transferable. The root mean square error of prediction, depending on the rubber composition, is between 0.7% and 1.3%. The reproducibility standard error is less than 0.2% in every case.

  8. Screening-Level Risk Assessment for Styrene-Acrylonitrile (SAN) Trimer Detected in Soil and Groundwater

    PubMed Central

    Kirman, C. R.; Gargas, M. L.; Collins, J. J.; Rowlands, J. C.

    2012-01-01

    A screening-level risk assessment was conducted for styrene-acrylonitrile (SAN) Trimer detected at the Reich Farm Superfund site in Toms River, NJ. Consistent with a screening-level approach, on-site and off-site exposure scenarios were evaluated using assumptions that are expected to overestimate actual exposures and hazards at the site. Environmental sampling data collected for soil and groundwater were used to estimate exposure point concentrations. Several exposure scenarios were evaluated to assess potential on-site and off-site exposures, using parameter values for exposures to soil (oral, inhalation of particulates, and dermal contact) and groundwater (oral, dermal contact) to reflect central tendency exposure (CTE) and reasonable maximum exposure (RME) conditions. Three reference dose (RfD) values were derived for SAN Trimer for short-term, subchronic, and chronic exposures, based upon its effects on the liver in exposed rats. Benchmark (BMD) methods were used to assess the relationship between exposure and response, and to characterize appropriate points of departure (POD) for each RfD. An uncertainty factor of 300 was applied to each POD to yield RfD values of 0.1, 0.04, and 0.03 mg/kg-d for short-term, subchronic, and chronic exposures, respectively. Because a chronic cancer bioassay for SAN Trimer in rats (NTP 2011a) does not provide evidence of carcinogenicity, a cancer risk assessment is not appropriate for this chemical. Potential health hazards to human health were assessed using a hazard index (HI) approach, which considers the ratio of exposure dose (i.e., average daily dose, mg/kg-d) to toxicity dose (RfD, mg/kg-d) for each scenario. All CTE and RME HI values are well below 1 (where the average daily dose is equivalent to the RfD), indicating that there is no concern for potential noncancer effects in exposed populations even under the conservative assumptions of this screening-level assessment. PMID:23030654

  9. Preparation and properties of carboxylated styrene-butadiene rubber/cellulose nanocrystals composites.

    PubMed

    Cao, Xiaodong; Xu, Chuanhui; Liu, Yuhong; Chen, Yukun

    2013-01-30

    A series of carboxylated styrene-butadiene rubber (XSBR)/cellulose nanocrystals (CNs) latex composites were successfully prepared. The vulcanization process, morphology, dynamic viscoelastic behavior, dynamic mechanical property, thermal and mechanical performance of the XSBR/CNs composites were investigated in detail. The results revealed that CNs were dispersed uniformly in the XSBR matrix and formed a strong filler-filler network. The dynamic mechanical analysis (DMA) showed that the glass transition temperature (T(g)) of XSBR matrix was shifted from 48.45 to 50.64 °C with 3 phr CNs, but decreased from 50.64 to 46.28 °C when further increasing CNs content up to 15 phr. The composites exhibited a significant enhancement in tensile strength (from 16.9 to 24.1 MPa) and tear strength (from 43.5 to 65.2 MPa) with loading CNs from 0 to 15 phr. In addition, the thermo-gravimetric analysis (TGA) showed that the temperature at 5% weight loss of the XSBR/CNs composites decreased slightly with an increase of the CNs content.

  10. Performance of Styrene Butadiene Rubber as a Concrete Repair Material in tropical climate

    NASA Astrophysics Data System (ADS)

    Radhakrishnan, R.; Prakash, V. Syam; Thampan, C. K.; Varma, Prasad

    2012-11-01

    Deterioration of Concrete due to variety of reasons like corrosion of steel, inferior quality of materials as well as workmanship and exposure to aggressive environment like thermal cycling affect the performance or damage a number of Reinforced cement concrete structures. In order to repair these structures for enhancing the service life, number of methods and materials are available. But the degree of success of any repair in concrete depends mainly on the correct choice and the method of application of repair materials. This paper discusses the details of an experimental investigation on the performance of Styrene ñ Butadiene Rubber (SBR) as a concrete repair material in tropical climatic conditions. Resistance to water penetration and tensile cracking are two important performance criteria for any repair material. Cement mortar cubes of mix proportion 1:3 with SBR added at the rate of 20% of the weight of cement, and control specimens without SBR were made. Compressive strength and sorptivity values of the cubes were determined. Shear Bond strength (by slant shear test) and splitting tensile strength of the repaired cylinder specimens of standard dimensions, in which SBR used as a bonding agent were determined. These values were compared with the values obtained for the similar specimens, in which the bonding agent applied was conventional cement slurry. The influence of thermal cycling on the properties of repaired concrete specimens were also studied. A comparison has also been made with the values required to meet the standard specifications of a repair material.

  11. About the cure kinetics in natural rubber/styrene Butadiene rubber blends at 433 K

    NASA Astrophysics Data System (ADS)

    Mansilla, M. A.; Marzocca, A. J.

    2012-08-01

    Vulcanized blends of elastomers are employed in several goods mainly to improve physical properties and reduce costs. One of the most used blends of this kind is that composed by natural rubber (NR) and styrene butadiene rubber (SBR). The cure kinetic of these blends depends mainly on the compound formulation and the cure temperature and time. The preparation method of the blends can influence the mechanical properties of the vulcanized compounds. In this work the cure kinetic at 433 K of NR/SBR blends vulcanized with the system sulfur/TBBS (N-t-butyl-2-benzothiazole sulfenamide) is analyzed in samples prepared by mechanical mixing and solution blending. The two methods produce elastomer domains of NR and SBR, which present different microstructure due to the cure level attained during vulcanization. The cure kinetics is studied by means of rheometer tests and the model proposed by Kamal and Sourour. The analysis of the cure rate is presented and is related to the structure obtained during the vulcanization process.

  12. The Synergy of Double Cross-linking Agents on the Properties of Styrene Butadiene Rubber Foams

    PubMed Central

    Shao, Liang; Ji, Zhan-You; Ma, Jian-Zhong; Xue, Chao-Hua; Ma, Zhong-Lei; Zhang, Jing

    2016-01-01

    Sulfur (S) cross-linking styrene butadiene rubber (SBR) foams show high shrinkage due to the cure reversion, leading to reduced yield and increased processing cost. In this paper, double cross-linking system by S and dicumyl peroxide (DCP) was used to decrease the shrinkage of SBR foams. Most importantly, the synergy of double cross-linking agents was reported for the first time to our knowledge. The cell size and its distribution of SBR foams were investigated by FESEM images, which show the effect of DCP content on the cell structure of the SBR foams. The relationships between shrinkage and crystalline of SBR foams were analyzed by the synergy of double cross-linking agents, which were demonstrated by FTIR, Raman spectra, XRD, DSC and TGA. When the DCP content was 0.6 phr, the SBR foams exhibit excellent physical and mechanical properties such as low density (0.223 g/cm3), reduced shrinkage (2.25%) and compression set (10.96%), as well as elevated elongation at break (1.78 × 103%) and tear strength (54.63 N/mm). The results show that these properties are related to the double cross-linking system of SBR foams. Moreover, the double cross-linking SBR foams present high electromagnetic interference (EMI) shielding properties compared with the S cross-linking SBR foams. PMID:27841307

  13. Styrene-butadiene rubber/halloysite nanotubes nanocomposites modified by sorbic acid

    NASA Astrophysics Data System (ADS)

    Guo, Baochun; Chen, Feng; Lei, Yanda; Liu, Xiaoliang; Wan, Jingjing; Jia, Demin

    2009-05-01

    Sorbic acid (SA) was used to improve the performance of styrene-butadiene rubber (SBR)/halloysite nanotubes (HNTs) nanocomposites by direct blending. The detailed mechanisms for the largely improved performance were studied by X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), differential scanning calorimetry (DSC), porosity analysis and crosslink density determination. The strong interfacial bonding between HNTs and rubber matrix is resulted through SA intermediated linkages. SA bonds SBR and HNTs through grafting copolymerization/hydrogen bonding mechanism. Significantly improved dispersion of HNTs in virtue of the interactions between HNTs and SA was achieved. Formation of zinc disorbate (ZDS) was revealed during the vulcanization of the composites. However, in the present systems, the contribution of ZDS to the reinforcement was limited. Effects of SA content on the vulcanization behavior, morphology and mechanical properties of the nanocomposites were investigated. Promising mechanical properties of SA modified SBR/HNTs nanocomposites were obtained. The changes in vulcanization behavior, mechanical properties and morphology were correlated with the interactions between HNTs and SA and the largely improved dispersion of HNTs.

  14. The Synergy of Double Cross-linking Agents on the Properties of Styrene Butadiene Rubber Foams

    NASA Astrophysics Data System (ADS)

    Shao, Liang; Ji, Zhan-You; Ma, Jian-Zhong; Xue, Chao-Hua; Ma, Zhong-Lei; Zhang, Jing

    2016-11-01

    Sulfur (S) cross-linking styrene butadiene rubber (SBR) foams show high shrinkage due to the cure reversion, leading to reduced yield and increased processing cost. In this paper, double cross-linking system by S and dicumyl peroxide (DCP) was used to decrease the shrinkage of SBR foams. Most importantly, the synergy of double cross-linking agents was reported for the first time to our knowledge. The cell size and its distribution of SBR foams were investigated by FESEM images, which show the effect of DCP content on the cell structure of the SBR foams. The relationships between shrinkage and crystalline of SBR foams were analyzed by the synergy of double cross-linking agents, which were demonstrated by FTIR, Raman spectra, XRD, DSC and TGA. When the DCP content was 0.6 phr, the SBR foams exhibit excellent physical and mechanical properties such as low density (0.223 g/cm3), reduced shrinkage (2.25%) and compression set (10.96%), as well as elevated elongation at break (1.78 × 103%) and tear strength (54.63 N/mm). The results show that these properties are related to the double cross-linking system of SBR foams. Moreover, the double cross-linking SBR foams present high electromagnetic interference (EMI) shielding properties compared with the S cross-linking SBR foams.

  15. Radiation-induced copolymerization of styrene/ n-butyl acrylate in the presence of ultra-fine powdered styrene-butadiene rubber

    NASA Astrophysics Data System (ADS)

    Yu, Haibo; Peng, Jing; Zhai, Maolin; Li, Jiuqiang; Wei, Genshuan; Qiao, Jinliang

    2007-11-01

    Styrene (St)/ n-butyl acrylate (BA) copolymers were prepared by two-stage polymerization: St/BA was pre-polymerized to a viscous state by bulk polymerization with initiation by benzoyl peroxide (BPO) followed by 60Co γ-ray radiation curing. The resultant copolymers had higher molecular weight and narrower molecular weight distribution than conventional methods. After incorporation of ultra-fine powdered styrene-butadiene rubber (UFSBR) with a particle size of 100 nm in the monomer, the glass transition temperature ( Tg) of St-BA copolymer increased at low rubber content. Both the St-BA copolymer and the St-BA copolymer/UFSBR composites had good transparency at BA content below 40%.

  16. Dynamic Evaluation of Acrylonitrile Butadiene Styrene Subjected to High-Strain-Rate Compressive Loads

    DTIC Science & Technology

    2014-12-01

    Approved for public release; distribution is unlimited. ii REPORT DOCUMENTATION PAGE Form Approved OMB No. 0704-0188 Public reporting...with a collection of information if it does not display a currently valid OMB control number. PLEASE DO NOT RETURN YOUR FORM TO THE ABOVE ADDRESS. 1... Form 298 (Rev. 8/98) Prescribed by ANSI Std. Z39.18 iii Contents List of Figures iv List of Tables iv 1. Introduction 1 2. Experimental

  17. A comparison of the characteristics of excimer and femtosecond laser ablation of acrylonitrile butadiene styrene (ABS)

    NASA Astrophysics Data System (ADS)

    See, Tian Long; Liu, Zhu; Li, Lin; Zhong, Xiang Li

    2016-02-01

    This paper presents an investigation on the ablation characteristics of excimer laser (λ = 248 nm, τ = 15 ns) and femtosecond laser (λ = 800 nm, τ = 100 fs) on ABS polymer sheets. The laser-material interaction parameters (ablation threshold, optical penetration depth and incubation factor) and the changes in material chemical properties were evaluated and compared between the two lasers. The work shows that the ablation threshold and effective optical penetration depth values are dependent on the wavelength of laser beam (photon energy) and the pulse width. The ablation threshold value is lower for the excimer laser ablation of ABS (Fth = 0.087 J/cm2) than that for the femtosecond laser ablation of ABS (Fth = 1.576 J/cm2), demonstrating a more dominating role of laser wavelength than the pulse width in influencing the ablation threshold. The ablation depth versus the logarithmic scale of laser fluence shows two linear regions for the fs laser ablation, not previously known for polymers. The effective optical penetration depth value is lower for excimer laser ablation (α-1 = 223 nm) than that for femtosecond laser ablation (α-1 = 2917 nm). The ablation threshold decreases with increasing number of pulses (NOP) due to the chain scission process that shortens the polymeric chains, resulting in a weaker polymeric configuration and the dependency is governed by the incubation factor. Excimer laser treatment of ABS eliminates the Cdbnd C bond completely through the chain scission process whereas Cdbnd C bond is partially eliminated through the femtosecond laser treatment due to the difference in photon energy of the two laser beams. A reduction in the Cdbnd C bond through the chain scission process creates free radical carbons which then form crosslinks with each other or react with oxygen, nitrogen and water in air producing oxygen-rich (Csbnd O and Cdbnd O bond) and nitrogen-rich (Csbnd N) functional groups.

  18. 21 CFR 177.1030 - Acrylonitrile/butadiene/styrene/methyl methacrylate copolymer.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... consists of: (1) 73 to 79 parts by weight of a matrix polymer containing 64 to 69 parts by weight of...) 5 to 10 parts by weight of a graft polymer having the same composition range as the matrix polymer... HEALTH AND HUMAN SERVICES (CONTINUED) INDIRECT FOOD ADDITIVES: POLYMERS Substances for Use as...

  19. Glass Transition and Molecular Mobility in Styrene-Butadiene Rubber Modified Asphalt.

    PubMed

    Khabaz, Fardin; Khare, Rajesh

    2015-11-05

    Asphalt, a soft matter consisting of more than a thousand chemical species, is of vital importance for the transportation infrastructure, yet it poses significant challenges for microscopic theory and modeling approaches due to its multicomponent nature. Polymeric additives can potentially enhance the thermo-mechanical properties of asphalt, thus helping reduce the road repair costs; rational design of such systems requires knowledge of the molecular structure and dynamics of these systems. We have used molecular dynamics (MD) simulations to investigate the volumetric, structural, and dynamic properties of the neat asphalt as well as styrene-butadiene rubber (SBR) modified asphalt systems. The volume-temperature behavior of the asphalt systems exhibited a glass transition phenomenon, akin to that observed in experiments. The glass transition temperature, room temperature density, and coefficient of volume thermal expansion of the neat asphalt systems so evaluated were in agreement with experimental data when the effect of the high cooling rate used in simulations was accounted for. While the volumetric properties of SBR modified asphalt were found to be insensitive to the presence of the SBR additive, the addition of SBR led to an increase in the aggregation of asphaltene molecules. Furthermore, addition of SBR caused a reduction in the mobility of the constituent molecules of asphalt, with the reduction being more significant for the larger constituent molecules. Similar to other glass forming liquids, the reciprocal of the diffusion coefficient of the selected molecules was observed to follow the Vogel-Fulcher-Tammann (VFT) behavior as a function of temperature. These results suggest the potential for using polymeric additives for enhancing the dynamic mechanical properties of asphalt without affecting its volumetric properties.

  20. Temperature dependence on free volume in cured natural rubber and styrene-butadiene rubber blends.

    PubMed

    Salgueiro, W; Somoza, A; Silva, L; Consolati, G; Quasso, F; Mansilla, M A; Marzocca, A J

    2011-05-01

    A systematic study on the evolution of free volume as a function of the temperature in vulcanized at 433 K natural rubber (NR) and styrene butadiene rubber (SBR) in 25-75, 50-50, 75-25 NR-SBR (percent content of pure NR and SBR, respectively) blends was studied by positron annihilation lifetime spectroscopy. All samples were prepared with sulfur and TBBS (n-t-butyl-2-benzothiazole sulfenamide) as accelerator. The glass transition temperatures of the samples studied were determined by differential scanning calorimetry (DSC) and from lifetime data. In general, a sigmoidal-like complex behavior of the long-lived lifetime component, linked to the nanohole free volume, as a function of the temperature was found. For SBR, the slope of the ortho-positronium lifetime against temperature curves could be well-fitted using a linear function. For blends and also for NR, two different linear functions were necessary. This last behavior is explained in terms of the supercooled process involving a reconfiguration of the elastomeric chains. In the case of blends, the state of cure of NR and SBR in each NR-SBR sample was also taken into account in the discussion of the results obtained. Besides, thermal expansion coefficients of the free volumes in the transition and glassy region of all compounds were estimated. The differences observed in the values of this parameter are discussed by taking into account the morphology and formulation of each blend, the crosslink densities, and the role of the interphases formed between both NR and SBR elastomers.

  1. Temperature dependence on free volume in cured natural rubber and styrene-butadiene rubber blends

    NASA Astrophysics Data System (ADS)

    Salgueiro, W.; Somoza, A.; Silva, L.; Consolati, G.; Quasso, F.; Mansilla, M. A.; Marzocca, A. J.

    2011-05-01

    A systematic study on the evolution of free volume as a function of the temperature in vulcanized at 433 K natural rubber (NR) and styrene butadiene rubber (SBR) in 25-75, 50-50, 75-25 NR-SBR (percent content of pure NR and SBR, respectively) blends was studied by positron annihilation lifetime spectroscopy. All samples were prepared with sulfur and TBBS (n-t-butyl-2-benzothiazole sulfenamide) as accelerator. The glass transition temperatures of the samples studied were determined by differential scanning calorimetry (DSC) and from lifetime data. In general, a sigmoidal-like complex behavior of the long-lived lifetime component, linked to the nanohole free volume, as a function of the temperature was found. For SBR, the slope of the ortho-positronium lifetime against temperature curves could be well-fitted using a linear function. For blends and also for NR, two different linear functions were necessary. This last behavior is explained in terms of the supercooled process involving a reconfiguration of the elastomeric chains. In the case of blends, the state of cure of NR and SBR in each NR-SBR sample was also taken into account in the discussion of the results obtained. Besides, thermal expansion coefficients of the free volumes in the transition and glassy region of all compounds were estimated. The differences observed in the values of this parameter are discussed by taking into account the morphology and formulation of each blend, the crosslink densities, and the role of the interphases formed between both NR and SBR elastomers.

  2. Genotoxicity of styrene-acrylonitrile trimer in brain, liver, and blood cells of weanling F344 rats.

    PubMed

    Hobbs, Cheryl A; Chhabra, Rajendra S; Recio, Leslie; Streicker, Michael; Witt, Kristine L

    2012-04-01

    Styrene-acrylonitrile Trimer (SAN Trimer), a by-product in production of acrylonitrile styrene plastics, was identified at a Superfund site in Dover Township, NJ, where childhood cancer incidence rates were elevated for a period of several years. SAN Trimer was therefore tested by the National Toxicology Program in a 2-year perinatal carcinogenicity study in F344/N rats and a bacterial mutagenicity assay; both studies gave negative results. To further characterize its genotoxicity, SAN Trimer was subsequently evaluated in a combined micronucleus (MN)/Comet assay in juvenile male and female F344 rats. SAN Trimer (37.5, 75, 150, or 300 mg/kg/day) was administered by gavage once daily for 4 days. Micronucleated reticulocyte (MN-RET) frequencies in blood were determined by flow cytometry, and DNA damage in blood, liver, and brain cells was assessed using the Comet assay. Highly significant dose-related increases (P < 0.0001) in MN-RET were measured in both male and female rats administered SAN Trimer. The RET population was reduced in high dose male rats, suggesting chemical-related bone marrow toxicity. Results of the Comet assay showed significant, dose-related increases in DNA damage in brain cells of male (P < 0.0074) and female (P < 0.0001) rats; increased levels of DNA damage were also measured in liver cells and leukocytes of treated rats. Chemical-related cytotoxicity was not indicated in any of the tissues examined for DNA damage. The results of this subacute MN/Comet assay indicate induction of significant genetic damage in multiple tissues of weanling F344 male and female rats after oral exposure to SAN Trimer.

  3. Effect of crosslinking density on biaxial relaxation of SBR by using reduced variables. [Styrene-Butadiene Rubber

    NASA Technical Reports Server (NTRS)

    Arenz, R. J.

    1974-01-01

    The use of reduced variables to account for the effect of crosslinking density in a styrene-butadiene rubber (SBR) system is demonstrated for general biaxial stress states. Recently published results from stress relaxation tests on five SBR vulcanizates crosslinked to different degrees by tetramethylthiuram disulfide were superposed by using the crosslinking density as a reduction variable. The equilibrium shear modulus calculated from the master relaxation curve at long reduced times was in satisfactory agreement with other results for SBR. The time-axis shifts were related in a linear logarithmic manner to the crosslinking density but had a slope slightly less than values previously reported for elastomer systems.

  4. Effect of Applied Potential on the Electrochemical Deposition of Styrene-Butadiene Co-Polymer Based Conducting Polymer Composite

    NASA Astrophysics Data System (ADS)

    Mathew, Anisha Mary; Neena, P.

    2011-10-01

    Homogeneous conducting polymer composite films with improved electrical properties are synthesized via electrochemical polymerization of polyaniline on Styrene butadiene rubber coated steel electrode. The electrochemical polymerization is carried out by potentiostatic method using an aqueous solution of 0.2 M aniline and 1.5 M sulphuric acid as electrolyte in a single compartment electrochemical cell. The optical studies show successful incorporation of polyaniline into the matrix polymer film. The effect of applied potential on the electrodeposition of composite is studied by cyclic voltammetry and by impedance spectroscopic measurements.

  5. Styrene-Butadiene Co-Polymer Based Highly Conducting and Flexible Polymer Composite Film with Low Percolation Threshold

    NASA Astrophysics Data System (ADS)

    Mathew, Anisha Mary; Neena, P.

    2011-10-01

    Conducting polymer composites are finding novel applications in various fields especially in device technology. In this work an effort has been made to synthesize polyaniline-synthetic rubber (Styrene-butadiene rubber) composite via ex-situ technique and its electrochemical properties are investigated. Highly conducting emeraldine form of polyaniline (20 S/cm) is prepared by the oxidative polymerization of aniline in aqueous acidic (CSA) media using ammonium peroxydisulfate as oxidizing agent. These composite films are characterized by UV-Visible spectroscopy to investigate their optical properties. The dc conductivity studies indicate that these composite films show extremely low percolation threshold.

  6. 21 CFR 177.1050 - Acrylonitrile/styrene copoly-mer modified with butadiene/styrene elastomer.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ..., DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) INDIRECT FOOD ADDITIVES: POLYMERS Substances for Use as... of a blend of: (1) 82-88 parts by weight of a matrix copolymer produced by polymerization of 77-82... by the method titled, “Determination of β-Dodecyl-mercaptopropionitrile in NR-16 Polymer,” which...

  7. Biomonitoring of 1,3-butadiene and related compounds.

    PubMed Central

    Osterman-Golkar, S; Bond, J A

    1996-01-01

    The 1990 Clean Air Act Amendments list several volatile organic chemicals as hazardous air pollutants, including ethylene oxide, butadiene, styrene, and acrylonitrile. The toxicology of many of these compounds shares several common elements such as carcinogenicity in laboratory animals, genotoxicity of the epoxide intermediates, involvement of cytochrome P450 for metabolic activation (except ethylene oxide), and involvement of at least two enzymes for detoxication of the epoxides (e.g., hydrolysis or conjugation with glutathione). These similarities facilitate research strategies for identifying and developing biomarkers of exposure. This article reviews the current knowledge about biomarkers of butadiene. Butadiene is carcinogenic in mice and rats, which raises concern for potential carcinogenicity in humans. Butadiene is metabolized to DNA-reactive metabolites, including 1,2-epoxy-3-butene and diepoxybutane. These epoxides are thought to play a critical role in butadiene carcinogenicity. Butadiene and some of its metabolites (e.g., epoxybutene) are volatile. Exhalation of unchanged butadiene and excretion of butadiene metabolites in urine represent major routes of elimination. Therefore, biomonitoring of butadiene exposure could be based on chemical analysis of butadiene in exhaled breath, blood levels of butadiene epoxides, excretion of butadiene metabolites in urine, or adducts of butadiene epoxides with DNA or blood proteins. Mutation induction in specific genes (e.g., HPRT) following butadiene exposure can be potentially used as a biomarker. Excretion of 1,2-dihydroxy-4-(N-acetylcysteinyl-S)butane or the product of epoxybutene with N-7 in guanine in urine, epoxybutene-hemoglobin adducts, and HPRT mutation have been used as biomarkers in recent studies of occupational exposure to butadiene. Data in laboratory animals suggest that diepoxybutane may be a more important genotoxic metabolite than epoxybutene. Biomonitoring methods need to be developed for

  8. Biomonitoring of 1,3-butadiene and related compounds.

    PubMed

    Osterman-Golkar, S; Bond, J A

    1996-10-01

    The 1990 Clean Air Act Amendments list several volatile organic chemicals as hazardous air pollutants, including ethylene oxide, butadiene, styrene, and acrylonitrile. The toxicology of many of these compounds shares several common elements such as carcinogenicity in laboratory animals, genotoxicity of the epoxide intermediates, involvement of cytochrome P450 for metabolic activation (except ethylene oxide), and involvement of at least two enzymes for detoxication of the epoxides (e.g., hydrolysis or conjugation with glutathione). These similarities facilitate research strategies for identifying and developing biomarkers of exposure. This article reviews the current knowledge about biomarkers of butadiene. Butadiene is carcinogenic in mice and rats, which raises concern for potential carcinogenicity in humans. Butadiene is metabolized to DNA-reactive metabolites, including 1,2-epoxy-3-butene and diepoxybutane. These epoxides are thought to play a critical role in butadiene carcinogenicity. Butadiene and some of its metabolites (e.g., epoxybutene) are volatile. Exhalation of unchanged butadiene and excretion of butadiene metabolites in urine represent major routes of elimination. Therefore, biomonitoring of butadiene exposure could be based on chemical analysis of butadiene in exhaled breath, blood levels of butadiene epoxides, excretion of butadiene metabolites in urine, or adducts of butadiene epoxides with DNA or blood proteins. Mutation induction in specific genes (e.g., HPRT) following butadiene exposure can be potentially used as a biomarker. Excretion of 1,2-dihydroxy-4-(N-acetylcysteinyl-S)butane or the product of epoxybutene with N-7 in guanine in urine, epoxybutene-hemoglobin adducts, and HPRT mutation have been used as biomarkers in recent studies of occupational exposure to butadiene. Data in laboratory animals suggest that diepoxybutane may be a more important genotoxic metabolite than epoxybutene. Biomonitoring methods need to be developed for

  9. The effect of multifunctional monomers/oligomers Additives on electron beam radiation crosslinking of poly (styrene-block-isoprene/butadiene-block-styrene) (SIBS)

    NASA Astrophysics Data System (ADS)

    Wu, Jinping; Soucek, Mark D.

    2016-02-01

    The effect of multifunctional monomers or oligomers (MFM/O) additives on electron beam (E-beam) radiation induced crosslinking of poly (styrene-block-isoprene/butadiene-block-styrene) (SIBS) was studied. Ten types of MFM/O were investigated, including trimethylolpropane trimethacrylate (TMPTMA), trimethylolpropane triacrylate (TMPTA), triallyl cyanurate (TAC), polybutadiene diacrylate (PB-diacrylate), ethylene glycol dimethylacrylate (EGDMA), butylene glycol dimethacrylate (BGDMA), 1,2-polybutadiene. The effects of MFM/O concentration and E-beam radiation dose on properties of SIBS were studied including tensile strength, elongation-at-break, modulus, gel content, equilibrium swelling and crosslink density. TMPTA significantly improved the tensile modulus and crosslink density of SIBS. SIBS with TMPTMA and TMTPMA with inhibitor showed a 50% increase in tensile strength. The solubility of MFM/O in SIBS was also investigated by a selective swelling method. The MFM/O were found to be soluble in both phases of SIBS. The viscosity of SIBS with methacrylate type MFM/O was stable at 200 °C.

  10. Styrene use and occupational exposure in the plastics industry.

    PubMed

    Tossavainen, A

    1978-01-01

    The commercial production of styrene was started in the 1930s. Currently 7 million tons of styrene a year is made worldwide by the catalytic dehydrogenation of ethylbenzene or by a process in which styrene is produced as a coproduct with propylene oxide. An estimated 62% of the styrene monomer is consumed in the manufacture of polystyrene, 12% in acrylonitrile-butadiene-styrene resins, 17% in styrene-butadiene rubber and latex, 7% in unsaturated polyester resins, and 2% in other applications. Occupational exposure to styrene occurs in monomer production and polymerization plants, during the fabrication of plastic products from monomeric or partly prepolymerized styrene, and during the transportation and handling of liquid styrene. Due to unreacted residual monomer or thermal degradation of the polymer, low concentrations of styrene can be detected during the use of plastic products. The most extensive and intensive exposure occurs in the reinforced plastics industry, in which over 200,000 workers are exposed to a styrene concentration typically ranging from 20 to 300 ppm.

  11. A styrene-butadiene rubber (SBR)/carbon nanotube-based smart force sensor for automotive tire deformation monitoring

    NASA Astrophysics Data System (ADS)

    Cho, Min-Young; Kim, Ji-Sik; Lee, Ho-Geun; Choi, Seung-Bok; Kim, Gi-Woo

    2016-04-01

    This paper provides a preliminary study on the piezoresistive effect of a styrene-butadiene Rubber (SBR), one of the main ingredients of automotive tire, dispersed with carbon nanotubes (CNTs) to explore its feasibility as a force sensor embedded in automotive tires. Typically, the application of CNTs has been successfully applied to the mechanical sensing technology such as a stress/strain and impact sensor. In this study, the potential of using the SBR/CNT as a force sensor for monitoring automotive tire deformation is evaluated for the first time. Experimental results show that the electrical resistance of the SBR/CNT composite changes in response to the sinusoidal loading, as well as static compressive load. These piezoresistive responses of the SBR/CNT composite will be used for sensing the tire deformation caused by the vehicle loading or cracks of tires.

  12. Prediction of Flexural Strength of Concretes Containing Silica Fume and Styrene-Butadiene Rubber (SBR) with an Empirical Model

    NASA Astrophysics Data System (ADS)

    Shafieyzadeh, M.

    2015-12-01

    In the flexural test, the theoretical maximum tensile stress at the bottom fiber of a test beam is known as the modulus of rupture or flexural strength. This work deals with the effects of Silica Fume and Styrene-Butadiene Latex (SBR) on flexural strength of concrete. An extensive experimentation was carried out to determine the effects of silica fume and SBR on flexural strength of concrete. Two water-binder ratios and several percentages of silica fume and SBR were considered. Abrams' Law, which was originally formulated for conventional concrete containing cement as the only cementations material, is used for prediction of flexural strength of these concretes. The aim of this work is to construct an empirical model to predict the flexural strength of silica fume-SBR concretes using concrete ingredients and time of curing in water. Also, the obtained results for flexural strength tests have been compared with predicted results.

  13. Improved ozone resistance of styrene-butadiene rubber cured by a combination of sulfur and ionizing radiation

    NASA Astrophysics Data System (ADS)

    Basfar, A. A.; Silverman, Joseph

    1995-09-01

    Fourier Transform Infrared (FTIR) studies performed in this work indicate that high ozone resistance of Styrene-Butadiene Rubber (SBR) formulations cured by a combination of sulfur and ionizing radiation is associated with unusually high vinyl concentration. On the other hand, sulfur cured SBR formulations with low vinyl concentration have poor ozone resistance. Curing with peroxides which involves chemistry similar to that of radiation curing, also leads to high vinyl concentration (relative to sulfur curing) and high ozone resistance. Increasing the absorbed dose in sulfur-radiation cured samples decreased the high vinyl content to a point where the ozone resistance declined greatly. Carbon black was shown to reduce the absorption of both the transvinylene and the vinyl unsaturation groups, but not to the same extent in all formulations. Also, The carbon black seems to play a greater role in the absorption of the unsaturation as sulfur increases.

  14. Innovative neutron shielding materials composed of natural rubber-styrene butadiene rubber blends, boron oxide and iron(III) oxide

    NASA Astrophysics Data System (ADS)

    Jumpee, C.; Wongsawaeng, D.

    2015-05-01

    Optimized flexible and lightweight neutron shielding materials were designed using the Monte Carlo N-Particle (MCNP) code. Thicknesses of 10 mm and 100 mm were tested for neutron shielding performances. Simulation results indicated that the 10 mm shielding material of natural rubber (NR) and styrene butadiene rubber (SBR) blend (1:1) with 60 part per hundred rubber (phr) boron oxide (B2O3) and 100 mm shielding material with four alternating layers of NR with 100 phr iron (III) oxide (Fe2O3) and of NR and SBR blend (1:1) with 10 phr B2O3 were most suitable for thermal neutron shielding and all-energy neutron shielding, respectively. Experimental results verified the shielding efficiency of these optimal designs and ease of fabrication.

  15. Industrial-hygiene survey report of Dow Chemical USA SB (styrene butadiene) Latex Facility, Freeport, Texas

    SciTech Connect

    Fajen, J.M.; Krishnan, E.R.

    1986-03-01

    The purpose of the survey was to obtain information on the SB latex production process and assess the potential for occupational exposure to 1,3-butadiene at the SB latex facility. The information will be used in determining the suitability of including the plant in an in-depth survey.

  16. Polymer composites prepared from heat-treated starch and styrene-butadiene latex

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Thermoplastic starch/latex polymer composites were prepared using styrene–butadiene (SB) latex and heat-treated cornstarch. The composites were prepared in a compression mold at 130 °C, with starch content 20%. An amylose-free cornstarch, waxy maize, was used for this research and the heat treatment...

  17. The influence of nano silica particles on gamma-irradiation ageing of elastomers based on chlorosulphonated polyethylene and acrylonitrile butadiene rubber

    NASA Astrophysics Data System (ADS)

    Marković, G.; Marinović-Cincović, M.; Tanasić, Lj.; Jovanović, V.; Samaržija-Jovanović, S.; Vukić, N.; Budinski-Simendić, J.

    2011-12-01

    The goal of this work was to study gamma irradiation ageing of rubber blends based on acrylonitrile butadiene rubber (NBR) and chlorosulphonated polyethylene rubber (CSM) reinforced by silica nano particles. The NBR/CSM compounds (50: 50, w/w) filled with different content of filler (0-100 phr) were crosslinked by sulfur. The vulcanization characteristics were assessed using the rheometer with an oscillating disk. The vulcanizates were prepared in a hydraulic press. The obtained materials were exposed to the different irradiation doses (100, 200, 300 and 400 kGy). The mechanical properties (hardness, modulus at 100% elongation, tensile strength and elongation at break) and swelling numbers were assessed before and after gamma irradiation ageing.

  18. Radiation preparation of nano-powdered styrene-butadiene rubber (SBR) and its toughening effect for polystyrene and high-impact polystyrene

    NASA Astrophysics Data System (ADS)

    Li, Daishuang; Xia, Haibing; Peng, Jing; Zhai, Maolin; Wei, Genshuan; Li, Jiuqiang; Qiao, Jinliang

    2007-11-01

    Nano-powdered styrene-butadiene rubber (NPSBR) was synthesized based on the styrene-butadiene rubber (SBR) latex via gamma radiation crosslinking followed by spray drying. Two functional monomers, 2-ethyl hexyl acrylate (2-EHA) and trimethylolpropane triacrylate (TMPTA) were used as crosslinking agents. It was found that both 2-EHA and TMPTA can improve the radiation crosslinking of SBR latex. Transmission electron microscope (TEM) and scanning electron microscope (SEM) revealed that the NPSBR has a particle size similar to that of SBR latex with a diameter of 100 nm due to the high degree of crosslinking of SBR. Mechanical testing results showed that NPSBR could toughen polystyrene (PS) and high-impact polystyrene (HIPS) effectively. In addition, NPSBR is more suitable to toughen HIPS than PS at low rubber content.

  19. An approach based on liquid chromatography/electrospray ionization–mass spectrometry to detect diol metabolites as biomarkers of exposure to styrene and 1,3-butadiene

    PubMed Central

    Shen, Shuijie; Zhang, Fan; Zeng, Su; Zheng, Jiang

    2012-01-01

    Styrene and 1,3-butadiene are important intermediates used extensively in the plastics industry. They are metabolized mainly through cytochrome P450-mediated oxidation to the corresponding epoxides, which are subsequently converted to diols by epoxide hydrolase or through spontaneous hydration. The resulting styrene glycol and 3-butene-1,2-diol have been suggested as biomarkers of exposure to styrene and 1,3-butadiene, respectively. Unfortunately, poor ionization of the diols within electrospray mass spectrometers becomes an obstacle to the detection of the two diols by liquid chromatography/electrospray ionization–mass spectrometry (LC/ESI–MS). We developed an LC/ESI–MS approach to analyze styrene glycol and 3-butene-1,2-diol by means of derivatization with 2-bromopyridine-5-boronic acid (BPBA), which not only dramatically increases the sensitivity of diol detection but also facilitates the identification of the diols. The analytical approach developed was simple, quick, and convincing without the need for complicated chemical derivatization. To evaluate the feasibility of BPBA as a derivatizing reagent of diols, we investigated the impact of diol configuration on the affinity of a selection of diols to BPBA using the established LC/ESI–MS approach. We found that both cis and trans diols can be derivatized by BPBA. In conclusion, BPBA may be used as a general derivatizing reagent for the detection of vicinal diols by LC/MS. PMID:19111668

  20. Surface modification of halloysite nanotubes by vulcanization accelerator and properties of styrene-butadiene rubber nanocomposites with modified halloysite nanotubes

    NASA Astrophysics Data System (ADS)

    Zhong, Bangchao; Jia, Zhixin; Hu, Dechao; Luo, Yuanfang; Guo, Baochun; Jia, Demin

    2016-03-01

    Vulcanization accelerant N-cyclohexyl-2-benzothiazole sulfenamide (CZ) was used as a surface modifier and chemically grafted on the surface of halloysite nanotubes (HNTs) to obtain CZ-functionalized HNTs (HNTs-s-CZ). It was found that HNTs-s-CZ could be homogeneously dispersed into styrene-butadiene rubber (SBR). The grafted CZ molecules, exactly located at the filler-rubber interface, reduced the activation energy of vulcanization of SBR/HNTs-s-CZ compounds. Besides, the density of chain segments introduced by the interfacial phase of SBR/HNTs-s-CZ nanocomposites was higher than the other nanocomposites with silane-modified HNTs (m-HNTs) or pristine HNTs, manifesting an indication of enhanced filler-rubber interfacial interaction in SBR/HNTs-s-CZ nanocomposites. Consequently, SBR/HNTs-s-CZ nanocomposites showed excellent mechanical properties. The tensile strength could be enhanced by as much as 38.6% and 102.5% compared to those of SBR/m-HNTs and SBR/HNTs nanocomposites, respectively, though containing equivalent accelerant component. The value of this work lies in the fact that apparent properties improvement of elastomer composites has been achieved by the incorporation of vulcanization accelerant-functionalized HNTs, which may be fruitful for the rational design of filler surface treatment and offer new scientific and technological opportunities for the preparation of high performance elastomer composites.

  1. Characterization on the phase separation behavior of styrene-butadiene rubber/polyisoprene/organoclay ternary blends under oscillatory shear

    NASA Astrophysics Data System (ADS)

    Liu, Xianggui; Dong, Xia; Liu, Wei; Xing, Qian; Zou, Fasheng; Han, Charles C.; Wang, Dujin; Liang, Aimin; Li, Chuanqing; Xie, Ximing

    2015-09-01

    The present work investigated the influence of organoclay (organo-montmorillonite, OMMT) on the phase separation behavior and morphology evolution of solution polymerized styrene-butadiene rubber (SSBR)/low vinyl content polyisoprene (LPI) blends with rheological methodology. It was found that the incorporation of OMMT not only reduced the droplet size of the dispersion phase, slowed down the phase separation kinetics, also enlarged the processing miscibility window of the blends. The determination on the wetting parameters indicated that due to the oscillatory shear effect, the OMMT sheets might localize at the interface between the two phases and act as compatibilizer or rigid barrier to prevent domain coarsening, resulting in slow phase separation kinetics, small droplet size, and stable morphology. The analysis of rheological data by the Palierne model provided further confirmation that the addition of OMMT can decrease the interfacial tension and restrict the relaxation of melt droplets. Therefore, a vivid "sea-fish-net" model was proposed to describe the effect of OMMT on the phase separation behavior of SSBR/LPI blends, in which the OMMT sheets acted as the barrier (net) to slow down the domain coarsening/coalescence in phase separation process of SSBR/LPI blends.

  2. Mortality of a cohort of workers in the styrene-butadiene polymer manufacturing industry (1943-1982).

    PubMed Central

    Matanoski, G M; Santos-Burgoa, C; Schwartz, L

    1990-01-01

    A cohort of 12,110 male workers employed 1 or more years in eight styrene-butadiene polymer (SBR) manufacturing plants in the United States and Canada has been followed for mortality over a 40-year period, 1943 to 1982. The all-cause mortality of these workers was low [standardized mortality ratio (SMR) = 0.81] compared to that of the general population. However, some specific sites of cancers had SMRs that exceeded 1.00. These sites were then examined by major work divisions. The sites of interest included leukemia and non-Hodgkin's lymphoma in whites. The SMRs for cancers of the digestive tract were higher than expected, especially esophageal cancer in whites and stomach cancer in blacks. The SMR for arteriosclerotic heart disease in black workers was significantly higher than would be expected based on general population rates. Employees were assigned to a work area based on job longest held. The SMRs for specific diseases differed by work area. Production workers showed increased SMRs for hematologic neoplasms and maintenance workers, for digestive cancers. A significant excess SMR for arteriosclerotic heart disease occurred only in black maintenance workers, although excess mortality from this disease occurred in blacks regardless of where they worked the longest. A significant excess SMR for rheumatic heart disease was associated with work in the combined, all-other work areas. For many causes of death, there were significant deficits in the SMRs. PMID:2401250

  3. Rheological properties of styrene-butadiene rubber filled with electron beam modified surface treated dual phase fillers

    NASA Astrophysics Data System (ADS)

    Shanmugharaj, A. M.; Bhowmick, Anil K.

    2004-01-01

    The rheological properties of styrene-butadiene rubber (SBR) loaded with dual phase filler were measured using Monsanto Processability Tester (MPT) at three different temperatures (100°C, 110°C and 130°C) and four different shear rates (61.3, 306.3, 613, and 1004.5 s -1). The effect of electron beam modification of dual phase filler in absence and presence of trimethylol propane triacrylate (TMPTA) or triethoxysilylpropyltetrasulphide (Si-69) on melt flow properties of SBR was also studied. The viscosity of all the systems decreases with shear rate indicating their pseudoplastic or shear thinning nature. The higher shear viscosity for the SBR loaded with the electron beam modified filler is explained in terms of variation in structure of the filler upon electron beam irradiation. Die swell of the modified filler loaded SBR is slightly higher than that of the unmodified filler loaded rubber, which is explained by calculating normal stress difference for the systems. Activation energy of the modified filler loaded SBR systems is also slightly higher than that of the control filler loaded SBR system.

  4. Mortality of a cohort of workers in the styrene-butadiene polymer manufacturing industry (1943-1982)

    SciTech Connect

    Matanoski, G.M.; Santos-Burgoa, C.; Schwartz, L. )

    1990-06-01

    A cohort of 12,110 male workers employed 1 or more years in eight styrene-butadiene polymer (SBR) manufacturing plants in the United States and Canada has been followed for mortality over a 40-year period, 1943 to 1982. The all-cause mortality of these workers was low (standardized mortality ratio (SMR) = 0.81) compared to that of the general population. However, some specific sites of cancers had SMRs that exceeded 1.00. These sites were then examined by major work divisions. The sites of interest included leukemia and non-Hodgkin's lymphoma in whites. The SMRs for cancers of the digestive tract were higher than expected, especially esophageal cancer in whites and stomach cancer in blacks. The SMR for arteriosclerotic heart disease in black workers was significantly higher than would be expected based on general population rates. Employees were assigned to a work area based on job longest held. The SMRs for specific diseases differed by work area. Production workers showed increased SMRs for hematologic neoplasms and maintenance workers, for digestive cancers. A significant excess SMR for arteriosclerotic heart disease occurred only in black maintenance workers, although excess mortality from this disease occurred in blacks regardless of where they worked the longest. A significant excess SMR for rheumatic heart disease was associated with work in the combined, all-other work areas. For many causes of death, there were significant deficits in the SMRs.

  5. Polar, Functional Diene-Based Materials: Free Radical Polymerization of 2-Cyanomethyl-1,3-Butadiene

    SciTech Connect

    Jing, Y

    2000-09-12

    This thesis presented here focuses on the synthesis of 2-cyanomethyl-l ,3-butadiene and the free-radical polymerization of this monomer. In addition to the bulk, solution and emulsion polymerizations,, copolymerization with styrene and acrylonitrile will also be discussed. The comonomers were chosen due to the potential applications mentioned above. Furthermore, the thermal properties and rnicrostructures of the homopolymers and the copolymers are examined.

  6. Water-responsive mechanically adaptive nanocomposites based on styrene-butadiene rubber and cellulose nanocrystals--processing matters.

    PubMed

    Annamalai, Pratheep K; Dagnon, Koffi L; Monemian, Seyedali; Foster, E Johan; Rowan, Stuart J; Weder, Christoph

    2014-01-22

    Biomimetic, stimuli-responsive polymer nanocomposites based on a hydrophobic styrene-butadiene rubber (SBR) matrix and rigid, rod-like cellulose nanocrystals (CNCs) isolated from cotton were prepared by three different approaches, and their properties were studied and related to the composition, processing history, and exposure to water as a stimulus. The first processing approach involved mixing an aqueous SBR latex with aqueous CNC dispersions, and films were subsequently formed by solution-casting. The second method utilized the first protocol, but films were additionally compression-molded. The third method involved the formation of a CNC organogel via a solvent exchange with acetone, followed by infusing this gel, in which the CNCs form a percolating network with solutions of SBR in tetrahydrofuran. The thermomechanical properties of the materials were established by dynamic mechanical thermal analysis (DMTA). In the dry state, all nanocomposites show much higher tensile storage moduli, E', than the neat SBR or the SBR latex. E' increases with the CNC content and depends strongly on the processing method, which appears to influence the morphology of the SBR nanocomposites produced. The highest E' values were observed for the solution cast samples involving an SBR latex, where E' increased from 3 MPa for the neat SBR to ca. 740 MPa for the nanocomposite containing 20% v/v CNCs. Upon submersion in deionized water, a dramatic reduction of E' was observed, for example from 740 to 5 MPa for the solution-cast nanocomposite containing 20% v/v CNCs. This change is interpreted as a disengagement of the percolating CNC network, on account of modest aqueous swelling and competitive hydrogen bonding of water molecules with the CNCs. It is shown that the method of preparation also influenced the swelling behavior and kinetics of modulus switching, consistent with different arrangements of the CNCs, which serve as channels for water absorption and transport within the

  7. Lymphatic and haematopoietic cancer mortality in a population attending school adjacent to styrene-butadiene facilities, 1963-1993

    PubMed Central

    Loughlin, J. E.; Rothman, K. J.; Dreyer, N. A.

    1999-01-01

    STUDY OBJECTIVE: To evaluate the risk of mortality from lymphatic and haematopoietic cancers and other causes among students. DESIGN: The study used school records, yearbooks, and Texas Department of Health records for the school years 1963-64 to 1992-93 to construct a cohort of 15,403 students. Three mortality databases were searched to identify deaths, and mortality rates in the cohort were compared with mortality rates from the United States and Texas. Computed standardised mortality ratios and 95% confidence intervals were used. SETTING: Eastern Texas high school adjacent to facilities that have been producing synthetic styrene-butadiene since 1943. MAIN RESULTS: 338 deaths were identified. The all causes standardised mortality ratio was 0.84 (95% confidence intervals 0.74, 0.95) for men and 0.89 (0.73, 1.09) for women. The standardised mortality ratio for all lymphatic and haematopoietic cancers was 1.64 (95% confidence intervals 0.85, 2.87) for men and 0.47 (0.06, 1.70) for women. The slight male excess in lymphatic and haematopoietic cancers was stronger among men who attended school for two years or less. CONCLUSIONS: The overall mortality from lymphatic and haematopoietic cancer among the students was little different from that of the United States as a whole. A moderate excess for men, predominantly among the shorter-term students, was offset by a deficit among women. These variations are compatible with random fluctuations; the overall pattern is not indicative of an effect of environmental exposure sustained while attending the high school.   PMID:10396534

  8. A method for the quantification of biomarkers of exposure to acrylonitrile and 1,3-butadiene in human urine by column-switching liquid chromatography-tandem mass spectrometry.

    PubMed

    Schettgen, T; Musiol, A; Alt, A; Ochsmann, E; Kraus, T

    2009-02-01

    1,3-Butadiene and acrylonitrile are important industrial chemicals that have a high production volume and are ubiquitous environmental pollutants. The urinary mercapturic acids of 1,3-butadiene and acrylonitrile-N-acetyl-S-(3,4-dihydroxybutyl)cysteine (DHBMA) and MHBMA (an isomeric mixture of N-acetyl-S-((1-hydroxymethyl)-2-propenyl)cysteine and N-acetyl-S-((2-hydroxymethyl)-3-propenyl)cysteine) for the former and N-acetyl-S-2-cyanoethylcysteine (CEMA) for the latter-are specific biomarkers for the determination of individual internal exposure to these chemicals. We have developed and validated a fast, specific, and very sensitive method for the simultaneous determination of DHBMA, MHBMA, and CEMA in human urine using an automated multidimensional LC/MS/MS method that requires no additional sample preparation. Analytes are stripped from urinary matrix by online extraction on a restricted access material, transferred to the analytical column, and subsequently determined by tandem mass spectrometry using labeled internal standards. The limits of quantification (LOQs) for DHBMA, MHBMA, and CEMA were 10 microg/L, 2 microg/L, and 1 microg/L urine, respectively, and were sufficient to quantify the background exposure of the general population. Precision within series and between series for all analytes ranged from 5.4 to 9.9%; mean accuracy was between 95 and 115%. We applied the method on spot urine samples from 210 subjects from the general population with no occupational exposure to 1,3-butadiene or acrylonitrile. A background exposure of the general population to acrylonitrile was discovered that is basically influenced by individual exposure to passive smoke as well as active smoking habits. Smokers showed a significantly higher excretion of MHBMA, whereas DHBMA levels did not differ significantly. Owing to its automation, our method is well suited for application in occupational or environmental studies.

  9. Effects of aminopropyltriethoxysilane (γ-APS) on tensile properties and morphology of polypropylene (PP), recycle acrylonitrile butadiene rubber (NBRr) and sugarcane bagasse (SCB) composites

    NASA Astrophysics Data System (ADS)

    Santiagoo, Ragunathan; Omar, Latifah; Zainal, Mustaffa; Ting, Sam Sung; Ismail, Hanafi

    2015-07-01

    The performance of sugarcane baggase (SCB) treated with γ-APS filled polypropylene (PP)/recycled acrylonitrile butadiene rubber (NBRr) biocomposites were investigated. The composites with different filler loading ranging from 5 to 30 wt % were prepared using heated two roll mill by melt mixing at temperature of 180 °C. Tensile properties of the PP/NBRr/SCB composites which is tensile strength, Young Modulus and elongation at break were investigated. Increasing of treated SCB filler loading in PP/NBRr/SCB composites have increased the Young modulus however decreased the tensile strength and elongation at break of the PP/NBRr/SCB composites. From the results, γ-APS treated SCB composites shown higher tensile strength and Young Modulus but lower elongation at break when compared to the untreated SCB composites. This is due to the stronger bonding between γ-APS treated SCB with PP/NBRr matrices. These findings was supported by micrograph pictures from morphological study. SCB filler treated with γ-APS has improved the adhesion as well as gave strong interfacial bonding between SCB filler and PP/NBRr matrices which results in good tensile strength of PP/NBRr/SCB composites.

  10. Heat shrinkable behavior, physico-mechanical and structure properties of electron beam cross-linked blends of high-density polyethylene with acrylonitrile-butadiene rubber

    NASA Astrophysics Data System (ADS)

    Reinholds, Ingars; Kalkis, Valdis; Merijs-Meri, Remo; Zicans, Janis; Grigalovica, Agnese

    2016-03-01

    In this study, heat-shrinkable composites of electron beam irradiated high-density polyethylene (HDPE) composites with acrylonitrile-butadiene rubber (NBR) were investigated. HDPE/NBR blends at a ratio of components 100/0, 90/10, 80/20, 50/50 and 20/80 wt% were prepared using a two-roll mill. The compression molded films were irradiated high-energy (5 MeV) accelerated electrons up to irradiation absorbed doses of 100-300 kGy. The effect of electron beam induced cross-linking was evaluated by the changes of mechanical properties, gel content and by the differences of thermal properties, detected by differential scanning calorimetry. The thermo-shrinkage forces were determined as the kinetics of thermorelaxation and the residual shrinkage stresses of previously oriented (stretched up to 100% at above melting temperature of HDPE and followed by cooling to room temperature) specimens of irradiated HDPE/NBR blends under isometric heating-cooling mode. The compatibility between the both components was enhanced due to the formation of cross-linked sites at amorphous interphase. The results showed increase of mechanical stiffness of composites with increase of irradiation dose. The values of gel fraction compared to thermorelaxation stresses increased with the growth of irradiation dose level, as a result of formation cross-linked sites in amorphous PP/NBR interphase.

  11. Styrene

    Integrated Risk Information System (IRIS)

    Styrene ; CASRN 100 - 42 - 5 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic Effects )

  12. Effect of winding layer and speed on kenaf/glass fiber hybrid reinforced acrylonitrile butadiene styrene (ABS) composites

    NASA Astrophysics Data System (ADS)

    Khoni, Norizzahthul Ainaa Abdul; Sharifah Shahnaz S., B.; Ghazali, Che Mohd Ruzaidi

    2016-07-01

    The usage of natural fiber is becoming significant in composite industries due to their good performance. Single and continuous natural fibers have relatively high mechanical properties; especially their young modulus can be as high as glass fibers. Filament winding is a method to produce technically aligned composites which have high fibers content. The properties of filament winding can be tailored to meet the end product requirements. This research studied the compression properties of kenaf/glass fibers hybrid reinforced composites. Kenaf/glass fibers hybrid composite samples were fabricated by filament winding technique and their properties were compared with the properties of neat kenaf fiber and glass fibers composites. The kenaf/glass fiber hybrid composites exhibited higher strength compared to the neat glass fibers composites. Composites of helical pattern, which produced at low winding speed showed better compression resistance than hoop pattern winding, which produced at high winding speed. As predicted, kenaf composite showed highest water absorption; followed by kenaf/glass fiber hybrid composites while neat glass fiber has lowest water absorption capability.

  13. Production of Acrylonitrile Butadiene Styrene/High-Density Polyethylene Composites from Waste Sources by Using Coupling Agents

    NASA Astrophysics Data System (ADS)

    Miskolczi, N.; Szakacs, H.; Sedlarik, V.; Kucharczyk, P.; Riegel, E.

    2014-07-01

    A possible way of recycling plastic wastes has been investigated. Polyalkenyl-poly-maleic-anhydride derivates were synthesized and employed in ABS and HDPE blends to eliminate their immiscibility. By this way, the recycling of ABS and HDPE could be performed with improved mechanical properties of reshaped specimens.

  14. Thermal behavior of vehicle plastic blends contained acrylonitrile-butadiene-styrene (ABS) in pyrolysis using TG-FTIR.

    PubMed

    Liu, Guicai; Liao, Yanfen; Ma, Xiaoqian

    2017-03-01

    As important plastic blends in End-of-Life vehicles (ELV), pyrolysis profiles of ABS/PVC, ABS/PA6 and ABS/PC were investigated using thermogravimetric-Fourier transform infrared spectrometer (TG-FTIR). Also, CaCO3 was added as plastic filler to discuss its effects on the pyrolysis of these plastics. The results showed that the interaction between ABS and PVC made PVC pyrolysis earlier and HCl emission slightly accelerated. The mixing of ABS and PA6 made their decomposition temperature closer, and ketones in PA6 pyrolysis products were reduced. The presence of ABS made PC pyrolysis earlier, and phenyl compounds in PC pyrolysis products could be transferred into alcohol or H2O. The interaction between ABS and other polymers in pyrolysis could be attributed to the intermolecular radical transfer, and free radicals from the polymer firstly decomposed led to a fast initiation the decomposition of the other polymer. As plastic filler, CaCO3 promoted the thermal decomposition of PA6 and PC, and had no obvious effects on ABS and PVC pyrolysis process. Also, CaCO3 made the pyrolysis products from PA6 and PC further decomposed into small-molecule compounds like CO2. The kinetics analysis showed that isoconversional method like Starink method was more suitable for these polymer blends. Starink method showed the average activation energy of ABS50/PVC50, ABS50/PA50 and ABS50/PC50 was 186.63kJ/mol, 239.61kJ/mol and 248.95kJ/mol, respectively, and the interaction among them could be reflected by the activation energy variation.

  15. Investigation of mechanisms of polycyclic aromatic hydrocarbons (PAHs) initiated from the thermal degradation of styrene butadiene rubber (SBR) in N2 atmosphere.

    PubMed

    Kwon, Eilhann; Castaldi, Marco J

    2008-03-15

    This study has been carried out to characterize the thermal decomposition of styrene-butadiene rubber (SBR), using thermogravimetric analysis (TGA) coupled to online GC/MS, and to investigate the formation and ultimate fate of chemical species produced during gasification of SBR. A preliminary mechanistic understanding has been developed to explain the formation and relationship of light hydrocarbons (C1-C4), substituted aromatics, and polycyclic aromatic hydrocarbons (PAHs) during the decomposition of SBR in a N2 atmosphere. Identification and absolute concentrations of over 50 major and minor species (from hydrogen to benzo[ghi]perylene) have been established, and the measurements have been carried out between 300 and 500 at 10 degrees C/min heating rate in a N2 atmosphere. The concentration of styrene reached 120 PPMV and the concentration of other substituted aromatics, such as toluene and ethyl benzene reached 20 and 5 PPMV, respectively. These measurements indicate PAH formation at a relatively lower temperature as compared to conventional fuel, such as coal and diesel. The PAH sequence is not simply the constructing of larger PAHs from smaller ones to achieve the complex polymer structures. It is possible to generate large PAH molecules while circumventing the typical construction pathway.

  16. Water soluble styrene butadiene rubber and sodium carboxyl methyl cellulose binder for ZnFe2O4 anode electrodes in lithium ion batteries

    NASA Astrophysics Data System (ADS)

    Zhang, Rongyu; Yang, Xu; Zhang, Dong; Qiu, Hailong; Fu, Qiang; Na, Hui; Guo, Zhendong; Du, Fei; Chen, Gang; Wei, Yingjin

    2015-07-01

    ZnFe2O4 nano particles as an anode material for lithium ion batteries are prepared by the glycine-nitrate combustion method. The mixture of styrene butadiene rubber and sodium carboxyl methyl cellulose (SBR/CMC) with the weight ratio of 1:1 is used as the binder for ZnFe2O4 electrode. Compared with the conventional polyvinylidene-fluoride (PVDF) binder, the SBR/CMC binder is much cheaper and environment benign. More significantly, this water soluble binder significantly improves the rate capability and cycle stability of ZnFe2O4. A discharge capacity of 873.8 mAh g-1 is obtained after 100 cycles at the 0.1C rate, with a very little capacity fading rate of 0.06% per cycle. Studies show that the SBR/CMC binder enhances the adhesion of the electrode film to the current collector, and constructs an effective three-dimensional network for electrons transport. In addition, the SBR/CMC binder helps to form a uniform SEI film thus prohibiting the formation of lithium dendrite. Electrochemical impedance spectroscopy shows that the SBR/CMC binder lowers the ohmic resistance of the electrode, depresses the formation of SEI film and facilitates the charge transfer reactions at the electrode/electrolyte interface. These advantages highlight the potential applications of SBR/CMC binder in lithium ion batteries.

  17. Characterization of free volume during vulcanization of styrene butadiene rubber by means of positron annihilation lifetime spectroscopy and dynamic mechanical test.

    PubMed

    Marzocca, A J; Cerveny, S; Salgueiro, W; Somoza, A; Gonzalez, L

    2002-02-01

    An experimental investigation was performed to study the effect on the free volume of the advance of the cross-linking reaction in a copolymer of styrene butadiene rubber by sulfur vulcanization. The dynamic modulus and loss tangent were evaluated over samples cured for different times at 433 K by dynamic mechanical tests over a range of frequencies between 5 and 80 Hz at temperatures between 200 and 300 K. Using the William-Landel-Ferry relationship, master curves were obtained at a reference temperature of 298 K and the coefficients c(0)(1) and c(0)(2) were evaluated. From these parameters the dependence of the free volume on the cure time is obtained. Positron annihilation lifetime spectroscopy was also used to estimate the size and number density of free volume sites in the material. The spectra were analyzed in terms of continuous distributions of free volume size. The results suggest an increase of the lower free volume size when cross linking takes place. Both techniques give similar results for the dependence of free volume on the time of cure of the polymer.

  18. Utilizing carbon dioxide as a reaction medium to mitigate production of polycyclic aromatic hydrocarbons from the thermal decomposition of styrene butadiene rubber.

    PubMed

    Kwon, Eilhann E; Yi, Haakrho; Castaldi, Marco J

    2012-10-02

    The CO(2) cofeed impact on the pyrolysis of styrene butadiene rubber (SBR) was investigated using thermogravimetric analysis (TGA) coupled to online gas chromatography/mass spectroscopy (GC/MS). The direct comparison of the chemical species evolved from the thermal degradation of SBR in N(2) and CO(2) led to a preliminary mechanistic understanding of the formation and relationship of light hydrocarbons (C(1-4)), aromatic derivatives, and polycyclic aromatic hydrocarbons (PAHs), clarifying the role of CO(2) in the thermal degradation of SBR. The identification and quantification of over 50 major and minor chemical species from hydrogen and benzo[ghi]perylene were carried out experimentally in the temperature regime between 300 and 500 °C in N(2) and CO(2). The significant amounts of benzene derivatives from the direct bond dissociation of the backbone of SBR, induced by thermal degradation, provided favorable conditions for PAHs by the gas-phase addition reaction at a relatively low temperature compared to that with conventional fuels such as coal and petroleum-derived fuels. However, the formation of PAHs in a CO(2) atmosphere was decreased considerably (i.e., ∼50%) by the enhanced thermal cracking behavior, and the ultimate fates of these species were determined by different pathways in CO(2) and N(2) atmospheres. Consequently, this work has provided a new approach to mitigate PAHs by utilizing CO(2) as a reaction medium in thermochemical processes.

  19. The industrial production and use of 1,3-butadiene.

    PubMed Central

    Morrow, N L

    1990-01-01

    This presentation provides a brief overview of the production and use of 1,3-butadiene in the United States. Starting as a coproduct of ethylene, the 1,3-butadiene monomer is extracted and purified, then transferred to consumers. Major uses of 1,3-butadiene include the manufacture of styrene-butadiene rubber, polybutadiene rubber, and adiponitrile. PMID:2205493

  20. Preparation and Characterization of Facilitated Transport Membranes Composed of Chitosan-Styrene and Chitosan-Acrylonitrile Copolymers Modified by Methylimidazolium Based Ionic Liquids for CO2 Separation from CH4 and N2

    PubMed Central

    Otvagina, Ksenia V.; Mochalova, Alla E.; Sazanova, Tatyana S.; Petukhov, Anton N.; Moskvichev, Alexandr A.; Vorotyntsev, Andrey V.; Afonso, Carlos A. M.; Vorotyntsev, Ilya V.

    2016-01-01

    CO2 separation was found to be facilitated by transport membranes based on novel chitosan (CS)–poly(styrene) (PS) and chitosan (CS)–poly(acrylonitrile) (PAN) copolymer matrices doped with methylimidazolium based ionic liquids: [bmim][BF4], [bmim][PF6], and [bmim][Tf2N] (IL). CS plays the role of biodegradable film former and selectivity promoter. Copolymers were prepared implementing the latest achievements in radical copolymerization with chosen monomers, which enabled the achievement of outstanding mechanical strength values for the CS-based membranes (75–104 MPa for CS-PAN and 69–75 MPa for CS-PS). Ionic liquid (IL) doping affected the surface and mechanical properties of the membranes as well as the gas separation properties. The highest CO2 permeability 400 Barrers belongs to CS-b-PS/[bmim][BF4]. The highest selectivity α (CO2/N2) = 15.5 was achieved for CS-b-PAN/[bmim][BF4]. The operational temperature of the membranes is under 220 °C. PMID:27294964

  1. Preparation and Characterization of Facilitated Transport Membranes Composed of Chitosan-Styrene and Chitosan-Acrylonitrile Copolymers Modified by Methylimidazolium Based Ionic Liquids for CO₂ Separation from CH₄ and N₂.

    PubMed

    Otvagina, Ksenia V; Mochalova, Alla E; Sazanova, Tatyana S; Petukhov, Anton N; Moskvichev, Alexandr A; Vorotyntsev, Andrey V; Afonso, Carlos A M; Vorotyntsev, Ilya V

    2016-06-09

    CO₂ separation was found to be facilitated by transport membranes based on novel chitosan (CS)-poly(styrene) (PS) and chitosan (CS)-poly(acrylonitrile) (PAN) copolymer matrices doped with methylimidazolium based ionic liquids: [bmim][BF₄], [bmim][PF₆], and [bmim][Tf₂N] (IL). CS plays the role of biodegradable film former and selectivity promoter. Copolymers were prepared implementing the latest achievements in radical copolymerization with chosen monomers, which enabled the achievement of outstanding mechanical strength values for the CS-based membranes (75-104 MPa for CS-PAN and 69-75 MPa for CS-PS). Ionic liquid (IL) doping affected the surface and mechanical properties of the membranes as well as the gas separation properties. The highest CO₂ permeability 400 Barrers belongs to CS-b-PS/[bmim][BF₄]. The highest selectivity α (CO₂/N₂) = 15.5 was achieved for CS-b-PAN/[bmim][BF₄]. The operational temperature of the membranes is under 220 °C.

  2. A comparison between the effects of gamma radiation and sulfur cure system on the microstructure and crosslink network of (styrene butadiene rubber/ethylene propylene diene monomer) blends in presence of nanoclay

    NASA Astrophysics Data System (ADS)

    Shoushtari Zadeh Naseri, Aida; Jalali-Arani, Azam

    2015-10-01

    Rubber blends based on (styrene-butadiene rubber (SBR)/ethylene-propylene-diene monomer (EPDM)) with and without organoclay (OC) were prepared through a melt mixing process. The concentration ratio of the rubber phases (EPDM/SBR; 50/50 wt%) and the amount of the OC were kept constant. The samples were then vulcanized by means of gamma radiation using a Co-60 gamma source as well as sulfur cure system. The effect of absorbed dose on the formation of the crosslinks was confirmed by the Fourier transform infrared spectroscopy (FTIR). The effects of absorbed dose, sulfur cure system and OC on the gel content, and crosslink density were evaluated by the chemical tests. Applying the Charlesby-Pinner equation to estimate the radiation chemical yield, revealed that the use of OC in the blend caused 20% reduction in the degradation/crosslinking ratio. Employing the swelling test data, some thermodynamic parameters were determined. Using field emission scanning electron microscopy (FE-SEM) to investigate microstructure of the samples revealed a more homogeneous structure and also an increase in compatibility of the blend components in the sample cured by the irradiation in comparison to that cured by the sulfur curing system.

  3. Polybenzoxazole-filled nitrile butadiene rubber compositions

    NASA Technical Reports Server (NTRS)

    Gajiwala, Himansu M. (Inventor); Guillot, David G. (Inventor)

    2008-01-01

    An insulation composition that comprises at least one nitrile butadiene rubber (NBR) having an acrylonitrile content that ranges from approximately 26% by weight to approximately 35% by weight and polybenzoxazole (PBO) fibers. The NBR may be a copolymer of acrylonitrile and butadiene and may be present in the insulation composition in a range of from approximately 45% by weight to approximately 56% by weight of a total weight of the insulation composition. The PBO fibers may be present in a range of from approximately 3% by weight to approximately 10% by weight of a total weight of the insulation composition. A rocket motor including the insulation composition and a method of insulating a rocket motor are also disclosed.

  4. Buffing dust as a filler of carboxylated butadiene-acrylonitrile rubber and butadiene-acrylonitrile rubber.

    PubMed

    Chronska, K; Przepiorkowska, A

    2008-03-01

    Buffing dust from chrome tanned leather is one of the difficult tannery wastes to manage. It is also hazardous to both human health and the environment. The scientific literature rarely reports studies on dust management, especially on its utilization as a filler for elastomers. In this connection we have made an attempt to use this leather waste as a filler for rubbers such as XNBR and NBR. The addition of the buffing dust to rubber mixes brought improvement in mechanical properties, and increase in resistance to thermal ageing as well as in electric conductivity and crosslink density of vulcalizates.

  5. Toxicologic profile of acrylonitrile.

    PubMed

    Woutersen, R A

    1998-01-01

    Acrylonitrile is a monomer used extensively as a raw material in the manufacturing of acrylic fibers, plastics, synthetic rubbers, and acrylamide. It has been classified as a probable human carcinogen according to the results of numerous chronic rat bioassays. The present report summarizes the toxicity data on acrylonitrile and reviews available data concerning the mechanism (genetic versus epigenetic) by which acrylonitrile is carcinogenic in rats. From the evaluation of the relevant toxicity data, it can be concluded that acrylonitrile is indeed carcinogenic to rats after either oral or inhalational exposure. However, information on other mammalian species is lacking, and, moreover, the exact mechanism of the carcinogenic process is unclear. Therefore, it is recommended to conduct an additional long-term inhalation carcinogenicity study with acrylonitrile in mice, as well as studies into the mechanism by which acrylonitrile induces (brain) tumors in rats (genetic versus epigenetic).

  6. HEALTH ASSESSMENT OF 1,3-BUTADIENE | Science ...

    EPA Pesticide Factsheets

    This assessment was conducted to review the new information that has become available since EPA's 1985 health assessment of 1,3-butadiene.1,3-Butadiene is a gas used commercially in the production of styrene-butadiene rubber, plastics, and thermoplastic resins. The major environmental source of 1,3-butadiene is the incomplete combustion of fuels from mobile sources (e.g., automobile exhaust). Tobacco smoke can be a significant source of 1,3-butadiene in indoor air.This assessment concludes that 1,3-butadiene is carcinogenic to humans by inhalation, based on the total weight of evidence. The specific mechanisms of 1,3-butadiene-induced carcinogenesis are unknown; however, it is virtually certain that the carcinogenic effects are mediated by genotoxic metabolites of 1,3-butadiene.Animal data suggest that females may be more sensitive than males for cancer effects; nevertheless, there are insufficient data from which to draw any conclusions on potentially sensitive subpopulations.The human incremental lifetime unit cancer (incidence) risk estimate is based on extrapolation from leukemias observed in an occupational epidemiologic study. A twofold adjustment to the epidemiologic-based unit cancer risk is then applied to reflect evidence from the rodent bioassays suggesting that the epidemiologic-based estimate may underestimate total cancer risk from 1,3-butadiene exposure in the general population. 1,3-Butadiene also causes a variety of reproductive and develop

  7. Carcinogenicity of 1,3-butadiene.

    PubMed Central

    Melnick, R L; Shackelford, C C; Huff, J

    1993-01-01

    1,3-Butadiene, a high-production volume chemical used largely in the manufacture of synthetic rubber, is a multiple organ carcinogen in rats and mice. In inhalation studies conducted in mice by the National Toxicology Program, high rates of early lethal lymphomas occurring at exposure levels of 625 ppm or higher reduced the development and expression of later developing tumors at other sites. Use of survival-adjusted tumor rates to account for competing risk factors provided a clearer indication of the dose responses for 1,3-butadiene-induced neoplasms. An increase in lung tumors in female mice was observed at exposure concentrations as low as 6.25 ppm, the lowest concentration ever used in a long-term carcinogenicity study of this gas. Human exposures to 1,3-butadiene by workers employed at facilities that produce this chemical and at facilities that produce styrene-butadiene rubber have been measured at levels higher than those that cause cancer in animals. Furthermore, epidemiology studies have consistently revealed associations between occupational exposure to 1,3-butadiene and excess mortality due to lymphatic and hematopoietic cancers. In response to the carcinogenicity findings for 1,3-butadiene in animals and in humans, the Occupational Safety and Health Administration has proposed lowering the occupational exposure standard for this chemical from 1000 ppm to 2 ppm. Future work is needed to understand the mechanisms of tumor induction by 1,3-butadiene; however, the pursuit of this research should not delay the reduction of human exposure to this chemical. PMID:8354171

  8. Acrylonitrile: a suspected human carcinogen.

    PubMed

    Koerselman, W; van der Graaf, M

    1984-01-01

    The literature on carcinogenicity of acrylonitrile (an important intermediate in the chemical industry) is reviewed. The three main conclusions are: (1) Acrylonitrile has genotoxic effects in various tests in microorganisms and in mammal cells. (2) Chronic exposure to acrylonitrile causes tumours in rats. (3) Results of epidemiological studies indicate that acrylonitrile may be a human carcinogen. From this it is clear that acrylonitrile is very probably carcinogenic to humans. Therefore the authors plead for a reduction of acrylonitrile standards to the lowest practicable limit.

  9. NTP Toxicology and Carcinogenesis Studies of 1,3-Butadiene (CAS No. 106-99-0) in B6C3F1 Mice (Inhalation Studies).

    PubMed

    1984-08-01

    1,3-Butadiene is used as an intermediate in the production of elastomers, polymers, and other chemicals. Of the 1,3-butadiene used in 1978, 44% was used to manufacture styrene-butadiene rubber (a substitute for natural rubber, produced by copolymerization of 1,3-butadiene with styrene), and 19% was used to produce polybutane elastomer (a substance that increases resistance of tire products to wear, heat degradation, and blowouts). Chloroprene monomer, derived from 1,3-butadiene, is used exclusively to manufacture neoprene elastomers for non-tire and latex applications. Commercial nitrile rubber, used largely in rubber hoses, seals, and gaskets for automobiles, is a copolymer of 1,3-butadiene and acrylonitrile. Acrylonitrile- butadiene- styrene resins, usually containing 20%-30% 1,3-butadiene by weight, are used to make parts for automobiles and appliances. Other polymer uses include specialty polybutadiene polymers, thermoplastic elastomers, nitrile barrier resins, and K resins(R). 1,3-Butadiene is used as an intermediate in the production of a variety of industrial chemicals, including two fungicides, captan and captofol. It is approved by the U.S. Food and Drug Administration for use in the production of adhesives used in articles for packaging, transporting, or holding food; in components of paper and paperboard that are in contact with dry food; and as a modifier in the production of semigrid and rigid vinyl chloride plastic food-contact articles. No information was located on the levels of monomer or on its elution rate from any of the commercially available polymers. It is not known if unreacted 1,3-butadiene migrated from packaging materials. Male and female B6C3F1 mice were exposed to air containing 1,3-butadiene (greater than 99% pure) at concentrations of 0-8,000 ppm in 15-day and 14-week inhalation studies. In the 15-day studies, survival was unaffected by dose, and no pathologic effects were observed; slight decreases in mean body weight occurred at the

  10. 40 CFR Table 6 to Subpart Jjj of... - Known Organic HAP Emitted From the Production of Thermoplastic Products

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... = methyl methacrylate acrylonitrile butadiene styrene resin. PET = poly(ethylene terephthalate) resin. SAN = styrene acrylonitrile resin. MBS = methyl methacrylate butadiene styrene resin. ...-diene (106-99-0) 1,4-Dioxane (123-91-1) Ethylene Glycol (107-21-1) Methanol (67-56-1) Methyl...

  11. Industrial hygiene walk-through survey report of the Goodyear Tire and Rubber Company, Houston Chemical Plant, Houston, Texas

    SciTech Connect

    Fajen, J.M.; Ungers, L.J.

    1986-04-01

    A walk-through survey was conducted at Goodyear Tire and Rubber Company, Houston, Texas in November, 1985. The purpose of the survey was to obtain information on production processes for styrene/butadiene rubber, styrene/butadiene latex and acrylonitrile/butadiene rubber, and to evaluate the potential for 1,3-butadiene exposure.

  12. Metabolism of acrylonitrile and interactions

    SciTech Connect

    Hogy, L.L.

    1986-01-01

    Metabolic activation by liver microsomes is necessary for the covalent binding to DNA of acrylonitrile, a widely used industrial chemical. However, tumor formation is localized in the brain, not in the liver. The reasons for such target organ specificity and the mechanism of carcinogenicity are unknown, and studies were performed to provide insights into these events. The metabolism of acrylonitrile was studied in isolated rat hepatocytes to establish the quantitative relationship between oxidative and conjugative metabolism. Approximately 85% of the acrylonitrile reacted with glutathione to form S-(2-cyanoethyl)glutathione while another 5% alkylated protein, especially by cyanoethylation of sulfhydryl groups. About 10% of the acrylonitrile was metabolized to the relatively stable epoxide, 2-cyanoethylene oxide. Further experiments were carried out to study in vivo any genetic damage by acrylonitrile and assess the role of 2-cyanoethylene oxide. Unscheduled DNA synthesis was observed in the livers, but not the brains of acrylonitrile-treated rats. When perfused rat livers were treated with acrylonitrile, 2-cyanoethylene oxide accumulated in the perfusate. 2-Cyano-(2,3-/sup 14/C)-ethylene oxide administered to rats intraperitoneally was found to label both liver and brain protein, but no covalent binding to nucleic acids was detected. These results demonstrate that acrylonitrile has some limited potential for genotoxicity in vivo and that the epoxide can circulate from the liver to the brain to alkylate macromolecules in a carcinogenic target organ generally less capable of DNA repair.

  13. The acrylonitrile dimer ion

    NASA Astrophysics Data System (ADS)

    Ervasti, Henri K.; Jobst, Karl J.; Burgers, Peter C.; Ruttink, Paul J. Ae; Terlouw, Johan K.

    2007-04-01

    Large energy barriers prohibit the rearrangement of solitary acrylonitrile ions, CH2CHCN+, into their more stable hydrogen-shift isomers CH2CCNH+ or CHCH-CNH+. This prompted us to examine if these isomerizations occur by self-catalysis in acrylonitrile dimer ions. Such ions, generated by chemical ionization experiments of acrylonitrile with an excess of carbon dioxide, undergo five dissociations in the [mu]s time frame, as witnessed by peaks at m/z 53, 54, 79, 80 and 105 in their metastable ion mass spectrum. Collision experiments on these product ions, deuterium labeling, and a detailed computational analysis using the CBS-QB3 model chemistry lead to the following conclusions: (i) the m/z 54 ions are ions CH2CHCNH+ generated by self-protonation in ion-dipole stabilized hydrogen-bridged dimer ions [CH2CHCN...H-C(CN)CH2]+ and [CH2CHCN...H-C(H)C(H)CN]+; the proton shifts in these ions are associated with a small reverse barrier; (ii) dissociation of the H-bridged ions into CH2CCNH+ or CHCH-CNH+ by self-catalysis is energetically feasible but kinetically improbable: experiment shows that the m/z 53 ions are CH2CHCN+ ions, generated by back dissociation; (iii) the peaks at m/z 79, 80 and 105 correspond with the losses of HCN, C2H2 and H, respectively. The calculations indicate that these ions are generated from dimer ions that have adopted the (much more stable) covalently bound "head-to-tail" structure [CH2CHCN-C(H2)C(H)CN]+; experiments indicate that the m/z 79 (C5H5N) and m/z 105 (C6H6N2) ions have linear structures but the m/z 80 (C4H4N2) ions consist of ionized pyrimidine in admixture with its stable pyrimidine-2-ylidene isomer. Acrylonitrile is a confirmed species in interstellar space and our study provides experimental and computational evidence that its dimer radical cation yields the ionized prebiotic pyrimidine molecule.

  14. 77 FR 67726 - Department of State: State Department Sanctions Information and Guidance

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-11-13

    ... potentially sanctionable. ``Petrochemical products'' includes any aromatic, olefin, and synthesis gas, and any of their derivatives, including ethylene, propylene, butadiene, benzene, toluene, xylene, ammonia..., acrylonitrile butadiene styrene, alachlor, ammonium nitrate, ammonium sulfate, anhydrous ammonia,...

  15. Melt processing and property testing of a model system of plastics contained in waste from electrical and electronic equipment.

    PubMed

    Triantou, Marianna I; Tarantili, Petroula A; Andreopoulos, Andreas G

    2015-05-01

    In the present research, blending of polymers used in electrical and electronic equipment, i.e. acrylonitrile-butadiene-styrene terpolymer, polycarbonate and polypropylene, was performed in a twin-screw extruder, in order to explore the effect process parameters on the mixture properties, in an attempt to determine some characteristics of a fast and economical procedure for waste management. The addition of polycarbonate in acrylonitrile-butadiene-styrene terpolymer seemed to increase its thermal stability. Also, the addition of polypropylene in acrylonitrile-butadiene-styrene terpolymer facilitates its melt processing, whereas the addition of acrylonitrile-butadiene-styrene terpolymer in polypropylene improves its mechanical performance. Moreover, the upgrading of the above blends by incorporating 2 phr organically modified montmorillonite was investigated. The prepared nanocomposites exhibit greater tensile strength, elastic modulus and storage modulus, as well as higher melt viscosity, compared with the unreinforced blends. The incorporation of montmorillonite nanoplatelets in polycarbonate-rich acrylonitrile-butadiene-styrene terpolymer/polycarbonate blends turns the thermal degradation mechanism into a two-stage process. Alternatively to mechanical recycling, the energy recovery from the combustion of acrylonitrile-butadiene-styrene terpolymer/polycarbonate and acrylonitrile-butadiene-styrene terpolymer/polypropylene blends was recorded by measuring the gross calorific value. Comparing the investigated polymers, polypropylene presents the higher gross calorific value, followed by acrylonitrile-butadiene-styrene terpolymer and then polycarbonate. The above study allows a rough comparative evaluation of various methodologies for treating plastics from waste from electrical and electronic equipment.

  16. Assessment of 1,3-butadiene epidemiology studies.

    PubMed Central

    Ott, M G

    1990-01-01

    Positive carcinogenicity studies in mice and rats have led to concerns that 1,3-butadiene may be carcinogenic in humans under exposure conditions that have existed in occupational settings and perhaps exist today. The principal settings of interest are the styrene-butadiene rubber (SBR) manufacturing industry, which uses large quantities of 1,3-butadiene, and the 1,3-butadiene monomer industry. The potential for 1,3-butadiene exposure is highest during monomer transfer operations and is lowest in finishing areas of polymerization plants where the polymer products are processed. Three large cohort mortality studies have been conducted in the SBR and monomer producing industries since 1980. These studies, which examined the mortality experience of over 17,000 men employed in one monomer and 10 SBR facilities, are the subject of this review. All but one of the facilities began operations during the early 1940s. The mortality experience observed within these employee cohorts is comparable to that seen in other long-term studies of men employed in the petroleum, chemical, and rubber industries for all causes of death, total malignant neoplasms, and for the specific cancers seen in excess in the toxicologic studies. This paper discusses discrepant findings observed in more detailed analyses within individual cohorts and among employment subgroups, as well as selected limitations of the particular studies. Additional efforts to refine 1,3-butadiene exposure categories are needed. Within the context of sample size limitations inherent in these studies, there is currently inadequate evidence to establish a relationship between cancer mortality outcomes and 1.3-butadiene exposure in humans. PMID:2205483

  17. 1,3-Butadiene

    Integrated Risk Information System (IRIS)

    1,3 - Butadiene ; CASRN 106 - 99 - 0 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic E

  18. Future directions in epidemiologic studies of 1,3-butadiene-exposed workers.

    PubMed Central

    Acquavella, J F

    1990-01-01

    To date, epidemiologic research on 1,3-butadiene has consisted of cohort mortality studies of workers in the styrene-butadiene rubber (SBR) and butadiene monomer industries. These studies have been extremely useful both in defining the focus on human health effects to the lymphopoietic cancers and in providing a perspective on which to evaluate the available animal models for human risk assessment. The next step for epidemiologic research will involve a lymphopoietic cancer case control approach to enable a more precise assessment of whether there is a relationship between 1,3-butadiene exposure and lymphopoietic cancer. In addition, periodic mortality updates of the 1,3-butadiene-exposed worker cohorts will be important to monitor trends in lymphopoietic cancer rates and to ensure that other cancers with long latency do not begin to show elevated rates. This paper describes an industry-sponsored program of case-control and cohort mortality update studies along with the critical elements in research design and analysis for each study. Epidemiological studies will play an important role in testing hypotheses developed from toxicological studies about potential biological mechanisms of 1,3-butadiene carcinogenesis in humans. PMID:2401253

  19. Future directions in epidemiologic studies of 1,3-butadiene-exposed workers

    SciTech Connect

    Acquavella, J.F. )

    1990-06-01

    To date, epidemiologic research on 1,3-butadiene has consisted of cohort mortality studies of workers in the styrene-butadiene rubber (SBR) and butadiene monomer industries. These studies have been extremely useful both in defining the focus on human health effects to the lymphopoietic cancers and in providing a perspective on which to evaluate the available animal models for human risk assessment. The next step for epidemiologic research will involve a lymphopoietic cancer case control approach to enable a more precise assessment of whether there is a relationship between 1,3-butadiene exposure and lymphopoietic cancer. In addition, periodic mortality updates of the 1,3-butadiene-exposed worker cohorts will be important to monitor trends in lymphopoietic cancer rates and to ensure that other cancers with long latency do not begin to show elevated rates. This paper describes an industry-sponsored program of case-control and cohort mortality update studies along with the critical elements in research design and analysis for each study. Epidemiological studies will play an important role in testing hypotheses developed from toxicological studies about potential biological mechanisms of 1,3-butadiene carcinogenesis in humans.

  20. Styrene-butadiene-styrene Tri-block Copolymers Modified wit Polyhedral Oligomeric Silsesquioxanes

    DTIC Science & Technology

    2006-05-31

    morphology.1-6 Polymer nano -composites are a new and active research area in the field of block copolymers. Block copolymers reinforced by various nano -sized...fillers have been prepared and studied; layered silicates-based nano -composites have drawn the most attention thus far. 7- 9 Although domain...morphology is not strongly influenced by the blending of layered- silicates, these nano -reinforced block copolymers have shown promising property enhancements

  1. Catalytic hydrophosphination of styrenes.

    PubMed

    Shulyupin, Mstislav O; Kazankova, Marina A; Beletskaya, Irina P

    2002-03-07

    [reaction: see text] The first example of intermolecular hydrophosphination of styrenes catalyzed by Ni and Pd complexes is described. The reaction of Ph2PH with styrene, 4-vinylpyridine, 2-vinylpyridine, 4-methoxystyrene, 2-methoxystyrene, and 5-vinyl-2-methylpyridine in benzene under Ni[P(OEt)3]4 catalysis proceeds with high yield and selectivity to give only anti-Markovnikov product.

  2. Blood styrene and urinary metabolites in styrene polymerisation.

    PubMed Central

    Wolff, M S; Lorimer, W V; Lilis, R; Selikoff, I J

    1978-01-01

    The results of the analysis of blood and urine samples for styrene and its metabolites in 491 workers in a styrene polymerisation plant in the United States are reported. The levels of exposure to styrene were estimated to be less than 10 ppm, but nevertheless styrene and metabolites were detectable in more than 50% of workers in polymerisation jobs, within 4 h of exposure. Workers involved in the manufacture and purification of styrene from ethyl benzene also had detectable blood styrene and urinary metabolites in 83% of recently exposed subjects. The relationship between styrene in blood and in subcutaneous fat and urinary metabolites as pharmacokinetic variables is discussed. PMID:737139

  3. Reduction of acrylamide and acrylonitrile emissions

    SciTech Connect

    Knee, W. R.; Cutie, S. S.

    1985-10-01

    A method comprising contacting a vapor stream resulting from air sparging of aqueous acrylamide containing acrylonitrile with sufficient activated carbon adsorbent to substantially remove acrylamide and acrylonitrile from the vapor stream. This is a particularly advantageous method when aqueous acrylamide is stored in remote locations.

  4. Ion-Molecule Association in Acrylonitrile

    NASA Technical Reports Server (NTRS)

    Wilson, Paul F.; Milligan, Daniel B.; McEwan, Murray J.

    1997-01-01

    Acrylonitrile (propernenitrile or vinyl cyanide) polymerizes readily via a radical mechanism in solution at room temparature. The propensity to polymerize is sufficiently strong that it is usual to add a radical scavenger to the solution to prevent polymerization when oxygen (an inhibitor) is removed. Polymerization of acrylonitrile is also know to occur via nucleophilic addition of an anion by a michael-type reaction.

  5. [Identification of migrants from nitrile-butadiene rubber gloves].

    PubMed

    Mutsuga, Motoh; Kawamura, Yoko; Wakui, Chiseko; Maitani, Tamio

    2003-04-01

    Polyvinyl chloride gloves containing di(2-ethylhexyl) phthalate are restricted for food contact use. In their place, disposable gloves made from nitrile-butadiene rubber (NBR) are used in contact with foodstuffs. Some unknown substances were found to migrate into n-heptane from NBR gloves. By GC/MS, HR-MS and NMR, their chemical structures were confirmed to be 2,2,4-trimethyl-1,3-pentanediol diisobutyrate (used as a plasticizer), 4,4'-butylidenedi(6-tert-butyl-m-cresol), a mixture of styrenated phenols consisting of 2-(alpha-methylbenzyl)phenol, 4-(alpha-methylbenzyl)phenol, 2,6-di(alpha-methylbenzyl)phenol, 2,4-di(alpha-methylbenzyl)phenol and 2,4,6-tri(alpha-methylbenzyl)phenol (used as antioxidants), and 2,4-di-tert-butylphenol, which seems to a degradation product of antioxidant. Migration levels of these compounds were 1.68 micrograms/cm2 of 2,4-di-tert-butylphenol, 2.80 micrograms/cm2 of 2,2,4-trimethyl-1,3-pentanediol diisobutyrate, 46.08 micrograms/cm2 of styrenated phenols and 4.22 micrograms/cm2 of 4,4'-butylidenedi(6-tert-butyl-m-cresol) into n-heptane, respectively. The content of total styrenated phenols was 6,900 micrograms/g in NBR gloves.

  6. 40 CFR 721.8965 - 1H-Pyrole-2, 5-dione, 1-(2,4,6-tribromophenyl)-.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... dewatering step during polymerization of acrylonitrile/butadiene/styrene), and (g)(5). (iii) Industrial... apply to releases of the PMN substance during the dewatering step of the polymerization reactions...

  7. Recycling of engineering plastics from waste electrical and electronic equipments: influence of virgin polycarbonate and impact modifier on the final performance of blends.

    PubMed

    Ramesh, V; Biswal, Manoranjan; Mohanty, Smita; Nayak, Sanjay K

    2014-05-01

    This study is focused on the recovery and recycling of plastics waste, primarily polycarbonate, poly(acrylonitrile-butadiene-styrene) and high impact polystyrene, from end-of-life waste electrical and electronic equipments. Recycling of used polycarbonate, acrylonitrile-butadiene-styrene, polycarbonate/acrylonitrile-butadiene-styrene and acrylonitrile-butadiene-styrene/high impact polystrene material was carried out using material recycling through a melt blending process. An optimized blend composition was formulated to achieve desired properties from different plastics present in the waste electrical and electronic equipments. The toughness of blended plastics was improved with the addition of 10 wt% of virgin polycarbonate and impact modifier (ethylene-acrylic ester-glycidyl methacrylate). The mechanical, thermal, dynamic-mechanical and morphological properties of recycled blend were investigated. Improved properties of blended plastics indicate better miscibility in the presence of a compatibilizer suitable for high-end application.

  8. 24 CFR 3280.803 - Power supply.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... rubber, neoprene, or other approved materials which have been found suitable for the purpose, and shall... polyethylene (PE), poly-vinylchloride (PVC) or acrylonitrile-butadiene-styrene (ABS) plastic tubing having...

  9. 24 CFR 3280.803 - Power supply.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... configuration shown. It shall be molded of butyl rubber, neoprene, or other approved materials which have been... acrylonitrile-butadiene-styrene (ABS) plastic tubing having a minimum wall thickness of nominal 1/8 inch....

  10. 29 CFR 1910.1045 - Acrylonitrile.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... fibers, acrylic plastics and resins, speciality polymers, nitrile rubbers, and other organic chemicals... Acrylonitrile. (a) Scope and application. (1) This section applies to all occupational exposures to... of finished polymers, and products fabricated from such finished polymers; (ii) Materials made...

  11. Species differences in metabolism of 1,3-butadiene

    SciTech Connect

    Henderson, R.F.

    1995-02-01

    1,3-Butadiene (BD) is a 4-carbon gaseous compound with two double bonds. Used in high tonnage to make styrene-butadiene polymers in the rubber industry. Because of large amounts in use, BD was tested for toxicity in 2-year inhalation exposures of both Sprague-Dawley rats and B6C3F{sub 1} mice. The results of the two-species studies were dramatically different. In the initial study in mice, BD was shown to be a potent multiple-site carcinogen at exposure levels of 625 and 1250 ppM. There were increased incidences of neoplasia in the heart, lung, mammary gland, and ovary; malignant lymphomas resulted in early deaths of the mice so that the planned 2-year study was stopped after only 61 weeks of exposure. The second study in mice was conducted at much lower exposure concentrations (6.25, 20, 62.5, 200, and 625 ppM) and lasted 104 weeks. Increased incidences of hemangiosarcomas of the heart and lung neoplasia were observed in males exposed to 62.5 ppM BD, while females had increased lung neoplasia even at the 6.25 ppM exposure level. Early deaths from lymphomas were again observed at the high exposure concentration (625 ppm). A noncancer toxicity observed in mice was a macrocytic, megaloblastic anemia.

  12. Acrylonitrile-induced oxidative DNA damage in rat astrocytes.

    PubMed

    Pu, Xinzhu; Kamendulis, Lisa M; Klaunig, James E

    2006-10-01

    Chronic administration of acrylonitrile results in a dose-related increase in astrocytomas in rat brain, but the mechanism of acrylonitrile carcinogenicity is not fully understood. The potential of acrylonitrile or its metabolites to induce direct DNA damage as a mechanism for acrylonitrile carcinogenicity has been questioned, and recent studies indicate that the mechanism involves the induction of oxidative stress in rat brain. The present study examined the ability of acrylonitrile to induce DNA damage in the DI TNC1 rat astrocyte cell line using the alkaline Comet assay. Oxidized DNA damage also was evaluated using formamidopyrimidine DNA glycosylase treatment in the modified Comet assay. No increase in direct DNA damage was seen in astrocytes exposed to sublethal concentrations of acrylonitrile (0-1.0 mM) for 24 hr. However, acrylonitrile treatment resulted in a concentration-related increase in oxidative DNA damage after 24 hr. Antioxidant supplementation in the culture media (alpha-tocopherol, (-)-epigallocathechin-3 gallate, or trolox) reduced acrylonitrile-induced oxidative DNA damage. Depletion of glutathione using 0.1 mM DL-buthionine-[S,R]-sulfoximine increased acrylonitrile-induced oxidative DNA damage (22-46%), while cotreatment of acrylonitrile with 2.5 mM L-2-oxothiazolidine-4-carboxylic acid, a precursor for glutathione biosynthesis, significantly reduced acrylonitrile-induced oxidative DNA damage (7-47%). Cotreatment of acrylonitrile with 0.5 mM 1-aminobenzotriazole, a suicidal inhibitor of cytochrome P450, prevented the oxidative DNA damage produced by acrylonitrile. Cyanide (0.1-0.5 mM) increased oxidative DNA damage (44-160%) in astrocytes. These studies demonstrate that while acrylonitrile does not directly damage astrocyte DNA, it does increase oxidative DNA damage. The oxidative DNA damage following acrylonitrile exposure appears to arise mainly through the P450 metabolic pathway; moreover, glutathione depletion may contribute to the

  13. IRIS Toxicological Review of Acrylonitrile (External Review Draft)

    EPA Science Inventory

    [UPDATE] New Schedule for IRIS Acrylonitrile Assessment

    In May 2012, EPA developed a new schedule for completing the IRIS acrylonitrile assessment. Acrylonitrile is primarily used in the manufacture of acrylic and modacrylic fibers, plastics, and nitrile rubbers. It ...

  14. Coconut shell powder as cost effective filler in copolymer of acrylonitrile and butadiene rubber.

    PubMed

    Keerthika, B; Umayavalli, M; Jeyalalitha, T; Krishnaveni, N

    2016-08-01

    Filler is one of the major additives in rubber compounds to enhance the physical properties. Even though numerous benefits obtained from agricultural by products like coconut shell, rice husk etc., still they constitute a large source of environmental pollution. In this investigation, one of the agricultural bye product coconut shell powder (CSP) is used as filler in the compounding KNB rubber. It shows the positive and satisfied result was achieved only by the use of filler Fast Extrusion Furnace (FEF) and coconut shell powder (CSP) which was used 50% in each. The effect of these fillers on the mechanical properties of a rubber material at various loading raging from 0 to 60PHP was studied. Mercaptodibanzothiazole disulphide (MBTS) was used as an accelerator. The result shows that presence of 25% and 50% of the composites has better mechanical properties like Hardness, Tensile strength, Elongation at break and Specific gravity when compared with other two combinations. Even though both 25% and 50% of composites shows good mechanical properties, 50% of CSP have more efficient than 25% of CSP.

  15. Molecular Simulation of Gas Solubility in Nitrile Butadiene Rubber.

    PubMed

    Khawaja, M; Sutton, A P; Mostofi, A A

    2017-01-12

    Molecular simulation is used to compute the solubility of small gases in nitrile butadiene rubber (NBR) with a Widom particle-insertion technique biased by local free volume. The convergence of the method is examined as a function of the number of snapshots upon which the insertions are performed and the number of insertions per snapshot and is compared to the convergence of the unbiased Widom insertion technique. The effect of varying the definition of local free volume is also investigated. The acrylonitrile content of the polymer is altered to examine its influence on the solubility of helium, CO2, and H2O, and the solubilities of polar gases are found to be enhanced relative to those of nonpolar gases, in qualitative agreement with experiment. To probe this phenomenon further, the solubilities are decomposed into contributions from the neighborhoods of different atoms, using a Voronoi cell construction, and a strong bias is found for CO2 and H2O in particular to be situated near nitrogen sites in the elastomer. Temperature is shown to suppress the solubility of CO2 and H2O but to increase that of helium. Increasing pressure is found to suppress the solubility of all gases but at different rates, according to a balance between their molecular sizes and electrostatic interactions with the polymer. These results are relevant to the use of NBR seals at elevated temperatures and pressures, such as in oil and gas wells.

  16. 21 CFR 180.22 - Acrylonitrile copolymers.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... analytical methods used to determine the complex and the acrylonitrile migration, and validation studies of... articles intended for repeated use: (1) Qualitative and quantitative migration values at a time equivalent... use. (2) Qualitative and quantitative migration values at the time of equilibrium...

  17. 21 CFR 180.22 - Acrylonitrile copolymers.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... determine the complex and the acrylonitrile migration, and validation studies of these analytical methods... repeated use: (1) Qualitative and quantitative migration values at a time equivalent to initial batch usage... quantitative migration values at the time of equilibrium extractions, utilizing solvents and...

  18. 21 CFR 180.22 - Acrylonitrile copolymers.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... determine the complex and the acrylonitrile migration, and validation studies of these analytical methods... repeated use: (1) Qualitative and quantitative migration values at a time equivalent to initial batch usage... quantitative migration values at the time of equilibrium extractions, utilizing solvents and...

  19. 21 CFR 180.22 - Acrylonitrile copolymers.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... determine the complex and the acrylonitrile migration, and validation studies of these analytical methods... repeated use: (1) Qualitative and quantitative migration values at a time equivalent to initial batch usage... quantitative migration values at the time of equilibrium extractions, utilizing solvents and...

  20. 21 CFR 180.22 - Acrylonitrile copolymers.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... determine the complex and the acrylonitrile migration, and validation studies of these analytical methods... repeated use: (1) Qualitative and quantitative migration values at a time equivalent to initial batch usage... quantitative migration values at the time of equilibrium extractions, utilizing solvents and...

  1. Cancer occurrence among workers exposed to acrylonitrile.

    PubMed

    Rothman, K J

    1994-10-01

    A MEDLINE search identified 12 published epidemiologic studies that have reported incidence or mortality experience among workers exposed to acrylonitrile. Many of the studies contain scanty descriptions of subject ascertainment, and most do not have good information on exposure assessment. Many also may have suffered from incomplete follow-up, as evinced by an overall deficit in the number of deaths observed, compared with the number expected from general population mortality rates. Such problems are not unique to studies on acrylonitrile, and to some extent they reflect the difficulties of conducting retrospective cohort studies. Despite these drawbacks, a simplified meta-analysis of the mortality experience reported for these cohorts revealed little evidence for carcinogenicity. Approximately the same number of cancer deaths was observed as was expected according to general population mortality rates (standardized mortality ratio 1.03, 90% confidence interval 0.92-1.15). The combined information from these studies is insufficient to support confidence about a lack of carcinogenicity at all sites. Nevertheless, despite the flaws in some of the individual studies, the summarized findings offer reassurance that workers exposed to acrylonitrile face no striking increases in mortality for all cancers or for respiratory cancer.

  2. 21 CFR 177.1040 - Acrylonitrile/styrene copoly-mer.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... Internal Standard Method”; “Infrared Spectrophotometric Determination of Polymer Extracted from Barex 210... °F) for the finished article is 0.04 barrer. 3 1 Use methods for determination of residual... Copolymers,” and “Analytical Method for 10% Solution Viscosity of Tyril,” which are incorproated by...

  3. 21 CFR 181.32 - Acrylonitrile copolymers and resins.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Acrylonitrile copolymers and resins. 181.32 Section 181.32 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... acrylonitrile monomer extraction for finished food-contact articles, determined by using the method of...

  4. 21 CFR 181.32 - Acrylonitrile copolymers and resins.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Acrylonitrile copolymers and resins. 181.32 Section 181.32 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... acrylonitrile monomer extraction for finished food-contact articles, determined by using the method of...

  5. ABSORPTION OF CO2 IN HIGH ACRYLONITRILE CONTENT COPOLYMERS: DEPENDENCE ON ACRYLONITRILE CONTENT. (R829555)

    EPA Science Inventory

    In continuation of our goal to determine the ability of CO2 to plasticize acrylonitrile (AN) copolymers and facilitate melt processing at temperatures below the onset of thermal degradation, a systematic study has been performed to determine the influence of AN cont...

  6. A VUV photoionization study of the multichannel reaction of phenyl radicals with 1,3-butadiene under combustion relevant conditions.

    PubMed

    Golan, Amir; Ahmed, Musahid; Mebel, Alexander M; Kaiser, Ralf I

    2013-01-07

    We studied the reaction of phenyl radicals (C(6)H(5)) with 1,3-butadiene (H(2)CCHCHCH(2)) exploiting a high temperature chemical reactor under combustion-like conditions (300 Torr, 873 K). The reaction products were probed in a supersonic beam by utilizing VUV radiation from the Advanced Light Source and by recording the experimental PIE curves at mass-to-charge ratios of m/z = 130 (C(10)H(10)(+)), 116 (C(9)H(8)(+)), and 104 (C(8)H(8)(+)). Our data suggest that the atomic hydrogen (H), methyl (CH(3)), and vinyl (C(2)H(3)) losses are open with estimated branching ratios of about 86 ± 4%, 8 ± 2%, and 6 ± 2%, respectively. The isomer distributions were probed further by fitting the experimentally recorded PIE curves with a linear combination of the PIE curves of individual C(10)H(10), C(9)H(8), and C(8)H(8) isomers. These fits indicate the formation of three C(10)H(10) isomers (trans-1,3-butadienylbenzene, 1,4-dihydronaphthalene, 1-methylindene), three C(9)H(8) isomers (indene, phenylallene, 1-phenyl-1-methylacetylene), and a C(8)H(8) isomer (styrene). A comparison with results from recent crossed molecular beam studies of the 1,3-butadiene-phenyl radical reaction and electronic structure calculations suggests that trans-1,3-butadienylbenzene (130 amu), 1,4-dihydronaphthalene (130 amu), and styrene (104 amu) are reaction products formed as a consequence of a bimolecular reaction between the phenyl radical and 1,3-butadiene. 1-Methylindene (130 amu), indene (116 amu), phenylallene (116 amu), and 1-phenyl-1-methylacetylene (116 amu) are synthesized upon reaction of the phenyl radical with three C(4)H(6) isomers: 1,2-butadiene (H(2)CCCH(CH(3))), 1-butyne (HCCC(2)H(5)), and 2-butyne (CH(3)CCCH(3)); these C(4)H(6) isomers can be formed from 1,3-butadiene via hydrogen atom assisted isomerization reactions or via thermal rearrangements of 1,3-butadiene involving hydrogen shifts in the high temperature chemical reactor.

  7. Styrene exposure and risk of cancer

    PubMed Central

    Huff, James; Infante, Peter F.

    2011-01-01

    Styrene is widely used in the manufacture of synthetic rubber, resins, polyesters and plastics. Styrene and the primary metabolite styrene-7,8-oxide are genotoxic and carcinogenic. Long-term chemical carcinogenesis bioassays showed that styrene caused lung cancers in several strains of mice and mammary cancers in rats and styrene-7,8-oxide caused tumours of the forestomach in rats and mice and of the liver in mice. Subsequent epidemiologic studies found styrene workers had increased mortality or incidences of lymphohematopoietic cancers (leukaemia or lymphoma or all), with suggestive evidence for pancreatic and esophageal tumours. No adequate human studies are available for styrene-7,8-oxide although this is the primary and active epoxide metabolite of styrene. Both are genotoxic and form DNA adducts in humans. PMID:21724974

  8. A numerical investigation on mechanical property improvement of styrene butadine rubber by static straight blade indentation

    NASA Astrophysics Data System (ADS)

    Setiyana, B.; Ismail, R.; Jamari, J.; Schipper, D. J.

    2016-04-01

    Mechanical property improvement of rubber is widely carried out by adding carbon black or silica as a filler in rubber. In general, this improvement aims on the increase of stiffness and abrasion resistance. By means of the static straight blade indentation technique, this paper studies the mechanical properties of Unfilled Styrene Butadiene Rubber (SBR-0) and Filled Styrene Butadiene Rubber that is compounded with carbon black (SBR-25). The numerical method applied was Finite Element Analysis (FEA) in which the rubber was modeled as a hyper-elastic material and indented by a blade indenter with various wedge angles i.e. 30, 45 and 60 degrees. At the same depth of indentation, the results showed that there was an increase in both rubber stiffness and maximum stress if the rubber was compounded. However, it is found that the rubber stiffness showed a regular slight increase, while the maximum stress experienced an irregularly significant increase. Especially for the 30 degree wedge angle, the maximum stress extremely increased at a certain depth of indentation.

  9. EFFECT OF SOY PROTEIN AND CARBOHYDRATE RATIO ON THE VISCOELASTIC PROPERTIES OF STYRENE-BUTADIENE COMPOSITES

    Technology Transfer Automated Retrieval System (TEKTRAN)

    When soy products including soy protein isolate, defatted soy flour, soy protein concentrate, and soy spent flakes were incorporated into rubber latex to form composites, they showed substantial reinforcement effects as measured by rheological and mechanical methods. It was observed that different ...

  10. Effect of soy protein and carbohydrate ratio on the viscoelastic properties of styrene-butadiene composites

    Technology Transfer Automated Retrieval System (TEKTRAN)

    When soy products including soy protein isolate (SPI), defatted soy flour, soy protein concentrate, and soy spent flakes (SSF) were incorporated into rubber latex to form composites, they showed substantial reinforcement effects as measured by rheological and mechanical methods. It was observed tha...

  11. Morphology and vulcanizate properties of ethylene-propylene-diene rubber/ styrene-butadiene rubber blends.

    PubMed

    Park, Gayoung; Kim, Yun Hee; Kim, Dong Soo; Ko, Young Chun

    2010-05-01

    Morphology and vulcanizate properties of EPDM/SBR blends were investigated. AAHR (a mixture of aliphatic and aromatic hydrocarbon resins) was used as a compatibilizer and bis(3-triethoxysilylpropyl)tetrasulfide (TESPT) was used as a coupling agent. The vulcanizate properties and the morphological studies revealed that EPDM and SBR were incompatible, and the addition of AAHR was very effective to enhance the compatibility between EPDM and SBR. The weight percent of bound rubbers was increased with increasing SBR contents. The addition of an AAHR increased the amounts of bound rubbers, and hence the vulcanizate properties such as tear strength and fatigue resistance of the EPDM/SBR blends were improved. The dynamic mechanical analysis and the morphological studies revealed that the addition of TESPT increased the weight of bound rubbers and provided better dispersion of carbon black, resulting in good mechanical properties such as tear strength and fatigue resistance of the vulcanized EPDM/SBR blends. The smaller particle of zinc oxide (i.e., 50 nm > 100 nm > 1000 nm) yielded to the better blending properties of the polymer blend.

  12. Reinforcement Effect of Alkali Hydrolyzed Wheat Gluten and Starch in Carboxylated Styrene-Butadiene Composites

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Wheat gluten (WG) and wheat starch (WS) are the protein and carbohydrate obtained from wheat flours. Wheat gluten is not water soluble or dispersible due to its hydrophobic nature. To prepare wheat gluten dispersions, an alkali hydrolysis reaction was carried out to produce a stable aqueous disper...

  13. Reinforcement effect of soy protein/carbohydrate ratio in styrene-butadiene polymer

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soy protein and carbohydrate at different ratios were blended with latex to form composites. The variation of protein to carbohydrate ratio has a sifnificant effect on the composite properties and the results from dynamic mechanical method showed a substantial reinforcement effect. The composites ...

  14. Extrudate characteristics and morphology of styrene butadiene rubber/high density polyethylene blends

    NASA Astrophysics Data System (ADS)

    Jayasree, T. K.; Manuvel, Jayan

    2013-06-01

    When HDPE is added to SBR, the melt elasticity of the system gets reduced. The morphology of the extrudates of the blends has been found to be dependent on the shear rate. Dynamic crosslinking with DCP has been improved the processability of SBR/HDPE blends by reducing the melt elasticity of the system considerably.

  15. Ultrasonic studies on polystyrene/styrene butadiene rubber polymer blends filled with glass fiber and talc.

    PubMed

    Higazy, A A; Afifi, H; Khafagy, A H; El-Shahawy, M A; Mansour, A M

    2006-12-22

    The compatibility of solid blends: PS/SBR, PS/SBR filled with glass fiber and PS/SBR filled with talc were studied using ultrasonic pulse echo technique. Measurements were carried out at room temperature (298 K) and a frequency of 3 MHz. The ultrasonic velocity for the compressional wave and that for shear wave have been measured to obtain the elastic moduli data by knowing of density. The variation of ultrasonic wave velocities and elastic moduli with weight percent of the blend was found to be linear in PS/SBR blend, indicating some degree of compatibility but the drawback of elastic moduli indicate incompatibility of the system blend, while it deviates from linearity in blends of PS/SBR filled with glass fiber and talc but the increase in elastic moduli indicates that there is an increase in degree of compatibility between PS and SBR due to adding of glass fiber or talc. The ultrasonic absorptions for longitudinal wave in the temperature range from 298 to 423 K in the studied system were measured using ultrasonic pulse echo technique. Typical results showing the temperature dependence of the ultrasonic absorption at frequencies of 1, 2, 3 and 5 MHz are illustrated for all samples of the different compositions. The study of compositional and temperature dependence of the ultrasonic absorption in the present studied blends reveals the same behavior of the compatibility degree of the blends. Density data of the blends confirmed the ultrasonic results. Also the correlation between hardness and elastic moduli for the present blend systems has been studied.

  16. Bacterial degradation of styrene involving a novel flavin adenine dinucleotide-dependent styrene monooxygenase.

    PubMed Central

    Hartmans, S; van der Werf, M J; de Bont, J A

    1990-01-01

    By using styrene as the sole source of carbon and energy in concentrations of 10 to 500 microM, 14 strains of aerobic bacteria and two strains of fungi were isolated from various soil and water samples. In cell extracts of 11 of the bacterial isolates, a novel flavin adenine dinucleotide-requiring styrene monooxygenase activity that oxidized styrene to styrene oxide (phenyl oxirane) was detected. In one bacterial strain (S5), styrene metabolism was studied in more detail. In addition to styrene monooxygenase, cell extracts from strain S5 contained styrene oxide isomerase and phenylacetaldehyde dehydrogenase activities. A pathway for styrene degradation via styrene oxide and phenylacetaldehyde to phenylacetic acid is proposed. PMID:2339888

  17. Thermodynamics of coil-hyperbranched poly(styrene-b-acrylated epoxidized soybean oil) block copolymers

    NASA Astrophysics Data System (ADS)

    Lin, Fang-Yi; Hohmann, Austin; Hernández, Nacú; Cochran, Eric

    Here we present the phase behavior of a new type of coil-hyperbranched diblock copolymer: poly(styrene- b-acrylated epoxidized soybean oil), or PS-PAESO. PS-PAESO is an example of a biorenewable thermoplastic elastomer (bio-TPE). To date, we have shown that bio-TPEs can be economical commercial substitutes for their petrochemically derived analogues--such as poly(styrene- b-butadiene- b-styrene) (SBS)--in a range of applications including pressure sensitive adhesives and bitumen modification. From a polymer physics perspective, PS-PAESO is an interesting material in that it couples a linear coil-like block with a highly branched block. Thus in contrast to the past five decades of studies on linear AB diblock copolymers, coil-hyperbranched block copolymers are relatively unknown to the community and can be expected to deviate substantially from the standard ``universal'' phase behavior in the AB systems. To explore these new materials, we have constructed a library of PS-PAESO materials spanning a range of molecular weight and composition values. The phase transition behavior and the morphology information will be interpreted by isochronal temperature scanning in dynamic shear rheology, small angle X-ray scattering and the corresponding transmission electron microscopy.

  18. Mutagenicity, carcinogenicity, and teratogenicity of acrylonitrile.

    PubMed

    Léonard, A; Gerber, G B; Stecca, C; Rueff, J; Borba, H; Farmer, P B; Sram, R J; Czeizel, A E; Kalina, I

    1999-05-01

    Acrylonitrile (AN) is an important intermediary for the synthesis of a variety of organic products, such as artificial fibres, household articles and resins. Although acute effects are the primary concern for an exposure to AN, potential genotoxic, carcinogenic and teratogenic risks of AN have to be taken seriously in view of the large number of workers employed in such industries and the world-wide population using products containing and possibly liberating AN. An understanding of the effect of acrylonitrile must be based on a characterization of its metabolism as well as of the resulting products and their genotoxic properties. Tests for mutagenicity in bacteria have in general been positive, those in plants and on unscheduled DNA synthesis doubtful, and those on chromosome aberrations in vivo negative. Wherever positive results had been obtained, metabolic activation of AN appeared to be a prerequisite. The extent to which such mutagenic effects are significant in man depends, however, also on the conditions of exposure. It appears from the limited data that the ultimate mutagenic factor(s), such as 2-cyanoethylene oxide, may have little opportunity to act under conditions where people are exposed because it is formed only in small amounts and is rapidly degraded. The carcinogenic action of AN has been evaluated by various agencies and ranged from 'reasonably be anticipated to be a human carcinogen' to 'cannot be excluded', the most recent evaluation being 'possibly carcinogenic to humans'. Animal data that confirm the carcinogenic potential of AN have certain limitations with respect to the choice of species, type of tumors and length of follow up. Epidemiological studies which sometimes, but not always, yielded positive results, encounter the usual difficulties of confounding factors in chemical industries. Exposure of workers to AN should continue to be carefully monitored, but AN would not have to be considered a cancer risk to the population provided

  19. Hesperidin, an antioxidant flavonoid, prevents acrylonitrile-induced oxidative stress in rat brain.

    PubMed

    El-Sayed, El-Sayed M; Abo-Salem, Osama M; Abd-Ellah, Mohamed F; Abd-Alla, Gamil M

    2008-01-01

    Acrylonitrile (ACN) is a volatile, toxic liquid used as a monomer in the manufacture of synthetic rubber, styrene plastics, acrylic fiber, and adhesives. ACN is a potent neurotoxin. A role for free radical mediated lipid peroxidation in the toxicity of ACN has been suggested. We examined the ability of hesperidin, an antioxidant flavonoid, to attenuate ACN-induced alterations in lipid peroxidation in rat brains. The daily oral administration of ACN to male albino rats in a dose of 50 mg/kg bwt for a period of 28 days produced a significant elevation in brain lipid peroxides measured as malondialdehyde (MDA) amounting to 107%, accompanied by a marked decrease in brain-reduced glutathione (GSH) content reaching 63%. In addition, ACN administration resulted in significant reductions in the enzymatic antioxidant parameters of brain; superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px), and glutathione-S-transferase (GST) recording 43%, 64%, 52%, and 43%, respectively. On the other hand, pretreatment with hesperidin and its coadministration with ACN once daily in a dose of 200 mg/kg bwt i.p. for 28 days ameliorated ACN-induced alterations in brain lipid peroxidation. These results suggest that hesperidin may have a beneficial role against ACN-induced oxidative stress in the brain; an effect that is mainly attributed to the antioxidant property of hesperidin.

  20. [Toxicology of acrylonitrile (AN) (author's transl)].

    PubMed

    Hashimoto, K

    1980-09-01

    Acrylonitrile (AN, CH2 = CH CN), a highly reactive compound having an active vinyl and cyanide group, has been widely used in various synthetic chemical industries. AN is known to produce toxic actions to human beings as well as experimental animals by inhalation and cutaneous contact. Its oral LD50 in animals are between 50 mg (for mouse) and 100 mg/kg (for rat, guinea pig, rabbit), and IC50 in 4 hours are between 110-140 ppm for mouse and dog, and 400-500 ppm for guinea pig. Although the mechanism of action of AN has not been completely understood, the action of both cyanide which is liberated in the organism and AN molecules themselves is considered to play some roles. Recent studies have shown that AN also produces chronic toxicity to human beings and experimental animals, and mutagenicity to microorganisms. In the U.S.A. experimental studies have shown an increased incidence of tumor in various organs after long-term administration of AN in rats. A preliminary report on an epidemiologic study conducted in the U.S.A. indicated excess cancer incidence and cancer mortality among workers exposed to AN. Further investigations will be needed to elucidate the carcinogenicity of the compound.

  1. 76 FR 54228 - Draft Toxicological Review of Acrylonitrile: In Support of Summary Information on the Integrated...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-31

    ... Acrylonitrile: In Support of Summary Information on the Integrated Risk Information System (IRIS)'' (EPA/635/R... Acrylonitrile: In Support of Summary Information on the Integrated Risk Information System (IRIS)'' is available... AGENCY Draft Toxicological Review of Acrylonitrile: In Support of Summary Information on the...

  2. Acrylonitrile butadiene rubber (NBR)/manganous tungstate (MnWO4) nanocomposites: Characterization, mechanical and electrical properties

    NASA Astrophysics Data System (ADS)

    Ramesan, M. T.; Abdu Raheem V., P.; Jayakrishnan, P.; Pradyumnan, P. P.

    2014-10-01

    Nanocomposites of NBR with manganous-tungstate nanoparticles were prepared through vulcanization process. The extent of interaction of nanoparticles with the polymer was studied by FTIR, SEM, XRD, TGA and AC conductivity. FTIR and XRD ascertain the interaction of NBR with MnWO4 nanoparticles. SEM analysis established that the nanopartilces were well dispersed in the macromolecular chain of NBR. The mechanical properties of the nanocomposites were studied as a function of filler loading. The nanocomposites exhibited enhanced thermal stability as seen in TGA. Conductivity and dielectric properties of nanocomposites increase with increase in concentration of MnWO4 nanoparticles (7phr) and thereafter the value decreases.

  3. Metabolism of Styrene Oxide and 2-Phenylethanol in the Styrene-Degrading Xanthobacter Strain 124X

    PubMed Central

    Hartmans, S.; Smits, J. P.; van der Werf, M. J.; Volkering, F.; de Bont, J. A. M.

    1989-01-01

    Styrene oxide and 2-phenylethanol metabolism in the styrene-degrading Xanthobacter sp. strain 124X was shown to proceed via phenylacetaldehyde and phenylacetic acid. In cell extracts 2-phenylethanol was oxidized by a phenazine methosulfate-dependent enzyme, probably a pyrroloquinoline quinone enzyme. Xanthobacter sp. strain 124X also contains a novel enzymatic activity designated as styrene oxide isomerase. Styrene oxide isomerase catalyzes the isomerization of styrene oxide to phenylacetaldehyde. The enzyme was partially purified and shown to have a very high substrate specificity. Of the epoxides tested, styrene oxide was the only substrate transformed. The initial step in styrene metabolism in Xanthobacter sp. strain 124X is oxygen dependent and probably involves oxidation of the aromatic nucleus. PMID:16348047

  4. REDUCING STYRENE EMISSIONS FROM SPRAYED FILLED RESINS

    EPA Science Inventory

    Styrene emissions are coming under increasing study as the U.S. Environmental Protection Agency (EPA) develops maximum achievable control technology standards. During the manufacture of fiber-reinforced plastics/composites products, styrene, a volatile organic compound and a haz...

  5. 29 CFR 1910.1051 - 1,3-Butadiene.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...,3-Butadiene. (a) Scope and application. (1) This section applies to all occupational exposures to 1... enter a regulated area. 1,3-Butadiene means an organic compound with chemical formula CH2=CH-CH=CH2 that... equipped with approved BD or organic vapor cartridges or canisters. Cartridges or canisters shall...

  6. Synthesis of (Z)-3-aryloxy-acrylonitriles, (E)-3-aryloxy-acrylonitriles and 3-cyanobenzofurans through the sequential reactions of phenols with propiolonitriles.

    PubMed

    Zhou, Wei; Zhang, Yicheng; Li, Pinhua; Wang, Lei

    2012-09-21

    A Na(2)CO(3)-promoted addition of phenols to propiolonitriles generated (Z)-3-aryloxy-acrylonitriles in nearly quantitative yields with exclusively Z-isomers, and a DABCO-promoted addition reaction of phenols with propiolonitriles afforded mainly (E)-3-aryloxy-acrylonitriles with high yields. The obtained (E)-3-aryloxy-acrylonitriles underwent intramolecular cyclization to give 3-cyanobenzofurans in good yields through palladium-catalyzed direct C-H bond functionalization.

  7. The role of acrylonitrile in controlling the structure and properties of nanostructured ionomer films.

    PubMed

    Tungchaiwattana, Somjit; Musa, Muhamad Sharan; Yan, Junfeng; Lovell, Peter A; Shaw, Peter; Saunders, Brian R

    2014-07-14

    Ionomers are polymers which contain ionic groups that are covalently bound to the main chain. The presence of a small percentage of ionic groups strongly affects the polymer's mechanical properties. Here, we examine a new family of nanostructured ionomer films prepared from core-shell polymer nanoparticles containing acrylonitrile (AN), 1,3-butadiene (Bd) and methacrylic acid (MAA). Three new AN-containing dispersions were investigated in this study. The core-shell nanoparticles contained a PBd core. The shells contained copolymerised Bd, AN and MAA, i.e., PBd-AN-MAA. Three types of crosslinking were present in these films: covalent crosslinks (from Bd); strong physical crosslinks (involving ionic bonding of RCOO(-) and Zn(2+)) and weaker physical crosslinks (from AN). We examined and compared the roles of AN and ionic crosslinking (from added Zn(2+)) on the structure and mechanical properties of the films. The FTIR spectroscopy data showed evidence for RCOOH-nitrile hydrogen bonding with tetrahedral geometry. DMTA studies showed that AN copolymerised within the PBd-AN-MAA phase uniformly. Tensile stress-strain data showed that inclusion of AN increased elasticity and toughness. Analysis showed that about 33 AN groups were required to provide an elastically-effective chain. However, only 1.5 to 2 ionically bonded RCOO(-) groups were required to generate an elastically-effective chain. By contrast to ionic bonding, AN inclusion increased the modulus without compromising ductility. Our results show that AN is an attractive, versatile, monomer for increasing the toughness of nanostructured ionomers and this should also be the case for other nanostructured polymer elastomers.

  8. Case-cohort study of styrene exposure and ischemic heart disease.

    PubMed

    Matanoski, Genevieve M; Tao, Xuguang

    2002-05-01

    Recent epidemiologic studies have consistently reported increased daily mortalities and hospital admissions associated with exposure to particulate air pollution. Ischemic heart disease (IHD*, International Classification of Diseases, Eighth Revision [ICD-8], codes 410-414) is among those diseases that contribute in large measure to this excess mortality. Some occupational studies have suggested elevated risk of IHD among workers exposed for short periods to styrene, which can be emitted from fossil fuel combustion, aircraft exhausts, and motor vehicle exhausts. Styrene is found in ambient air at average concentrations of a few micrograms per cubic meter or less but may reach very high concentrations at particular locations and times. Unmeasured aerosols of styrene may also increase population exposures. This case-cohort study explored a possible association and dose-response relation between styrene exposure and risk of acute IHD in an occupational setting. The population under study was 6587 male workers employed between 1943 and 1982 in two US plants manufacturing styrene-butadiene polymers used in synthetic rubber. The study assessed all 498 subjects who died from IHD along with a subcohort of twice that size, 997 subjects, selected as a 15% random sample of the full target cohort. IHD deaths during the study led to some overlap between cases and the subcohort, leaving 1424 unique subjects. Job histories were collected for all subjects. Industrial hygienists and engineers from the industry estimated relative exposures for all jobs. Exposure data were collected for many of the jobs from different sources. For any job with no available exposure measurements, z scores were used to estimate job exposure in each plant from the relative exposure level for that job in similar plants and the measurement distribution parameters of the study plant. Standardized mortality ratio (SMR) analyses were used to examine the overall risk of dying from IHD among study subjects

  9. Radiation-induced graft copolymerization of binary monomer mixture containing acrylonitrile onto polyethylene films

    NASA Astrophysics Data System (ADS)

    Choi, Seong-Ho; Nho, Young Chang

    2000-04-01

    Graft copolymerization of acrylonitrile (AN)/acrylic acid (AA), acrylonitrile (AN)/methacrylic acid (MA), and acrylonitrile (AN)/glycidyl methacrylate (GMA) onto pre-irradiated polyethylene (PE) films were studied. The effect of reaction conditions such as solvents, additives, and monomer composition on the grafting yields was investigated. The extent of grafting was found to increase with increasing sulfuric acid concentration when sulfuric acid as an additive was added to the grafting solution. In AN/AA mixture, the proportion of acrylonitrile in the copolymer increased with an increasing AN component in feed monomers. On the other hand, in AN/MA mixture, acrylonitrile component in copolymer was very slight in spite of the increase AN component in feed monomers. In the AN/GMA mixture, the proportion of acrylonitrile in the copolymer increased with increasing acrylonitrile component in AN/GMA feed monomer.

  10. Gas Phase Raman Spectra of Butadiene and BUTADIENE-d_{6} and the Internal Rotation Potential Energy Function

    NASA Astrophysics Data System (ADS)

    Boopalachandran, Praveenkumar; Laane, Jaan; Craig, Norman C.

    2009-06-01

    The Raman spectrum of butadiene has been previously reported by Carreira and by Engeln and co-workers. Both studies reported a series of bands corresponding to double quantum jumps of ν_{13}, the internal rotation vibration, of the trans rotamer. Both studies also reported weaker bands assigned to the higher energy conformer. Carriera assigned these to the cis form while Engeln assigned them to the gauche form. Recent high level calculations by Feller and Craig also assign the higher energy form as gauche. In the present study we report the gas phase Raman spectrum of butadiene and its d_{6} isotopomer at both 25^°C and 260^°C. Several new spectral features in the 330 to 210 cm^{-1} region were observed and the effect of heating on the band intensities was studied. In addition, combination bands were observed in the 630 to 690 cm^{-1} (ν_{12} + ν_{13}) and 1130 to 1180 cm^{-1} (ν_{10} + ν_{13}) regions. A periodic potential energy function with V_{1}, V_{2}, V_{3}, V_{4}, and V_{6} terms was utilized to fit the data. This function was compared to the results from previous work and to the theoretical calculation. L. Carreira, J. Phys. Chem. 62, 3851 (1975). R. Engeln, D. Consalvo, and J. Reuss, J. Chem. Phys. 160, 427 (1992). D. Feller and N. C. Craig, J. Phys. Chem. 113, 1601 (2009).

  11. IRIS Toxicological Review of Acrylonitrile (Interagency Science Consultation Draft)

    EPA Science Inventory

    On June 30, 2011, the draft Toxicological Review of Acrylonitrile and the charge to external peer reviewers were released for external peer review and public comment. The Toxicological Review and charge were reviewed internally by EPA and by other federal agencies and White House...

  12. Genotoxicity of Styrene–Acrylonitrile Trimer in Brain, Liver, and Blood Cells of Weanling F344 Rats

    PubMed Central

    Hobbs, Cheryl A.; Chhabra, Rajendra S.; Recio, Leslie; Streicker, Michael; Witt, Kristine L.

    2012-01-01

    Styrene–acrylonitrile Trimer (SAN Trimer), a by-product in production of acrylonitrile styrene plastics, was identified at a Superfund site in Dover Township, NJ, where childhood cancer incidence rates were elevated for a period of several years. SAN Trimer was therefore tested by the National Toxicology Program in a 2-year perinatal carcinogenicity study in F344/N rats and a bacterial mutagenicity assay; both studies gave negative results. To further characterize its genotoxicity, SAN Trimer was subsequently evaluated in a combined micronucleus (MN)/Comet assay in juvenile male and female F344 rats. SAN Trimer (37.5, 75, 150, or 300 mg/kg/day) was administered by gavage once daily for 4 days. Micronucleated reticulocyte (MN-RET) frequencies in blood were determined by flow cytometry, and DNA damage in blood, liver, and brain cells was assessed using the Comet assay. Highly significant dose-related increases (P < 0.0001) in MN-RET were measured in both male and female rats administered SAN Trimer. The RET population was reduced in high dose male rats, suggesting chemical-related bone marrow toxicity. Results of the Comet assay showed significant, dose-related increases in DNA damage in brain cells of male (P < 0.0074) and female (P < 0.0001) rats; increased levels of DNA damage were also measured in liver cells and leukocytes of treated rats. Chemical-related cytotoxicity was not indicated in any of the tissues examined for DNA damage. The results of this subacute MN/Comet assay indicate induction of significant genetic damage in multiple tissues of weanling F344 male and female rats after oral exposure to SAN Trimer. PMID:22351108

  13. Morphological Behavior of Sulfonated Styrene-Ethylene/Propylene-Styrene Triblock Copolymers

    DTIC Science & Technology

    2006-02-01

    ionomers possessing short (1K g/mol) styrene blocks and various rubber block lengths were synthesized via sequential anionic polymerization of styrene...isoprene, and styrene followed by hydrogenation and sulfonation. The ionomers were then characterized by small-angle x-ray scattering (SAXS) and atomic...spherical. 15. SUBJECT TERMS block copolymer, SAXS, ionomer , sulfonated polystyrene, SEPS 16. SECURITY CLASSIFICATION OF: 19a. NAME OF RESPONSIBLE

  14. Laboratory-scale biofiltration of acrylonitrile by Rhodococcus rhodochrous DAP 96622 in a trickling bed bioreactor.

    PubMed

    Zhang, Jie; Pierce, George E

    2009-07-01

    Acrylonitrile (ACN), a volatile component of the waste generated during the production of acrylamide, also is often associated with aromatic contaminants such as toluene and styrene. Biofiltration, considered an effective technique for the treatment of volatile hydrocarbons, has not been used to treat volatile nitriles. An experimental laboratory-scale trickling bed bioreactor using cells of Rhodococcus rhodochrous DAP 96622 supported on granular activated carbon (GAC) was developed and evaluated to assess the ability of biofiltration to treat ACN. In addition to following the course of treatability of ACN, kinetics of ACN biodegradation during both recycle batch and open modes of operation by immobilized and free cells were evaluated. For fed-batch mode bioreactor with immobilized cells, almost complete ACN removal (>95%) was achieved at a flow rate of 0.1 microl/min ACN and 0.8 microl/min toluene (TOL) (for comparative purposes this is equivalent to 6.9 mg l(-1) h(-1) ACN and 83.52 mg l(-1) h(-1) TOL). In a single-pass mode bioreactor with immobilized cells, at ACN inlet loads of 100-200 mg l(-1) h(-1) and TOL inlet load of approximately 400 mg l(-1) h(-1), with empty bed retention time (EBRT) of 8 min, ACN removal efficiency was approximately 90%. The three-dimensional structure and characteristics of the biofilm were investigated using confocal scanning laser microscopy (CSLM). CLSM images revealed a robust and heterogeneous biofilm, with microcolonies interspersed with voids and channels. Analysis of the precise measurement of biofilm characteristics using COMSTAT agreed with the assumption that both biomass and biofilm thickness increased along the carbon column depth.

  15. Cooxidation of styrene by horseradish peroxidase (HRP) and 4-methylphenol

    SciTech Connect

    Grab, L.A.; Ortiz, P.R.

    1987-05-01

    Styrene is cooxidized to styrene oxide in a system containing HRP/H/sub 2/O/sub 2/ and 4-methylphenol. Styrene oxide is not formed in the absence of any of these components, or if the reaction is run under anaerobic conditions. Styrene oxide formation is inhibited by ascorbic acid and catalase but not mannitol or superoxide dismutase. Incubation with /sup 18/O/sub 2/ resulted in more than 90% incorporation of label into styrene oxide. The epoxidation of trans-(1-/sup 2/H)styrene occurred with partial loss of stereochemistry. The products expected from addition of the phenoxy radical to styrene were synthesized and shown not to be formed. Finally, EPR evidence was obtained for formation of 4-methyl catechol in the presence, but not absence, of styrene. The results imply that a peroxy radical is formed by addition of oxygen to the HRP-generated 4-methylphenoxy radical, and that this peroxy radical then cooxidizes styrene.

  16. Poly (acrylonitrile - co -1-vinylimidazole): A New Melt Processable Carbon Fiber Precursor

    DTIC Science & Technology

    2011-01-01

    REPORT Poly (acrylonitrile – co -1-vinylimidazole): A new melt processable carbon fiber precursor 14. ABSTRACT 16. SECURITY CLASSIFICATION OF...Research Triangle Park, NC 27709-2211 15. SUBJECT TERMS Carbon fiber precursor, Thermal cross-linking, Melt processable Wesley P. Hoffman, Dennis W...Z39.18 - Poly (acrylonitrile – co -1-vinylimidazole): A new melt processable carbon fiber precursor Report Title ABSTRACT Acrylonitrile/1-vinylimidazole

  17. Acrylonitrile-Induced Oxidative Stress and Oxidative DNA Damage in Male Sprague-Dawley Rats

    PubMed Central

    Kamendulis, Lisa M.; Klaunig, James E.

    2009-01-01

    Studies have demonstrated that the induction of oxidative stress may be involved in brain tumor induction in rats by acrylonitrile. The present study examined whether acrylonitrile induces oxidative stress and DNA damage in rats and whether blood can serve as a valid surrogate for the biomonitoring of oxidative stress induced by acrylonitrile in the exposed population. Male Sprague-Dawley rats were treated with 0, 3, 30, 100, and 200 ppm acrylonitrile in drinking water for 28 days. One group of rats were also coadministered N-acetyl cysteine (NAC) (0.3% in diet) with acrylonitrile (200 ppm in drinking water) to examine whether antioxidant supplementation was protective against acrylonitrile-induced oxidative stress. Direct DNA strand breakage in white blood cells (WBC) and brain was measured using the alkaline comet assay. Oxidative DNA damage in WBC and brain was evaluated using formamidopyrimidine DNA glycosylase (fpg)-modified comet assay and with high-performance liquid chromatography-electrochemical detection. No significant increase in direct DNA strand breaks was observed in brain and WBC from acrylonitrile-treated rats. However, oxidative DNA damage (fpg comet and 8′hydroxyl-2-deoxyguanosine) in brain and WBC was increased in a dose-dependent manner. In addition, plasma levels of reactive oxygen species (ROS) increased in rats administered acrylonitrile. Dietary supplementation with NAC prevented acrylonitrile-induced oxidative DNA damage in brain and WBC. A slight, but significant, decrease in the GSH:GSSG ratio was seen in brain at acrylonitrile doses > 30 ppm. These results provide additional support that the mode of action for acrylonitrile-induced astrocytomas involves the induction of oxidative stress and damage. Significant associations were seen between oxidative DNA damage in WBC and brain, ROS formation in plasma, and the reported tumor incidences. Since oxidative DNA damage in brain correlated with oxidative damage in WBC, these results suggest

  18. Laser transmission welding of ABS: Effect of CNTs concentration and process parameters on material integrity and weld formation

    NASA Astrophysics Data System (ADS)

    Rodríguez-Vidal, E.; Quintana, I.; Gadea, C.

    2014-04-01

    This paper reports a study of the laser transmission welding of polymeric joints composed by two ABS (acrylonitrile/butadiene/styrene) sheets, one transparent (natural ABS) and the other absorbent (filled by different percentages of carbon nanotubes (CNTs)). The objective of this work is to analyze the effect of process parameters and CNTs concentrations on weld formation and mechanical resistance of the weld joints.

  19. New dual-phase polymer electrolytes prepared from NBR/SBR lattices. [polyacryloNitrile-Butadiene Rubber/poly(Styrene-Butadiene) copolymer Rubber

    SciTech Connect

    Matsumoto, Morihiko; Ichino, Toshihiro; Rutt, J.S.; Nishi, Shiro . NTT Interdisciplinary Research Lab.)

    1993-10-01

    A new type of Li[sup +] ion conducting polymer electrolytes consisting of two phases, one of which is a highly polar region (impregnated with lithium salt solution), forming ion-conductive channels, while the other is a nonpolar region, forming supporting polymer matrices have been prepared from NBR/SBR lattices. TEM measurement and EDX analysis show evidence that dual-phase structure is constructed in the electrolyte. Ionic conductivity of the electrolyte increases with increase of lithium salt solution content. Maximum ionic conductivity of 2.2 [times] 10[sup [minus]3] S/cm is obtained at the lithium salt solution content of 60.5% (w/w). The electrolyte retains rubber-like film with good mechanical strength despite the presence of the solution.

  20. Hepatoprotective activity of quercetin against acrylonitrile-induced hepatotoxicity in rats.

    PubMed

    Abo-Salem, Osama M; Abd-Ellah, Mohamed F; Ghonaim, Mabrouk M

    2011-01-01

    Acrylonitrile is a potent hepatotoxic, mutagen, and carcinogen. A role for free radical-mediated lipid peroxidation in the toxicity of acrylonitrile has been suggested. The present study was designed to assess the hepatoprotective effect of quercetin against acrylonitrile-induced hepatotoxicity in rats. Liver damage was induced by oral administration of acrylonitrile (50 mg/kg/day/5 weeks). Acrylonitrile produced a significant elevation of malondialdehyde (138.9%) with a marked decrease in reduced glutathione (72.4%), and enzymatic antioxidants; superoxide dismutase (81%), and glutathione peroxidase (53.2%) in the liver. Serum aspartate aminotransferase, alanine aminotransferases, direct bilirubin, and total bilirubin showed a significant increase in acrylonitrile alone treated rats (115.5%, 110.8%, 1006.8%, and 1000.8%, respectively). Pretreatment with quercetin (70 mg/kg/day/6 weeks) and its coadministration with acrylonitrile prevented acrylonitrile-induced alterations in hepatic lipid peroxides and enzymatic antioxidants as well as serum aminotransferases and bilirubin. Histopathological findings supported the biochemical results. We suggest that querectin possess hepatoprotective effect against acrylonitrile-induced hepatotoxicity through its antioxidant activity.

  1. Construction of a bacterial biosensor for styrene.

    PubMed

    Alonso, Sergio; Navarro-Llorens, Juana María; Tormo, Antonio; Perera, Julián

    2003-05-08

    A new bacterial biosensor for styrene has been developed and characterized. A translational fusion of the lacZ gene to the sty promoter of Pseudomonas sp. strain Y2 has been inserted into miniTn5. Transposition of the recombinant transposon to the chromosome of Pseudomonas sp. strain Y2 resulted in a whole-cell biosensor able to detect and degrade styrene. In this biosensor, the endogenous StyS/StyR system detects the presence of styrene and turns on the expression of the exogenous reporter gene from the transferred construction. Other compounds such as toluene, epoxystyrene, phenylacetaldehyde and 2-phenylethanol also induced expression of beta-galactosidase although quantitative differences in their effect are clearly detected. Non-inducing compounds affect differently the sensitivity to inducing compounds when present in a mixture.

  2. Occupational exposure of workers to 1,3-butadiene.

    PubMed Central

    Fajen, J M; Roberts, D R; Ungers, L J; Krishnan, E R

    1990-01-01

    Researchers from the National Institute for Occupational Safety and Health (NIOSH) conducted an extent-of-exposure study of the 1,3-butadiene monomer, polymer, and end-user industries to determine the size of the exposed workforce, evaluate control technologies and personal protective equipment programs, and assess occupational exposure to 1,3-butadiene. A new analytical method was developed for 1,3-butadiene that increased the sensitivity and selectivity of the previous NIOSH method. The new method is sensitive to 0.2 microgram per 1,3-butadiene sample. Walk-through surveys were conducted in 11 monomer, 17 polymer, and 2 end-user plants. In-depth industrial hygiene surveys were conducted at 4 monomer, 5 polymer, and 2 end-user plants. Airborne exposure concentrations of 1,3-butadiene were determined using personal sampling for each job category. A total of 692 full shift and short-term personnel and 259 area air samples were examined for the presence of 1,3-butadiene. Sample results indicated that all worker exposures were well below the current OSHA PEL of 1000 ppm. Exposures ranged from less than 0.006 ppm to 374 ppm. The average exposure for all samples was less than 2 ppm. The present American Conference of Governmental Industrial Hygienists (ACGIH) threshold limit value for 1,3-butadiene is 10 ppm. To reduce the potential for occupational exposure, it is recommended that quality control sampling be conducted using a closed loop system. Also all process pumps should be retrofitted with dual mechanical seals, magnetic gauges should be used in loading and unloading rail cars, and engineering controls should be designed for safely voiding quality control cylinders. PMID:2401251

  3. Occupational exposure of workers to 1,3-butadiene.

    PubMed

    Fajen, J M; Roberts, D R; Ungers, L J; Krishnan, E R

    1990-06-01

    Researchers from the National Institute for Occupational Safety and Health (NIOSH) conducted an extent-of-exposure study of the 1,3-butadiene monomer, polymer, and end-user industries to determine the size of the exposed workforce, evaluate control technologies and personal protective equipment programs, and assess occupational exposure to 1,3-butadiene. A new analytical method was developed for 1,3-butadiene that increased the sensitivity and selectivity of the previous NIOSH method. The new method is sensitive to 0.2 microgram per 1,3-butadiene sample. Walk-through surveys were conducted in 11 monomer, 17 polymer, and 2 end-user plants. In-depth industrial hygiene surveys were conducted at 4 monomer, 5 polymer, and 2 end-user plants. Airborne exposure concentrations of 1,3-butadiene were determined using personal sampling for each job category. A total of 692 full shift and short-term personnel and 259 area air samples were examined for the presence of 1,3-butadiene. Sample results indicated that all worker exposures were well below the current OSHA PEL of 1000 ppm. Exposures ranged from less than 0.006 ppm to 374 ppm. The average exposure for all samples was less than 2 ppm. The present American Conference of Governmental Industrial Hygienists (ACGIH) threshold limit value for 1,3-butadiene is 10 ppm. To reduce the potential for occupational exposure, it is recommended that quality control sampling be conducted using a closed loop system. Also all process pumps should be retrofitted with dual mechanical seals, magnetic gauges should be used in loading and unloading rail cars, and engineering controls should be designed for safely voiding quality control cylinders.

  4. 21 CFR 177.1820 - Styrene-maleic anhydride copolymers.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Styrene-maleic anhydride copolymers. 177.1820... Basic Components of Single and Repeated Use Food Contact Surfaces § 177.1820 Styrene-maleic anhydride copolymers. Styrene-maleic anhydride copolymers identified in paragraph (a) of this section may be...

  5. The Iodochlorination of Styrene: An Experiment that Makes a Difference

    ERIC Educational Resources Information Center

    Amiet, R. Gary; Urban, Sylvia

    2008-01-01

    The iodochlorination of styrene, involving the addition of iodine monochloride to styrene, followed by the sodium methoxide-initiated dehydrohalogenation of the product results in a variable mixture of substituted styrenes by way of various substitution and elimination reaction mechanisms. As a result individual results are obtained for each…

  6. Copper-catalyzed radical carbooxygenation: alkylation and alkoxylation of styrenes.

    PubMed

    Liao, Zhixiong; Yi, Hong; Li, Zheng; Fan, Chao; Zhang, Xu; Liu, Jie; Deng, Zixin; Lei, Aiwen

    2015-01-01

    A simple copper-catalyzed direct radical carbooxygenation of styrenes is developed utilizing alkyl bromides as radical resources. This catalytic radical difunctionalization accomplishes both alkylation and alkoxylation of styrenes in one pot. A broad range of styrenes and alcohols are well tolerated in this transformation. The EPR experiment shows that alkyl halides could oxidize Cu(I) to Cu(II) in this transformation.

  7. 21 CFR 177.1810 - Styrene block polymers.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Styrene block polymers. 177.1810 Section 177.1810...) INDIRECT FOOD ADDITIVES: POLYMERS Substances for Use as Basic Components of Single and Repeated Use Food Contact Surfaces § 177.1810 Styrene block polymers. The styrene block polymers identified in paragraph...

  8. 76 FR 38387 - Draft Toxicological Review of Acrylonitrile: In Support of Summary Information on the Integrated...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-30

    ... Review of Acrylonitrile: In Support of Summary Information on the Integrated Risk Information System... Information on the Integrated Risk Information System (IRIS)'' is available primarily via the Internet on the... AGENCY Draft Toxicological Review of Acrylonitrile: In Support of Summary Information on the...

  9. Effects of polystyrene-b-poly(aminomethyl styrene)s as stabilizers on dispersion polymerization of styrene in alcoholic media.

    PubMed

    Itoh, Tomomichi; Fukutani, Kaori; Hino, Masato; Ihara, Eiji; Inoue, Kenzo

    2009-02-15

    The effects of polystyrene-b-poly(aminomethyl styrene) (PS(n)-b-PAMS(m)) stabilizers on the particle size (D(n)) and size distribution (PSD) in dispersion polymerization of styrene were investigated. The block copolymers, PS(n)-b-PAMS(m), were prepared as follows: (i) atom transfer radical polymerization (ATRP) of styrene (PS-Br), (ii) ATRP of vinylbenzylphthalimide with the PS-Br (PS-b-PVBP), and (iii) treatment of the PS-b-PVBP with hydrazine. When the dispersion polymerization of styrene proceeded at 60 degrees C in ethanol with PS(19)-b-PAMS(130) stabilizer, spherical polystyrene particles with D(n)=0.91 microm (PSD=1.01) were obtained. The particle size was strongly affected by the copolymer composition. With an increase in PAMS block length from m=54 to 100 in PS(17)-b-PAMS(m), particle diameter became smaller from 1.55 to 0.91 microm. On the other hand, an increase in the length from m=20 to 82 in PS(34)-b-PAMS(m)s caused an increase in particle size from 0.35 to 0.70 microm. Titration of the particles suggests that 14-81% of stabilizers used in the polymerization system were attached on the polystyrene particle surfaces, depending on the composition of the block copolymers. Thus, for the dispersion polymerization of styrene, PS(n)-b-PAMS(m) block copolymers have both functions as a stabilizer during polymerization and surface-modification sites of polystyrene particles.

  10. Polystyrene cups and containers: styrene migration.

    PubMed

    Tawfik, M S; Huyghebaert, A

    1998-07-01

    The level of styrene migration from polystyrene cups was monitored in different food systems including: water, milk (0.5, 1.55 and 3.6% fat), cold beverages (apple juice, orange juice, carbonated water, cola, beer and chocolate drink), hot beverages (tea, coffee, chocolate and soup (0.0, 0.5, 1, 2, and 3.6% fat), take away foods (yogurt, jelly, pudding and ice-cream), as well as aqueous food simulants (3% acetic acid, 15, 50, and 100% ethanol) and olive oil. Styrene migration was found to be strongly dependent upon the fat content and storage temperature. Drinking water gave migration values considerably lower than all of the fatty foods. Ethanol at 15% showed a migration level equivalent to milk or soup containing 3.6% fat. Maximum observed migration for cold or hot beverages and take-away foods was 0.025% of the total styrene in the cup. Food simulants were responsible for higher migration (0.37% in 100% ethanol). A total of 60 food samples (yogurt, rice with milk, fromage, biogardes, and cheese) packed in polystyrene containers were collected from retail markets in Belgium, Germany, and the Netherlands. The level of styrene detected in the foods was always fat dependent.

  11. Reaction of disubstituted aromatic compounds with styrene

    SciTech Connect

    Grushin, A.I.; Grigor'ev, V.V.; Prokof'ev, K.V.; Kozlova, N.M.

    1988-03-20

    Hydrocarbons of the 1,1-diphenylethane type were obtained by the reaction of styrene with various disubstituted derivatives of benzene in the presence of titanium tetrachloride. It was found that the yield of the desired compound depends on the strength of the electron-donating substituents and on steric factors in the aromatic ring.

  12. Health Assessment Document for 1,3-Butadiene (External Review Draft)

    EPA Science Inventory

    This risk assessment of 1,3-butadiene, a gas used commercially in the production of various resins and plastics, concludes that 1,3-butadiene is a known human carcinogen, based on three types of evidence: 1) excess leukemias in workers occupationally exposed to 1,3-butadiene (by ...

  13. 46 CFR 154.1750 - Butadiene or vinyl chloride: Refrigeration system.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 5 2013-10-01 2013-10-01 false Butadiene or vinyl chloride: Refrigeration system. 154... and Operating Requirements § 154.1750 Butadiene or vinyl chloride: Refrigeration system. A refrigeration system for butadiene or vinyl chloride must not use vapor compression unless it: (a) Avoids...

  14. 46 CFR 154.1750 - Butadiene or vinyl chloride: Refrigeration system.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 5 2012-10-01 2012-10-01 false Butadiene or vinyl chloride: Refrigeration system. 154... and Operating Requirements § 154.1750 Butadiene or vinyl chloride: Refrigeration system. A refrigeration system for butadiene or vinyl chloride must not use vapor compression unless it: (a) Avoids...

  15. 46 CFR 154.1750 - Butadiene or vinyl chloride: Refrigeration system.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 5 2014-10-01 2014-10-01 false Butadiene or vinyl chloride: Refrigeration system. 154... and Operating Requirements § 154.1750 Butadiene or vinyl chloride: Refrigeration system. A refrigeration system for butadiene or vinyl chloride must not use vapor compression unless it: (a) Avoids...

  16. 46 CFR 154.1750 - Butadiene or vinyl chloride: Refrigeration system.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Butadiene or vinyl chloride: Refrigeration system. 154... and Operating Requirements § 154.1750 Butadiene or vinyl chloride: Refrigeration system. A refrigeration system for butadiene or vinyl chloride must not use vapor compression unless it: (a) Avoids...

  17. 46 CFR 154.1750 - Butadiene or vinyl chloride: Refrigeration system.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 5 2011-10-01 2011-10-01 false Butadiene or vinyl chloride: Refrigeration system. 154... and Operating Requirements § 154.1750 Butadiene or vinyl chloride: Refrigeration system. A refrigeration system for butadiene or vinyl chloride must not use vapor compression unless it: (a) Avoids...

  18. 40 CFR 80.55 - Measurement methods for benzene and 1,3-butadiene.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 16 2011-07-01 2011-07-01 false Measurement methods for benzene and 1... Measurement methods for benzene and 1,3-butadiene. (a) Sampling for benzene and 1,3-butadiene must be... 86.109. (b) Benzene and 1,3-butadiene must be analyzed by gas chromatography. Expected values...

  19. 40 CFR 80.55 - Measurement methods for benzene and 1,3-butadiene.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 17 2013-07-01 2013-07-01 false Measurement methods for benzene and 1... Measurement methods for benzene and 1,3-butadiene. (a) Sampling for benzene and 1,3-butadiene must be... 86.109. (b) Benzene and 1,3-butadiene must be analyzed by gas chromatography. Expected values...

  20. 40 CFR 80.55 - Measurement methods for benzene and 1,3-butadiene.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 17 2012-07-01 2012-07-01 false Measurement methods for benzene and 1... Measurement methods for benzene and 1,3-butadiene. (a) Sampling for benzene and 1,3-butadiene must be... 86.109. (b) Benzene and 1,3-butadiene must be analyzed by gas chromatography. Expected values...

  1. 40 CFR 80.55 - Measurement methods for benzene and 1,3-butadiene.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 17 2014-07-01 2014-07-01 false Measurement methods for benzene and 1... Measurement methods for benzene and 1,3-butadiene. (a) Sampling for benzene and 1,3-butadiene must be... 86.109. (b) Benzene and 1,3-butadiene must be analyzed by gas chromatography. Expected values...

  2. 40 CFR 80.55 - Measurement methods for benzene and 1,3-butadiene.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 16 2010-07-01 2010-07-01 false Measurement methods for benzene and 1... Measurement methods for benzene and 1,3-butadiene. (a) Sampling for benzene and 1,3-butadiene must be... 86.109. (b) Benzene and 1,3-butadiene must be analyzed by gas chromatography. Expected values...

  3. Vibrations of acrylonitrile in N 1s excited states

    NASA Astrophysics Data System (ADS)

    Ilakovac, V.; Carniato, S.; Gallet, J.-J.; Kukk, E.; Horvatić, D.; Ilakovac, A.

    2008-01-01

    The N 1s near edge x-ray absorption fine structure spectra of acrylonitrile gas are accurately reproduced by a complete ab initio multidimensional vibrational analysis. The role of π∗ -orbital localization and hybridization on vibrations accompanying core excitation is discussed. Transition to the π⊥∗(C=C-C≡N) delocalized orbital excites mostly stretching vibrations of the whole spinal column of the molecule. Promoting a core electron to the localized π∥∗(C≡N) produces C≡N stretching vibration combined with two strong bending modes of the C-C≡N end of the molecule, related to the change of carbon hybridization.

  4. Activity of sulphate reducing bacteria according to COD/SO4(2-) ratio of acrylonitrile wastewater containing high sulphate.

    PubMed

    Byun, I G; Lee, T H; Kim, Y O; Song, S K; Park, T J

    2004-01-01

    This study was performed to evaluate the biodegradability of acrylonitrile wastewater, microbial inhibition effect of acrylonitrile wastewater on removal efficiency and the activity of sulphate reducing bacteria (SRB) according to COD/sulphate ratio. Acrylonitrile wastewater was hardly biodegradable in a biodegradability test, however, SRB activity was 57% for overall consumption of electron donor and it was relatively high value compared to 17% of reference test with glucose. COD removal of acrylonitrile wastewater was improved to 57% and 61% from 20% as the COD/sulphate ratio were 0.5 and 0.3 by sulphate addition to acrylonitrile wastewater. First order reaction rate constants k on organic removal of acrylonitrile wastewater were 0.001, 0.004 and 0.004 at each COD/sulphate ratio of 0.9, 0.5 and 0.3. Thus it was suggested that the activity of SRB was a significant factor for removing organics and sulphate simultaneously in acrylonitrile wastewater.

  5. Gender differences in the metabolism of 1,3-butadiene to butadiene diepoxide in Sprague-Dawley rats

    SciTech Connect

    Thornton-Manning, J.R.; Dahl, A.R.; Bechtold, W.E.

    1995-12-01

    1,3-Butadiene (BD), a gaseous compound used in the production of rubber, is a potent carcinogen in mice and a weak carcinogen in rats. The mechanism of BD-induced carcinogenicity is thought to involve genotoxic effects of its reactive epoxide metabolites butadiene monoepoxide (BDO) and butadiene diepoxide (BDO{sub 2}). Studies in our laboratory have shown that levels of the epoxides, particularly BDO{sub 2}, are greater in mice-the more sensitive species-than rats. While both epoxides are genotoxic in a number of assays, BDO{sub 2} is mutagenic in TK6 human lymphoblastoid cells at concentrations approximately 100-fold lower than BDO. Species differences in carcinogenicity of BD have posed a dilemma to investigators deciding which animal model is most appropriate for BD risk assessment.

  6. 40 CFR 63.500 - Back-end process provisions-carbon disulfide limitations for styrene butadiene rubber by emulsion...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... accepted chemical engineering principles, measurable process parameters, or physical or chemical laws or... engineering assessment, as described in paragraph (c)(2) of this section. (1) The owner or operator may choose... run. (2) The owner or operator may use engineering assessment to demonstrate compliance with...

  7. Effects of interfacial interaction on the properties of poly(vinyl chloride)/styrene-butadiene rubber blends

    NASA Astrophysics Data System (ADS)

    Zhu, Shuihan

    PVC/SBR blends---new thermoplastic elastomer material---were developed. They have potential applications due to low costs and low-temperature elasticity. A unique compatibilization method was employed to enhance the mechanical properties of the materials a compatibilizer miscible with one of the blend components can react chemically with the other component(s). Improvements in tensile and impact behavior were observed as a result of the compatibilization. A novel characterization technique to study the interface of PVC/SBR blends was developed. This technique involves the observation of the unstained sample under electron beam irradiation by a transmission electron microscope (TEM). An enrichment of rubber at the interface between PVC and SBR was detected in the compatiblized PVC/SBR blends. Magnetic relaxation measurements show that the rubber concentration in the proximity of PVC increases with the degree of covulcanization between NBR and SBR. The interface development and the rheological effect during processing were investigated. The interfacial concentration profile and the interfacial thickness were obtained by grayscale measurements on TEM micrographs, evaluation of SIMS images, and measurements of micromechanical properties.

  8. Effect of electron beam irradiation on the properties of natural rubber (NR)/styrene-butadiene rubber (SBR) blend

    NASA Astrophysics Data System (ADS)

    Manshaie, R.; Nouri Khorasani, S.; Jahanbani Veshare, S.; Rezaei Abadchi, M.

    2011-01-01

    In this study, physico-mechanical properties of NR/SBR blends cured by electron beam irradiation and sulfur were compared. The NR/SBR blends were prepared using a two-roll mill. Electron beam irradiations of 100-400 kGy were applied to cure the blends and changes in physico-mechanical properties were studied as a function of irradiation. Also, oil resistance and the effect of thermal ageing on mechanical properties of the blends were investigated. The results show that the irradiated blends have better mechanical properties than those cured by sulfur system. The irradiation cured samples also exhibited better heat stability than the sulfur cured samples. The blend cured by the highest dose shows the lowest swelling and high oil resistance compared with the other samples cured by irradiation.

  9. Mechanical properties of melt-processed polymer blend of amorphous corn flour composite filler and styrene-butadiene rubber

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The corn flour composite fillers were prepared by blending corn flour with rubber latex, dried, and cryogenically ground into powders, which were then melt-blended with rubber polymers in an internal mixer to form composites with enhanced mechanical properties. The composites prepared with melt-blen...

  10. Reinforcement Effect of Alkali-Hydrolyzed Wheat Gluten and Shear-Degraded Wheat Starch in Carboxylated Styrene-Butadiene Composites

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Wheat gluten (WG) and wheat starch (WS) are the protein and carbohydrate obtained from wheat flours. Wheat gluten is not water soluble or dispersible due to its hydrophobic nature. To prepare wheat gluten dispersions, an alkali hydrolysis reaction was carried out to produce a stable aqueous disper...

  11. Mechanical properties of heterophase polymer blends of cryogenically fractured soy flour composite filler and poly(styrene-butadiene)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Reinforcement effect of cryogenically fractured soy Flour composite filler in soft polymer was investigated in this study. Polymer composites were prepared by melt-mixing polymer and soy flour composite fillers in an internal mixer. Soy flour composite fillers were prepared by blending aqueous dis...

  12. Aggregate structure and effect of phthalic anhydride modified soy protein on the mechanical properties of styrene-butadiene copolymer

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The aggregate structure of phthalic anhydride (PA) modified soy protein isolate (SPI) was investigated by estimating its fractal dimension from the equilibrated dynamic strain sweep experiments. The estimated fractal dimensions of the filler aggregates were less than 2, indicating that these partic...

  13. Poly(acrylonitrile)chitosan composite membranes for urease immobilization.

    PubMed

    Gabrovska, Katya; Georgieva, Aneliya; Godjevargova, Tzonka; Stoilova, Olya; Manolova, Nevena

    2007-05-10

    (Poly)acrylonitrile/chitosan (PANCHI) composite membranes were prepared. The chitosan layer was deposited on the surface as well as on the pore walls of the base membrane. This resulted in the reduction of the pore size of the membrane and in an increase of their hydrophilicity. The pore structure of PAN and PANCHI membranes were determined by TEM and SEM analyses. It was found that the average size of the pore under a selective layer base PAN membrane is 7 microm, while the membrane coated with 0.25% chitosan shows a reduced pore size--small or equal to 5 microm and with 0.35% chitosan--about 4 microm. The amounts of the functional groups, the degree of hydrophilicity and transport characteristics of PAN/Chitosan composite membranes were determined. Urease was covalently immobilized onto all kinds of PAN/chitosan composite membranes using glutaraldehyde. Both the amount of bound protein and relative activity of immobilized urease were measured. The highest activity (94%) was measured for urease bound to PANCHI2 membranes (0.25% chitosan). The basic characteristics (pH(opt), pH(stability), T(opt), T(stability), heat inactivation and storage stability) of immobilized urease were determined. The obtained results show that the poly(acrylonitrile)chitosan composite membranes are suitable for enzyme immobilization.

  14. Kinetic and equilibrium studies of acrylonitrile binding to cytochrome c peroxidase and oxidation of acrylonitrile by cytochrome c peroxidase compound I.

    PubMed

    Chinchilla, Diana; Kilheeney, Heather; Vitello, Lidia B; Erman, James E

    2014-01-03

    Ferric heme proteins bind weakly basic ligands and the binding affinity is often pH dependent due to protonation of the ligand as well as the protein. In an effort to find a small, neutral ligand without significant acid/base properties to probe ligand binding reactions in ferric heme proteins we were led to consider the organonitriles. Although organonitriles are known to bind to transition metals, we have been unable to find any prior studies of nitrile binding to heme proteins. In this communication we report on the equilibrium and kinetic properties of acrylonitrile binding to cytochrome c peroxidase (CcP) as well as the oxidation of acrylonitrile by CcP compound I. Acrylonitrile binding to CcP is independent of pH between pH 4 and 8. The association and dissociation rate constants are 0.32±0.16 M(-1) s(-1) and 0.34±0.15 s(-1), respectively, and the independently measured equilibrium dissociation constant for the complex is 1.1±0.2 M. We have demonstrated for the first time that acrylonitrile can bind to a ferric heme protein. The binding mechanism appears to be a simple, one-step association of the ligand with the heme iron. We have also demonstrated that CcP can catalyze the oxidation of acrylonitrile, most likely to 2-cyanoethylene oxide in a "peroxygenase"-type reaction, with rates that are similar to rat liver microsomal cytochrome P450-catalyzed oxidation of acrylonitrile in the monooxygenase reaction. CcP compound I oxidizes acrylonitrile with a maximum turnover number of 0.61 min(-1) at pH 6.0.

  15. Radical-initiated controlled synthesis of homo- and copolymers based on acrylonitrile

    NASA Astrophysics Data System (ADS)

    Grishin, D. F.; Grishin, I. D.

    2015-07-01

    Data on the controlled synthesis of polyacrylonitrile and acrylonitrile copolymers with other (meth)acrylic and vinyl monomers upon radical initiation and metal complex catalysis are analyzed. Primary attention is given to the use of metal complexes for the synthesis of acrylonitrile-based (co)polymers with defined molecular weight and polydispersity in living mode by atom transfer radical polymerization. The prospects for using known methods of controlled synthesis of macromolecules for the preparation of acrylonitrile homo- and copolymers as carbon fibre precursors are estimated. The major array of published data analyzed in the review refers to the last decade. The bibliography includes 175 references.

  16. Cancer risk assessment of 1,3-butadiene.

    PubMed Central

    Cote, I L; Bayard, S P

    1990-01-01

    This paper discusses the Environmental Protection Agency's (EPA) risk assessment of 1,3-butadiene. The assessment focuses on estimation of increased cancer risk to populations living near industrial sources of 1,3-butadiene emissions rather than occupationally exposed populations. Incremental cancer risk estimates based on extrapolation from laboratory animal data are presented. Pharmacokinetic data published since the EPA's 1985 assessment are incorporated, which somewhat alters the earlier assessment of cancer risk. Characterization of emission sources, estimates of ambient air concentrations, and population exposure are also discussed. The estimate presented in this paper of excess cancer cases resulting from point source exposure to 1,3-butadiene is decreased to approximately 40% of the estimate published in 1985 from 6.4 in 10 to 2.5 chances in 10 for a lifetime exposure to 1 ppm. The current estimate is no more than eight additional cancer incidences in the general population. Increased risk to the most exposed individuals is not anticipated to be greater than 1 in 10. This reduction in the risk estimate is due to a change in the estimate of 1,3-butadiene potency (i.e., incremental unit risk estimate) based on incorporation of new pharmacokinetic data. PMID:2205485

  17. Recycling tires? Reversible crosslinking of poly(butadiene).

    PubMed

    Trovatti, Eliane; Lacerda, Talita M; Carvalho, Antonio J F; Gandini, Alessandro

    2015-04-01

    Furan-modified poly(butadiene) prepared by the thiol-ene click reaction is crosslinked with bismaleimides through the Diels-Alder reaction, giving rise to a novel recyclable elastomer. This is possible because of the thermal reversibility of the adducts responsible for the formation of the network. The use of this strategy provides the possibility to produce recyclable tires.

  18. Quantitative risk assessment of exposures to butadiene in EU occupational settings based on the University of Alabama at Birmingham epidemiological study.

    PubMed

    Sielken, Robert L; Valdez-Flores, Ciriaco

    2013-03-01

    The excess risks due to 1,3-butadiene (BD) inhalation in EU occupational settings are quantified for leukemia, AML, CLL, CML, lymphoid neoplasms, and myeloid neoplasms. The most recent data from the University of Alabama at Birmingham epidemiological study of North American workers in the styrene-butadiene rubber industry are modeled. The number of high-intensity tasks (HITs) and other exposure covariates may be more important predictors than cumulative BD ppm-years alone. For example, all of the 71 leukemia decedents in the UAB study who were exposed to BD had some BD HITs. None of the 1192 exposed workers without BD HITs had leukemia mortalities. The authors' best estimate (consolidated over all endpoints) of the average occupational BD exposure concentration for 45 years of exposure starting at age 20 corresponding to an added risk of 1/10,000 by age 70 is 7.2 ppm. Cumulative BD ppm-years is not statistically significantly associated with CML, AML, or myeloid neoplasms or (after any one of eight exposure covariates is included in the modeling) leukemia. The statistical significance of the slopes for leukemia, CLL, and lymphoid neoplasms unadjusted for covariate effects disappears when modeling is restricted to person years with less than 200 cumulative BD ppm-years.

  19. Simple Replica Micromolding of Biocompatible Styrenic Elastomers†

    PubMed Central

    Bielawski, Kevin S.; Sniadecki, Nathan J.; Jenkel, Colin F.; Vogt, Bryan D.; Posner, Jonathan D.

    2013-01-01

    In this work, we introduce a simple solvent-assisted micromolding technique for the fabrication of high-fidelity styrene-ethylene/butylene-styrene (SEBS) microfluidic devices with high polystyrene (PS) content (42 wt% PS). SEBS triblock copolymers are styrenic thermoplastic elastomers that exhibit both glassy thermoplastic and elastomeric properties resulting from their respective hard PS and rubbery ethylene/butylene fractions. The PS fraction gives SEBS microdevices many of the appealing properties of pure PS devices, while the elastomeric fraction simplifies fabrication of the devices, similar to PDMS. SEBS42 devices have wettable, stable surfaces (both contact angle and zeta potential) that support cell attachment and proliferation consistent with tissue culture dish substrates, do not adsorb hydrophobic molecules, and have high bond strength to wide range of substrates (glass, PS, SEBS). Furthermore, SEBS42 devices are mechanically robust, thermally stable, as well as exhibit low auto-fluorescence and high transmissivity. We characterize SEBS42 surface properties by contact angle measurements, cell culture studies, zeta potential measurements, and the adsorption of hydrophobic molecules. The PS surface composition of SEBS microdevices cast on different substrates is determined by time-of-flight secondary ion mass spectrometry (ToF-SIMS). The attractive SEBS42 material properties, coupled with the simple fabrication method, make SEBS42 a quality substrate for microfluidic applications where the properties of PS are desired but the ease of PDMS micromolding is favoured. PMID:23670166

  20. Hydration of acrylonitrile to produce acrylamide using biocatalyst in a membrane dispersion microreactor.

    PubMed

    Li, Jiahui; Chen, Jie; Wang, Yujun; Luo, Guangsheng; Yu, Huimin

    2014-10-01

    In this work, a membrane dispersion microreactor was utilized for the hydration of acrylonitrile to produce acrylamide. Through observation using a microscopy, it was found that the acrylonitrile was dispersed into the continuous phase (the aqueous phase contains nitrile hydratase (NHase)) as droplets with a diameter ranged from 25 to 35 μm, hence the mass transfer specific surface area was significantly increased, and the concentration of acrylamide reached 52.5 wt% within 50 min. By contrast, in stirred tanks, the concentration of acrylamide only got 39.5 wt% within 245 min. Moreover, only a few amounts of acrylonitrile were accumulated in this microreactor system. Through optimizing the flow rate, the concentration of acrylamide reached 45.8 wt% within 35 min, the short reaction time greatly weakened the inhibition of acrylonitrile and acrylamide on the enzyme activity, which is suitable for prolonging the life of free cell.

  1. Photoactuation behavior of styrene-b-isoprene-b-styrene filled with covalently modified carbon nanotubes

    NASA Astrophysics Data System (ADS)

    Mosnáček, Jaroslav; Ilčíková, Markéta; Chorvát, Dušan; Czaniková, Klaudia; Krupa, Igor

    2012-07-01

    Styrene-b-isoprene-b-styrene (Kraton) was used as polymer matrix for preparation of multiwall carbon nanotubes (MWCNT) based nanocomposites. In order to suppress aggregation of the he carbon nanotubes and to improve the interations with the Kraton matrix, the MWCNT were modified with cholesteryl molecules and/or polystyrene chains. The effect of the modification on the composite materials was evaluated by using DMTA. The nanocomposite materials were thermoformed to achieve Braille text elements and their elastic response to light (photoactuation) was tested by atomic force microscopy in a contact mode.

  2. Hydrolyzed Poly(acrylonitrile) Electrospun Ion-Exchange Fibers

    PubMed Central

    Jassal, Manisha; Bhowmick, Sankha; Sengupta, Sukalyan; Patra, Prabir K.; Walker, Douglas I.

    2014-01-01

    Abstract A potential ion-exchange material was developed from poly(acrylonitrile) fibers that were prepared by electrospinning followed by alkaline hydrolysis (to convert the nitrile group to the carboxylate functional group). Characterization studies performed on this material using X-ray photoelectron spectroscopy, scanning electron microscopy, Fourier-Transform infra-red spectroscopy, and ion chromatography confirmed the presence of ion-exchange functional group (carboxylate). Optimum hydrolysis conditions resulted in an ion-exchange capacity of 2.39 meq/g. Ion-exchange fibers were used in a packed-bed column to selectively remove heavy-metal cation from the background of a benign, competing cation at a much higher concentration. The material can be efficiently regenerated and used for multiple cycles of exhaustion and regeneration. PMID:24963270

  3. A risk assessment for acrylonitrile in consumer products.

    PubMed

    Johnston, P K; Rock, A R

    1990-12-15

    A carcinogenic risk assessment for acrylonitrile in consumer products was prepared as part of the Second Workshop on Pragmatics of Risk Assessment, Bethesda, MD. Data from one inhalation and two oral rat bioassays served as input into several high-to-low-dose mathematical risk extrapolation models. The final unit risk estimates for humans were based on maximum likelihood estimates from the Global83 implementation of the multistage model after adjustments for surface area differences, continuous versus intermittent exposures, and the proportion of lifetime exposed. The unit risk estimates for lifetime exposure to 1 mg kg-1 day-1 by inhalation and ingestion were 0.0531 and 0.2385, respectively. These risks are equivalent to risks of 3.3 x 10(-8) for inhalation of 1 ppt in air and 3.4 x 10(-9) for ingestion of 1 ng day.-1

  4. Pervaporative removal of acrylonitrile from aqueous streams through polydimethylsiloxane membrane.

    PubMed

    Aliabadi, Majid; Aroujalian, Abdolreza; Raisi, Ahmadreza

    2011-01-01

    This study describes the successful separation of acrylonitrile (ACN) from dilute aqueous streams using pervaporation process. The influences of ACN feed concentration, permeate pressure, operating temperature, feed flow rate and membrane thickness on the membrane separation performance were investigated. The results showed that with an increase in ACN concentration in the feed solution, the permeation flux of ACN increased while the enrichment factor decreased. It was also indicated that increasing the permeate pressure reduced the driving force for mass transfer and consequently the permeation flux dropped while the enrichment factor enhanced. Polydimethylsiloxane membranes used in this study showed very good properties in the separation process, leading to enrichment factors in the range of 70-140. Furthermore, the activation energy for pervaporation of both ACN and water calculated from Arrhenius plot indicated that the permeation of water through the membrane was more temperature dependant than ACN.

  5. Styrene dimers and trimers affect reproduction of daphnid (Ceriodaphnia dubia).

    PubMed

    Tatarazako, Norihisa; Takao, Yuji; Kishi, Katsuyuki; Onikura, Norio a; Arizono, Koji; Iguchi, Taisen

    2002-08-01

    The endocrine disruptor activity of styrene in humans and other vertebrates appears to be negligible. However, offspring numbers were reduced in Ceriodaphnia dubia bred in polystyrene cups. Styrene dimers and trimers were found to be eluted from the polystyrene cups by hexane and methanol with gas chromatography-mass spectrometry. Styrene dimers and trimers at concentrations of 0.04-1.7 microg/l affected C. dubia fertility (25% reduction after seven days), suggesting that styrenes have the potential to impair crustacean populations in the aquatic environment.

  6. Styrene polymerization in three-component cationic microemulsions

    SciTech Connect

    Perez-Luna, V.H.; Puig, J.E. ); Castano, V.M. ); Rodriguez, B.E.; Murthy, A.K.; Kaler, E.W. )

    1990-06-01

    The polymerization of styrene in three-component dodecyltrimethylammonium bromide (DTAB) microemulsions is reported. The structure of the unpolymerized microemulsions, determined by conductimetry and quasielastic light scattering (QLS), is consistent with styrene-swollen micelles in equilibrium with regular micelles, both dispersed in an aqueous phase. Polymerization of these transparent microemulsions, monitored by QLS an dilatometry, produced stable, bluish monodisperse microlatices with particle radii ranging from 20 to 30 nm, depending on styrene content. Polymerization initiation appears to occur in the styrene-swollen micelles, and the polymer particles grow by recruiting monomer and surfactant from uninitiated droplets and small micelles.

  7. Mechanistic Studies of Single-Step Styrene Production Using a Rhodium(I) Catalyst.

    PubMed

    Vaughan, Benjamin A; Khani, Sarah K; Gary, J Brannon; Kammert, James D; Webster-Gardiner, Michael S; McKeown, Bradley A; Davis, Robert J; Cundari, Thomas R; Gunnoe, T Brent

    2017-02-01

    The direct and single-step conversion of benzene, ethylene, and a Cu(II) oxidant to styrene using the Rh(I) catalyst ((Fl)DAB)Rh(TFA)(η(2)-C2H4) [(Fl)DAB = N,N'-bis(pentafluorophenyl)-2,3-dimethyl-1,4-diaza-1,3-butadiene; TFA = trifluoroacetate] has been reported to give quantitative yields (with Cu(II) as the limiting reagent) and selectivity combined with turnover numbers >800. This report details mechanistic studies of this catalytic process using a combined experimental and computational approach. Examining catalysis with the complex ((Fl)DAB)Rh(OAc)(η(2)-C2H4) shows that the reaction rate has a dependence on catalyst concentration between first- and half-order that varies with both temperature and ethylene concentration, a first-order dependence on ethylene concentration with saturation at higher concentrations of ethylene, and a zero-order dependence on the concentration of Cu(II) oxidant. The kinetic isotope effect was found to vary linearly with the order in ((Fl)DAB)Rh(OAc)(η(2)-C2H4), exhibiting no KIE when [Rh] was in the half-order regime, and a kH/kD value of 6.7(6) when [Rh] was in the first-order regime. From these combined experimental and computational studies, competing pathways, which involve all monomeric Rh intermediates and a binuclear Rh intermediate in the other case, are proposed.

  8. The Rotational Spectrum of Acrylonitrile to 1.67 THz

    NASA Astrophysics Data System (ADS)

    Kisiel, Zbigniew; Pszczółkowski, Lech; Drouin, Brian J.; Brauer, Carolyn S.; Yu, Shanshan; Pearson, John C.

    2009-06-01

    Acrylonitrile (vinyl cyanide) is an astrophysical molecule of sufficient abundance for detection of its ^{13}C isotopologues. In fact this molecule has been identified as one of the 'weed' species, that will contribute a plethora of lines in broadband submillimetre spectra from the new tools of radioastronomy, such as the Herschel Space Observatory or ALMA. We presently report the first stage in extending the knowledge of the rotational spectrum of acrylonitrile well into the THz region. The spectrum was recorded with the jpl cascaded harmonic multiplication instrument in the form of several broadband segments covering 390-540, 818-930, 967-1160, and 1576-1669 GHz. The analysis of the ground state spectrum has been extended up to J=128, K_a=29, and a combined data set of over 3000 fitted lines. It is found that transitions in all measurable vibrational states, inclusive of the ground state, show evidence of perturbations with other states. Several different perturbations between the ground state and v_{11}=1 at 228 cm^{-1} were identified and have been successfully fitted, resulting in E_{11}=228.29994(3) cm^{-1}, to compare with a direct far-infrared value of 228.83(18) cm^{-1}. H.S.P.Müller et al., J. Mol. Spectrosc., 251, 319-325 (2008). B.J.Drouin, F.W.Maiwald, J.C.Pearson, Rev. Sci. Instrum., 76, 093113-1-10 (2005). A.R.H.Cole, A.A.Green, J. Mol. Spectrosc., 48, 246-253 (1973).

  9. A vinylic Rosenmund-von Braun reaction: practical synthesis of acrylonitriles.

    PubMed

    Pradal, Alexandre; Evano, Gwilherm

    2014-10-14

    An efficient system based on acetone cyanohydrin and catalytic amounts of copper(I) iodide and 1,10-phenanthroline is reported for the cyanation of alkenyl iodides. A wide range of polysubstituted acrylonitriles could be obtained in fair to good yields and with complete retention of the geometry of the double bond. This extension of the Rosenmund-von Braun reaction also enabled a straightforward formal synthesis of the naturally occurring acrylonitrile alliarinoside.

  10. 40 CFR 721.10151 - Modified styrene, divinylbenzene polymer (generic).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... polymer (generic). 721.10151 Section 721.10151 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.10151 Modified styrene, divinylbenzene polymer (generic). (a) Chemical... as modified styrene, divinylbenzene polymer (PMN P-07-642) is subject to reporting under this...

  11. 40 CFR 721.10151 - Modified styrene, divinylbenzene polymer (generic).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... polymer (generic). 721.10151 Section 721.10151 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.10151 Modified styrene, divinylbenzene polymer (generic). (a) Chemical... as modified styrene, divinylbenzene polymer (PMN P-07-642) is subject to reporting under this...

  12. 40 CFR 721.10151 - Modified styrene, divinylbenzene polymer (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... polymer (generic). 721.10151 Section 721.10151 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.10151 Modified styrene, divinylbenzene polymer (generic). (a) Chemical... as modified styrene, divinylbenzene polymer (PMN P-07-642) is subject to reporting under this...

  13. 21 CFR 177.1810 - Styrene block polymers.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Styrene block polymers. 177.1810 Section 177.1810... FOR HUMAN CONSUMPTION (CONTINUED) INDIRECT FOOD ADDITIVES: POLYMERS Substances for Use as Basic Components of Single and Repeated Use Food Contact Surfaces § 177.1810 Styrene block polymers. The...

  14. 40 CFR 721.10151 - Modified styrene, divinylbenzene polymer (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... polymer (generic). 721.10151 Section 721.10151 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.10151 Modified styrene, divinylbenzene polymer (generic). (a) Chemical... as modified styrene, divinylbenzene polymer (PMN P-07-642) is subject to reporting under this...

  15. 21 CFR 177.1810 - Styrene block polymers.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Styrene block polymers. 177.1810 Section 177.1810... FOR HUMAN CONSUMPTION (CONTINUED) INDIRECT FOOD ADDITIVES: POLYMERS Substances for Use as Basic Components of Single and Repeated Use Food Contact Surfaces § 177.1810 Styrene block polymers. The...

  16. 21 CFR 177.1810 - Styrene block polymers.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Styrene block polymers. 177.1810 Section 177.1810... FOR HUMAN CONSUMPTION (CONTINUED) INDIRECT FOOD ADDITIVES: POLYMERS Substances for Use as Basic Components of Single and Repeated Use Food Contact Surfaces § 177.1810 Styrene block polymers. The...

  17. 40 CFR 721.10151 - Modified styrene, divinylbenzene polymer (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... polymer (generic). 721.10151 Section 721.10151 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.10151 Modified styrene, divinylbenzene polymer (generic). (a) Chemical... as modified styrene, divinylbenzene polymer (PMN P-07-642) is subject to reporting under this...

  18. 21 CFR 177.1810 - Styrene block polymers.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Styrene block polymers. 177.1810 Section 177.1810... FOR HUMAN CONSUMPTION (CONTINUED) INDIRECT FOOD ADDITIVES: POLYMERS Substances for Use as Basic Components of Single and Repeated Use Food Contact Surfaces § 177.1810 Styrene block polymers. The...

  19. Natural formation of styrene by cinnamon mold flora.

    PubMed

    Lafeuille, J-L; Buniak, M-L; Vioujas, M-C; Lefevre, S

    2009-08-01

    Tests on 106 dried pure cinnamon samples of diverse origins showed that some samples were naturally contaminated with high levels of styrene, up to 524 microg/g. Styrene taint can be associated with high water activity levels and thus with microorganism growth. The mold flora of a Korintji cinnamon sample in which styrene had been found at a 50 microg/g concentration was analyzed and 5 species of mold were isolated. An investigation into the ability of the 5 species of mold to produce styrene showed that 3 of them--namely, Penicillium citrinum, Penicillium oxalicum, Aspergillus niger--produced styrene in vitro in buffered peptone water at 25 degrees C within 5 d in the presence of several natural cinnamon volatile constituents containing the styrene structure. The conversion of these compounds into styrene by these 3 cinnamon fungal species has never been previously reported. A standardized inoculation with the 3 mold species was carried out on 10 g cinnamon samples of various origins followed by a 10-d incubation and highlighting styrene production except for Sri Lanka origin.

  20. Copolymerization of carbon dioxide and butadiene via a lactone intermediate.

    PubMed

    Nakano, Ryo; Ito, Shingo; Nozaki, Kyoko

    2014-04-01

    Although carbon dioxide has attracted broad interest as a renewable carbon feedstock, its use as a monomer in copolymerization with olefins has long been an elusive endeavour. A major obstacle for this process is that the propagation step involving carbon dioxide is endothermic; typically, attempted reactions between carbon dioxide and an olefin preferentially yield olefin homopolymerization. Here we report a strategy to circumvent the thermodynamic and kinetic barriers for copolymerizations of carbon dioxide and olefins by using a metastable lactone intermediate, 3-ethylidene-6-vinyltetrahydro-2H-pyran-2-one, which is formed by the palladium-catalysed condensation of carbon dioxide and 1,3-butadiene. Subsequent free-radical polymerization of the lactone intermediate afforded polymers of high molecular weight with a carbon dioxide content of 33 mol% (29 wt%). Furthermore, the protocol was applied successfully to a one-pot copolymerization of carbon dioxide and 1,3-butadiene, and one-pot terpolymerizations of carbon dioxide, butadiene and another 1,3-diene. This copolymerization technique provides access to a new class of polymeric materials made from carbon dioxide.

  1. Copolymerization of carbon dioxide and butadiene via a lactone intermediate

    NASA Astrophysics Data System (ADS)

    Nakano, Ryo; Ito, Shingo; Nozaki, Kyoko

    2014-04-01

    Although carbon dioxide has attracted broad interest as a renewable carbon feedstock, its use as a monomer in copolymerization with olefins has long been an elusive endeavour. A major obstacle for this process is that the propagation step involving carbon dioxide is endothermic; typically, attempted reactions between carbon dioxide and an olefin preferentially yield olefin homopolymerization. Here we report a strategy to circumvent the thermodynamic and kinetic barriers for copolymerizations of carbon dioxide and olefins by using a metastable lactone intermediate, 3-ethylidene-6-vinyltetrahydro-2H-pyran-2-one, which is formed by the palladium-catalysed condensation of carbon dioxide and 1,3-butadiene. Subsequent free-radical polymerization of the lactone intermediate afforded polymers of high molecular weight with a carbon dioxide content of 33 mol% (29 wt%). Furthermore, the protocol was applied successfully to a one-pot copolymerization of carbon dioxide and 1,3-butadiene, and one-pot terpolymerizations of carbon dioxide, butadiene and another 1,3-diene. This copolymerization technique provides access to a new class of polymeric materials made from carbon dioxide.

  2. Conversion of 2,3-butanediol to butadiene

    DOEpatents

    Lilga, Michael A.; Frye, Jr, John G.; Lee, Suh-Jane; Albrecht, Karl O.

    2016-09-06

    A composition comprising 2,3-butanediol is dehydrated to methyl vinyl carbinol and/or 1,3-butadiene by exposure to a catalyst comprising (a) M.sub.xO.sub.y wherein M is a rare earth metal, a group IIIA metal, Zr, or a combination thereof, and x and y are based upon an oxidation state of M, or (b) M.sup.3.sub.a(PO.sub.4).sub.b where M.sup.3 is a group IA, a group IIA metal, a group IIIA metal, or a combination thereof, and a and b are based upon the oxidation state of M.sup.3. Embodiments of the catalyst comprising M.sub.xO.sub.y may further include M.sup.2, wherein M.sup.2 is a rare earth metal, a group IIA metal, Zr, Al, or a combination thereof. In some embodiments, 2,3-butanediol is dehydrated to methyl vinyl carbinol and/or 1,3-butadiene by a catalyst comprising M.sub.xO.sub.y, and the methyl vinyl carbinol is subsequently dehydrated to 1,3-butadiene by exposure to a solid acid catalyst.

  3. 75 FR 9438 - Americas Styrenics, LLC-Marietta Plant a Subsidiary of Americas Styrenics, LLLC Formerly Known as...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-02

    ... Styrenics, LLLC Formerly Known as Chevron Phillips Chemical Co. LP Including On-Site Leased Workers From... Styrenics LLC-Marietta Plant was formerly known as Chevron Phillips Chemical Co. LP. Some workers separated... (UI) tax accounts for Chevron Phillips Chemical Co. LP. Accordingly, the Department is amending...

  4. Genotoxicity of styrene-7,8-oxide and styrene in Fisher 344 rats: a 4-week inhalation study.

    PubMed

    Gaté, Laurent; Micillino, Jean-Claude; Sébillaud, Sylvie; Langlais, Cristina; Cosnier, Frédéric; Nunge, Hervé; Darne, Christian; Guichard, Yves; Binet, Stéphane

    2012-06-20

    The cytogenetic alterations in leukocytes and the increased risk for leukemia, lymphoma, or all lymphohematopoietic cancer observed in workers occupationally exposed to styrene have been associated with its hepatic metabolisation into styrene-7,8-oxide, an epoxide which can induce DNA damages. However, it has been observed that styrene-7,8-oxide was also found in the atmosphere of reinforced plastic industries where large amounts of styrene are used. Since the main route of exposure to these compounds is inhalation, in order to gain new insights regarding their systemic genotoxicity, Fisher 344 male rats were exposed in full-body inhalation chambers, 6 h/day, 5 days/week for 4 weeks to styrene-7,8-oxide (25, 50, and 75 ppm) or styrene (75, 300, and 1000 ppm). Then, the induction of micronuclei in circulating reticulocytes and DNA strand breaks in leukocytes using the comet assay was studied at the end of the 3rd and 20th days of exposure. Our results showed that neither styrene nor styrene-7,8-oxide induced a significant increase of the micronucleus frequency in reticulocytes or DNA strand breaks in white blood cells. However, in the presence of the formamidopyridine DNA glycosylase, an enzyme able to recognize and excise DNA at the level of some oxidized DNA bases, a significant increase of DNA damages was observed at the end of the 3rd day of treatment in leukocytes from rats exposed to styrene but not to styrene-7,8-oxide. This experimental design helped to gather new information regarding the systemic genotoxicity of these two chemicals and may be valuable for the risk assessment associated with an occupational exposure to these molecules.

  5. Acrylonitrile is a multisite carcinogen in male and female B6C3F1 mice.

    PubMed

    Ghanayem, Burhan I; Nyska, Abraham; Haseman, Joseph K; Bucher, John R

    2002-07-01

    Acrylonitrile is a heavily produced unsaturated nitrile, which is used in the production of synthetic fibers, plastics, resins, and rubber. Acrylonitrile is a multisite carcinogen in rats after exposure via gavage, drinking water, or inhalation. No carcinogenicity studies of acrylonitrile in a second animal species were available. The current studies were designed to assess the carcinogenicity of acrylonitrile in B6C3F1 mice of both sexes. Acrylonitrile was administered by gavage at 0, 2.5, 10, or 20 mg/kg/day, 5 days per week, for 2 years. Urinary thiocyanate and N-acetyl-S-(2-cyanoethyl)-L-cysteine were measured as markers of exposure to acrylonitrile. In general, there were dose-related increases in urinary thiocyanate and N-acetyl-S-(2-cyanoethyl)-L-cysteine concentrations in all dosed groups of mice and at all time points. Survival was significantly (p < 0.001) reduced in the top dose (20 mg/kg) group of male and female mice relative to controls. The incidence of forestomach papillomas and carcinomas was increased in mice of both sexes in association with an increase in forestomach epithelial hyperplasia. The incidence of Harderian gland adenomas and carcinomas was also markedly increased in the acrylonitrile-dosed groups. In female mice, the incidence of benign or malignant granulosa cell tumors (combined) in the ovary in the 10 mg/kg dose group was greater than that in the vehicle control group, but because of a lack of dose response, this was considered an equivocal finding. In addition, the incidences of atrophy and cysts in the ovary of the 10 and 20 mg/kg dose groups were significantly increased. The incidences of alveolar/bronchiolar adenoma or carcinoma (combined) were significantly increased in female mice treated with acrylonitrile at 10 mg/kg/day for 2 years. This was also considered an equivocal result. In conclusion, these studies demonstrated that acrylonitrile causes multiple carcinogenic effects after gavage administration to male and female B6

  6. 1,3-butadiene in urban and industrial areas and its role in photochemical processes

    NASA Astrophysics Data System (ADS)

    Czader, Beata; Rappenglück, Bernhard

    2015-04-01

    1,3-butadiene is an important pollutant in terms of public health and important driver for photochemical processes influencing ozone formation in the area of Houston. Ambient levels of 1,3-butadiene were simulated with the Community Multiscale Air Quality model (CMAQ) including the SAPRC99-extended mechanism and the results were compared to spatially and temporally resolved observations of 1,3-butadiene for an episodic period during Summer 2006. Relative contributions of different type of emissions and chemical reactions to 1,3-butadiene concentrations were examined, the highest contribution was found to be from industrial emission sources. 1,3-butadiene mixing ratios in the urban area were found to be lower than in the industrial area. Although emissions of 1,3-butadiene peak during daytime its mixing ratios are lower during daytimes as compared to nighttime. 1,3-butadiene is removed from the surface through vertical upward transport (~90%) and chemical reactions (~10%). During daytime 1,3-butadiene reacts mainly with the OH radical (90%), during nighttime this reaction pathway is still significant in the industrial area (57% of all reaction pathways). Reaction with NO3 during nighttime contributes 33% in industrial and 56% in urban areas, where high NOx emissions occur. Reaction with ozone contributes 10% and 13% in industrial and urban areas, respectively. Analysis of measured data revealed that episodically very high emissions spikes of 1,3-butadiene occur. CMAQ often underpredicts 1,3-butadiene mixing ratios when sites are exposed to sporadic releases from industrial facilities. These releases are not accounted for in the emission inventory. It also appears that emissions of 1,3-butadiene from point sources have much more variability than those listed in the emission inventory.

  7. Modeling of 1,3-butadiene in urban and industrial areas

    NASA Astrophysics Data System (ADS)

    Czader, Beata H.; Rappenglück, Bernhard

    2015-02-01

    1,3-butadiene is an important pollutant in terms of public health and important driver for photochemical processes influencing ozone formation in the area of Houston. Ambient levels of 1,3-butadiene were simulated with the Community Multiscale Air Quality model (CMAQ) including the SAPRC99-extended mechanism and the results were compared to spatially and temporally resolved observations of 1,3-butadiene for an episodic period during Summer 2006. Relative contributions of different type of emissions and chemical reactions to 1,3-butadiene concentrations were examined, the highest contribution was found to be from industrial emission sources. 1,3-butadiene mixing ratios in the urban area were found to be lower than in the industrial area. Although emissions of 1,3-butadiene peak during daytime its mixing ratios are lower during daytimes as compared to nighttime. 1,3-butadiene is removed from the surface through vertical upward transport (∼90%) and chemical reactions (∼10%). During daytime 1,3-butadiene reacts mainly with the OH radical (90%), during nighttime this reaction pathway is still significant in the industrial area (57% of all reaction pathways). Reaction with NO3 during nighttime contributes 33% in industrial and 56% in urban areas, where high NOx emissions occur. Reaction with ozone contributes 10% and 13% in industrial and urban areas, respectively. Analysis of measured data revealed that episodically very high emissions spikes of 1,3-butadiene occur. CMAQ often underpredicts 1,3-butadiene mixing ratios when sites are exposed to sporadic releases from industrial facilities. These releases are not accounted for in the emission inventory. It also appears that emissions of 1,3-butadiene from point sources have much more variability than those listed in the emission inventory.

  8. Immobilization of urease onto chemically modified acrylonitrile copolymer membranes.

    PubMed

    Godjevargova, T; Gabrovska, K

    2003-06-26

    Poly (acrylonitrile-methylmethacrylate-sodium vinylsulfonate) membranes were subjected to seven different chemical modifications. The amounts of new groups incorporated in the membranes with the modifications were determined. Urease was covalently immobilized on the modified membranes. Both the amount of bound protein and relative activity of immobilized urease were measured. The highest activity was found for urease bound to membranes modified with hydroxylammonium sulfate (68%) and hydrazinium sulfate (67%). Optimum pH of free urease was determined to be 5.8. For positively charged membranes, pH optimum was shifted to higher values, while for negatively charged membranes-to lower pH. The charge of the matrix affected also the rate of the enzyme reaction. The highest rate was measured with urease immobilized on membranes modified with hydroxylammonium sulfate and hydrazinium sulfate. The major part of the immobilized enzyme on different modified membranes remained stable-only ca. 20% of enzyme activity was lost for 4 h at 70 degrees C while the free enzyme was totally inactivated.

  9. Role of neutrophils in acrylonitrile-induced gastric mucosal damage.

    PubMed

    Hamdy, Nadia M; Al-Abbasi, Fahad A; Alghamdi, Hassan A; Tolba, Mai F; Esmat, Ahmed; Abdel-Naim, Ashraf B

    2012-01-25

    Acrylonitrile (ACN) is a widely used intermediate in the manufacture of plastics, acrylic fibers, synthetic rubbers and resins that are used in a variety of products including food containers and medical devices. ACN is a possible human carcinogen and a documented animal carcinogen, with the stomach being an important target of its toxicity. ACN has been previously reported to require metabolic activation to reactive intermediates and finally to cyanide (CN⁻). The current study aimed at exploring the potential role of neutrophils in ACN-induced gastric damage in rats. Experimental neutropenia was attained by injecting rats with methotrexate. This significantly ameliorated gastric mucosal injury induced by ACN. This is evidenced by protection against the increase in gastric ulcer index, myeloperoxidase (MPO) activity and CN⁻ level. Also, neutropenia guarded against the decrease in prostaglandin E2 (PGE2), induction of oxidative stress and reduction of total nitrites and alleviated histopathological alterations in rat stomachs. These data indicate that neutrophil infiltration is, at least partly, involved in ACN-induced gastric damage in rats.

  10. Antioxidants do not prevent acrylonitrile-induced toxicity.

    PubMed

    Carrera, M P; Antolín, I; Martín, V; Sainz, R M; Mayo, J C; Herrera, F; García-Santos, G; Rodríguez, C

    2007-03-30

    Several reports have recently described that acrylonitrile (ACN) toxicity resides in its capacity for inducing oxidative stress. ACN can be conjugated with glutathione (GSH), diminishing its cellular content, or being metabolized to cyanide. In the present report, we determine the effect of ACN on the viability of primary-cultured astrocytes as well as the oxidative damage generated by ACN by measuring GSH levels in primary cultured astrocytes. We also analyzed whether the ACN (2.5mM) toxicity could be avoided by using antioxidants such as taurine (5mM), N-acetylcysteine (20 mM), trolox (100 microM), estradiol (10 microM) and melatonin (100 nM-1mM). In this cell culture model, antioxidants were not able to prevent ACN-induced cell damage, with the exception of NAC, confirming that only GSH seems to play a key role in ACN-derived toxicity. Additionally, we measured different parameters of oxidative stress such as catalase activity, lipid peroxidation and GSH concentration, as indicators of the potential oxidative stress mediated by the toxicity of ACN, after exposure of Wistar rats to a concentration of 200 ppm ACN for 14 days. At the concentration assayed, we did not find any evidence of oxidative damage in the brain of ACN-treated rats.

  11. Lactoperoxidase catalyzes in vitro activation of acrylonitrile to cyanide.

    PubMed

    Nasralla, Sherry N; Ghoneim, Asser I; Khalifa, Amani E; Gad, Mohamed Z; Abdel-Naim, Ashraf B

    2009-12-15

    Acrylonitrile (ACN) is a widely used industrial chemical. Although it is a well reported animal carcinogen, its current designation to humans is "possibly carcinogenic". The present study aimed at investigating the ability of LPO enzyme system to oxidize ACN to cyanide (CN(-)) in vitro. Detection of CN(-) served as a marker for the possible generation of free radical intermediates implicated in ACN induced toxicity in the activation process. Optimum conditions for the oxidation of ACN to CN(-) were characterized with respect to pH, temperature and time of incubation as well as ACN, LPO and H(2)O(2) concentrations in incubation mixtures. Maximum reaction velocity (V(max)) and Michaelis-Menten constant (K(m)) were assessed. Addition of nitrite (NO(2)(-)) salts to the reaction mixtures significantly enhanced the rate of the reaction. Free radical scavengers (quercetin and trolox C), LPO enzyme inhibitor (resorcinol) and competitors for LPO binding (sodium azide and indomethacin) were found to reduce the rate of CN(-) production. Inclusion of the sulfhydryl compounds glutathione (GSH), NAC (N-acetylcysteine), D-penicillamine or L-cysteine enhanced the rate of ACN oxidation. The present results demonstrate the ability of LPO enzyme system to oxidize ACN to CN(-) and provide insight for the elucidation of ACN chronic toxicity.

  12. Assessment of risk from exposure to acrylonitrile: the general approach used by a consultant.

    PubMed

    Page, N P; Cook, B

    1990-12-15

    The concern from low-level exposure to acrylonitrile is primarily due to its potential for carcinogenicity. Several epidemiology studies provide suggestive evidence for an association of lung cancer in workers exposed to acrylonitrile; however, smoking may be a contributing factor and therefore the role of acrylonitrile as a causative factor is unclear. Seven animal bioassays, using three routes of exposure and two strains of rats, have provided consistent results. Tumors were induced in all studies, with the primary sites of tumor induction being the brain, ear canal, gastrointestinal tract and mammary glands. The linearized multistage model was used for extrapolation purposes. The risk based on brain tumors (astrocytomas) and stomach tumors following oral exposures ranged from 1 x 10(-1) to 4 x 10(-1)mg-1kg-1day-1. The risk of inhalation exposure is somewhat less, (2-3) x 10(-2). Support for carcinogenic potential is obtained from mutagenicity studies. Acrylonitrile has been found to be mutagenic and also binds with DNA. It has been speculated that acrylonitrile is metabolized to 2-cyanoethylene oxide, which is the proximate carcinogen.

  13. Biocompatibility and characterization of polylactic acid/styrene-ethylene-butylene-styrene composites.

    PubMed

    Tsou, Chi-Hui; Kao, Bo-Jyue; Yang, Ming-Chien; Suen, Maw-Cherng; Lee, Yi-Hsuan; Chen, Jui-Chin; Yao, Wei-Hua; Lin, Shang-Ming; Tsou, Chih-Yuan; Huang, Shu-Hsien; De Guzman, Manuel; Hung, Wei-Song

    2015-01-01

    Polylactic acid (PLA)/styrene-ethylene-butylene-styrene (SEBS) composites were prepared by melt blending. Differential scanning calorimetry (DSC) and wide angle X-ray diffraction (WXRD) were used to characterize PLA and PLA/SEBS composites in terms of their melting behavior and crystallization. Curves from thermal gravimetric analysis (TGA) illustrated that thermostability increased with SEBS content. Further morphological analysis of PLA/SEBS composites revealed that SEBS molecules were not miscible with PLA molecules in PLA/SEBS composites. The tensile testing for PLA and PLA/SEBS composites showed that the elongation at the break was enhanced, but tensile strength decreased with increasing SEBS content. L929 fibroblast cells were chosen to assess the cytocompatibility; the cell growth of PLA was found to decrease with increasing SEBS content. This study proposes possible reasons for these properties of PLA/SEBS composites.

  14. Effect of shutdown on styrene removal in a biofilter inoculated with Pseudomonas sp. SR-5.

    PubMed

    Jang, Jong Hee; Hirai, Mitsuyo; Shoda, Makoto

    2006-02-28

    Styrene gas removal was carried out in a biofilter inoculated with a styrene-degrading Pseudomonas sp. SR-5 using a mixed packing material of peat and ceramic under the non-sterile condition. More than 86% removal efficiency was obtained at styrene load of 5-93 g m(-3) h(-1) for 62 days operation period and 78% carbon of removed styrene was converted to CO2. Thereafter, three kinds of styrene shutdown experiments were conducted: (i) air and mineral medium were supplied for 4 days, (ii) complete shutdown, namely no styrene, air and moisture supply was conducted for 3 days, and (iii) only air was supplied for 11 days. When styrene gas was re-supplied after (i) and (iii) shutdown experiments, styrene removal efficiency rapidly recovered, but after (ii) shutdown, recovery of styrene removal was significantly delayed. Supply of air during shutdown period was found to be enough to resume microbial activity to degrade styrene.

  15. SOME INSIGHTS INTO THE MODE OF ACTION OF BUTADIENE BY EXAMINING THE GENOTOXICITY OF ITS METABOLITES

    EPA Science Inventory

    1,3-Butadiene (BTD) is an important commodity chemical and air pollutant that has been shown to be a potent carcinogen in mice, and to a lesser extent, a carcinogen in rats. To better assess butadiene's carcinogenic risk to humans, it is important to understand its mode of action...

  16. In vitro and in vivo genotoxicity of 1,3-butadiene and metabolites.

    PubMed Central

    Arce, G T; Vincent, D R; Cunningham, M J; Choy, W N; Sarrif, A M

    1990-01-01

    1,3-Butadiene and two major genotoxic metabolites 3,4-epoxybutene (EB) and 1,2:3,4-diepoxybutane (DEB) were used as model compounds to determine if genetic toxicity findings in animal and human cells can aid in extrapolating animal toxicity data to man. Sister chromatid exchange (SCE) and micronucleus induction results indicated 1,3-butadiene was genotoxic in the bone marrow of the mouse but not the rat. This paralleled the chronic bioassays which showed mice to be more susceptible than rats to 1,3-butadiene carcinogenicity. However, 1,3-butadiene did not induce unscheduled DNA synthesis (UDS) in the rat or mouse hepatocytes following in vivo exposure. Likewise, UDS in rat and mouse hepatocytes in vitro was not induced by EB or DEB. Salmonella typhimurium gene mutation (Ames) tests of 1,3-butadiene using strains TA1535, TA97, TA98, and TA100 and employing rat, mouse, and human liver S9 metabolic systems were barely 2-fold above background only in strain TA1535 at 30% 1,3-butadiene in air with induced and uninduced rat S9 and mouse S9 (uninduced). 1,3-Butadiene was negative in in vitro SCE studies in human whole blood lymphocytes cultures treated in the presence of rat, mouse, or human liver S9 metabolic activation. In general, 1,3-butadiene is genotoxic in vivo but is a weak in vitro genotoxin. PMID:2205494

  17. A brief survey of butadiene health effects: a role for metabolic differences.

    PubMed Central

    Birnbaum, L S

    1993-01-01

    1,3-Butadiene is a major monomer in the rubber and plastics industry and is one of the highest-production industrial chemicals in the United States. Although not highly acutely toxic to rodents, inhalation of concentrations as low as 6.25 ppm causes tumors in mice. Butadiene is oncogenic in rats, but much higher exposure concentrations are required than in mice. Chronic toxicity targets the gonads and hematopoietic system. Butadiene is also a potent mutagen and clastogen. Differences in the absorption, distribution, and elimination of butadiene appear to be relatively minor between rats and mice, although mice do retain more butadiene and its metabolites after exposure to the same concentration and have a higher rate of metabolic elimination. Recent studies have demonstrated that major species differences appear to occur in the rate of detoxication of the primary metabolite, 3-epoxybutene (butadiene monoepoxide [BDMO]). Mice have the greatest rate of production of BDMO as compared to other species, but the rate of removal of BDMO appears to be less than in other species. Mice have low levels of epoxide hydrolase; rats have intermediate levels; monkeys and humans appear to have high levels of this detoxifying enzyme. Thus, while only low levels of butadiene exposure may result in an accumulation of BDMO in the mouse, much higher levels would be required to result in an elevation of circulating BDMO in other species. The level of this reactive metabolite may be correlated with the species differences in butadiene sensitivity. PMID:8020440

  18. 75 FR 31713 - 2-Propenoic acid polymer, with 1,3-butadiene and ethenylbenzene; Tolerance Exemption

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-04

    ... AGENCY 40 CFR Part 180 2-Propenoic acid polymer, with 1,3-butadiene and ethenylbenzene; Tolerance... establishes an exemption from the requirement of a tolerance for residues of 2-propenoic acid polymer, with 1... a maximum permissible level for residues of 2-propenoic acid polymer, with 1,3-butadiene...

  19. 40 CFR 721.10280 - Benzene ethenyl-, polymer with 1,3-butadiene, brominated.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Benzene ethenyl-, polymer with 1,3... Specific Chemical Substances § 721.10280 Benzene ethenyl-, polymer with 1,3-butadiene, brominated. (a... benzene ethenyl-, polymer with 1,3-butadiene, brominated (PMN P-10-476; CAS No. 1195978-93-8)) is...

  20. 40 CFR 721.10280 - Benzene ethenyl-, polymer with 1,3-butadiene, brominated.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Benzene ethenyl-, polymer with 1,3... Specific Chemical Substances § 721.10280 Benzene ethenyl-, polymer with 1,3-butadiene, brominated. (a... benzene ethenyl-, polymer with 1,3-butadiene, brominated (PMN P-10-476; CAS No. 1195978-93-8)) is...

  1. Butadiene-Isoprene Block Copolymers and Their Hydrogenated Derivatives.

    DTIC Science & Technology

    1981-04-01

    polymerization reactivities butadienes dienes i soprene benzene compounds * anions chemorheo logy AB1STRACT (000010 an 0ee 06 It nese.m ill fdef’ 6F...Foclur, A. G. Kitchen, C. C. Baird , Am. Chem. Soc. Div. Og Coat. Plast. Chem. Pap., 34(1), 130, (1974). 11. O.L. Marrs, F. E. Naylor, and L.O. Edmonds , J...York (1977). 2. A. V. Tobolsky, "Properties and Structure of Polymers," Chap. V, John Wiley & Sons, NY (1960). 3. K. Arai and Y. Naito, J. Soc. Rheol

  2. Telomerization of butadiene with starch under mild conditions.

    PubMed

    Mesnager, Julien; Quettier, Claude; Lambin, Anne; Rataboul, Franck; Pinel, Catherine

    2009-01-01

    The design of industrial products based on bioresources is a challenging issue. Modification of starch, by hydrophobic chemical substituents, results in an innovative hydrophobic material. Herein, the hydrophobic part of the derivative, comprised of octadienyl chains, is introduced through catalytic butadiene telomerization. The process is efficiently conducted on starch in its granular form in an aqueous medium using hydrosoluble palladium complexes. After optimization, a turnover number (TON) of up to 550 was achieved in the presence of [(pi-allyl)PdCl](2) catalyst and, unusually, by using dimethylisosorbide as a cosolvent.

  3. [The airborne 1,3-butadiene concentrations in rubber and plastic processing plants].

    PubMed

    Yoshida, Toshiaki; Tainaka, Hidetsugu; Matsunaga, Ichiro; Goto, Sumio

    2002-03-01

    Environment pollution by 1,3-butadiene had considerably increased in Japan. The main cause of the pollution is the automotive exhaust gas, and leaks from factories, smoking, and burning of rubber and plastic products are considered to be minor sources. The object of this study was to determine the contamination levels of airborne 1,3-butadiene in factories processing rubber and plastics containing 1,3-butadiene. The concentrations of airborne 1,3-butadiene were measured in 21 plants (10 rubber processing plants and 11 plastics processing plants) in Osaka. 1,3-Butadiene in air was collected for 10 minutes with a charcoal tube and a portable small pump adjusted to a 250 ml/min flow rate. In each plant, indoor air samples at five points and an outdoor air sample at one point outside the plant were collected. The samples were subjected to gas chromatography/mass spectrometry after thermal desorption from the charcoal. The concentrations of airborne 1,3-butadiene in the rubber processing plants and the plastics processing plants were 0.14-2.20 micrograms/m3 (geometric mean: 0.48 microgram/m3) and 0.23-4.51 micrograms/m3 (geometric mean: 0.80 microgram/m3), respectively. In all plants examined, indoor 1,3-butadiene concentrations were higher than the outdoor concentrations around the plants. Therefore, 1,3-butadiene was considered to arise from the processing of rubber or plastics, but the indoor 1,3-butadiene concentrations were much lower than the PEL-TWA (1 ppm = 2.21 mg/m3) of OSHA and the TLV-TWA (2 ppm) of ACGIH. The concentrations in the plants with closed room conditions without ventilation were higher than the concentrations in the other plants. It was suggested that ventilation affected the 1,3-butadiene concentration in the plants.

  4. Pre-irradiation induced emulsion graft polymerization of acrylonitrile onto polyethylene nonwoven fabric

    NASA Astrophysics Data System (ADS)

    Liu, Hanzhou; Yu, Ming; Deng, Bo; Li, Linfan; Jiang, Haiqing; Li, Jingye

    2012-01-01

    Acrylonitrile has been widely used in the modification of polymers by graft polymerization. In the present work, pre-irradiation induced emulsion graft polymerization method is used to introduce acrylonitrile onto PE nonwoven fabric instead of the traditional reaction in organic solvents system. The degree of grafting (DG) is measured by gravimetric method and the kinetics of the graft polymerization is studied. The existence of the graft chains is proven by Fourier transform infrared spectroscopy (FT-IR) analysis. Thermal stability of the grafted polymer is measured by Thermogravimetric analysis (TGA).

  5. Asymmetric Palladium-Catalyzed Directed Intermolecular Fluoroarylation of Styrenes

    PubMed Central

    2015-01-01

    A mild catalytic asymmetric direct fluoro-arylation of styrenes has been developed. The palladium-catalyzed three-component coupling of Selectfluor, a styrene and a boronic acid, provides chiral monofluorinated compounds in good yield and in high enantiomeric excess. A mechanism proceeding through a Pd(IV)-fluoride intermediate is proposed for the transformation and synthesis of an sp3 C–F bond. PMID:24617344

  6. Synaptic contacts impaired by styrene-7,8-oxide toxicity

    SciTech Connect

    Corsi, P. D'Aprile, A.; Nico, B.; Costa, G.L.; Assennato, G.

    2007-10-01

    Styrene-7,8-oxide (SO), a chemical compound widely used in industrial applications, is a potential hazard for humans, particularly in occupational settings. Neurobehavioral changes are consistently observed in occupationally exposed individuals and alterations of neurotransmitters associated with neuronal loss have been reported in animal models. Although the toxic effects of styrene have been extensively documented, the molecular mechanisms responsible for SO-induced neurotoxicity are still unclear. A possible dopamine-mediated effect of styrene neurotoxicity has been previously demonstrated, since styrene oxide alters dopamine neurotransmission in the brain. Thus, the present study hypothesizes that styrene neurotoxicity may involve synaptic contacts. Primary striatal neurons were exposed to styrene oxide at different concentrations (0.1-1 mM) for different time periods (8, 16, and 24 h) to evaluate the dose able to induce synaptic impairments. The expression of proteins crucial for synaptic transmission such as Synapsin, Synaptophysin, and RAC-1 were considered. The levels of Synaptophysin and RAC-1 decreased in a dose-dependent manner. Accordingly, morphological alterations, observed at the ultrastructural level, primarily involved the pre-synaptic compartment. In SO-exposed cultures, the biochemical cascade of caspases was activated affecting the cytoskeleton components as their target. Thus the impairments in synaptic contacts observed in SO-exposed cultures might reflect a primarily morphological alteration of neuronal cytoskeleton. In addition, our data support the hypothesis developed by previous authors of reactive oxygen species (ROS) initiating events of SO cytotoxicity.

  7. Styrene-Associated Health Outcomes at a Windblade Manufacturing Plant

    PubMed Central

    McCague, Anna-Binney; Cox-Ganser, Jean M.; Harney, Joshua M.; Alwis, K. Udeni; Blount, Benjamin C.; Cummings, Kristin J.; Edwards, Nicole; Kreiss, Kathleen

    2015-01-01

    Background Health risks of using styrene to manufacture windblades for the green energy sector are unknown. Methods Using data collected from 355 (73%) current windblade workers and regression analysis, we investigated associations between health outcomes and styrene exposure estimates derived from urinary styrene metabolites. Results The median current styrene exposure was 53.6 mg/g creatinine (interquartile range: 19.5–94.4). Color blindness in men and women (standardized morbidity ratios 2.3 and 16.6, respectively) was not associated with exposure estimates, but was the type previously reported with styrene. Visual contrast sensitivity decreased and chest tightness increased (odds ratio 2.9) with increasing current exposure. Decreases in spirometric parameters and FeNO, and increases in the odds of wheeze and asthma-like symptoms (odds ratios 1.3 and 1.2, respectively) occurred with increasing cumulative exposure. Conclusions Despite styrene exposures below the recommended 400 mg/g creatinine, visual and respiratory effects indicate the need for additional preventative measures in this industry. PMID:26305283

  8. Ordered, microphase-separated, noncharged-charged diblock copolymers via the sequential ATRP of styrene and styrenic imidazolium monomers

    SciTech Connect

    Shi, ZX; Newell, BS; Bailey, TS; Gin, DL

    2014-12-15

    A series of imidazolium-based noncharged-charged diblock copolymers (1) was synthesized by the direct, sequential ATRP of styrene and styrenic imidazolium bis(trifluoromethyl)sulfonamide monomers with methyl, n-butyl, and n-decyl side-chains. Small-angle X-ray scattering studies on initial examples of 1 with a total of 50 repeat units and styrene:imidazolium-styrene repeat unit ratios of 25:25, 20:30, and 15:35 showed that their ability to form ordered nanostructures (i.e., sphere and cylinder phases) in their neat states depends on both the block ratio and the length of the alkyl side-chain on the imidazolium monomer. To our knowledge, the synthesis of imidazolium-based BCPs that form ordered, phase-separated nanostructures via direct ATRP of immiscible co-monomers is unprecedented. (C) 2014 Elsevier Ltd. All rights reserved.

  9. High throughput HPLC-ESI(-)-MS/MS methodology for mercapturic acid metabolites of 1,3-butadiene: Biomarkers of exposure and bioactivation.

    PubMed

    Kotapati, Srikanth; Esades, Amanda; Matter, Brock; Le, Chap; Tretyakova, Natalia

    2015-11-05

    1,3-Butadiene (BD) is an important industrial and environmental carcinogen present in cigarette smoke, automobile exhaust, and urban air. The major urinary metabolites of BD in humans are 2-(N-acetyl-L-cystein-S-yl)-1-hydroxybut-3-ene/1-(N-acetyl-L-cystein-S-yl)-2-hydroxybut-3-ene (MHBMA), 4-(N-acetyl-L-cystein-S-yl)-1,2-dihydroxybutane (DHBMA), and 4-(N-acetyl-L-cystein-S-yl)-1,2,3-trihydroxybutyl mercapturic acid (THBMA), which are formed from the electrophilic metabolites of BD, 3,4-epoxy-1-butene (EB), hydroxymethyl vinyl ketone (HMVK), and 3,4-epoxy-1,2-diol (EBD), respectively. In the present work, a sensitive high-throughput HPLC-ESI(-)-MS/MS method was developed for simultaneous quantification of MHBMA and DHBMA in small volumes of human urine (200 μl). The method employs a 96 well Oasis HLB SPE enrichment step, followed by isotope dilution HPLC-ESI(-)-MS/MS analysis on a triple quadrupole mass spectrometer. The validated method was used to quantify MHBMA and DHBMA in urine of workers from a BD monomer and styrene-butadiene rubber production facility (40 controls and 32 occupationally exposed to BD). Urinary THBMA concentrations were also determined in the same samples. The concentrations of all three BD-mercapturic acids and the metabolic ratio (MHBMA/(MHBMA+DHBMA+THBMA)) were significantly higher in the occupationally exposed group as compared to controls and correlated with BD exposure, with each other, and with BD-hemoglobin biomarkers. This improved high throughput methodology for MHBMA and DHBMA will be useful for future epidemiological studies in smokers and occupationally exposed workers.

  10. Thermo Stability of Highly Sulfonated Poly(Styrene-Isobutylene-Styrene) Block Copolymers: Effects of Sulfonation and Counter-Ion Substitution

    DTIC Science & Technology

    2008-01-01

    poly(styrene-isobutylene- styrene) (SIBS) tri-block co-polymer (2, 3). The major component of the tri-block co-polymer is polyisobutylene ( PIB ...which comprises 70% by weight of the base polymer. The PIB gives the material low temperature flexibility as well as excellent barrier properties. The... PIB matrix (4). The fraction of PS controls the resultant morphology, which can be for example cylinders, lamellae, spheres, or a complex mixture

  11. Optimization of injection molding parameters for poly(styrene-isobutylene-styrene) block copolymer

    NASA Astrophysics Data System (ADS)

    Fittipaldi, Mauro; Garcia, Carla; Rodriguez, Luis A.; Grace, Landon R.

    2016-03-01

    Poly(styrene-isobutylene-styrene) (SIBS) is a widely used thermoplastic elastomer in bioimplantable devices due to its inherent stability in vivo. However, the properties of the material are highly dependent on the fabrication conditions, molecular weight, and styrene content. An optimization method for injection molding is herein proposed which can be applied to varying SIBS formulations in order to maximize ultimate tensile strength, which is critical to certain load-bearing implantable applications. The number of injection molded samples required to ascertain the optimum conditions for maximum ultimate tensile strength is limited in order to minimize experimental time and effort. Injection molding parameters including nozzle temperature (three levels: 218, 246, and 274 °C), mold temperature (three levels: 50, 85, and 120 °C), injection speed (three levels: slow, medium and fast) and holding pressure time (three levels: 2, 6, and 10 seconds) were varied to fabricate dumbbell specimens for tensile testing. A three-level L9 Taguchi method utilizing orthogonal arrays was used in order to rank the importance of the different injection molding parameters and to find an optimal parameter setting to maximize the ultimate tensile strength of the thermoplastic elastomer. Based on the Taguchi design results, a Response Surface Methodology (RSM) was applied in order to build a model to predict the tensile strength of the material at different injection parameters. Finally, the model was optimized to find the injection molding parameters providing maximum ultimate tensile strength. Subsequently, the theoretically-optimum injection molding parameters were used to fabricate additional dumbbell specimens. The experimentally-determined ultimate tensile strength of these samples was found to be in close agreement (1.2%) with the theoretical results, successfully demonstrating the suitability of the Taguchi Method and RSM for optimizing injection molding parameters of SIBS.

  12. Fire and Flammability Characteristics of Materials Used in Rail Passenger Cars. A Literature Survey.

    DTIC Science & Technology

    1980-04-01

    materials investigated were vinyls, acrylics, acrylonitrile- butadiene-styrene (ABS) resins, aromatic polyamides , polyimides, poly- carbonate, polysulfone...thermochemistry of an aromatic polyamide fabric used in the interiors of commercial jet aircraft. It was intended to identify the products produced during...861. N. Einhorn, D. A. Chatfield, and R. W. Mickelson, "Analysis of the Products of Thermal Decomposition of an Aromatic Polyamide Fabric Used as an

  13. The relative fire resistance of select thermoplastic materials. [for aircraft interiors

    NASA Technical Reports Server (NTRS)

    Kourtides, D. A.; Parker, J. A.

    1978-01-01

    The relative thermal stability, flammability, and related thermochemical properties of some thermoplastic materials currently used in aircraft interiors as well as of some candidate thermoplastics were investigated. Currently used materials that were evaluated include acrylonitrile butadiene styrene, bisphenol A polycarbonate, polyphenylene oxide, and polyvinyl fluoride. Candidate thermoplastic materials evaluated include: 9,9-bis(4-hydroxyphenyl)fluorene polycarbonate-poly(dimethylsiloxane) block polymer, chlorinated polyvinylchloride homopolymer, phenolphthalein polycarbonate, polyethersulfone, polyphenylene sulfide, polyarylsulfone, and polyvinylidene fluoride.

  14. Toxicity of Pyrolysis Gases from Elastomers

    NASA Technical Reports Server (NTRS)

    Hilado, Carlos J.; Kosola, Kay L.; Solis, Alida N.; Kourtides, Demetrius A.; Parker, John A.

    1977-01-01

    The toxicity of the pyrolysis gases from six elastomers was investigated. The elastomers were polyisoprene (natural rubber), styrene-butadiene rubber (SBR), ethylene propylene diene terpolymer (EPDM), acrylonitrile rubber, chlorosulfonated polyethylene rubber, and polychloroprene. The rising temperature and fixed temperature programs produced exactly the same rank order of materials based on time to death. Acryltonitrile rubber exhibited the greatest toxicity under these test conditions; carbon monoxide was not found in sufficient concentrations to be the primary cause of death.

  15. Determination of Cd and Cr in an ABS candidate reference material by instrumental neutron activation analysis.

    PubMed

    Park, Kwangwon; Kang, Namgoo; Cho, Kyunghaeng; Lee, Jounghae

    2008-12-01

    In order to practically better cope with technical barriers to trade (TBT) of a great number of resin goods, our research presents first-ever results for the determination of Cd and Cr in acrylonitrile butadiene styrene (ABS) candidate reference material using instrumental neutron activation analysis (INAA) recently recognized as a candidate primary ratio method with a particular attention to the estimation of involved measurement uncertainties.

  16. Immunohistochemical characterization of spontaneous and acrylonitrile-induced brain tumors in the rat.

    PubMed

    Kolenda-Roberts, Holly Meredith; Harris, Nancy; Singletary, Emily; Hardisty, Jerry F

    2013-01-01

    Twenty-eight spontaneously occurring glial tumors (previously diagnosed as astrocytomas, oligodendrogliomas, and gliomas) and eleven granular cell tumors (GCTs) were selected for evaluation using a panel of immunohistochemistry (IHC) stains (Ricinus communis agglutinin type 1 [RCA-1], ionized calcium-binding adapter molecule 1 [Iba-1], OX-6/major immunohistocompatibility complex class II, oligodendrocytes transcription factor 2 [Olig2], glial fibrillary acidic protein [GFAP], S100 beta, glutamine synthetase, neurofilament, proliferating cell nuclear antigen). In addition, nine brain tumors from a 2-year drinking water study for acrylonitrile were obtained from the Acrylonitrile Group, Inc. Based on IHC staining characteristics, Olig2+ oligodendrogliomas were the most commonly diagnosed spontaneous tumor in these animals. Many of the spontaneous tumors previously diagnosed as astrocytomas were RCA-1+, Iba-1+ and negative for GFAP, S100beta, and glutamine synthetase; the diagnosis of malignant microglial tumor is proposed for these neoplasms. Three mixed tumors were identified with Olig2+ (oligodendrocytes) and Iba-1+ (macrophage/microglia) cell populations. The term mixed glioma is not recommended for these tumors, as it is generally used to refer to oligoastrocytomas, which were not observed in this study. GCT were positive for RCA-1 and Iba-1. All acrylonitrile tumors were identified as malignant microglial tumors. These results may indicate that oligodendrogliomas are more common as spontaneous tumors, while acrylonitrile-induced neoplasms are microglial/histiocytic in origin. No astrocytomas (GFAP, S100 beta, and/or glutamine synthetase-positive neoplasms) were observed.

  17. ABSORPTION OF CO2 AND SUBSEQUENT VISCOSITY REDUCTION OF AN ACRYLONITRILE COPOLYMER. (R829555)

    EPA Science Inventory

    Acrylonitrile (AN) copolymers (AN content greater than about 85 mol%) are traditionally solution processed to avoid a cyclization and crosslinking reaction that takes place at temperatures where melt processing would be feasible. It is well known that carbon dioxide (CO

  18. Glutathione transferases and glutathionylated hemoglobin in workers exposed to low doses of 1,3-butadiene.

    PubMed

    Primavera, Alessandra; Fustinoni, Silvia; Biroccio, Antonino; Ballerini, Sabrina; Urbani, Andrea; Bernardini, Sergio; Federici, Giorgio; Capucci, Enrico; Manno, Maurizio; Lo Bello, Mario

    2008-11-01

    We evaluated glutathione transferase (GST) activities and the levels of glutathionylated hemoglobin in the RBC of 42 workers exposed to 1,3-butadiene in a petrochemical plant, using 43 workers not exposed to 1,3-butadiene and 82 foresters as internal and external controls, respectively. Median 1,3-butadiene exposure levels were 1.5, 0.4, and 0.1 microg/m3 in 1,3-butadiene-exposed workers, in workers not directly exposed to 1,3-butadiene, and in foresters, respectively. In addition, we determined in the peripheral blood lymphocytes of the same individuals the presence of GST polymorphic genes GSTT1 and GSTM1 and the distribution of GSTP1 allelic variants. Comparing the mean values observed in petrochemical workers with those of control foresters, we found a marked decrease of GST enzymatic activity and a significant increase of glutathionylated hemoglobin in the petrochemical workers. A weak but significant negative correlation was found between levels of 1,3-butadiene exposure and GST activity, whereas a positive correlation was found between 1,3-butadiene exposure and glutathionylated hemoglobin. A negative correlation was also observed between GST activity and glutathionylated hemoglobin. No influence of confounders was observed. Using a multiple linear regression model, up to 50.6% and 41.9% of the variability observed in glutathionylated hemoglobin and GST activity, respectively, were explained by 1,3-butadiene exposure, working setting, and GSTT1 genotype. These results indicate that occupational exposure to 1,3-butadiene induces an oxidative stress that impairs the GST balance in RBC, and suggest that GST activity and glutathionylated hemoglobin could be recommended as promising biomarkers of effect in petrochemical workers.

  19. Induction of oxidative stress in rat brain by acrylonitrile (ACN).

    PubMed

    Jiang, J; Xu, Y; Klaunig, J E

    1998-12-01

    Chronic treatment with acrylonitrile (ACN) has been shown to produce a dose-related increase in glial cell tumors (astrocytomas) in rats. The mechanism(s) for ACN-induced carcinogenicity remains unclear. While ACN has been reported to induce DNA damage in a number of short-term systems, evidence for a genotoxic mechanism of tumor induction is the brain is not strong. Other toxic mechanisms appear to participate in the induction of tumor or induce the astrocytomas solely. In particular, nongenotoxic mechanisms of carcinogen induction have been implicated in this ACN-induced carcinogenic effect in the rat brain. One major pathway of ACN metabolism is through glutathione (GSH) conjugation. Extensive utilization and depletion of GSH, an important intracellular antioxidant, by ACN may lead to cellular oxidative stress. The present study examined the ability of ACN to induce oxidative stress in male Sprague-Dawley rats. Rats were administered ACN at concentrations of 0, 5, 10, 100, or 200 ppm in the drinking water and sampled after 14, 28, or 90 days of continuous treatment. Oxidative DNA damage indicated by the presence of 8-hydroxy-2'-deoxyguanosine (OH8dG) and lipid peroxidation indicated by the presence of malondialdehyde (MDA), a lipid peroxidation product, in rat brains and livers were examined. The levels of reactive oxygen species (ROS) were also determined in different rat tissues. Both the levels of nonenzymatic antioxidants (GSH, vitamin E) and the activities of enzymatic antioxidants (catalase, superoxide dismutase, glutathione peroxidase) in rat brains and livers were measured. Increased levels of OH8dG, MDA, and ROS were found in the brains of ACN-treated rats. Decreased levels of GSH and activities of catalase and SOD were also observed in the brains of ACN-treated rats compared to the control group. Interestingly, there were no changes of these indicators of oxidative stress in the livers of ACN-treated rats. Rat liver is not a target for ACN

  20. Controlled polymerization of acrylonitrile proceeded along with the Belousov-Zhabotinsky oscillator by changing its stirring conditions

    NASA Astrophysics Data System (ADS)

    Furue, Yuuka; Okano, Kunihiko; Banno, Taisuke; Asakura, Kouichi

    2016-02-01

    Chemical oscillations of the manganese-ion catalyzed Belousov-Zhabotinsky (BZ) reaction system were found to be controlled by changing its stirring conditions. The oscillation stopped at a high stirring rate, while it reappeared immediately by reducing the stirring rate. It is known in the BZ reaction system, that the radical polymerization takes place along with the oscillation when acrylic monomers are added. By the addition of acrylonitrile to the system stirred at a high stirring rate, the oscillation as well as the polymerization of acrylonitrile stopped. The radical polymerization of acrylonitrile by the BZ oscillator is thus found to be made controllable by changing the mixing conditions.

  1. Neuropharmacological and cochleotoxic effects of styrene. Consequences on noise exposures.

    PubMed

    Campo, Pierre; Venet, Thomas; Thomas, Aurélie; Cour, Chantal; Brochard, Céline; Cosnier, Frédéric

    2014-01-01

    Occupational noise exposure can damage workers' hearing, particularly when combined with exposure to cochleotoxic chemicals such as styrene. Although styrene-induced cochlear impairments only become apparent after a long incubation period, the pharmacological impact of styrene on the central nervous system (CNS) can be rapidly measured by determining the threshold of the middle-ear acoustic reflex (MER) trigger. The aim of the study was to evaluate the effects of a noise (both continuous and impulse), and a low concentration of styrene [300ppm<(threshold limit value×10) safety factor] on the peripheral auditory receptor, and on the CNS in rats. The impact of the different conditions on hearing loss was assessed using distortion product oto-acoustic emissions, and histological analysis of cochleae. Although the LEX,8h (8-hour time-weighted average exposure) of the impulse noise was lower (80dB SPL sound pressure level) than that of the continuous noise (85dB SPL), it appeared more detrimental to the peripheral auditory receptors. A co-exposure to styrene and continuous noise was less damaging than exposure to continuous noise alone. In contrast, the traumatic effects of impulse noise on the organ of Corti were enhanced by co-exposure to styrene. The pharmacological effects of the solvent on the CNS were discussed to put forward a plausible explanation of these surprising results. We hypothesize that CNS effects of styrene may account for this apparent paradox. Based on the present results, the temporal structure of the noise should be reintroduced as a key parameter in hearing conservation regulations.

  2. Effect of heating rate on toxicity of pyrolysis gases from some elastomers

    NASA Technical Reports Server (NTRS)

    Hilado, C. J.; Kosola, K. L.; Solis, A. N.

    1977-01-01

    The effect of heating rate on the toxicity of the pyrolysis gases from six elastomers was investigated, using a screening test method. The elastomers were polyisoprene (natural rubber), styrene-butadiene rubber (SBR), ethylene propylene diene terpolymer (EPDM), acrylonitrile rubber, chlorosulfonated polyethylene rubber, and polychloroprene. The rising temperature and fixed temperature programs produced exactly the same rank order of materials based on time to death. Acrylonitrile rubber exhibited the greatest toxicity under these test conditions, and carbon monoxide was not found in sufficient concentrations to be the primary cause of death.

  3. The use of poly(styrene-block-isobutylene-block-styrene) as a microshunt to treat glaucoma

    PubMed Central

    Pinchuk, Leonard; Riss, Isabelle; Batlle, Juan F.; Kato, Yasushi P.; Martin, John B.; Arrieta, Esdras; Palmberg, Paul; Parrish, Richard K.; Weber, Bruce A.; Kwon, Yongmoon; Parel, Jean-Marie

    2016-01-01

    The InnFocus MicroShunt® is a minimally invasive glaucoma drainage microtube used to shunt aqueous humor from the anterior chamber of the eye to a flap formed under the conjunctiva and Tenon’s capsule. The safety and clinical performance of this device approaches that of trabeculectomy with mitomycin C, the current ‘gold standard’ treatment for advanced glaucoma. The invention of a new biomaterial called poly(styrene-block-isobutylene-block-styrene) or ‘SIBS’ is the enabling factor which led to the success of this product. SIBS is ultrastable with virtually no foreign body reaction in the body, which manifests as clinically insignificant inflammation and capsule formation in the eye. The lack of capsule formation enables unobstructed flow through the 70 µm lumen tube and the achievement of controlled low intraocular pressure, which is important for the management of glaucoma. This article summarizes the integration of SIBS into a glaucoma drainage device and confirms its functionality with clinical success over a 2-year period. PMID:27047682

  4. Morphological and physical characterization of poly(styrene-isobutylene-styrene) block copolymers and ionomers thereof

    NASA Astrophysics Data System (ADS)

    Baugh, Daniel Webster, III

    Poly(styrene-isobutylene-styrene) block copolymers made by living cationic polymerization using a difunctional initiator and the sequential monomer addition technique were analyzed using curve-resolution software in conjunction with high-resolution GPC. Fractional precipitation and selective solvent extraction were applied to a representative sample in order to confirm the identity of contaminating species. The latter were found to be low molecular weight polystyrene homopolymer, diblock copolymer, and higher molecular weight segmented block copolymers formed by intermolecular electrophilic aromatic substitution linking reactions occurring late in the polymerization of the styrene outer blocks. Solvent-cast films of poly(styrene-isobutylene-styrene) (PS-PIB-PS) block copolymers and block ionomers were analyzed using small-angle X-ray scattering (SAXS) and transmission electron microscopy (TEM). Four block copolymer samples with center block molecular weights of 52,000 g/mol and PS volume fractions (o sbPS) ranging from 0.17 to 0.31 were studied. All samples exhibited hexagonally packed cylinders of PS within the PIB matrix. Cylinder spacing was in the range 32 to 36 nm for most samples, while cylinder diameters varied from 14 to 21 nm. Porod analysis of the scattering data indicated the presence of isolated phase mixing and sharp phase boundaries. PS-PIB-PS block copolymers and ionomers therefrom were analyzed using dynamic mechanical analysis (DMA) and tensile testing. The study encompassed five block copolymer samples with similar PIB center blocks with molecular weights of approx52,000 g/mol and PS weight fractions ranging from 0.127 to 0.337. Ionomers were prepared from two of these materials by lightly sulfonating the PS outer blocks. Sulfonation levels varied from 1.7 to 4.7 mol % and the sodium and potassium neutralized forms were compared to the parent block copolymers. Dynamic mechanical analysis (DMA) of the block copolymer films indicated the existence

  5. Production of biorenewable styrene: utilization of biomass-derived sugars and insights into toxicity.

    PubMed

    Lian, Jieni; McKenna, Rebekah; Rover, Marjorie R; Nielsen, David R; Wen, Zhiyou; Jarboe, Laura R

    2016-05-01

    Fermentative production of styrene from glucose has been previously demonstrated in Escherichia coli. Here, we demonstrate the production of styrene from the sugars derived from lignocellulosic biomass depolymerized by fast pyrolysis. A previously engineered styrene-producing strain was further engineered for utilization of the anhydrosugar levoglucosan via expression of levoglucosan kinase. The resulting strain produced 240 ± 3 mg L(-1) styrene from pure levoglucosan, similar to the 251 ± 3 mg L(-1) produced from glucose. When provided at a concentration of 5 g L(-1), pyrolytic sugars supported styrene production at titers similar to those from pure sugars, demonstrating the feasibility of producing this important industrial chemical from biomass-derived sugars. However, the toxicity of contaminant compounds in the biomass-derived sugars and styrene itself limit further gains in production. Styrene toxicity is generally believed to be due to membrane damage. Contrary to this prevailing wisdom, our quantitative assessment during challenge with up to 200 mg L(-1) of exogenously provided styrene showed little change in membrane integrity; membrane disruption was observed only during styrene production. Membrane fluidity was also quantified during styrene production, but no changes were observed relative to the non-producing control strain. This observation that styrene production is much more damaging to the membrane integrity than challenge with exogenously supplied styrene provides insight into the mechanism of styrene toxicity and emphasizes the importance of verifying proposed toxicity mechanisms during production instead of relying upon results obtained during exogenous challenge.

  6. (η(4)-Butadiene)Sn(0) Complexes: A New Approach for Zero-Valent p-Block Elements Utilizing a Butadiene as a 4π-Electron Donor.

    PubMed

    Kuwabara, Takuya; Nakada, Marisa; Hamada, Jumpei; Guo, Jing Dong; Nagase, Shigeru; Saito, Masaichi

    2016-09-07

    Research on zero-valent p-block elements is a recent hot topic in synthetic and theoretical chemistry because of their novel electronic states having two lone pairs in both the s- and p-orbitals. It is considered that σ-donating ligands bearing large substituents are essential to stabilize these species. Herein, we propose a new approach using butadiene as a 4π-electron donor to stabilize zero-valent group 14 elements. During our study to explore the coordination chemistry of stannacyclopentadienyl ligands, unexpected products, in which the tin atom is coordinated by a butadiene in a η(4)-fashion, were obtained. Because butadiene is a neutral 4π-electron donating ligand, the formal oxidation number of the tin atoms of the products should be zero, which is supported by X-ray diffraction analysis and theoretical calculations. A mechanism for the formation of the products is also described.

  7. hprt mutant lymphocyte frequencies in workers at a 1,3-butadiene production plant.

    PubMed Central

    Ward, J B; Ammenheuser, M M; Bechtold, W E; Whorton, E B; Legator, M S

    1994-01-01

    1,3-Butadiene is a major industrial chemical that has been shown to be a carcinogen at multiple sites in mice and rats at concentrations as low as 6.25 ppm. Occupational exposures have been reduced in response to these findings, but it may not be possible to determine by using traditional epidemiological methods, whether current exposure levels are adequate for protection of worker health. However, it is possible to evaluate the biological significance of exposure to genotoxic chemicals at the time of exposure by measuring levels of genetic damage in exposed populations. We have conducted a pilot study to evaluate the effects of butadiene exposure on the frequencies of lymphocytes containing mutations at the hypoxanthine-guanine phosphoribosyl transferase (hprt) locus in workers in a butadiene production plant. At the same time, urine specimens from the same individuals were collected and evaluated for the presence of butadiene-specific metabolites. Eight workers from areas of the plant where the highest exposures to butadiene occur were compared to five workers from plant areas where butadiene exposures were low. In addition, six subjects with no occupational exposure to butadiene were also studied as outside controls. All of the subjects were nonsmokers. An air sampling survey conducted for 6 months, and ending about 3 months before the study, indicated that average butadiene levels in the air of the high-exposure areas were about 3.5 +/- 7.5 ppm. They were 0.03 +/- 0.03 ppm in the low-exposure areas. Peripheral blood lymphocytes from the subjects were assayed using an autoradiographic test for hprt mutations.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7698091

  8. Cesium promotion in styrene epoxidation on silver catalysts.

    PubMed

    Zhou, Ling; Gorin, Craig F; Madix, Robert J

    2010-01-20

    The adsorption of a small amount of cesium on Ag(110) redirects the partial oxidation products of styrene from phenylacetaldehyde and phenylketene to styrene oxide. The cesium stabilizes the oxametallacycle intermediate and hinders its transformation to the intermediate that leads to the other products. Cesium does not appear to create any electronic effects on the bonding of the intermediates. Low coverages of cesium induce a (1 x 2) missing-row reconstruction of the entire clean Ag(110) surface and a (3 x 5) surface oxide structure on the cesium-reconstructed Ag(110) surface. This (3 x 5)-ordered surface oxide is superimposed on the Ag(111) microfacets produced by the cesium-induced reconstruction, which leads to selectivity and reactivity very similar to those of the extended (111) surface. These studies provide insight into the microscopic origins of the structural effects of cesium in styrene epoxidation on silver catalysts.

  9. Evaluation of a liquid chemical scrubber system for styrene removal

    SciTech Connect

    Felix, L.; Merritt, R.; Williamson, A.

    1994-12-01

    The report gives results of a study of the styrene removal efficiency of a pilot-scale version of the QUAD Chemtact scrubber, quantified by continuously measuring the total hydrocarbon (THC) content of spray booth exhaust air entering and exiting the device with THC analyzers and, for some tests, by collecting EPA Method 18 samples (adsorption tube procedure) at the inlet and exit of the device. Average styrene removal efficiencies approached but were never >55%. The test was carried out at a facility (Eljer Plumbingware in Wilson, NC) that manufactures polyester bathtubs and shower stalls by spraying styrene-based resins onto molds in vented, open spray booths. A side stream of air, exhausted from one of the spray booths in the gel coating part of the process, was used for the test.

  10. 21 CFR 573.870 - Poly(2-vinylpyridine-co-styrene).

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Poly(2-vinylpyridine-co-styrene). 573.870 Section... ANIMALS Food Additive Listing § 573.870 Poly(2-vinylpyridine-co-styrene). The food additive poly(2-vinylpyridine-co-styrene) may be safely used as nutrient protectant in feed for beef cattle and dairy cattle...

  11. 21 CFR 573.870 - Poly(2-vinylpyridine-co-styrene).

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Poly(2-vinylpyridine-co-styrene). 573.870 Section... ANIMALS Food Additive Listing § 573.870 Poly(2-vinylpyridine-co-styrene). The food additive poly(2-vinylpyridine-co-styrene) may be safely used as nutrient protectant in feed for beef cattle and dairy cattle...

  12. 21 CFR 573.870 - Poly(2-vinylpyridine-co-styrene).

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Poly(2-vinylpyridine-co-styrene). 573.870 Section... ANIMALS Food Additive Listing § 573.870 Poly(2-vinylpyridine-co-styrene). The food additive poly(2-vinylpyridine-co-styrene) may be safely used as nutrient protectant in feed for beef cattle and dairy cattle...

  13. 21 CFR 573.870 - Poly(2-vinylpyridine-co-styrene).

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Poly(2-vinylpyridine-co-styrene). 573.870 Section... ANIMALS Food Additive Listing § 573.870 Poly(2-vinylpyridine-co-styrene). The food additive poly(2-vinylpyridine-co-styrene) may be safely used as nutrient protectant in feed for beef cattle and dairy cattle...

  14. 21 CFR 573.870 - Poly(2-vinylpyridine-co-styrene).

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Poly(2-vinylpyridine-co-styrene). 573.870 Section... ANIMALS Food Additive Listing § 573.870 Poly(2-vinylpyridine-co-styrene). The food additive poly(2-vinylpyridine-co-styrene) may be safely used as nutrient protectant in feed for beef cattle and dairy cattle...

  15. 40 CFR 721.9492 - Polymers of styrene, cyclohexyl methacrylate and substituted methacrylate.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Polymers of styrene, cyclohexyl... Significant New Uses for Specific Chemical Substances § 721.9492 Polymers of styrene, cyclohexyl methacrylate...) The chemical substances identified generically as polymers of styrene, cyclohexyl methacrylate...

  16. 40 CFR 721.9492 - Polymers of styrene, cyclohexyl methacrylate and substituted methacrylate.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Polymers of styrene, cyclohexyl... Significant New Uses for Specific Chemical Substances § 721.9492 Polymers of styrene, cyclohexyl methacrylate...) The chemical substances identified generically as polymers of styrene, cyclohexyl methacrylate...

  17. 40 CFR 721.9492 - Polymers of styrene, cyclohexyl methacrylate and substituted methacrylate.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Polymers of styrene, cyclohexyl... Significant New Uses for Specific Chemical Substances § 721.9492 Polymers of styrene, cyclohexyl methacrylate...) The chemical substances identified generically as polymers of styrene, cyclohexyl methacrylate...

  18. 40 CFR 721.9492 - Polymers of styrene, cyclohexyl methacrylate and substituted methacrylate.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Polymers of styrene, cyclohexyl... Significant New Uses for Specific Chemical Substances § 721.9492 Polymers of styrene, cyclohexyl methacrylate... generically as polymers of styrene, cyclohexyl methacrylate and substituted methacrylate (PMNs...

  19. 40 CFR 721.9492 - Polymers of styrene, cyclohexyl methacrylate and substituted methacrylate.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Polymers of styrene, cyclohexyl... Significant New Uses for Specific Chemical Substances § 721.9492 Polymers of styrene, cyclohexyl methacrylate...) The chemical substances identified generically as polymers of styrene, cyclohexyl methacrylate...

  20. POTENTIAL FOR REDUCING STYRENE EXPOSURES FROM COPIED PAPER THROUGH USE OF LOW-EMITTING TONERS

    EPA Science Inventory

    The paper reports results of tests, conducted using 53-L chambers to determine styrene emission rates from freshly copied paper produced on a single photocopier using two toners manufactured for the copier having different styrene contents. Copied-paper styrene emissions with bot...

  1. 40 CFR 721.3800 - Formaldehyde, condensated polyoxyethylene fatty acid, ester with styrenated phenol, ethylene...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... polyoxyethylene fatty acid, ester with styrenated phenol, ethylene oxide adduct. 721.3800 Section 721.3800... Formaldehyde, condensated polyoxyethylene fatty acid, ester with styrenated phenol, ethylene oxide adduct. (a... generically as formaldehyde, condensated polyoxyethylene fatty acid, ester with styrenated phenol,...

  2. 40 CFR 721.3800 - Formaldehyde, condensated polyoxyethylene fatty acid, ester with styrenated phenol, ethylene...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... polyoxyethylene fatty acid, ester with styrenated phenol, ethylene oxide adduct. 721.3800 Section 721.3800... Formaldehyde, condensated polyoxyethylene fatty acid, ester with styrenated phenol, ethylene oxide adduct. (a... generically as formaldehyde, condensated polyoxyethylene fatty acid, ester with styrenated phenol,...

  3. 40 CFR 721.3800 - Formaldehyde, condensated polyoxyethylene fatty acid, ester with styrenated phenol, ethylene...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... polyoxyethylene fatty acid, ester with styrenated phenol, ethylene oxide adduct. 721.3800 Section 721.3800... Formaldehyde, condensated polyoxyethylene fatty acid, ester with styrenated phenol, ethylene oxide adduct. (a... generically as formaldehyde, condensated polyoxyethylene fatty acid, ester with styrenated phenol,...

  4. 40 CFR 721.3800 - Formaldehyde, condensated polyoxyethylene fatty acid, ester with styrenated phenol, ethylene...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... polyoxyethylene fatty acid, ester with styrenated phenol, ethylene oxide adduct. 721.3800 Section 721.3800... Formaldehyde, condensated polyoxyethylene fatty acid, ester with styrenated phenol, ethylene oxide adduct. (a... generically as formaldehyde, condensated polyoxyethylene fatty acid, ester with styrenated phenol,...

  5. 40 CFR 721.3800 - Formaldehyde, condensated polyoxyethylene fatty acid, ester with styrenated phenol, ethylene...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... polyoxyethylene fatty acid, ester with styrenated phenol, ethylene oxide adduct. 721.3800 Section 721.3800... Formaldehyde, condensated polyoxyethylene fatty acid, ester with styrenated phenol, ethylene oxide adduct. (a... generically as formaldehyde, condensated polyoxyethylene fatty acid, ester with styrenated phenol,...

  6. Bioconversion of acrylonitrile to acrylamide using polyacrylamide entrapped cells of Rhodococcus rhodochrous PA-34.

    PubMed

    Raj, J; Prasad, S; Sharma, N N; Bhalla, T C

    2010-09-01

    The nitrile hydratase (NHase) of Rhodococcus rhodochrous PA-34 catalyzed the conversion of acrylonitrile to acrylamide. The resting cells (having NHase activity) (8 %; 1 mL corresponds to 22 mg dry cell mass, DCM) were immobilized in polyacrylamide gel containing 12.5 % acrylamide, 0.6 % bisacrylamide, 0.2 % diammonium persulfate and 0.4 % TEMED. The polyacrylamide entrapped cells (1.12 mg DCM/mL) completely converted acrylonitrile in 3 h at 10 °C, using 0.1 mol/L potassium phosphate buffer. In a partitioned fed batch reactor, 432 g/L acrylamide was accumulated after 1 d. The polyacrylamide discs were recycled up to 3×; 405, 210 and 170 g/L acrylamide was produced in 1st, 2nd and 3rd recycling reactions. In four cycles, a total of 1217 g acrylamide was produced by recycling the same mass of entrapped cells.

  7. Urinary excretion of the acrylonitrile metabolite 2-cyanoethylmercapturic acid is correlated with a variety of biomarkers of tobacco smoke exposure and consumption.

    PubMed

    Minet, Emmanuel; Cheung, Francis; Errington, Graham; Sterz, Katharina; Scherer, Gerhard

    2011-02-01

    Acrylonitrile is an IARC class 2B carcinogen present in cigarette smoke. Urinary 2-cyanoethylmercapturic acid (CEMA) is an acrylonitrile metabolite and a potential biomarker for acrylonitrile exposure. The objective of this work was to study the dose response of CEMA in urine of non-smokers and smokers of different ISO tar yield cigarettes. We observed that smokers excreted >100-fold higher amounts of urinary CEMA than non-smokers. The CEMA levels in smokers were significantly correlated with ISO tar yield, daily cigarette consumption, and urinary biomarkers of smoke exposure. In conclusion, urinary CEMA is a suitable biomarker for assessing smoking-related exposure to acrylonitrile.

  8. Urinary excretion of the acrylonitrile metabolite 2-cyanoethylmercapturic acid is correlated with a variety of biomarkers of tobacco smoke exposure and consumption

    PubMed Central

    Minet, Emmanuel; Cheung, Francis; Errington, Graham; Sterz, Katharina; Scherer, Gerhard

    2011-01-01

    Acrylonitrile is an IARC class 2B carcinogen present in cigarette smoke. Urinary 2-cyanoethylmercapturic acid (CEMA) is an acrylonitrile metabolite and a potential biomarker for acrylonitrile exposure. The objective of this work was to study the dose response of CEMA in urine of non-smokers and smokers of different ISO tar yield cigarettes. We observed that smokers excreted >100-fold higher amounts of urinary CEMA than non-smokers. The CEMA levels in smokers were significantly correlated with ISO tar yield, daily cigarette consumption, and urinary biomarkers of smoke exposure. In conclusion, urinary CEMA is a suitable biomarker for assessing smoking-related exposure to acrylonitrile. PMID:21108560

  9. Three-generation reproduction study of rats receiving acrylonitrile in drinking water.

    PubMed

    Friedman, M A; Beliles, R P

    2002-06-24

    Acrylonitrile, a high volume organic chemical, was tested for reproductive effects in a three generation drinking water study with two matings per generation. Sprague-Dawley rats were exposed to acrylonitrile in drinking water at 0, 100, or 500 ppm. This corresponds to 0, 11+/-5 and 37+/-10 mg/kg, respectively, for males and 0, 20+/-3 and 40+/-8 mg/kg per day for the females, respectively. Water consumption was reduced in F0 rats in the 100 and 500 ppm groups. At 500 ppm, acrylonitrile reduced body weight gain and food intake of the first generation parental rats (F0). These parameters were not investigated at subsequent generations. The pup survival (both viability and lactation indices) was reduced at the 500 ppm treatment level in both matings of all three generations. Fostering the 500 ppm pups onto untreated mothers following the second mating lessened mortality, suggesting a maternal effect consistent with decreased water consumption. There was no remarkable change in the reproductive capacity in any of matings in rats at the 100 ppm concentration. In contrast, in all three generations, the body weights of the pups of the 500 ppm treatment level were reduced on Day 21 at both matings. No adverse findings were observed in the tissues of a limited number of third generation weanlings (F3b) upon gross and microscopic evaluation. No effect on the sciatic nerve was evident among the adult female rats held for 20 weeks after weaning of the second litter. There was a dose-related effect of acrylonitrile on gross masses in female rats at each parental generation held 20 weeks after the weaning of the second litter. Histopathological evaluation of these dams showed an increase in astrocytomas and zymbal gland tumors.

  10. Sorption studies on Cr (VI) removal from aqueous solution using cellulose grafted with acrylonitrile monomer.

    PubMed

    Hajeeth, T; Sudha, P N; Vijayalakshmi, K; Gomathi, T

    2014-05-01

    Graft copolymerization of acrylonitrile on to cellulosic material derived from sisal fiber can be initiated effectively with ceric ammonium nitrate. The grafting conditions were optimized by changing the concentration of initiator and monomer. The change in crystallinity of the grafted polymeric samples was concluded from the XRD patterns. The prepared cellulose grafted acrylonitrile copolymer was used as an adsorbent to remove Cr (VI) ions from aqueous solutions. The efficiency of the adsorbent was identified from the variation in the percentage of adsorption with contact time, adsorbent dose and pH. From the observed results it was evident that the adsorption of metal ions increases with the increase in contact time and metal ion concentration. An optimum pH was found to be 5.0 for the removal of Cr (VI) from the aqueous solution. The results of the Langmuir, Freundlich, and pseudo first- and second-order studies revealed that the adsorption was found to fit well with Freundlich isotherm and follows pseudo second-order kinetics. From the above results, it was concluded that the cellulose-g-acrylonitrile copolymer was found to be an efficient adsorbent for the removal of Cr (VI) from aqueous waste generated from industries.

  11. Occupational exposures to styrene in Denmark 1955-88.

    PubMed

    Jensen, A A; Breum, N O; Bacher, J; Lynge, E

    1990-01-01

    An assessment of the occupational exposure to styrene and associated chemicals in Denmark was carried out by retrieving all measurements from the archives of the Danish National Institute of Occupational Health. A total of 2,528 air samples containing styrene had been collected from 256 workplaces during the years 1955-88 and analyzed by the chemical laboratory at the Institute. The mean for all samples was 265 mg/m3. The concentration decreased from 714 mg/m3 in the early period (1955-70) to 172 mg/m3 in the late period (1981-88). Spraying and unspecified lay-up and production of boats, carriages, and stationary containers were associated with the highest concentration. A total of 34 chemicals were measured. The most frequent co-contaminant to styrene was acetone, which was measured in 2,263 samples with a mean concentration of 131 mg/m3. Dichloromethane was measured in 208 samples with a mean concentration of 51 mg/m3, xylene in 148 samples with a mean concentration of 49 mg/m3, and toluene in 116 samples with a mean concentration of 113 mg/m3. The study was undertaken to analyze historical styrene concentrations in air to aid in the selection of industrial cohorts to be included in epidemiologic studies.

  12. 21 CFR 177.1830 - Styrene-methyl methacrylate copolymers.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... methacrylate copolymers identified in this section may be safely used as components of plastic articles... weight percent of polymer units derived from styrene. (b) The finished plastic food-contact article, when... not to exceed an absorbance of 0.15. (3) Ultraviolet-absorbing distilled water and 8 and 50...

  13. Kinetics of styrene biodegradation by Pseudomonas sp. E-93486.

    PubMed

    Gąszczak, Agnieszka; Bartelmus, Grażyna; Greń, Izabela

    2012-01-01

    The research into kinetics of styrene biodegradation by bacterial strain Pseudomonas sp. E-93486 coming from VTT Culture Collection (Finland) was presented in this work. Microbial growth tests in the presence of styrene as the sole carbon and energy source were performed both in batch and continuous cultures. Batch experiments were conducted for initial concentration of styrene in the liquid phase changed in the range of 5-90 g m(-3). The Haldane model was found to be the best to fit the kinetic data, and the estimated constants of the equation were: μ (m) = 0.1188 h(-1), K(S) = 5.984 mg l(-1), and K (i) = 156.6 mg l(-1). The yield coefficient mean value [Formula in text] for the batch culture was 0.72 g(dry cells weight) (g(substrate))(-1). The experiments conducted in a chemostat at various dilution rates (D = 0.035-0.1 h(-1)) made it possible to determine the value of the coefficient for maintenance metabolism m (d) = 0.0165 h(-1) and the maximum yield coefficient value [Formula in text]. Chemostat experiments confirmed the high value of yield coefficient [Formula in text] observed in the batch culture. The conducted experiments showed high activity of the examined strain in the styrene biodegradation process and a relatively low sensitivity to inhibition of its growth at higher concentrations of styrene in the solution. Such exceptional features of Pseudomonas sp. E-93486 make this bacterial strain the perfect candidate for technical applications.

  14. Metabolism of styrene by Rhodococcus rhodochrous NCIMB 13259.

    PubMed Central

    Warhurst, A M; Clarke, K F; Hill, R A; Holt, R A; Fewson, C A

    1994-01-01

    Rhodococcus rhodochrous NCIMB 13259 grows on styrene, toluene, ethylbenzene, and benzene as sole carbon sources. Simultaneous induction tests with cells grown on styrene or toluene showed high rates of oxygen consumption with toluene cis-glycol and 3-methylcatechol, suggesting the involvement of a cis-glycol pathway. 3-Vinylcatechol accumulated when intact cells were incubated with styrene in the presence of 3-fluorocatechol to inhibit catechol dioxygenase activity. Experiments with 18O2 showed that 3-vinylcatechol was produced following a dioxygenase ring attack. Extracts contained a NAD-dependent cis-glycol dehydrogenase, which converted styrene cis-glycol to 3-vinylcatechol. Both catechol 1,2- and 2,3-dioxygenase activities were present, and these were separated from each other and from the activities of cis-glycol dehydrogenase and 2-hydroxymuconic acid semialdehyde hydrolase by ion-exchange chromatography of extracts. 2-Vinylmuconate accumulated in the growth medium when cells were grown on styrene, apparently as a dead-end product, and extracts contained no detectable muconate cycloisomerase activity. 3-Vinylcatechol was cleaved by catechol 2,3-dioxygenase to give a yellow compound, tentatively identified as 2-hydroxy-6-oxoocta-2,4,7-trienoic acid, and the action of 2-hydroxymuconic acid semialdehyde hydrolase on this produced acrylic acid. A compound with the spectral characteristics of 2-hydroxypenta-2,4-dienoate was produced by the action of 2-hydroxymuconic acid semialdehyde hydrolase on the 2,3-cleavage product of 3-methylcatechol. Extracts were able to transform 2-hydroxypenta-2,4-dienoate and 4-hydroxy-2-oxopentanoate into acetaldehyde and pyruvate.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:8017910

  15. Planning and Management of Aircraft Pavement Construction

    DTIC Science & Technology

    1993-01-01

    weather cracking can be achieved buy using elasometric polymers such as natural latex , 3 styrene / butadien rubber , styrene / butadiene block polymers and...as slurries, overlays or even full depth sections. CHARACTERISTICS OF POLYMER-MODIFIED ASPHALT Modifier Unique Performance Deficiec Styrene / butadiene ...outstanding * mixing/blending block copolymer toughness * melt storage (SBS) * excellent elastic stability recovery * ductility Styrene / butadiene

  16. Photochemical isomerization in solution. Photophysics of diphenyl butadiene

    NASA Astrophysics Data System (ADS)

    Velsko, Stephan P.; Fleming, Graham R.

    1982-04-01

    We have examined the radiative and nonradiative decay rates of diphenyl butadiene in hydrocarbon and polar solvents as a function of temperature and pressure. We demonstrate that the radiative rate constant has a small dependence on solvent polarizability, in contrast to what is observed for diphenylhexatriene. We make an explicit separation of the internal molecular barrier to isomerization and the barrier due to frictional forces in the solvent. The energy of the internal barrier to isomerization is less than the activation energy observed in solution, and depends on the polarizability and polarity of the solvent. In contrast to diphenylhexatriene, it decreases, in more polar solvents. We compare the viscosity dependence of the barrier crossing process with Kramers' theory, the recent kinetic theory result of Skinner and Wolynes [J. Chem. Phys. 69, 2143 (1978)], and the free volume theory of Gegiou, Muzkat, and Fischer, [J. Amer. Chem. Soc. 90, 12 (1968)]. Our data clearly show that the isomerization process is in the intermediate friction limit and we obtain experimental values for the parameters of the three theories. Over the viscosity region studied, Kramers' and Skinner and Wolynes' equations coincide exactly and do not reproduce the functional dependence of the radiationless rate pre-exponential factor as well as the free volume theory. We speculate that it may be necessary to consider the frequency dependence of medium viscosity.

  17. Electron scattering from 2-methyl-1,3-butadiene, C5H8 , molecules: Role of methylation

    NASA Astrophysics Data System (ADS)

    Szmytkowski, Czesław; Stefanowska, Sylwia; Zawadzki, Mateusz; Ptasińska-Denga, ElŻbieta; MoŻejko, Paweł

    2016-10-01

    We report cross-section results from experimental and theoretical investigations into electron collisions with the 2-methyl-1,3-butadiene [C5H8] molecule. The current results are compared with our previous results for the 1,3-butadiene [C4H6] molecule, a structural homologue of 2-methyl-1,3-butadiene, to investigate how the methylation (the substitution of hydrogen atom by a methyl group) affects the shape and/or magnitude of the total cross sections (TCSs). Both experimental TCS energy dependencies have certain features in common: the Ramsauer-Townsend-like minimum located within 1.4-1.6 eV; the resonant maximum centered at 3.4 eV for the 2-methyl-1,3-butadiene molecule and at 3.2 eV for 1,3-butadiene; a weak shoulder in the vicinity of 7 eV; and the pronounced broad enhancement peaking around 8.5 eV for 2-methyl-1,3-butadiene and near 9.5 eV for 1,3-butadiene. The magnitude of the TCS for 2-methyl-1,3-butadiene appears to be higher than that for 1,3-butadiene over the whole investigated energy range. Closer analysis of data shows that the TCS for 2-methyl-1,3-butadiene can be reasonably reproduced by the sum of TCSs for 1,3-butadiene and half of the TCS for the ethane [C2H6] molecule—that stays for the TCS of the methyl unit [CH3] . That result can be extended to homologous series of methyl-substituted allenes, ethylenes, and acetylenes.

  18. Assessment of the potential risk to workers from exposure to 1,3-butadiene.

    PubMed Central

    Turnbull, D; Rodricks, J V; Brett, S M

    1990-01-01

    The available epidemiologic data provide equivocal evidence that 1,3-butadiene is carcinogenic in humans; some available studies suggest that the lymphopoietic system is a target, but there are inconsistencies among studies in the types of tumors associated with 1,3-butadiene exposure, and there is no evidence of a relationship between length of exposure and cancer risk, as one might expect if there was a true causal relationship between 1,3-butadiene exposure and cancer risk. The available chronic animal studies, however, show an increase in tumor incidence associated with exposure to high concentrations of 1,3-butadiene. In addition to the general uncertainty of the relevance of animal data to humans, there are several additional reasons why the National Toxicology Program's mouse study may not be appropriate for assessing possible human risks. These include: a) the possible involvement of a species-specific tumor virus (MuLV) in the response in mice; b) apparent differences between mice and humans in the rate of metabolism of 1,3-butadiene to reactive epoxides that may be proximate carcinogens; c) use of high dose levels that caused excess early mortality; and d) exposure of animals to 1,3-butadiene for only about half their lifetime. While recognizing the uncertainty in using the available animal data for risk assessment, we have performed low-dose extrapolation of the data to examine the implications of the data if humans were as sensitive as rats or mice to 1,3-butadiene, and to examine how the predictions of the animal data compare to that observed in the epidemiologic studies. With the mouse data, because the study was of less than lifetime duration, we have used the Hartley-Sielken time-to-tumor model to permit estimation of lifetime risk from the less than lifetime exposure of the study. With the rat data, we have used three plausible models for assessing low-dose risk: the multistage model, the Weibull model, and the Mantel-Bryan probit model. With both

  19. Comparative studies on the removal of heavy metals ions onto cross linked chitosan-g-acrylonitrile copolymer.

    PubMed

    Shankar, P; Gomathi, Thandapani; Vijayalakshmi, K; Sudha, P N

    2014-06-01

    The graft copolymerization of acrylonitrile onto cross linked chitosan was carried out using ceric ammonium nitrate as an initiator. The prepared cross linked chitosan-g-acrylonitrile copolymer was characterized using FT-IR and XRD studies. The adsorption behavior of chromium(VI), copper(II) and nickel(II) ions from aqueous solution onto cross linked chitosan graft acrylonitrile copolymer was investigated through batch method. The efficiency of the adsorbent was identified from the varying the contact time, adsorbent dose and pH. The results evident that the adsorption of metal ions increases with the increase of shaking time and metal ion concentration. An optimum pH was found to be 5.0 for both Cr(VI) and Cu(II), whereas the optimum pH is 5.5 for the adsorption of Ni(II) onto cross linked chitosan-g-acrylonitrile copolymer. The Langmuir and Freundlich adsorption models were applied to describe the isotherms and isotherm constants. Adsorption isothermal data could be well interpreted by the Freundlich model. The kinetic experimental data properly correlated with the second-order kinetic model. From the above results it was concluded that the cross linked chitosan graft acrylonitrile copolymer was found to be the efficient adsorbent for removing the heavy metals under optimum conditions.

  20. PRODUCTS OF THE GAS-PHASE REACTIONS OF 1,3-BUTADIENE WITH OH AND NO3 RADICALS. (R825252)

    EPA Science Inventory

    1,3-Butadiene is emitted into the atmosphere from a number of sources
    including combustion sources and is listed in the United States as a hazardous
    air pollutant. In the atmosphere, 1,3-butadiene reacts with OH radicals,
    NO3 radicals, and O3 ...

  1. Significance of 1,3-butadiene to the US air toxics regulatory effort.

    PubMed

    Morrow, N L

    2001-06-01

    Because of its prevalence, particularly as a combustion by-product, 1,3-butadiene is a particularly important air toxic. It plays a significant role in all air toxics regulatory efforts in the US. The various requirements of the Federal Clean Air Act (CAA) dealing with air toxics are reviewed and the significance of 1,3-butadiene in each area is discussed in light of what is known about its emissions and health effects. The impacts of the changes in the understanding of 1,3-butadiene cancer potency over the past 15 years demonstrates the possible impact of such benchmarks and the importance of using the best science in understanding public health risks.

  2. Mechanical Properties and Vulcanization Characteristics of Styrene-Butadiene Rubber (sbr) Based Compounds Filled with Eggshell Powder as a Bio-Filler

    NASA Astrophysics Data System (ADS)

    Saeb, Mohammad Reza; Dakhel, Hadi Ramezani; Ghaffari, Akbar

    2008-08-01

    Egg shell is an ordered bioceramic composite with five different layers [1, 2]. In this study, the effect of using various types of eggshell powder including after and before hatching eggshell and boiled eggshell on the mechanical properties and vulcanization characteristics of SBR compounds has been investigated. The obtained results were compared with calcium carbonate filled compounds. Evaluation of mechanical properties exhibited that incorporation of eggshell increased almost all of the mechanical properties of the compounds. BET test demonstrated higher specific area of eggshell powders compare with calcium carbonate. Some of the observed results attributed to higher specific area of eggshell powder. However, there is no definitive reason for some other results at this time. Vulcanization characteristics of the compounds showed that incorporation of eggshell powder had no considerable effect on curing time. The results of this research showed that all kinds of eggshell powders can be used in SBR based compounds successfully.

  3. Development of Polyclonal Antibodies for the Detection of Styrene Oxide Modified Proteins

    PubMed Central

    Yuan, Wei; Chung, Jouku; Gee, Shirley; Hammock, Bruce D.; Zheng, Jiang

    2008-01-01

    Styrene is widely used as one of the most important industrial materials for the production of synthetic rubbers, plastic, insulation, fiberglass, and automobile parts. Inhaled styrene has been reported to produce respiratory toxicity in humans and animals. Styrene oxide, a reactive metabolite of styrene formed via cytochrome P450 enzymes, has been reported to form covalent bonds with proteins, such as albumin and hemoglobin. Among all of the amino acids, cysteine is the most reactive amino acid to be modified by electrophilic species. The purpose of this study is to develop polyclonal antibodies for the detection of styrene oxide cysteinyl protein adducts. Two immunogens were designed, synthesized, and used to induce polyclonal antibodies in rabbits. Immune responses were observed from the raised antibodies by antiserum dilution tests. Competitive ELISA demonstrated that the resulting antibodies specifically recognized the styrene oxide-derived N-acetylcysteine adduct. Western blot results showed that the antibodies recognize styrene oxide-modified albumin. The binding was found to depend on the amount of protein adducts blotted and hapten loading in protein adducts. No cross reaction was observed from the native protein. Competitive Western blots further indicated that these antibodies specifically recognized styrene oxide cysteinyl–protein adducts. Immunoblots revealed the presence of several bands at a molecular weight ranging from 50 to 80 kDa in rat nasal mucosa treated with styrene. In conclusion, we successfully raised polyclonal antibodies to detect styrene oxide-derived protein/cysteine adducts. PMID:17266334

  4. Metabolism and hepatorenal toxicity due to repeated exposure to styrene in spontaneously hypertensive rats (SHR)

    SciTech Connect

    Decarie, S.; Chakrabarti, S. )

    1989-01-01

    Groups of adult make rats (5 rats per group), either normotensive (WKY) or spontaneously hypertensive (SHR), were exposed by inhalation to 0, 821, and 3018 ppm styrene, 5h per day for 3 consecutive days. After the exposure, the urines were collected for 24h and the animals were then sacrificed. The various biochemical parameters of henatorenal toxicity due to styrene as well as its urinary metabolites were measured. Hepatotoxicity due to styrene was not further increased at any exposure level due to hypertension. However, repeated exposure of SHR rats to 3018 ppm styrene showed significant increases in the urinary excretion of {gamma}-glutamyl transpeptidase, proteins, and volume of urine, compared to WKY treated rats, whereas no such changes were observed due to repeated exposure to 821 ppm styrene. Studies of in vivo metabolism of styrene at higher exposure level showed significant decrease in the urinary excretion of mandelic, phenylglyoxylic, and hippuric acids in SHR rats compared to WKY-treated rats, suggestion an inhibition of deactivation of styrene reactive intermediate involving the epoxide hydrase pathway due to hypertension. At the same time, a significant increase in the urinary excretion of a potential nephrotoxic metabolite of styrene (e.g., mercapturates or thioethers) was observed in SHR-treated rats when compared to WKY-treated rats. These results demonstrate the spontaneous hpertension has the potential to further increase the nephrotoxicity due to repeated exposure to styrene, and the metabolism of styrene plays an important role in modifying such toxicity in the hypertensive state.

  5. 1,3-Butadiene: linking metabolism, dosimetry, and mutation induction.

    PubMed Central

    Bond, J A; Csanady, G A; Gargas, M L; Guengerich, F P; Leavens, T; Medinsky, M A; Recio, L

    1994-01-01

    There is increasing concern for the potential adverse health effects of human exposures to chemical mixtures. To better understand the complex interactions of chemicals within a mixture, it is essential to develop a research strategy which provides the basis for extrapolating data from single chemicals to their behavior within the chemical mixture. 1,3-Butadiene (BD) represents an interesting case study in which new data are emerging that are critical for understanding interspecies differences in carcinogenic/genotoxic response to BD. Knowledge regarding mechanisms of BD-induced carcinogenicity provides the basis for assessing the potential effects of mixtures containing BD. BD is a multisite carcinogen in B6C3F1 mice and Sprague-Dawley rats. Mice exhibit high sensitivity relative to the rat to BD-induced tumorigenesis. Since it is likely that BD requires metabolic activation to mutagenic reactive epoxides that ultimately play a role in carcinogenicity of the chemical, a quantitative understanding of the balance of activation and inactivation is essential for improving our understanding and assessment of human risk following exposure to BD and chemical mixtures containing BD. Transgenic mice exposed to 625 ppm BD for 6 hr/day for 5 days exhibited significant mutagenicity in the lung, a target organ for the carcinogenic effect of BD in mice. In vitro studies designed to assess interspecies differences in the activation of BD and inactivation of BD epoxides reveal that significant differences exist among mice, rats, and humans. In general, the overall activation/detoxication ratio for BD metabolism was approximately 10-fold higher in mice compared to rats or humans.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7698092

  6. Evaporative emissions of 1,3-butadiene from petrol-fuelled motor vehicles

    NASA Astrophysics Data System (ADS)

    Ye, Y.; Galbally, I. E.; Weeks, I. A.; Duffy, B. L.; Nelson, P. F.

    This study reports the identification and quantification of 1,3-butadiene in petrol and in the evaporative emissions from Australian light-duty passenger vehicles. The mass fraction of 1,3-butadiene in each of the different grades of any brand of Australian petrol was found to be relatively constant for a given marketing area. However, the mass fractions vary significantly between the different brands (or refineries) from 0.004±0.001% to 0.047±0.008%. The measurements of the evaporative emissions of 1,3-butadiene from in-service motor vehicles were performed using standard Australian Design Rule 37/00 (ADR 37/00) Sealed Housing Evaporative Determination (SHED) tests. For post-1985 catalyst equipped vehicles fuelled with unleaded petrol, average evaporative emissions of 1,3-butadiene were 9.4 (0.7-22) and 5.0 (0.1-23) mg per test for diurnal and hot soak SHED tests, respectively. The corresponding average evaporative emissions for the older, pre-1986 non-catalyst equipped vehicles fuelled with leaded petrol were 26.5 (11.7-45.4) and 9.2 (4.3-13.1) mg per test, respectively, about double the observed emissions from newer vehicles. For the complete vehicle set (all ages), the average mass fraction of 1,3-butadiene in the total hydrocarbon (sum of C 1-C 10 hydrocarbons) emission was 0.21±0.14% from the diurnal phase and was 0.11±0.06% from the hot-soak phase. Evaporative emissions were estimated to contribute about 4% (ranging from 1-15%) of the total (exhaust and evaporative) emissions of 1,3-butadiene from Australian motor vehicles.

  7. Oligomer formation in the radiation-induced polymerization of styrene

    NASA Astrophysics Data System (ADS)

    Harayma, Hiroshi; Al-Sheikhly, Mohamad; Silverman, Joseph

    2003-12-01

    Analyses of the oligomers formed in radiation-induced polymerization of purified styrene were performed. The principal dimeric products were cis- and trans-diphenyl-cyclobutane with a relatively small amount of 1-phenyltetralin; the trimeric products were the optical isomers of 1-phenyl-4-[1'-phenylethyl-(1')]-tetralin in gamma-ray and 60 MeV proton irradiation. Oligomer formation increased with increasing dose, but more gradually than the linear formation of high polymer with dose. The yield was 0.25-3.1 μmol/J at low doses and decreased to an asymptotic value of 0.15 at higher doses. It appears that oligomers act as chain transfer agents during the polymerization reaction which would account for the observed decrease in molecular weight of the high polymer with increase in dose. Although the thermal and radiation-induced polymerization of styrene have different initiation steps, the oligomers produced by both reactions are similar in composition.

  8. Styrene-based shape memory foam: fabrication and mathematical modeling

    NASA Astrophysics Data System (ADS)

    Yao, Yongtao; Zhou, Tianyang; Qin, Chao; Liu, Yanju; Leng, Jinsong

    2016-10-01

    Shape memory polymer foam is a promising kind of structure in the biomedical and aerospace field. Shape memory styrene foam with uniform and controlled open-cell structure was successfully fabricated using a salt particulate leaching method. Shape recovery capability exists for foam programming in both high-temperature compression and low-temperature compression (styrene foams during the compression process.

  9. Comparison of genotoxic potency of styrene 7,8-oxide with gamma radiation and human cancer risk estimation of styrene using the rad-equivalence approach.

    PubMed

    Godderis, Lode; Aka, P; Kirsch-Volders, M; Veulemans, H

    2007-05-01

    Styrene is suspected to cause lympho-hematopoietic malignancies through the formation of styrene 7,8-oxide. However, we are still unable to calculate the cancer risk for workers exposed to styrene using epidemiological data. The aims of this study were to determine the blood dose after styrene exposure and to compare the genotoxic potency of styrene 7,8-oxide and gamma radiation in order to calculate the cancer risk by means of the rad-equivalence approach. Leucocytes of 20 individuals were exposed to 0, 0.1, 0.2 or 0.3 mM styrene 7,8-oxide (1 h) or 1, 2 or 3 gray (=100, 200, 300 rad) gamma radiation. Genotoxicity was evaluated with the cytokinesis-block micronucleus assay. Comparison of the two slopes of the regression lines between micronuclei and dose revealed a genotoxic potency for styrene 7,8-oxide of 37 rad/mMh, corresponding with a median value derived from mutagenicity studies (1, 37, 208 rad/mMh). At exposure levels of 1 ppm styrene, a blood styrene 7,8-oxide concentration between 0.03 x 10(-)(6) and 0.42 x 10(-)(6) mM is to be expected using data of toxicokinetic models and human exposure studies. With the cancer risk per unit dose of gamma radiation as benchmark, we calculated a lifetime risk of acquiring a fatal lympho-hematopoietic cancer of 0.17 in 10(3) workers (between 0.037 x 10(-)(3) and 5.0 x 10(-)(3)) exposed to 20 ppm styrene during 40 years.

  10. Mechanism of Selective Ammoxidation of Propene to Acrylonitrile on Bismuth Molybdates from Quantum Mechanical Calculations

    SciTech Connect

    Pudar, Sanja; Oxgaard, Jonas; Goddard, William A

    2010-08-25

    In order to understand the mechanism for selective ammoxidation of propene to acrylonitrile by bismuth molybdates, we report quantum mechanical studies (using the B3LYP flavor of density functional theory) for the various steps involved in converting the allyl-activated intermediate to acrylonitrile over molybdenum oxide (using a Mo3O9 cluster model) under conditions adjusted to describe both high and low partial pressures of NH3 in the feed. We find that the rate-determining step in converting of allyl to acrylonitrile at all feed partial pressures is the second hydrogen abstraction from the nitrogen-bound allyl intermediate (Mo-NH-CH2-CH=CH2) to form Mo-NH=CH-CH=CH2). We find that imido groups (Mo=NH) have two roles: (1) a direct effect on H abstraction barriers, H abstraction by an imido moiety is (~8 kcal/mol) more favorable than abstraction by an oxo moiety (Mo=O), and (2) an indirect effect, the presence of spectator imido groups decreases the H abstraction barriers by an additional ~15 kcal/mol. Therefore, at higher NH3 pressures (which increases the number of Mo=NH groups), the second H abstraction barrier decreases significantly, in agreement with experimental observations that propene conversion is higher at higher partial pressures of NH3. At high NH3 pressures we find that the final hydrogen abstraction has a high barrier [ΔHfourth-ab = 31.6 kcal/mol compared to ΔHsecond-ab = 16.4 kcal/mol] due to formation of low Mo oxidation states in the final state. However, we find that reoxidizing the surface prior to the last hydrogen abstraction leads to a significant reduction of this barrier to ΔHfourth-ab = 15.9 kcal/mol, so that this step is no longer rate determining. Therefore, we conclude that reoxidation during the reaction is necessary for facile conversion of allyl to

  11. Synthesis, Acaricidal Activity, and Structure-Activity Relationships of Pyrazolyl Acrylonitrile Derivatives.

    PubMed

    Yu, Haibo; Cheng, Yan; Xu, Man; Song, Yuquan; Luo, Yanmei; Li, Bin

    2016-12-28

    A series of novel pyrazolyl acrylonitrile derivatives was designed, targeting Tetranychus cinnabarinus, and synthesized. Their structures were identified by combination of (1)H NMR, (13)C NMR, and MS spectra. The structures of compounds 18 and 19 were further confirmed by X-ray diffraction. Extensive greenhouse bioassays indicated that compound 19 exhibits excellent acaricidal activity against all developmental stages of T. cinnabarinus, which is better than the commercialized compounds cyenopyrafen and spirodiclofen. It was shown that the acute toxicity of compounds 19 to mammals is quite low. The structure-activity relationships are also discussed.

  12. Poly(styrene-b-dimethylsiloxane-b-styrene) Membranes in Pervaporation for In Situ Product Recovery during Fermentation

    NASA Astrophysics Data System (ADS)

    Shin, Chaeyoung; Baer, Zachary; Ozcam, Ali Evren; Clark, Douglas; Balsara, Nitash

    2014-03-01

    In situ product recovery was investigated in fermentation experiments to enable the development of a continuous fermentation process. Our pervaporation membranes are based on poly(styrene-b-dimethylsiloxane-b-styrene) (SDS) block copolymers. Polydimethylsiloxane (PDMS) is the best known organophilic pervaporation membrane material and was utilized as the transporting phase for selective permeation of organic molecules. The polystyrene (PS) block added structural integrity to the membrane due to the high modulus of PS. SDS membranes were found to have both the enhanced robustness as well as comparable pervaporation performance to that of cross-linked PDMS membranes. The permeabilities of water and organic components through SDS membranes were studied to elucidate the sorption and transport phenomena in this system. Furthermore, experiments combining fermentation with pervaporation were performed, and continuous fermentation by using pervaporation as the sole means of removing products was successfully demonstrated for the first time.

  13. Transport Properties of Sulfonated Poly (Styrene-b-isobutylene-b-styrene) Triblock Copolymers at High Ion-Exchange Capacities

    DTIC Science & Technology

    2005-10-20

    2-propanol (Burdick & Jackson, HPLC Grade), cyclohexanone (Aldrich, reagent grade), butanol (J.T. Baker, reagent grade), and water (J.T. Baker, HPLC...explored. S-SIBS-29 was solution cast from a number of different solvents: chloroform, methylene chloride, THF, cyclo- hexanol, benzene, cyclohexanone ...styrene ) × 100 (1) 400 Elabd et al. Macromolecules, Vol. 39, No. 1, 2006 48 h. S-SIBS-29 was solution-cast from cyclohexanone and cylohexanol with

  14. Alkyltransferase-mediated Toxicity of 1,3-Butadiene Diepoxide

    PubMed Central

    Kalapila, Aley G.; Loktionova, Natalia A.; Pegg, Anthony E.

    2008-01-01

    Human O6-alkylguanine-DNA alkyltransferase (hAGT) expression increases mutations and cytotoxicity following exposure to 1,3-butadiene diepoxide (BDO) and hAGT-DNA cross-links are formed in the presence of BDO. We have used hAGT mutants to investigate the mechanism of cross-link formation and genotoxicity. Formation of a hAGT-DNA conjugate in vitro was observed with C145S and C145A mutant proteins but was considerably diminished with the C145A/C150S double mutant confirming that cross-linking primarily involves either of these two cysteine residues, which are located in the active site pocket of the protein. Cross-link formation by BDO occurred both via (a) an initial reaction of BDO with hAGT followed by attack of the reactive hAGT complex on DNA, and (b) the initial reaction of BDO with DNA followed by a reaction between hAGT and the DNA adduct. These results differ from those with 1,2-dibromoethane (DBE) where Cys145 is the only site of attachment and pathway (b) does not occur. The complex formed between hAGT at Cys145 and BDO was very unstable in aqueous solution. However, the BDO-hAGT complex at Cys150 exhibited stability for more than 1 h. The effect of hAGT and mutants on BDO-induced genotoxicity was studied in E. coli using the forward assay to rifampicin resistance. Both mutations and cell killing were greatly increased by wild type hAGT and there was a smaller but significant effect with the C145A mutant. The R128A mutant and R128A/C145A and C145A/C150S double mutants were ineffective supporting the hypothesis that the formation of hAGT-DNA cross-links is responsible for the enhanced genotoxicity detected in this biological system. In the absence of hAGT, there were equal proportions of G:C to A:T transitions, G:C to T:A transversions and A:T to T:A transversions. Wild type hAGT expression yielded significantly greater G:C to A:T and A:T to G:C transitions, whereas C145A mutant expression resulted in more transitions and transversions at A:T base

  15. Quantitation of DNA Adducts Induced by 1,3-Butadiene

    NASA Astrophysics Data System (ADS)

    Sangaraju, Dewakar; Villalta, Peter W.; Wickramaratne, Susith; Swenberg, James; Tretyakova, Natalia

    2014-07-01

    Human exposure to 1,3-butadiene (BD) present in automobile exhaust, cigarette smoke, and forest fires is of great concern because of its potent carcinogenicity. The adverse health effects of BD are mediated by its epoxide metabolites such as 3,4-epoxy-1-butene (EB), which covalently modify genomic DNA to form promutagenic nucleobase adducts. Because of their direct role in cancer, BD-DNA adducts can be used as mechanism-based biomarkers of BD exposure. In the present work, a mass spectrometry-based methodology was developed for accurate, sensitive, and precise quantification of EB-induced N-7-(1-hydroxy-3-buten-2-yl) guanine (EB-GII) DNA adducts in vivo. In our approach, EB-GII adducts are selectively released from DNA backbone by neutral thermal hydrolysis, followed by ultrafiltration, offline HPLC purification, and isotope dilution nanoLC/ESI+-HRMS3 analysis on an Orbitrap Velos mass spectrometer. Following method validation, EB-GII lesions were quantified in human fibrosarcoma (HT1080) cells treated with micromolar concentrations of EB and in liver tissues of rats exposed to sub-ppm concentrations of BD (0.5-1.5 ppm). EB-GII concentrations increased linearly from 1.15 ± 0.23 to 10.11 ± 0.45 adducts per 106 nucleotides in HT1080 cells treated with 0.5-10 μM DEB. EB-GII concentrations in DNA of laboratory rats exposed to 0.5, 1.0, and 1.5 ppm BD were 0.17 ± 0.05, 0.33 ± 0.08, and 0.50 ± 0.04 adducts per 106 nucleotides, respectively. We also used the new method to determine the in vivo half-life of EB-GII adducts in rat liver DNA (2.20 ± 0.12 d) and to detect EB-GII in human blood DNA. To our knowledge, this is the first application of nanoLC/ESI+-HRMS3 Orbitrap methodology to quantitative analysis of DNA adducts in vivo.

  16. Cooperative effects for CYP2E1 differ between styrene and its metabolites.

    PubMed

    Hartman, Jessica H; Boysen, Gunnar; Miller, Grover P

    2013-09-01

    Cooperative interactions are frequently observed in the metabolism of drugs and pollutants by cytochrome P450s; nevertheless, the molecular determinants for cooperativity remain elusive. Previously, we demonstrated that steady-state styrene metabolism by CYP2E1 exhibits positive cooperativity. We hypothesized that styrene metabolites have lower affinity than styrene toward CYP2E1 and limited ability to induce cooperative effects during metabolism. To test the hypothesis, we determined the potency and mechanism of inhibition for styrene and its metabolites toward oxidation of 4-nitrophenol using CYP2E1 Supersomes® and human liver microsomes. Styrene inhibited the reaction through a mixed cooperative mechanism with high affinity for the catalytic site (67 µM) and lower affinity for the cooperative site (1100 µM), while increasing substrate turnover at high concentrations. Styrene oxide and 4-vinylphenol possessed similar affinity for CYP2E1. Styrene oxide behaved cooperatively like styrene, but 4-vinylphenol decreased turnover at high concentrations. Styrene glycol was a very poor competitive inhibitor. Among all compounds, there was a positive correlation with binding and hydrophobicity. Taken together, these findings for CYP2E1 further validate contributions of cooperative mechanisms to metabolic processes, demonstrate the role of molecular structure on those mechanisms and underscore the potential for heterotropic cooperative effects between different compounds.

  17. Risk assessment of butadiene in ambient air; the approach used in the UK.

    PubMed

    Fielder, R J

    1996-10-28

    The UK Committee on Carcinogenicity of Chemicals in Food, Consumer Products and the Environment (COC) and the related Committee on Mutagenicity provided advice on 1,3-butadiene in 1992. This followed detailed consideration of the available mutagenicity, animal carcinogenicity and epidemiology data plus information on toxicokinetics. They concluded that 1,3-butadiene was an in vivo mutagen, a potent genotoxic animal carcinogen and should be regarded as a probable human carcinogen. The Department of Health is not aware of more recent data warranting reconsideration of these conclusions. General advice on setting air quality standards for carcinogenic air pollutants was given by the COC. Although the prudent assumption of the absence of any safe level for genotoxic carcinogens was preferred, a pragmatic approach based essentially on assessment of the exposure at which no increased risk would be detected, plus a safety factor, was considered reasonable for compounds like butadiene where exposure cannot be totally avoided. This approach, plus recognition that it is unadvisable to allow ambient levels of genotoxic carcinogens to rise, is used in the UK. The procedure by which the Department of Environment's Expert Panel on Air Quality Standards recommended a value of 1 ppb for butadiene based on these principles is described.

  18. THE OZONE REACTION WITH BUTADIENE: FORMATION OF TOXIC PRODUCTS. (R826236)

    EPA Science Inventory

    Abstract

    The formation yields of acrolein, 1,2-epoxy-3-butene and OH radicals have been measured from reaction of ozone with 1,3-butadiene at room temperature and atmosphere pressure. 1,3,5-Trimethyl benzene was added to scavenge OH radicals in measurements of product ...

  19. HYDROXYL RADICAL AND OZONE INITIATED PHOTOCHEMICAL REACTIONS OF 1,3-BUTADIENE. (R826247)

    EPA Science Inventory

    1,3-Butadiene, classified as hazardous in the 1990 Clean Air Act Amendments, is an important ambient air pollutant. Understanding its atmospheric transformation is useful for its own sake, and is also helpful for eliciting isoprene's fate in the atmosphere (isoprene dominates ...

  20. EFFECTS OF 1,3-BUTADIENE, ISOPRENE, AND THEIR PHOTOCHEMICAL DEGRADATION PRODUCTS ON HUMAN LUNG CELLS

    EPA Science Inventory

    Because of potential exposure both in the workplace and from ambient air, the known carcinogen 1,3-butadiene (BD) is considered a priority hazardous air pollutant. BD and its 2-methyl analog, isoprene (ISO), are chemically similar but have very different toxicities, with ISO show...

  1. Transition-Metal-Free Synthesis of 1,3-Butadiene-Containing π-Conjugated Polymers.

    PubMed

    Cai, Xuediao; Liu, Yating; Lu, Tian; Yang, Rui; Luo, Chuxin; Zhang, Qi; Chai, Yonghai

    2016-12-01

    This work describes the synthesis of π-conjugated polymers possessing arylene and 1,3-butadiene alternating units in the main chain by the reaction of α,β-unsaturated ester/nitrile containing γ-H with aromatic/heteroaromatic aldehyde compound. By using 4-(4-formylphenyl)-2-butylene acid ethyl ester as a model monomer, the different polymerization conditions, including catalyst, catalyst amount, and solvent, are optimized. The polymerization of 4-(4-formylphenyl)-2-butylene acid ethyl ester is carried out by refluxing in ethanol for 72 h with 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) as a catalyst to give a 1,3-butadiene-containing π-conjugated polymer, poly(phenylene-1,3-butadiene), in 84.3% yield with M¯n and M¯w/M¯n (PDI) estimated as 6172 and 1.65, respectively. Based on this new methodology, a series of π-conjugated polymers containing 1,3-butadiene units with different substituents are obtained in high yields. A possible mechanism is proposed for the polymerization through a six-membered ring transition state and then a 1,5-H shift intermediate.

  2. Carbon-nanotube/silver networks in nitrile butadiene rubber for highly conductive flexible adhesives.

    PubMed

    Ma, Rujun; Kwon, Seoyoung; Zheng, Qing; Kwon, Hyeok Yong; Kim, Jae Il; Choi, Hyouk Ryeol; Baik, Seunghyun

    2012-07-03

    An adhesive with high conductivity, flexibility, cyclability, oxidation resistance, and good adhesion is developed using microscale silver flakes, multiwalled carbon nanotubes decorated with nanoscale silver particles, and nitrile butadiene rubber. Light-emitting-diode chips are attached to the conductive, flexible adhesive pattern on a poly(ethylene terephthalate) substrate as a visual demonstration. The brightness is invariant during bending tests.

  3. Exposure and risk assessment of 1,3-butadiene in Japan.

    PubMed

    Higashino, Haruyuki; Mita, Kazuaki; Yoshikado, Hiroshi; Iwata, Mitsuo; Nakanishi, Junko

    2007-03-20

    1,3-Butadiene is on the list of Substances Requiring Priority Action published by the Central Environmental Council of Japan in 1996. Emission of 1,3-butadiene has been controlled by a voluntary reduction program since 1997. Although the industrial emission of 1,3-butadiene in Japan has decreased in recent years, primarily due to a voluntary industrial emissions reduction program, the risks of exposure to it remain largely unknown. We assessed the risks and consequences of exposure to 1,3-butadiene on human health. A remarkable advantage of our risk assessment approach is the detailed assessment of exposure. Previously, we developed two different models that can be applied for the assessment of exposure: the first, the AIST-ADMER model estimates regional concentration distributions, whereas the second, the METI-LIS model estimates concentration distributions in the vicinity of factories. Both models were used for the assessment of exposure to 1,3-butadiene. Using exposure concentration and carcinogenic potency determined and reported by Environment Canada and Health Canada, we evaluated the excess lifetime cancer risk for persons exposed to 1,3-butadiene over the course of a lifetime. The results suggested that the majority of the population in Japan has an excess lifetime cancer risk of less than 10(-5), whereas a small number of people living close to industrial sources had a risk of greater than 10(-5). The results of the present assessment also showed that 1,3-butadiene in the general environment originates primarily from automobile emissions, such that a countermeasure of reducing emissions from cars is expected to be effective at reducing the total cancer risk among Japanese. On the other hand, individual risks among a population living in the vicinity of certain industrial sources were found to be significantly higher than those of the population living elsewhere, such that a reduction in emissions from a small number of specific industrial sources should be

  4. Emission of 1,3-butadiene from petrol-driven motor vehicles

    NASA Astrophysics Data System (ADS)

    Ye, Y.; Galbally, I. E.; Weeks, I. A.

    This study reports the measurement of 1,3-butadiene emissions from 30 petrol-driven vehicles from the Australian car fleet using the Australian Design Rule 37/00 vehicle test procedure. Six of the cars tested were not equipped with catalytic converters and used leaded petrol as fuel. The remaining 24 cars were fitted with catalytic converters and used unleaded petrol. 1,3-Butadiene in exhaust samples was found to degrade rapidly in SUMMA treated stainless steel canisters and the degradation followed first-order kinetics. The rate coefficient of the decay can be represented by a linear dependence on the concentration of nitrogen oxides in the exhaust ( r2 = 0.79, n = 43), and the gas-phase reaction of NO 2 and 1,3-butadiene may have a major role in this loss. The 1,3-butadiene concentrations used to estimate vehicle emissions were corrected for this loss using the decay rate constant either observed from replicate analyses or from the NO x concentrations in the samples. The measurements showed that 1,3-butadiene was emitted at a rate of 20.7 ± 9.2 mg km -1 from 6 non-catalyst vehicles. There was considerable scatter in the observations from catalyst equipped vehicles and we infer that this was due to the malfunction of the emission control devices on some vehicles. The 19 vehicles that appeared to have functioning catalyst emission control devices had an average emission rate of 2.1 ± 1.5 mg km -1. These emission rates are consistent with atmospheric observations and are much higher than those reported previously. We calculate that more than 90% of the 1,3-butadiene in engine exhaust comes from the common alkane and aromatic constituents of the fuel. A comparison of emissions in the different phases of the drive cycle indicates that current emission controls remove more than 90% of the 1,3-butadiene from the initial exhaust mixture.

  5. Two-dimensional spectra of electron collisions with acrylonitrile and methacrylonitrile reveal nuclear dynamics

    NASA Astrophysics Data System (ADS)

    Regeta, K.; Allan, M.

    2015-05-01

    Detailed experimental information on the motion of a nuclear packet on a complex (resonant) anion potential surface is obtained by measuring 2-dimensional (2D) electron energy loss spectra. The cross section is plotted as a function of incident electron energy, which determines which resonant anion state is populated, i.e., along which normal coordinate the wave packet is launched, and of the electron energy loss, which reveals into which final states each specific resonant state decays. The 2D spectra are presented for acrylonitrile and methacrylonitrile, at the incident energy range 0.095-1.0 eV, where the incoming electron is temporarily captured in the lowest π∗ orbital. The 2D spectra reveal selectivity patterns with respect to which vibrations are excited in the attachment and de-excited in the detachment. Further insight is gained by recording 1D spectra measured along horizontal, vertical, and diagonal cuts of the 2D spectrum. The methyl group in methacrylonitrile increases the resonance width 7 times. This converts the sharp resonances of acrylonitrile into boomerang structures but preserves the essence of the selectivity patterns. Selectivity of vibrational excitation by higher-lying shape resonances up to 8 eV is also reported.

  6. Two-dimensional spectra of electron collisions with acrylonitrile and methacrylonitrile reveal nuclear dynamics

    SciTech Connect

    Regeta, K. Allan, M.

    2015-05-14

    Detailed experimental information on the motion of a nuclear packet on a complex (resonant) anion potential surface is obtained by measuring 2-dimensional (2D) electron energy loss spectra. The cross section is plotted as a function of incident electron energy, which determines which resonant anion state is populated, i.e., along which normal coordinate the wave packet is launched, and of the electron energy loss, which reveals into which final states each specific resonant state decays. The 2D spectra are presented for acrylonitrile and methacrylonitrile, at the incident energy range 0.095-1.0 eV, where the incoming electron is temporarily captured in the lowest π{sup ∗} orbital. The 2D spectra reveal selectivity patterns with respect to which vibrations are excited in the attachment and de-excited in the detachment. Further insight is gained by recording 1D spectra measured along horizontal, vertical, and diagonal cuts of the 2D spectrum. The methyl group in methacrylonitrile increases the resonance width 7 times. This converts the sharp resonances of acrylonitrile into boomerang structures but preserves the essence of the selectivity patterns. Selectivity of vibrational excitation by higher-lying shape resonances up to 8 eV is also reported.

  7. A preliminary regional PBPK model of lung metabolism for improving species dependent descriptions of 1,3-butadiene and its metabolites

    DOE PAGES

    Campbell, Jerry; Van Landingham, Cynthia; Crowell, Susan; ...

    2015-06-12

    1,3-Butadiene (BD), a volatile organic chemical (VOC), is used in synthetic rubber production and other industrial processes. It is detectable at low levels in ambient air as well as in tobacco smoke and gasoline vapors. Inhalation exposures to high concentrations of BD have been associated with lung cancer in both humans and experimental animals, although differences in species sensitivity have been observed. Metabolically active lung cells such as Pulmonary Type I and Type II epithelial cells and club cells (Clara cells)1 are potential targets of BD metabolite-induced toxicity. Metabolic capacities of these cells, their regional densities, and distributions vary throughoutmore » the respiratory tract as well as between species and cell types. Here we present a physiologically based pharmacokinetic (PBPK) model for BD that includes a regional model of lung metabolism, based on a previous model for styrene, to provide species-dependent descriptions of BD metabolism in the mouse, rat, and human. Since there are no in vivo data on BD pharmacokinetics in the human, the rat and mouse models were parameterized to the extent possible on the basis of in vitro metabolic data. Where it was necessary to use in vivo data, extrapolation from rat to mouse was performed to evaluate the level of uncertainty in the human model. A kidney compartment and description of downstream metabolism were also included in the model to allow for eventual use of available urinary and blood biomarker data in animals and humans to calibrate the model for estimation of BD exposures and internal metabolite levels. Results from simulated inhalation exposures to BD indicate that incorporation of differential lung region metabolism is important in describing species differences in pulmonary response and that these differences may have implications for risk assessments of human exposures to BD.« less

  8. A preliminary regional PBPK model of lung metabolism for improving species dependent descriptions of 1,3-butadiene and its metabolites

    SciTech Connect

    Campbell, Jerry; Van Landingham, Cynthia; Crowell, Susan; Gentry, Robinan; Kaden, Debra; Fiebelkorn, Stacy; Loccisano, Anne; Clewell, Harvey

    2015-06-12

    1,3-Butadiene (BD), a volatile organic chemical (VOC), is used in synthetic rubber production and other industrial processes. It is detectable at low levels in ambient air as well as in tobacco smoke and gasoline vapors. Inhalation exposures to high concentrations of BD have been associated with lung cancer in both humans and experimental animals, although differences in species sensitivity have been observed. Metabolically active lung cells such as Pulmonary Type I and Type II epithelial cells and club cells (Clara cells)1 are potential targets of BD metabolite-induced toxicity. Metabolic capacities of these cells, their regional densities, and distributions vary throughout the respiratory tract as well as between species and cell types. Here we present a physiologically based pharmacokinetic (PBPK) model for BD that includes a regional model of lung metabolism, based on a previous model for styrene, to provide species-dependent descriptions of BD metabolism in the mouse, rat, and human. Since there are no in vivo data on BD pharmacokinetics in the human, the rat and mouse models were parameterized to the extent possible on the basis of in vitro metabolic data. Where it was necessary to use in vivo data, extrapolation from rat to mouse was performed to evaluate the level of uncertainty in the human model. A kidney compartment and description of downstream metabolism were also included in the model to allow for eventual use of available urinary and blood biomarker data in animals and humans to calibrate the model for estimation of BD exposures and internal metabolite levels. Results from simulated inhalation exposures to BD indicate that incorporation of differential lung region metabolism is important in describing species differences in pulmonary response and that these differences may have implications for risk assessments of human exposures to BD.

  9. [Study of amount of evaporation residue in extracts from plastic kitchen utensils into four food-simulating solvents].

    PubMed

    Ohno, Hiroyuki; Suzuki, Masako; Kawamura, Yoko

    2011-01-01

    The amount of evaporation residue was investigated as an index of total amount of non-volatile substances that migrated from plastic kitchen utensils into four food-simulating solvents (water, 4% acetic acid, 20% ethanol and heptane). The samples were 71 products made of 12 types of plastics for food contact use. The amount was determined in accordance with the Japanese testing method. The quantitation limit was 5 µg/mL. In the cases of polyethylene, polypropylene, polystyrene, acrylonitrile styrene resin, acrylonitrile butadiene styrene resin, polyvinyl chloride, polyvinylidene chloride, polymethylpentene, polymethylmethacrylate and polyethylene terephthalate samples, the amount was highest for heptane and very low for the other solvents. On the other hand, in the cases of melamine resin and polyamide samples, the amount was highest for 4% acetic acid or 20% ethanol and lowest for heptane. These results enabled the selection of the most suitable solvent, and the rapid and efficient determination of evaporation residue.

  10. Combustion products of 1,3-butadiene are cytotoxic and genotoxic to human bronchial epithelial cells.

    PubMed

    Catallo, W J; Kennedy, C H; Henk, W; Barker, S A; Grace, S C; Penn, A

    2001-09-01

    Adverse health effects of airborne toxicants, especially small respirable particles and their associated adsorbed chemicals, are of growing concern to health professionals, governmental agencies, and the general public. Areas rich in petrochemical processing facilities (e.g., eastern Texas and southern California) chronically have poor air quality. Atmospheric releases of products of incomplete combustion (e.g., soot) from these facilities are not subject to rigorous regulatory enforcement. Although soot can include respirable particles and carcinogens, the toxicologic and epidemiologic consequences of exposure to environmentally relevant complex soots have not been well investigated. Here we continue our physico-chemical analysis of butadiene soot and report effects of exposure to this soot on putative targets, normal human bronchial epithelial (NHBE) cells. We examined organic extracts of butadiene soot by gas chromatography-mass spectrometry (GC-MS), probe distillation MS, and liquid chromatography (LC)-MS-MS. Hundreds of aromatic hydrocarbons and polycyclic aromatic hydrocarbons with molecular mass as high as 1,000 atomic mass units were detected, including known and suspected human carcinogens (e.g., benzo(a)pyrene). Butadiene soot particles also had strong, solid-state free-radical character in electron spin resonance analysis. Spin-trapping studies indicated that fresh butadiene soot in a buffered aqueous solution containing dimethylsulfoxide (DMSO) oxidized the DMSO, leading to CH(3)* radical formation. Butadiene soot DMSO extract (BSDE)-exposed NHBE cells displayed extranuclear fluorescence within 4 hr of exposure. BSDE was cytotoxic to > 20% of the cells at 72 hr. Morphologic alterations, including cell swelling and membrane blebbing, were apparent within 24 hr of exposure. These alterations are characteristic of oncosis, an ischemia-induced form of cell death. BSDE treatment also produced significant genotoxicity, as indicated by binucleated cell

  11. Combustion products of 1,3-butadiene are cytotoxic and genotoxic to human bronchial epithelial cells.

    PubMed Central

    Catallo, W J; Kennedy, C H; Henk, W; Barker, S A; Grace, S C; Penn, A

    2001-01-01

    Adverse health effects of airborne toxicants, especially small respirable particles and their associated adsorbed chemicals, are of growing concern to health professionals, governmental agencies, and the general public. Areas rich in petrochemical processing facilities (e.g., eastern Texas and southern California) chronically have poor air quality. Atmospheric releases of products of incomplete combustion (e.g., soot) from these facilities are not subject to rigorous regulatory enforcement. Although soot can include respirable particles and carcinogens, the toxicologic and epidemiologic consequences of exposure to environmentally relevant complex soots have not been well investigated. Here we continue our physico-chemical analysis of butadiene soot and report effects of exposure to this soot on putative targets, normal human bronchial epithelial (NHBE) cells. We examined organic extracts of butadiene soot by gas chromatography-mass spectrometry (GC-MS), probe distillation MS, and liquid chromatography (LC)-MS-MS. Hundreds of aromatic hydrocarbons and polycyclic aromatic hydrocarbons with molecular mass as high as 1,000 atomic mass units were detected, including known and suspected human carcinogens (e.g., benzo(a)pyrene). Butadiene soot particles also had strong, solid-state free-radical character in electron spin resonance analysis. Spin-trapping studies indicated that fresh butadiene soot in a buffered aqueous solution containing dimethylsulfoxide (DMSO) oxidized the DMSO, leading to CH(3)* radical formation. Butadiene soot DMSO extract (BSDE)-exposed NHBE cells displayed extranuclear fluorescence within 4 hr of exposure. BSDE was cytotoxic to > 20% of the cells at 72 hr. Morphologic alterations, including cell swelling and membrane blebbing, were apparent within 24 hr of exposure. These alterations are characteristic of oncosis, an ischemia-induced form of cell death. BSDE treatment also produced significant genotoxicity, as indicated by binucleated cell

  12. Ultrasonic velocity and absorption study of binary mixtures of cyclohexane with acrylonitrile by interferometric method at different frequencies

    NASA Astrophysics Data System (ADS)

    Pawar, N. R.; Chimankar, O. P.; Bhandakkar, V. D.; Padole, N. N.

    2012-12-01

    The ultrasonic velocity (u), absorption (α), density (ρ), and viscosity (η) has been measured at different frequencies (1MHz to 10MHz) in the binary mixtures of cyclohexane with acrylonitriile over the entire range of composition at temperature 303K. Vander Waal's constant (b), adiabatic compressibility (βa), acoustic impedance (Z), molar volume (V), free length (Lf), free volume, internal pressure, intermolecular radius and relative association have been also calculated. A special application for acrylonitrile is in the manufacture of carbon fibers. These are produced by paralysis of oriented poly acrylonitrile fibers and are used to reinforce composites for high-performance applications in the aircraft, defense and aerospace industries. Other applications of acrylonitrile are in the production of fatty amines, ion exchange resins and fatty amine amides used in cosmetics, adhesives, corrosion inhibitors and water-treatment resins. Cyclohexane derivatives can be used for the synthesis of pharmaceuticals, dyes, herbicides, plant growth regulator, plasticizers, rubber chemicals, nylon, cyclamens and other organic compounds. In the view of these extensive applications of acrylonitrile and cyclohexane in the engineering process, textile and pharmaceutical industries present study provides qualitative information regarding the nature and strength of interaction in the liquid mixtures through derive parameters from ultrasonic velocity and absorption measurement.

  13. A personal sampling method for the determination of styrene exposure.

    PubMed

    Brown, R H; Saunders, K J; Walkin, K T

    1987-09-01

    A diffusive sampler, which is suitable for the determination of time-weighted average personal and static exposures to styrene, is described. The sampler is based on a commercially available tube design that is amenable to fully-automated thermal desorption. The performance of the sampler has been evaluated using a protocol, developed by the U.K. Health and Safety Executive, involving both laboratory and field experiments. The sampler has been shown to give results that are similar both in magnitude and precision to those obtained using conventional sorbent tube and pump methods. The diffusive method is preferred because of its simplicity and convenience.

  14. Synergetic effect of copper-plating wastewater as a catalyst for the destruction of acrylonitrile wastewater in supercritical water oxidation.

    PubMed

    Shin, Young Ho; Lee, Hong-shik; Lee, Young-Ho; Kim, Jaehoon; Kim, Jae-Duck; Lee, Youn-Woo

    2009-08-15

    A new supercritical water oxidation process for the simultaneous treatment of mixed wastewater containing wastewater from acrylonitrile manufacturing processes and copper-plating processes was investigated using a continuous tubular reactor system. Experiments were carried out at temperatures ranging from 400 to 600 degrees C and a pressure of 25 MPa. The residence time was fixed at 2s by changing the flow rates of feeds, depending on reaction temperature. The initial total organic carbon (TOC) concentration of the wastewaters and the O(2) concentration at the reactor inlet were kept constant at 0.49 and 0.74 mol/L. It was confirmed that the copper-plating wastewater accelerated the TOC conversion of acrylonitrile wastewater from 17.6% to 67.3% at a temperature of 450 degrees C. Moreover, copper and copper oxide nanoparticles were generated in the process of supercritical water oxidation (SCWO) of mixed wastewater. 99.8% of copper in mixed wastewater was recovered as solid copper and copper oxides at a temperature of 600 degrees C, with their average sizes ranging from 150 to 160 nm. Our study showed that SCWO provides a synergetic effect for simultaneous treatment of acrylonitrile and copper-plating wastewater. During the reaction, the oxidation rate of acrylonitrile wastewater was enhanced due to the in situ formation of nano-catalysts of copper and/or copper oxides, while the exothermic decomposition of acrylonitrile wastewater supplied enough heat for the recovery of solid copper and copper oxides from copper-plating wastewater. The synergetic effect of wastewater treatment by the newly proposed SCWO process leads to full TOC conversion, color removal, detoxification, and odor elimination, as well as full recovery of copper.

  15. EVALUATION OF TRICKLE-BED AIR BIOFILTER PERFORMANCE FOR STYRENE REMOVAL

    EPA Science Inventory

    A pilot-scale trickle-bed air biofilter (TBAB) was evaluated for the removal of styrene from a waste gas stream. Six-millimeter (6 mm) Celite pellets (R-635) were used as the biological attachment medium. The operating parameters considered in the study included the styrene vol...

  16. Initiation precursors and initiators in laser-induced copolymerization of styrene and maleic anhydride in acetone

    NASA Technical Reports Server (NTRS)

    Miner, Gilda A.; Meador, Willard E.; Chang, C. Ken

    1990-01-01

    The initiation step of photopolymerized styrene/maleic anhydride copolymer was investigated at 365 nm. UV absorption measurements provide decisive evidence that the styrene/maleic anhydride charge transfer complex is the sole absorbing species; however, key laser experiments suggest intermediate reactions lead to a monoradical initiating species. A mechanism for the photoinitiation step of the copolymer is proposed.

  17. 21 CFR 177.2710 - Styrene-divinylbenzene resins, cross-linked.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ....2710 Section 177.2710 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... for Use Only as Components of Articles Intended for Repeated Use § 177.2710 Styrene-divinylbenzene resins, cross-linked. Styrene-divinylbenzene cross-linked copolymer resins may be safely used as...

  18. 21 CFR 177.2710 - Styrene-divinylbenzene resins, cross-linked.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ....2710 Section 177.2710 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... for Use Only as Components of Articles Intended for Repeated Use § 177.2710 Styrene-divinylbenzene resins, cross-linked. Styrene-divinylbenzene cross-linked copolymer resins may be safely used as...

  19. 21 CFR 177.2710 - Styrene-divinylbenzene resins, cross-linked.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ....2710 Section 177.2710 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... for Use Only as Components of Articles Intended for Repeated Use § 177.2710 Styrene-divinylbenzene resins, cross-linked. Styrene-divinylbenzene cross-linked copolymer resins may be safely used as...

  20. AN EMPIRICAL MODEL TO PREDICT STYRENE EMISSIONS FROM FIBER-REINFORCED PLASTICS FABRICATION PROCESSES

    EPA Science Inventory

    Styrene is a designated hazardous air pollutant, per the 1990 Clean Air Act Amendments. It is also a tropospheric ozone precursor. Fiber-reinforced plastics (FRP) fabrication is the primary source of anthropogenic styrene emissions in the United States. This paper describes an em...

  1. ADDENDUM TO ASSESSMENT OF STYRENE EMISSION CONTROLS FOR FRP/C AND BOAT BUILDING INDUSTRIES

    EPA Science Inventory

    This report is an addendum to a 1996 report, Assessment of Styrene Emission Controls for FRP/C and Boat Building Industries. It presents additional evaluation of the biological treatment of styrene emissions, Dow Chemical Company's Sorbathene solvent vapor recovery system, Occupa...

  2. EVALUATION OF STYRENE EMISSIONS FROM A SHOWER STALL/BATHTUB MANUFACTURING FACILITY

    EPA Science Inventory

    The report gives results of emissions measurements carried out at a representative facility (Eljer Plumbingware in Wilson, NC) that manufactures polyester-resin-reinforced shower stalls and bathtubs by spraying styrene-based resins onto molds in vented, open, spray booths. Styren...

  3. Letter to the Editor: Styrene-producing microbes in food-stuff

    Technology Transfer Automated Retrieval System (TEKTRAN)

    An article was published in Journal of Food Science, August 2009 (Vol. 74, Nr 6) entitled “Natural formation of styrene by cinnamon mold flora”. In the article, the authors reported on the production of styrene from several fungi typically found on cinnamon, and used cinnamic acid and similar analog...

  4. Comparison of mouse strains for susceptibility to styrene-induced hepatotoxicity and pneumotoxicity

    SciTech Connect

    Carlson, G.P.

    1997-10-01

    Styrene is known to cause both hepatotoxicity and pneumotoxicity in mice. Strain differences have been reported by other investigators suggesting that Swiss mice are less susceptible than non-Swiss mice to styrene-induced liver damage. In this study, All and C57BL16 mice were found to be similar to non-Swiss albino (NSA) mice in susceptibility whereas CD-1 (Swiss) mice were more resistant to hepatotoxicity as assessed by serum sorbitol dehydrogenase levels and pneumotoxicity as determined by gamma-glutamyltranspeptidase and lactate dehydrogenase measurements in bronchoalveolar ravage fluid. Styrene was hepatotoxic in CD-1 mice treated with pyridine to induce CYP2E1. CYP2E1 apoprotein levels and p-nitrophenol hydroxylase activities in control and pyridine-induced mice were similar in the two strains. Hepatic and pulmonary microsomal preparations from both strains metabolized styrene to styrene oxide at similar rates. CD-1 mice were as susceptible as the NSA mice to the effects of styrene oxide. The data suggest that there are no differences in the bioactivation of styrene to styrene oxide or innate susceptibility to the active metabolite that would account for the differences between the CD-1 and NSA mice. 26 refs., 6 tabs.

  5. 40 CFR 721.6920 - Butyl acrylate, polymer with substituted methyl styrene, methyl methacrylate, and substituted...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Butyl acrylate, polymer with... acrylate, polymer with substituted methyl styrene, methyl methacrylate, and substituted silane. (a... butyl acrylate, polymer with substituted methyl styrene, methyl methacrylate, and substituted...

  6. 76 FR 77709 - Butyl acrylate-methacrylic acid-styrene polymer; Tolerance Exemption

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-14

    ... AGENCY 40 CFR Part 180 Butyl acrylate-methacrylic acid-styrene polymer; Tolerance Exemption AGENCY... from the requirement of a tolerance for residues of 2-Propenoic acid, 2-methyl-, polymer with butyl 2...-styrene polymer when used as an inert ingredient in a pesticide chemical formulation....

  7. 40 CFR 721.6920 - Butyl acrylate, polymer with substituted methyl styrene, methyl methacrylate, and substituted...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Butyl acrylate, polymer with... acrylate, polymer with substituted methyl styrene, methyl methacrylate, and substituted silane. (a... butyl acrylate, polymer with substituted methyl styrene, methyl methacrylate, and substituted...

  8. 40 CFR 721.6920 - Butyl acrylate, polymer with substituted methyl styrene, methyl methacrylate, and substituted...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Butyl acrylate, polymer with... acrylate, polymer with substituted methyl styrene, methyl methacrylate, and substituted silane. (a... butyl acrylate, polymer with substituted methyl styrene, methyl methacrylate, and substituted...

  9. 40 CFR 721.6920 - Butyl acrylate, polymer with substituted methyl styrene, methyl methacrylate, and substituted...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Butyl acrylate, polymer with... acrylate, polymer with substituted methyl styrene, methyl methacrylate, and substituted silane. (a... butyl acrylate, polymer with substituted methyl styrene, methyl methacrylate, and substituted...

  10. 40 CFR 721.6920 - Butyl acrylate, polymer with substituted methyl styrene, methyl methacrylate, and substituted...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Butyl acrylate, polymer with... acrylate, polymer with substituted methyl styrene, methyl methacrylate, and substituted silane. (a... butyl acrylate, polymer with substituted methyl styrene, methyl methacrylate, and substituted...

  11. POTENTIAL FOR REDUCING INDOOR STYRENE EXPOSURE FROM COPIED PAPER THROUGH USE OF LOW-EMITTING TONERS

    EPA Science Inventory

    Tests were conducted, using 53-L dynamic chambers, to determine airborne styrene emission rates over time from freshly copied paper. Copies were produced on a single photocopier, using two toners manufactured for this copier but having different styrene contents. The resulting em...

  12. Acid-catalyzed ortho-alkylation of anilines with styrenes: an improved route to chiral anilines with bulky substituents.

    PubMed

    Cherian, Anna E; Domski, Gregory J; Rose, Jeffrey M; Lobkovsky, Emil B; Coates, Geoffrey W

    2005-11-10

    [reaction: see text] Reaction of para-substituted anilines with styrene derivatives at elevated temperatures, when catalyzed by CF3SO3H, results in highly chemoselective ortho-alkylation of the aniline. When R = H, dialkylation can be achieved by varying the ratio of styrene to aniline. Several different substituted anilines and styrenes were examined, and good yields (42-87%) were obtained, except in the case where electron-withdrawing substituents are present on the styrene.

  13. Effects of simultaneous administration of ethanol on styrene metabolism under fed and fasted conditions in the perfused rat liver.

    PubMed

    Sripaung, N; Motohashi, Y; Nakata, K; Nakamura, K; Takano, T

    1995-08-01

    The purpose of this study was to clarify the simultaneous administration of ethanol on styrene metabolism in the perfused rat liver under fed and fasted conditions. Styrene uptake rate, production rate of styrene glycol, oxygen consumption rate, and changes in reduced pyridine nucleotide fluorescence were monitored in the perfused rat liver. The effects of ethanol on parameters of styrene metabolism were observed in rat livers under fed and fasted conditions: fed (group I), fasted (group II), and fasted with xylitol in the perfusate (group III). The simultaneous administration of ethanol and styrene significantly decreased styrene uptake rate, production rate of styrene glycol, and oxygen consumption rate, and produced significant reduction of pyridine nucleotide fluorescence as compared with the single administration of styrene in groups I and III. In contrast, the simultaneous administration of ethanol and styrene significantly increased the production of styrene glycol and oxygen consumption as compared with the single administration of styrene in group II. Significant effects on the styrene uptake rate and the reduced pyridine nucleotide fluorescence were observed with regard to factors of both nutritional status and the interaction between ethanol and nutritional status by two-way analysis of variance. These findings showed that the effects of ethanol on styrene metabolism in the liver were dependent upon the nutritional status of the animal. The fed and fasted conditions affected the effect of ethanol on styrene metabolism by changing the supply of NADPH to the mixed-function oxidase system. In conclusion, ethanol suppressed styrene metabolism in the fed condition, but enhanced it in the fasted condition. This phenomenon should be considered in the prevention of occupational hazard of styrene exposure in industrial workers with alcohol drinking habits and nutritional problems.

  14. Conversion of ethanol to 1,3-butadiene over Na doped ZnxZryOz mixed metal oxides

    SciTech Connect

    Baylon, Rebecca A.; Sun, Junming; Wang, Yong

    2016-01-01

    Despite numerous studies on different oxide catalysts for the ethanol to 1,3-butadiene reaction, few have identified active sites (i.e., type of acidity) correlated to the catalytic performances. In this work, the type of acidity needed for ethanol to 1,3-butadiene conversion has been studied over Zn/Zr mixed oxide catalysts. Specifically, synthesis method, Zn/Zr ratio, and Na doping have been used to control the surface acid-base properties, as confirmed by characterizations such as NH3-TPD and IR-Py techniques. The 2000 ppm Na doped Zn1Zr10Oz-H with balanced base and weak Bronsted acid sites was found to give not only high selectivity to 1,3-butadiene (47%) at near complete ethanol conversion (97%), but also exhibited a much higher 1,3-butadiene productivity than other mixed oxides studied.

  15. An integrated approach to biomonitoring exposure to styrene and styrene-(7,8)-oxide using a repeated measurements sampling design.

    PubMed

    Fustinoni, S; Campo, L; Manini, P; Buratti, M; Waidyanatha, S; De Palma, G; Mutti, A; Foa, V; Colombi, A; Rappaport, S M

    2008-09-01

    The aim of this work was to investigate urinary analytes and haemoglobin and albumin adducts as biomarkers of exposure to airborne styrene (Sty) and styrene-(7,8)-oxide (StyOX) and to evaluate the influence of smoking habit and genetic polymorphism of metabolic enzymes GSTM1 and GSTT1 on these biomarkers. We obtained three or four air and urine samples from each exposed worker (eight reinforced plastics workers and 13 varnish workers), one air and urine samples from 22 control workers (automobile mechanics) and one blood sample from all subjects. Median levels of exposure to Sty and StyOX, respectively, were 18.2 mg m(-3) and 133 microg m(-3) for reinforced plastics workers, 3.4 mg m(-3) and 12 microg m(-3) for varnish workers, and <0.3 mg m(-3) and <5 microg m(-3) for controls. Urinary levels of styrene, mandelic acid, phenylglyoxylic acid, phenylglycine (PHG), 4-vinylphenol (VP) and mercapturic acids (M1+M2), as well as cysteinyl adducts of serum albumin (but not those of haemoglobin) were significantly associated with exposure status (controls

  16. Proton exchange membranes prepared by grafting of styrene/divinylbenzene into crosslinked PTFE membranes

    NASA Astrophysics Data System (ADS)

    Li, Jingye; Ichizuri, Shogo; Asano, Saneto; Mutou, Fumihiro; Ikeda, Shigetoshi; Iida, Minoru; Miura, Takaharu; Oshima, Akihiro; Tabata, Yoneho; Washio, Masakazu

    2005-07-01

    Thin PTFE membranes were prepared by coating the PTFE dispersion onto the aluminum films. Thus the thin crosslinked PTFE (RX-PTFE) membranes were obtained by means of electron beam irradiation above the melting temperature of PTFE under oxygen-free atmosphere. The RX-PTFE membranes were pre-irradiated and grafted by styrene with or without divinylbenzene (DVB) in liquid phase. The existence of DVB accelerated the initial grafting rate. The styrene grafted RX-PTFE membranes are white colored, on the other hand, the styrene/DVB grafted RX-PTFE membranes are colorless. The proton exchange membranes (PEMs) were obtained by sulfonating the grafted membranes using chlorosulfonic acid. The ion exchange capacity (IEC) values of the PEMs ranging from 1.5 to 2.8 meq/g were obtained. The PEMs made from the styrene/DVB grafted membranes showed higher chemical stability than those of the styrene grafted membranes under oxidative circumstance.

  17. 40 CFR 721.7020 - Distillates (petroleum), C(3-6), polymers with styrene and mixed terpenes (generic name).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...), polymers with styrene and mixed terpenes (generic name). 721.7020 Section 721.7020 Protection of...), C(3-6), polymers with styrene and mixed terpenes (generic name). (a) Chemical substance and...), polymers with styrene and mixed terpenes (PMN P-89-676) is subject to reporting under this section for...

  18. 40 CFR 721.7020 - Distillates (petroleum), C(3-6), polymers with styrene and mixed terpenes (generic name).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...), polymers with styrene and mixed terpenes (generic name). 721.7020 Section 721.7020 Protection of...), C(3-6), polymers with styrene and mixed terpenes (generic name). (a) Chemical substance and...), polymers with styrene and mixed terpenes (PMN P-89-676) is subject to reporting under this section for...

  19. 40 CFR 721.7020 - Distillates (petroleum), C(3-6), polymers with styrene and mixed terpenes (generic name).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...), polymers with styrene and mixed terpenes (generic name). 721.7020 Section 721.7020 Protection of...), C(3-6), polymers with styrene and mixed terpenes (generic name). (a) Chemical substance and...), polymers with styrene and mixed terpenes (PMN P-89-676) is subject to reporting under this section for...

  20. 40 CFR 721.7020 - Distillates (petroleum), C(3-6), polymers with styrene and mixed terpenes (generic name).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...), polymers with styrene and mixed terpenes (generic name). 721.7020 Section 721.7020 Protection of...), C(3-6), polymers with styrene and mixed terpenes (generic name). (a) Chemical substance and...), polymers with styrene and mixed terpenes (PMN P-89-676) is subject to reporting under this section for...

  1. 40 CFR 721.7020 - Distillates (petroleum), C(3-6), polymers with styrene and mixed terpenes (generic name).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...), polymers with styrene and mixed terpenes (generic name). 721.7020 Section 721.7020 Protection of...), C(3-6), polymers with styrene and mixed terpenes (generic name). (a) Chemical substance and...), polymers with styrene and mixed terpenes (PMN P-89-676) is subject to reporting under this section for...

  2. Thermogravimetric and Spectroscopic Characterization of Sulfonated Poly(Styrene-Isobutylene-Styrene) Block Copolymers: Effects of Processing Conditions

    DTIC Science & Technology

    2006-05-01

    tetrahydrofuran [THF], benzene, CHCl3, CH2Cl2, cyclohexanone , and cyclohexanol). 2. Experimental 2.1 Materials The poly(styrene-isobutylene...Methylene chloride 10 21 — 24 48 Cyclohexanone 6.0 21 50 — — Cyclohexanol 4.0 — 21 24 48 2.3 Thermogravimetric Analysis The thermal history and...Methylene Chloride 19.8 290 ± 2 448 ± 1 21 ± 1 S-SIBS-29 Cyclohexanone 20.3 286 ± 2 446 ± 2 30 ± 3 S-SIBS-29 Cyclohexanol 23.3 290 ± 2 444 ± 2 9 ± 2

  3. The Effect of Uncertainty in Exposure Estimation on the Exposure-Response Relation between 1,3-Butadiene and Leukemia

    PubMed Central

    Graff, John J.; Sathiakumar, Nalini; Macaluso, Maurizio; Maldonado, George; Matthews, Robert; Delzell, Elizabeth

    2009-01-01

    In a follow-up study of mortality among North American synthetic rubber industry workers, cumulative exposure to 1,3-butadiene was positively associated with leukemia. Problems with historical exposure estimation, however, may have distorted the association. To evaluate the impact of potential inaccuracies in exposure estimation, we conducted uncertainty analyses of the relation between cumulative exposure to butadiene and leukemia. We created the 1,000 sets of butadiene estimates using job-exposure matrices consisting of exposure values that corresponded to randomly selected percentiles of the approximate probability distribution of plant-, work area/job group-, and year specific butadiene ppm. We then analyzed the relation between cumulative exposure to butadiene and leukemia for each of the 1,000 sets of butadiene estimates. In the uncertainty analysis, the point estimate of the RR for the first non zero exposure category (>0–<37.5 ppm-years) was most likely to be about 1.5. The rate ratio for the second exposure category (37.5–<184.7 ppm-years) was most likely to range from 1.5 to 1.8. The RR for category 3 of exposure (184.7–<425.0 ppm-years) was most likely between 2.1 and 3.0. The RR for the highest exposure category (425.0+ ppm-years) was likely to be between 2.9 and 3.7. This range off RR point estimates can best be interpreted as a probability distribution that describes our uncertainty in RR point estimates due to uncertainty in exposure estimation. After considering the complete probability distributions of butadiene exposure estimates, the exposure-response association of butadiene and leukemia was maintained. This exercise was a unique example of how uncertainty analyses can be used to investigate and support an observed measure of effect when occupational exposure estimates are employed in the absence of direct exposure measurements. PMID:19826555

  4. A flexible Li polymer primary cell with a novel gel electrolyte based on poly(acrylonitrile)

    NASA Astrophysics Data System (ADS)

    Akashi, Hiroyuki; Tanaka, Ko-ichi; Sekai, Koji

    The performance of a Li polymer primary cell with fire-retardant poly(acrylonitrile) (PAN)-based gel electrolytes is reported. By optimizing electrodes, electrolytes, the packaging material, and the structural design of the polymer cell, we succeeded in developing a "film-like" Li polymer primary cell with sufficient performance for practical use. The cell is flexible and less than 0.5 mm thick, which makes it suitable for a power source for some smart devices, such as an IC card. Fast cation conduction in the gel electrolyte minimizes the drop of the discharge capacity even at -20 °C. The high chemical stability of the gel electrolytes and the new packaging material allow the self-discharge rate to be limited to under 4.3%, which is equivalent to that of conventional coin-shaped or cylindrical Li-MnO 2 cells.

  5. Dielectric Relaxation Behavior of Poly(acrylonitrile-co-methacrylonitrile) Microcapsules Dispersed in a Silicone Matrix

    NASA Technical Reports Server (NTRS)

    Park, Taigyoo; OBrien, Emmett; Lizotte, Jeremy R.; Glass, Thomas E.; Ward, Thomas C.; Long, Timothy E.; Leo, Donald J.

    2006-01-01

    The dielectric relaxation behavior of poly(acrylonitrile-co-methacrylonitrile) dispersed in a cured polydimethyl siloxane (PDMS) matrix as microcapsules was investigated over multiple thermal cycles and at varying concentrations. The copolymer microcapsules contained an isopentane core. In the PDMS matrix this copolymer displayed a pronounced relaxation signal at temperatures above the glass transition of the copolymers due to Maxwell-Wagner-Sillars (MWS) relaxation. The mechanism of MWS relaxation interpreted by the Havriliak-Negami and Kohlrausch-Williams-Watts relaxation functions was found to be very similar to previous studies of neat polyacrylonitrile and its copolymer. The activation energy of the relaxation decreased over successive thermal cycling coincident with a decreasing strength of the relaxation. These observations were attributed to the decreasing concentration of nitrile groups due to intramolecular cyclizations.

  6. Synthesis, characterization, and antimicrobial activity of poly(acrylonitrile-co-methyl methacrylate) with silver nanoparticles.

    PubMed

    El-Aassar, M R; Hafez, Elsayed E; Fouda, Moustafa M G; Al-Deyab, Salem S

    2013-10-01

    Nanotechnology is expected to open some new aspects to fight and prevent diseases using atomic-scale tailoring of materials. The main aim of this study is to biosynthesize silver nanoparticles (AgNPs) using Trichoderma viride (HQ438699); the metabolite of this fungus will help either in reduction of the silver nitrate-adding active materials which will be loaded on the surface of the produced AgNPs. Poly(acrylonitrile-co-methyl methacrylate) copolymer (poly (AN-co-MMA)) was grafted with the prepared AgNPs. The poly(AN-co-MMA)/AgNPs were examined against ten different pathogenic bacterial strains, and the result was compared with another four different generic antibiotics. The produced poly(AN-co-MMA)/AgNPs showed high antibacterial activity compared with the four standard antibiotics. Moreover, the grafting of these AgNPs into the copolymer has potential application in the biomedical field.

  7. Carcinogenicity and other health effects of acrylonitrile with reference to occupational exposure limit.

    PubMed

    Sakurai, H

    2000-04-01

    The occupational exposure limit for acrylonitrile (AN) has been set by many organizations on the basis of its carcinogenicity. However, recent epidemiological studies do not afford evidence supporting the hypothesis that AN is carcinogenic to humans. Review of the 18 published cohort studies revealed that, although there is not adequate evidence in humans for carcinogenicity of AN, the possibility of a causal association between high exposure to AN and lung cancer in humans cannot be excluded. It was pointed out that carcinogenic potential of AN may be weak, if any, to humans, and the current occupational exposure limit (OEL) for AN of 2 ppm was evaluated as appropriate in view of AN exposure levels reported by epidemiological studies. Based also on review of the literature on health effects other than carcinogenicity, it was concluded that the current OEL for AN is a reasonable value and there is no need for a revision at present.

  8. Comparison of cancer risks projected from animal bioassays to epidemiologic studies of acrylonitrile-exposed workers.

    PubMed

    Ward, C E; Starr, T B

    1993-10-01

    Bioassay findings have demonstrated that acrylonitrile (ACN) is a rodent carcinogen, but the available epidemiologic evidence provides little support for the human carcinogenicity of ACN. This discordance between laboratory animal and human study findings is explored by determining post hoc the statistical power of 11 epidemiologic studies of ACN-exposed workers to detect the all-site and brain cancer excesses that are projected from rodent drinking water bioassay data. At reasonable estimates of the level and duration of exposures among the occupational cohorts, a majority of the human studies had sufficient power (> 80%) to detect the projected excesses, yet such responses were consistently absent. We conclude, subject to certain caveats, that the upper bound estimate of ACN's inhalation cancer potency of 1.5 x 10(-4) per ppm is too high to be consistent with the human ACN experience.

  9. Cytotoxic effects of acrylonitrile on human umbilical cord mesenchymal stem cells in vitro.

    PubMed

    Sun, Xiaochun; Sun, Min; Xie, Yan; Zhai, Wei; Zhu, Wei; Ma, Rui; Lu, Rongzhu; Xu, Wenrong

    2014-01-01

    The effects of acrylonitrile (ACN) on human umbilical cord mesenchymal stem cells (hUC‑MSCs) remain unknown. The proliferation, differentiation, clonogenicity and apoptosis effects of ACN and/or N‑acetyl‑L‑cysteine (NAC) on hUC‑MSCs were investigated. The results showed that although ACN at a concentration of 0.1 µg/ml did not affect proliferation or the morphology of hUC‑MSCs compared with the control, osteogenic differentiation and the positive rate of alkaline phosphatase staining in the experimental group were significantly lower compared with the control (P<0.01). All of the effects of ACN were counteracted using NAC, a typical antioxidant. Using a flow cytometry assay, it was observed that ACN induced apoptosis in hUC‑MSCs. The results indicated that the toxic effect produced by ACN on hUC‑MSCs is based on a redox mechanism.

  10. Studies of plastic crystal gel polymer electrolytes based on poly(vinylidene chloride-co-acrylonitrile)

    NASA Astrophysics Data System (ADS)

    Hambali, D.; Zainuddin, Z.; Supa'at, I.; Osman, Z.

    2016-02-01

    In this work, we have prepared systems of poly(vinylidene chloride-co-acrylonitrile) (PVdC-co-AN) based gel polymer electrolytes (GPEs) which are single plasticized-GPEs and double plasticized-GPEs. Both systems comprised plastic crystal succinonitrile SN to form plastic crystal gel polymer electrolyte (PGPE) films. The ionic conductivity of the PGPE films were analysed by means of a.c. impedance spectroscopy at room temperature as well as at the temperature range of 303 K to 353 K. The temperature dependence ionic conductivity was found to obey the VTF rule. To study the interactions among the constituents in the PGPEs, Fourier Transform Infrared Spectroscopy (FTIR) was carried out and hence, the complexation between them has also been confirmed.

  11. Prevention of acrylonitrile-induced gastrointestinal bleeding by sulfhydryl compounds, atropine and cimetidine

    SciTech Connect

    Ghanayem, B.I.; Ahmed, A.E.

    1986-07-01

    We have recently demonstrated that acrylonitrile (VCN) causes acute gastric hemorrhage and mucosal erosions. The current studies were undertaken to investigate the effects of the sulfhydryl-containing compounds, cysteine and cysteamine, the cholinergic blocking agent atropine and the histamine H2 receptor antagonist, cimetidine on the VCN-induced gastrointestinal (GI) bleeding in rats. Our data shows that pretreatment with L-cysteine, cysteamine, atropine or cimetidine has significantly protected rats against the VCN-induced GI bleeding. A possible mechanism of the VCN-induced GI bleeding may involve the interaction of VCN with critical sulfhydryl groups that, in turn, causes alteration of acetylcholine muscarinic receptors to lead to gastric hemorrhagic lesions and bleeding.

  12. Intumescent flame retardants for polymers. I. The poly(acrylonitrile)-ammonium polyphosphate-hexabromocyclododecane system

    SciTech Connect

    Ballistreri, A.; Montaudo, G.; Puglisi, C.; Scamporrino, E.; Vitalini, D.

    1983-05-01

    The influence of ammonium polyphosphate (APP) and hexabromocyclododecane (HBCD) as flame retardant (FR) on poly(acrylonitrile) (PAN) has been examined. The APP-HBCD system behaves as an intumescent flame retardant (IFR) formulation, APP being the char-forming agent and HBCD the blowing agent. A negligible gas-phase mode of action was ascertained for HBCD with this substrate. A synergism between the two FR agents was observed, corresponding to about 50% increased efficacy with respect to the separate effects of the two components. Thermogravimetry (TG), oxygen index (OI), nitrous oxide index (NOI) experiments and phosphorous residue measurements were performed to substantiate the conclusion that a condensed phase mechanism of action accounts for all the facts observed.

  13. Covalent immobilization of glucose oxidase onto new modified acrylonitrile copolymer/silica gel hybrid supports.

    PubMed

    Godjevargova, Tzonka; Nenkova, Ruska; Dimova, Nedyalka

    2005-08-12

    New polymer/silica gel hybrid supports were prepared by coating high surface area of silica gel with modified acrylonitrile copolymer. The concentrations of the modifying agent (NaOH) and the modified polymer were varied. GOD was covalently immobilized on these hybrid supports and the relative activity and the amount of bound protein were determined. The highest relative activity and sufficient amount of bound protein of the immobilized GOD were achieved in 10% NaOH and 2% solution of modified acrylonitrile copolymer. The influence of glutaraldehyde concentration and the storage time on enzyme efficiency were examined. Glutaraldehyde concentration of 0.5% is optimal for the immobilized GOD. It was shown that the covalently bound enzyme (using 0.5% glutaraldehyde) had higher relative activity than the activity of the adsorbed enzyme. Covalently immobilized GOD with 0.5% glutaraldehyde was more stable for four months in comparison with the one immobilized on pure silica gel, hybrid support with 10% glutaraldehyde and the free enzyme. The effect of the pore size on the enzyme efficiency was studied on four types of silica gel with different pore size. Silica with large pores (CPC-Silica carrier, 375 A) presented higher relative activity than those with smaller pore size (Silica gel with 4, 40 and 100 A). The amount of bound protein was also reduced with decreasing the pore size. The effect of particle size was studied and it was found out that the smaller the particle size was, the greater the activity and the amount of immobilized enzyme were. The obtained results proved that these new polymer/silica gel hybrid supports were suitable for GOD immobilization.

  14. Photoinitiated decomposition of substituted ethylenes: The photodissociation of vinyl chloride and acrylonitrile at 193 nm

    SciTech Connect

    Blank, D.A.; Suits, A.G.; Lee, Y.T.

    1997-04-01

    Ethylene and its substituted analogues (H{sub 2}CCHX) are important molecules in hydrogen combustion. As the simplest {pi}-bonded hydrocarbons these molecules serve as prototypical systems for understanding the decomposition of this important class of compounds. The authors have used the technique of photofragment translational spectroscopy at beamline 9.0.2.1 to investigate the dissociation of vinyl chloride (X=Cl) and acrylonitrile (X=CN) following absorption at 193 nm. The technique uses a molecular beam of the reactant seeded in helium which is crossed at 90 degrees with the output of an excimer laser operating on the ArF transition, 193.3 nm. The neutral photoproducts which recoil out of the molecular beam travel 15.1 cm where they are photoionized by the VUV undulator radiation, mass selected, and counted as a function of time. The molecular beam source is rotatable about the axis of the dissociation laser. The authors have directly observed all four of the following dissociation channels for both systems: (1) H{sub 2}CCHX {r_arrow} H + C{sub 2}H{sub 2}X; (2) H{sub 2}CCHX {r_arrow} X + C{sub 2}H{sub 3}; (3) H{sub 2}CCHX {r_arrow} H{sub 2} + C{sub 2}HX; and (4) H{sub 2}CCHX {r_arrow} HX + C{sub 2}H{sub 2}. They measured translational energy distributions for all of the observed channels and measured the photoionization onset for many of the photoproducts which provided information about their chemical identity and internal energy content. In the case of acrylonitrile, selective product photoionization provided the ability to discriminate between channels 2 and 4 which result in the same product mass combination.

  15. Immunoassay of haemoglobin-acrylonitrile adduct in rat as a biomarker of exposure.

    PubMed

    L Wong Yu Ting Zheng Junyu Li Carlo H Tamburro Frederick W Benz, J

    1998-01-01

    Acrylonitrile (AN) is a rat carcinogen. Human exposure may come from chemical industries and smoking. A haemoglobin adduct of acrylonitrile (Hb-AN) has been used as a biomarker of exposure by means of gas chromatography-mass spectrometry (GC-MS) analysis. We have developed specific monoclonal antibodies (Mab) to human Hb-AN and wish to report evaluation of an immunoassay in rats using an Mab that cross-reacts with rat Hb-AN. A dose response study of LD 0, 10, 50, and 90 in Sprague-Dawley rats was undertaken, with each rat receiving \\[2,3-14C]AN at 50 Ci kg-1 sc, and Hb from an aliquot of blood was taken for covalent binding analysis by liquid scintillation spectrometry and fluorescence ELISA. The dose responses of rats at 0.25, 0.5, 1.0, and 2.0 h after AN doses of 20, 50, 80, 115 mg kg-1 were compared by both methods with Hb and globin samples. Regression analysis showed a linear relationship between immunoassay and 14C-AN binding. This indicates that an antigenic form of Hb-AN may be used as a surrogate of Hb-AN adduct. The sensitivity of ELISA was tested in rats exposed for 1 h to sub-toxic doses of AN (10-1.1 mg kg-1). Quantification of Hb-AN by immunoassay was achieved by calibration with a synthetic adduct HbAN4h, a reference adduct prepared by treating rat Hb with excess AN for 4 h. ELISA and GC-MS analysis of N-terminal valine-AN in the Hb-AN adduct were compared and similar detection levels were found. This rat study appears to have validated the new immunoassay method for biomonitoring of AN exposure.

  16. Studies of the mutagenic effects of styrene to man: conclusions for the surveillance of styrene-exposed workers

    NASA Astrophysics Data System (ADS)

    Rothe, Roland; Schmidt, P.; Grummt, T.; Grummt, H. J.; Kersten, N.; Weigmann, Hans-Juergen

    1993-03-01

    One hundred fifty-six styrene-exposed workers had a fourfold higher rate of chromosome aberrations in peripheral lymphocytes than the control persons. The parameters of clinical chemistry (liver, kidney, and blood) remained in the normal range. Further analyses of the data of this study revealed no connections of the degree of effects in clinical chemistry and the exposure level. But a connection exists to the duration of exposure (3 - 26 years): in the comparison of the mean values (all mean values within the normal range) significant differences were found between long-term exposed workers (more than ten years) and control persons. In the higher age groups (above 45 years) also the GAP-rate differences are more pronounced. Seventy percent of the TWA-values were found to be below 85 mg/m3; the arithmetic mean of the TWA-values 72,3 mg/m3. A health surveillance program to styrene-exposed workers is to be reviewed (clinical chemistry and genetic effects). Proposals concerning both problems are presented.

  17. Palladium-catalyzed 1,4-difunctionalization of butadiene to form skipped polyenes.

    PubMed

    McCammant, Matthew S; Liao, Longyan; Sigman, Matthew S

    2013-03-20

    A palladium-catalyzed 1,4-addition across the commodity chemical 1,3-butadiene to afford skipped polyene products is reported. Through a palladium σ → π → σ allyl isomerization, two new carbon-carbon bonds are formed with high regioselectivity and trans stereoselectivity of the newly formed alkene. The utility of this method is highlighted by the successful synthesis of the ripostatin A skipped triene core.

  18. An isotopic dilution approach for 1,3-butadiene tailpipe emissions and ambient air monitoring.

    PubMed

    Riservato, Manuela; Rolla, Antonio; Davoli, Enrico

    2004-01-01

    An isotopic dilution approach for 1,3-butadiene analysis in gaseous samples is presented. The methodology is based on active sampling on sorbent tubes and subsequent analysis by thermal desorption into a gas chromatography/mass spectrometry system. By adding a perdeuterated internal standard onto the sorbent tubes before sampling, and using mass spectrometric detection, the methodology gives high accuracy for this unstable analyte. The method has been used to monitor 1,3-butadiene ambient air concentrations in a residential area in proximity to a heavy-traffic roadway over a one-week period, for comparison with other traffic-related pollutants analysed by standard procedures. It has also been used to determine tailpipe emissions of two vehicles by standard emission testing procedures in a dynamometer. These vehicles were chosen as examples of low- and high-end emission rate vehicles, i.e., an old no-catalytic converter Otto engine and a new direct-injection diesel engine with catalytic converter. Exhaust gas emissions were 0.052 and 35.85 mg/km, reflecting differences in fuel, engine design, age, and presence (or not) of a catalytic abatement system. The ambient air results showed a weekly average concentration of 1,3-butadiene of 0.53 microg/m(3).

  19. 32P-postlabelling of diastereomeric 7-alkylguanine adducts of butadiene monoepoxide.

    PubMed

    Kumar, R; Vodicka, P; Koivisto, P; Peltonen, K; Hemminki, K

    1996-06-01

    The reaction of 3,4-epoxy-1-butene (BMO) with deoxyguanosine-3'-monophosphate (3'-dGMP) resulted in the formation of two pairs of diastereomeric 7-alkyl-3'-dGMP derivatives corresponding to two isomers C¿-1 and C¿-2. The T4 polynucleotide kinase-mediated phosphorylation with [gamma-32P]-ATP showed preferential labelling of diastereo- mers of the C¿-1 isomer. The diastereomers 1 and 2 of the C¿-1 isomer had labelling efficiencies of 42%. However, the labelling efficiencies of diastereomers 3 and 4 of the C¿-2 isomer were 11 and 10%, respectively. The 32P-postlabelling of BMO-modified DNA yielded four isomers in the ratio of 4:4:1:1 with overall recoveries being 14%. The two isomers had a half-life of 270 min (C¿-1 isomer) and 300 min (C¿-2 isomer) which is in accordance with the stability predicted by other similar adduct experiments. The molecular modelling experiments showed more pronounced restricted rotation of butadiene residue in C¿-2 isomers due to steric interaction between butadiene residue at N-7 and O(6) atom of guanine than in C¿-1 isomer. The butadiene residue also leads to steric overcrowding at 3'-phosphate in C¿-2 isomer which probably restricts the access to the active site of T4 polynucleotide kinase.

  20. Inhalation developmental toxicology studies: Teratology study of 1,3-butadiene in mice: Final report

    SciTech Connect

    Hackett, P.L.; Sikov, M.R.; Mast, T.J.; Brown, M.G.; Buschbom, R.L.; Clark, M.L.; Decker, J.R.; Evanoff, J.J.; Rommereim, R.L.; Rowe, S.E.; Westerberg, R.B.

    1987-11-01

    Maternal toxicity, reproductive performance and developmental toxicology were evaluated in CD-1 mice following whole-body, inhalation exposures to 0, 40, 200 and 1000 ppM of 1,3-butadiene. The female mice, which had mated with unexposed males were exposed to the chemical for 6 hours/day on 6 through 15 dg and sacrificed on 18 dg. Maternal animals were weighed prior to mating and on 0, 6, 11 and 18 dg; the mice were observed for mortality, morbidity and signs of toxicity during exposure and examined for gross tissue abnormalities at necropsy. Live fetuses were weighed and subjected to external, visceral and skeletal examinations to detect growth retardation and morphologic anomalies. Significant concentration-related decreases were detected in a number of maternal body weight measures. There was a significant concentration-related depression of fetal body weights and placental weights. Body weights of male fetuses of all exposed groups were significantly lower than values for control fetuses; weights of female fetuses were significantly depressed in the mice exposed to 200 and 1000 ppM. In the 200- and 1000-ppM exposure groups, weights of placentas of male fetuses were significantly decreased, but placental weights of female fetuses were significantly affected only in litters exposed to the highest 1,3-butadiene concentration. This exposure regimen produced significant signs of maternal toxicity at concentrations of 200 and 1000 ppM 1,3-butadiene.

  1. Full Configuration Interaction Excitations of Ethene and Butadiene: Resolution of an Ancient Question.

    PubMed

    Daday, Csaba; Smart, Simon; Booth, George H; Alavi, Ali; Filippi, Claudia

    2012-11-13

    We employ the recently developed full configuration interaction quantum Monte Carlo (FCIQMC) method to compute the π → π* vertical excitation energies of ethene and all-trans butadiene. These excitations have been the subject of extensive theoretical studies, and their location with respect to the corresponding absorption band maximum is the source of a long lingering debate. Here, we reliably estimate the vertical excitations of ethene and butadiene by performing FCIQMC calculations for spaces as large as 10(18) and 10(29) Slater determinants, respectively. For ethene, we obtain a vertical excitation energy in the range 7.89-7.96 eV, depending on the particular equilibrium ground-state geometry employed, and definitely higher than the absorption maximum located at 7.66 eV. For the computationally more challenging case of butadiene, our calculations provide a robust estimate of about 6.3 eV for this excitation, that is, 0.4 eV higher than the corresponding absorption band maximum. Our FCIQMC excitation energies represent a reliable benchmarking reference for future calculations.

  2. Technoeconomic evaluation of bio-based styrene production by engineered Escherichia coli.

    PubMed

    Claypool, Joshua T; Raman, D Raj; Jarboe, Laura R; Nielsen, David R

    2014-08-01

    Styrene is an important commodity chemical used in polymers and resins, and is typically produced from the petrochemical feedstocks benzene and ethylene. Styrene has recently been produced biosynthetically for the first time using engineered Escherichia coli, and this bio-based route may represent a lower energy and renewable alternative to petroleum-derived styrene. However, the economics of such an approach has not yet been investigated. Using an early-stage technoeconomic evaluation tool, a preliminary economic analysis of bio-based styrene from C(6)-sugar feedstock has been conducted. Owing to styrene's limited water solubility, it was assumed that the resulting fermentation broth would spontaneously form two immiscible liquid phases that could subsequently be decanted. Assuming current C(6) sugar prices and industrially achievable biokinetic parameter values (e.g., product yield, specific growth rate), commercial-scale bio-based styrene has a minimum estimated selling price (MESP) of 1.90 USD kg(-1) which is in the range of current styrene prices. A Monte Carlo analysis revealed a potentially large (0.45 USD kg(-1)) standard deviation in the MESP, while a sensitivity analysis showed feedstock price and overall yield as primary drivers of MESP.

  3. Assessment of the peripheral, central, and autonomic nervous system function in styrene workers

    SciTech Connect

    Murata, K.; Araki, S.; Yokoyama, K. )

    1991-01-01

    To investigate the effects of styrene exposure on peripheral, central, and autonomic nervous system functions in man, we measured the distribution of nerve conduction velocities (DCV), short-latency somatosensory evoked potentials (SSEP), and variability in electrocardiographic R-R interval (CVRR) as well as conventional sensory and motor median nerve conduction velocities (SCV and MCV) in eleven styrene-exposed workers. The styrene workers' urinary phenylglyoxylic acid levels ranged from 31 to 419 (mean 169) mg/g creatinine at the end of the work shift on the examination day (estimated exposure to styrene of 22 ppm in air). Control subjects, matched to each styrene worker by sex and age, were selected from healthy adults without cardiovascular, neurologic and other potentially confounding disorders. In the styrene workers, we found that the V80 velocity of the DCV, below which 80% of active nerve fibers lie, and the SCV were both significantly slowed; the CVRR was also significantly reduced. There were no significant differences in SSEP latencies, MCV, or heart rate between the exposed workers and controls. These data, despite the small sample size, suggest that styrene affects the faster myelinated fibers of the peripheral sensory nerves, and that it also affects autonomic nervous activity.

  4. Leaching of styrene and other aromatic compounds in drinking water from PS bottles.

    PubMed

    Ahmad, Maqbool; Bajahlan, Ahmad S

    2007-01-01

    Bottled water may not be safer, or healthier, than tap water. The present studies have proved that styrene and some other aromatic compounds leach continuously from polystyrene (PS) bottles used locally for packaging. Water sapmles in contact with PS were extracted by a preconcentration technique called as "purge and trap" and analysed by gas chromatograph-mass spectrometer (GC/MS). Eleven aromatic compounds were identified in these studies. Maximum concentration of styrene in PS bottles was 29.5 microg/L. Apart from styrene, ethyl benzene, toluene and benzene were also quantified but their concentrations were much less than WHO guide line values. All other compounds were in traces. Quality of plastic and storage time were the major factor in leaching of styrene. Concentration of styrene was increased to 69.53 microg/L after one-year storage. In Styrofoam and PS cups studies, hot water was found to be contaminated with styrene and other aromatic compounds. It was observed that temperature played a major role in the leaching of styrene monomer from Styrofoam cups. Paper cups were found to be safe for hot drinks.

  5. Trends in Occupational Exposure to Styrene in the European Glass Fibre-Reinforced Plastics Industry

    PubMed Central

    Van Rooij, J. G. M.; Kasper, A.; Triebig, G.; Werner, P.; Kromhout, H.

    2008-01-01

    Aim: This study presents temporal trends of styrene exposure for workers in the European glass fibre-reinforced plastics (GRP) industry during the period 1966–2002. Methods: Data of personal styrene exposure measurements were retrieved from reports, databases and peer-reviewed papers. Only sources with descriptive statistics of personal measurements were accepted. The styrene exposure data cover personal air samples and biological monitoring data, that is, urinary styrene metabolites (mandelic acid and/or phenylglyoxylic acid) and styrene in blood. Means of series of measurements were categorized by year, country, production process, job and sampling strategy. Linear mixed models were used to identify temporal trends and factors affecting exposure levels. Results: Personal exposure measurements were available from 60 reports providing data on 24145 1–8-h time-weighted average shift personal air samples. Available data of biological exposure indicators included measurements of mandelic acid in post-shift urine (6361 urine samples being analysed). Trend analyses of the available styrene exposure data showed that the average styrene concentration in the breathing zone of open-mould workers in the European GRP industry has decreased on average by 5.3% per year during the period 1966–1990 and by only 0.4% annually in the period after 1990. The highest exposures were measured in Southern Europe and the lowest exposures in Northern Europe with Central Europe in between. Biological indicators of styrene (mandelic acid in post-shift urine) showed a somewhat steeper decline (8.9%), most likely because urine samples were collected in companies that showed a stronger decrease of styrene exposure in air than GRP companies where no biological measurements were carried out. PMID:18550625

  6. Cooperativity in CYP2E1 metabolism of acetaminophen and styrene mixtures.

    PubMed

    Hartman, Jessica H; Letzig, Lynda G; Roberts, Dean W; James, Laura P; Fifer, E Kim; Miller, Grover P

    2015-10-01

    Risk assessment for exposure to mixtures of drugs and pollutants relies heavily on in vitro characterization of their bioactivation and/or metabolism individually and extrapolation to mixtures assuming no interaction. Herein, we demonstrated that in vitro CYP2E1 metabolic activation of acetaminophen and styrene mixtures could not be explained through the Michaelis-Menten mechanism or any models relying on that premise. As a baseline for mixture studies with styrene, steady-state analysis of acetaminophen oxidation revealed a biphasic kinetic profile that was best described by negative cooperativity (Hill coefficient=0.72). The best-fit mechanism for this relationship involved two binding sites with differing affinities (Ks=830μM and Kss=32mM). Introduction of styrene inhibited that reaction less than predicted by simple competition and thus provided evidence for a cooperative mechanism within the mixture. Likewise, acetaminophen acted through a mixed-type inhibition mechanism to impact styrene epoxidation. In this case, acetaminophen competed with styrene for CYP2E1 (Ki=830μM and Ksi=180μM for catalytic and effector sites, respectively) and resulted in cooperative impacts on binding and catalysis. Based on modeling of in vivo clearance, cooperative interactions between acetaminophen and styrene resulted in profoundly increased styrene activation at low styrene exposure levels and therapeutic acetaminophen levels. Current Michaelis-Menten based toxicological models for mixtures such as styrene and acetaminophen would fail to detect this concentration-dependent relationship. Hence, future studies must assess the role of alternate CYP2E1 mechanisms in bioactivation of compounds to improve the accuracy of interpretations and predictions of toxicity.

  7. Biomonitoring for Exposure Assessment to Styrene in the Fibreglass Reinforced Plastic Industry: Determinants and Interferents.

    PubMed

    Bonanni, Rossana Claudia; Gatto, Maria Pia; Paci, Enrico; Gordiani, Andrea; Gherardi, Monica; Tranfo, Giovanna

    2015-10-01

    Fifty-eight workers exposed to styrene were monitored in four fibreglass reinforced plastic industries of Central Italy. The aim of the study was to explore the factors that can influence the levels of styrene exposure biomarkers of the workers and the aspects that might interfere with the exposure assessment measures, such as the co-exposure to acetone. Personal monitoring of professional exposure to airborne styrene and acetone was carried out by Radiello samplers and GC/MS analysis. Biological monitoring was performed by the determination of urinary metabolites, mandelic (MA), and phenylglyoxylic (PGA) acids with HPLC/MS/MS and unmetabolized styrene in saliva and venous blood by HS/GC/MS. The median values of the four sites ranged between 24.1 to 94.0mg m(-3) and 7.3 to 331.1mg g(-1) creatinine for airborne styrene and MA + PGA, respectively. A good linear correlation was found between styrene in air and its urinary metabolites (r = 0.854). The median value for airborne styrene was found to exceed the (Threshold Limit Value - Time Weighted Average) of 85 mg m(-3) in one site for all the workers and in two if only moulders are considered. The multiple linear regression model showed that the determinants of urinary MA + PGA excretion were the type of process, workers' tasks, level of acetone co-exposure, and the use of respiratory protection devices. Data show that the simultaneous exposure to acetone modify the styrene metabolism with a reduction in the levels of (MA + PGA) excreted. A significant linear log-correlation was found between salivary levels of styrene and blood concentration (r = 0.746) sampled at the same t x time.

  8. Interfacing microbial styrene production with a biocompatible cyclopropanation reaction.

    PubMed

    Wallace, Stephen; Balskus, Emily P

    2015-06-08

    The introduction of new reactivity into living organisms is a major challenge in synthetic biology. Despite an increasing interest in both the development of small-molecule catalysts that are compatible with aqueous media and the engineering of enzymes to perform new chemistry in vitro, the integration of non-native reactivity into metabolic pathways for small-molecule production has been underexplored. Herein we report a biocompatible iron(III) phthalocyanine catalyst capable of efficient olefin cyclopropanation in the presence of a living microorganism. By interfacing this catalyst with E. coli engineered to produce styrene, we synthesized non-natural phenyl cyclopropanes directly from D-glucose in single-vessel fermentations. This process is the first example of the combination of nonbiological carbene-transfer reactivity with cellular metabolism for small-molecule production.

  9. 40 CFR 63.484 - Storage vessel provisions.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...-butadiene latex; (2) Storage vessels containing latex products other than styrene-butadiene latex, located downstream of the stripping operations; (3) Storage vessels containing high conversion latex products;...

  10. 40 CFR 63.484 - Storage vessel provisions.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...-butadiene latex; (2) Storage vessels containing latex products other than styrene-butadiene latex, located downstream of the stripping operations; (3) Storage vessels containing high conversion latex products;...

  11. 40 CFR 63.484 - Storage vessel provisions.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...-butadiene latex; (2) Storage vessels containing latex products other than styrene-butadiene latex, located downstream of the stripping operations; (3) Storage vessels containing high conversion latex products;...

  12. 40 CFR 63.484 - Storage vessel provisions.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...-butadiene latex; (2) Storage vessels containing latex products other than styrene-butadiene latex, located downstream of the stripping operations; (3) Storage vessels containing high conversion latex products;...

  13. Free-radical copolymerization of fullerenes with styrene

    SciTech Connect

    Cao, T.; Webber, S.E.

    1995-05-08

    Various methods to chemically modify the fullerenes have been reported in the last few years since the production of large-scale amounts of fullerene soot that contains primarily C{sub 60}, a lesser amount of C{sub 70}, and traces of higher fullerenes. Fortunately, these components can be separated from each other by standard chromatographic methods, permitting convenient experimentation on relatively pure components. The authors have found that C{sub 60} and C{sub 70} copolymerize with styrene in a standard free-radical polymerization, either in the bulk or codissolved in an aromatic solvent. The resulting polymers are soluble in common solvents that dissolve polystyrene and possess a dark brown color. The absorption spectrum of the copolymer is strongly modified from that of the parent fullerene, and the fluorescence is blue-shifted and much stronger. The present paper describes a very simple method for direct incorporation of C{sub 60} or C{sub 70} into polystyrene by direct free-radical copolymerization under routine conditions. While a great deal remains to be done to characterize fullerenes as comonomers in free-radical polymerization, this method is so direct and simple that it may be of interest to a wide range of researchers working in the area of fullerene chemistry. The authors note a report by Gong et al. in which a polymerization of styrene and {alpha}-methylstyrene was carried out in the presence of C{sub 60} using benzoyl peroxide as an initiator. These authors explicitly state that the C{sub 60} retains its normal absorption spectrum and is dispersed within the resulting solid polymer matrix. No other characterization is presented to demonstrate if chemical attachment of the C{sub 60} to the polymer occurred.

  14. Simultaneous determination of aromatic acid metabolites of styrene and styrene-oxide in rat urine by gas chromatography-flame ionization detection.

    PubMed

    Cosnier, Frédéric; Nunge, Hervé; Cossec, Benoît; Gaté, Laurent

    2012-06-01

    A convenient and reliable gas chromatographic method was developed for the simultaneous determination of six aromatic acid metabolites of styrene and styrene-oxide in rat urine; i.e., benzoic (BA), phenylacetic (PAA), mandelic (MA), phenylglyoxylic (PGA), hippuric (HA) and phenylaceturic (PAUA) acids. The method involves a one-pot esterification-extraction procedure, performed directly on urine without prior treatment. Analyses were performed on a RTX-1701 capillary column and the recovered isopropyl esters derivatives were detected by flame ionization detection. The analytical method was validated for selectivity, linearity, detection and quantification limits, recovery and intra-day and inter-day precisions. Calibration curves showed linearity in the range of 8-800 mg/L, except for HA and PAUA (40-800 mg/L). Limits of detection were between 0.2 (PPA) and 7.0 (PAUA) mg/L. The intra-day precisions determined at three concentrations levels were less than 5% for BA, PAA, MA and PGA and 9% for HA and PAUA, respectively. The corresponding mean inter-day precisions for these two groups were 8 and 16%, respectively. The method was successfully applied to quantitatively analyze styrene, styrene-oxide, ethylbenzene and toluene metabolites in urine samples from rats exposed by inhalation to these compounds at levels close to the occupational threshold limit values. Provided that this method can be transposed to human urine, it could have applications as part of biological monitoring for workers exposed to styrene or related compounds.

  15. Ionic polymer-metal composite actuators employing sulfonated poly (styrene-ethylene-butylene-styrene) as ionic-exchange membranes

    NASA Astrophysics Data System (ADS)

    Wang, Xuan-Lun; Oh, Il-Kwon; Lu, Jun; Ju, Jin-Hun; Lee, Sun-Woo

    2007-07-01

    There is growing interest in biomimetic motions by employing ionic polymer-metal composites (IPMCs) as the candidates for the fabrication of artificial muscle. However, the membrane materials currently used in IPMC actuators have been limited to a few commercially available perfluorinated ionic polymers, such as Nafion, and they suffer from several shortcomings among which their high cost presents a major obstacle for wide application. With excellent proton conductivity and high water uptake capacity, commercially available Sulfonated poly (styrene-ethylene-butylene-styrene) (SEBS) of low cost has been investigated for many years as a fuel cell membrane. Herein, we report the preparation of a novel IPMC actuator based on the sulfonated SEBS (SSEBS) membrane. The platinum electrodes of the SEBS actuators were obtained with electroless plating procedure, and the cation exchange with lithium was performed by soaking the composite membranes into a 1.5N LiCl solution. The surface and cross-sectional morphologies of the SSEBS actuators were observed by using scanning electron microscopy (SEM), which revealed that the platinum layer up to 8µm was deposited on the top and bottom surfaces of the SSEBS membrane. The electromechanical bending responses were investigated under alternating current excitations with various driving frequencies and voltage amplitudes, which showed high electrical strains under sinusoidal signal. The effect of the membrane thickness on the performance of the actuators was also addressed in this presentation. This kind of IPMC has great potentials for the applications in biomimetic sensors and actuators, which can be utilized to mimic the locomotion of fish and insects and can be applied to micro-robots and bio-medical devices as well.

  16. Levels of selected urinary metabolites of volatile organic compounds among children aged 6-11 years.

    PubMed

    Jain, Ram B

    2015-10-01

    Data from National Health and Nutrition Examination Survey for the years 2011-2012 were used to evaluate variability in the observed levels of 20 urinary metabolites of volatile organic compounds (VOCs) by age, gender, and race/ethnicity among children aged 6-11 years. Exposure to environmental tobacco smoke was positively associated with the levels of selected metabolites of acrylonitrile, 1,3-butadiene, cyanide, and propylene oxide in a dose-response manner. Levels of the selected metabolites of acrolein, acrylonitrile, 1,3-butadiene, styrene, toluene, and xylene decreased with increase in age. Levels of 1-bromopropane decreased with number of rooms in the house but the reverse was true for 1,3-butadiene, carbon-disulfide, and N,N-dimethylformamide. Levels of most of the 20 metabolites did not vary with gender. Non-Hispanic white children had higher adjusted levels of N-Acetyl-S-(3,4-dihydroxybutyl)-L-cysteine (DHBMA), N-Acetyl-S-(N-methylcarbamoyl)-L-cysteine (AMCC), and phenylglyoxylic acid (PGA) than non-Hispanic black children. Non-Hispanic white children had statistically significantly higher adjusted levels of N-Acetyl-S-(2-carbamoyl-2-hydroxyethyl)-L-cysteine (GAMA), trans, trans-Muconic acid (MU), and N-Acetyl-S-(N-methylcarbamoyl)-L-cysteine (AMCC) than non-Hispanic Asian children but statistically significantly lower levels of N-Acetyl-S-(n-propyl)-L-cysteine (BPMA) than non-Hispanic Asian children. Non-Hispanic Asian children had the lowest levels of 13 of the 20 metabolites among four major racial/ethnic groups but highest levels for three metabolites. For selected metabolites of acrolein, acrylamide, acrylonitrile-vinyl chloride-ethylene oxide, benzene, 1,3-butadien, crotonaldehyde, cyanide, ethylbenzene-styrene, and toluene, children had statistically significantly higher levels than nonsmoking adults. These results demonstrate how vulnerable children are to being exposed to harmful chemicals like VOCs in their own homes.

  17. 21 CFR 173.70 - Chloromethylated aminated styrene-divinylbenzene resin.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... conditions: (a) The additive is an aqueous dispersion of styrene-divinylbenzene copolymers, first... resin dispersion. (c) The additive is used as a decolorizing and clarification agent for treatment...

  18. PALLADIUM-CATALYZED OXIDATION OF STYRENE AND ALKENES IN PRESENCE OF IONIC LIQUIDS (WACKER REACTION)

    EPA Science Inventory

    The use of ionic liquids in various synthetic transformations is gaining significance due to the enhanced reaction rates, potential for recycling and compatibility with various organic compounds and organometallic catalysts. Palladium-catalyzed oxidation of styrene and other alk...

  19. EPR investigation on radiation-induced graft copolymerization of styrene onto polyethylene: Energy transfer effects

    NASA Astrophysics Data System (ADS)

    Salih, M. A.; Buttafava, A.; Ravasio, U.; Mariani, M.; Faucitano, A.

    2007-08-01

    In this paper, energy transfer phenomena concerning the in-source graft copolymerization of styrene onto LDPE were investigated through the EPR analysis of the radical intermediates. The model solution experiments have shown a substantial deviation of the experimental G (radicals) values with respect to the additivity law, which reflect the negative effect of the styrene monomer concentration on the initiation rate of the graft copolymerization. The EPR measurements performed on polyethylene- co-styrene graft copolymers of various composition following low-temperature vacuum gamma irradiation have confirmed the decrease of the total radical yields with increasing the styrene concentration. The effect was partly attributed to the heterogeneity of the graft copolymer matrix and to the lack of molecular mobility in the solid state at low temperature, which prevents the attainment of the favourable geometrical configurations in intermolecular energy and charge transfer events.

  20. Formation of styrene dependent on fermentation management during wheat beer production.

    PubMed

    Schwarz, Katrin J; Stübner, René; Methner, Frank-Jürgen

    2012-10-15

    Styrene is formed by the thermal decarboxylation of cinnamic acid during wort boiling or by enzymatic decarboxylation during fermentation. The enzymatic reactions proceed in parallel to the decarboxylation of ferulic- and p-cumaric acid to 4-vinylguaiacol and 4-vinylphenol by the same decarboxylase enzyme. However, the formation of styrene occurs much faster and all available cinnamic acid in wort was converted completely within a few hours. Moreover, the comparison of various manufacturing parameters shows that a higher fermentation temperature of 25 °C compared to 16 °C and an open fermentation management lead to a rapid decrease of styrene. This allows minimising the content of styrene in beer while maintaining the typical wheat beer flavours.

  1. Deconvolution of high resolution GPC chromatograms and fractionation of poly(styrene-isobutylene-styrene) block copolymers made by living cationic polymerization

    SciTech Connect

    Storey, R.F.; Baugh, D.W.

    1996-10-01

    A poly(styrene-isobutylene-styrene) block copolymer made by living cationic polymerization using a difunctional initiator and the sequential monomer addition technique was analyzed using curve-resolution software in conjunction with high-resolution GPC. Additionally, fractional precipitation was applied to the sample in order to both determine the identity of contaminating species and to produce a narrow MWD sample for morphological characterization using transmission electron microscopy (TEM). Contaminating species were found to be low molecular weight homopolymers as well as higher molecular weight segmented block copolymers formed by interchain electrophilic aromatic substitution linking reactions occurring late in the polymerization of the styrene outer blocks. TEM revealed hexagonally packed PS cylinders ({approximately}11 nm dia.) dispersed in a PIB matrix.

  2. Serum hepatic biochemical activity in two populations of workers exposed to styrene

    PubMed Central

    Brodkin, C; Moon, J; Camp, J; Echeverria, D; Redlich, C; Willson, R; Checkoway, H

    2001-01-01

    OBJECTIVE—To determine whether hepatic biochemical changes, as measured by routinely available tests indicative of hepatocellular necrosis, cholestasis, or altered hepatic clearance of bilirubin, occur in association with low to moderate exposure to styrene commonly experienced in industrial production.
METHODS—Two independent cross sectional studies were performed comparing serum hepatic transaminases (alanine aminotransferase (ALT) and aspartate aminotransferase (AST)), cholestatic enzymes (alkaline phosphatase (AP) and γ glutamyl transpeptidase (GGT)), and bilirubin in (a) 47 workers of fibreglass reinforced plastics who were exposed to styrene and (b) 21 boat and tank fabricators, with separate referent groups of unexposed workers. Exposure to styrene was assessed in air by dosimetry, and in venous blood by headspace analysis. Hepatic biochemical variables were assessed across strata of exposure to styrene defined as 25 ppm in air, or 0.275 mg/l in blood, adjusting for age, sex, body mass index, and ethanol consumption.
RESULTS—A consistent and significant linear trend for increasing direct bilirubin and direct/total bilirubin ratio was found in association with increasing exposure to styrene, by both air and blood monitoring, in both studies. Mean direct bilirubin concentrations increased from 0.05-0.08 mg% in referents to 0.12-0.19 in workers exposed above 25 ppm, with a significant exposure-response trend (p<0.005). Significantly increased direct/total bilirubin ratios, ranging from 0.22 to 0.35 were associated with exposure to styrene (p<0.001), indicating diminished hepatic clearance of conjugated bilirubin. Also, a significant linear association between the hepatic transaminases ALT and AST and exposure to styrene was found in pooled regression analyses, with an increase in AP of about 10 IU/ml in workers exposed above 25 ppm air or 0.275 mg/l blood styrene in pooled analyses from both studies.
CONCLUSIONS—The consistent finding

  3. Updated evaluation of the migration of styrene monomer and oligomers from polystyrene food contact materials to foods and food simulants.

    PubMed

    Genualdi, Susan; Nyman, Patricia; Begley, Timothy

    2014-04-01

    Due to the 2011 labelling of styrene monomer as "reasonably anticipated to be a human carcinogen" by the National Institutes of Health's National Toxicology Program (NTP) and the controversy over whether styrene oligomers mimic the physiological effects of estrogen, an updated review of styrene monomer and oligomers in food and food contact materials (FCMs) was performed. The concentrations of styrene monomer and oligomers were determined in 24 polystyrene (PS) products and ranged from 9.3 to 3100 mg kg(-1) for the styrene monomer, 130-2900 mg kg(-1) for the sum of three styrene dimers, and 220-16,000 mg kg(-1) for the sum of six styrene trimers. Foods in contact with PS packaging had styrene monomer concentrations ranging from 2.6 to 163 ng g(-1); dimer concentrations from the limit of quantitation (LOQ) to 4.8 ng g(-1) and trimer concentrations were all below the LOQ (2 ng g(-1)). Diffusion coefficients (Dp) and partition coefficients (K) were also calculated for styrene dimers and trimers. The results presented here indicate that styrene monomer concentrations in foods have not significantly changed since the 1980s and monomer concentrations in food packaging quantified in this study were all below USFDA limits. Although styrene dimers and trimers are present in higher concentrations in PS FCMs than the monomer, their migration to food is limited because of their high K values (4 × 10(2) to 2 × 10(6)) and their low diffusion coefficients in PS products. Additionally, diffusion coefficients calculated using USFDA-recommended food simulants and Arrhenius plots describing the temperature dependence of styrene dimers and trimers can be used in future calculations of dietary intake of the styrene oligomers.

  4. Styrene-terminated polysulfone oligomers as matrix material for graphite reinforced composites: An initial study

    NASA Technical Reports Server (NTRS)

    Garcia, Dana; Bowles, Kenneth J.; Vannucci, Raymond D.

    1987-01-01

    Styrene terminated polysulfone oligomers are part of an oligomeric class of compounds with end groups capable of thermal polymerization. These materials can be used as matrices for graphite reinforced composites. The initial evaluation of styrene terminated polysulfone oligomer based composites are summarized in terms of fabrication methods, and mechanical and environmental properties. In addition, a description and evaluation is provided of the NASA/Industry Fellowship Program for Technology Transfer.

  5. Mechanism of the Initiation of the Cationic Polymerization of Styrenes by Silanes and Activated Covalent Esters

    DTIC Science & Technology

    1989-03-23

    the triflic acid formed by the hvdrolysis of trimethyl silyl triflate. Polmer end aroups do not contain silvl groups, polymnerization is stronglyv...Lewis acids but which are not active alone. Styrenes are also polymerized by mixtures of different acetates and acids 10 , 1 1. The resulting polymers...in different solvents and found that initiation occurs via traces of acids formed by hydrolysis of 1. Experimental Styrenes and solvents were purified

  6. Synthesis and Characterization of Phosphonium-Containing Cationic Poly(styrene) Polymers

    DTIC Science & Technology

    2009-12-01

    ionomeric system designed as an anion exchange membrane for these types of applications. Styrene monomer has been copolymerized with 4... Ionomer , phophonium, cationic, RAFT, polymer 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT UU 18. NUMBER OF PAGES 14 19a...drastically altered even at low phosphonium contents. Homopolymer poly(styrene) typically has a glass transition temperature (Tg) around 100 °C; low

  7. Surface modification of poly(styrene-b-(ethylene-co-butylene)-b-styrene) elastomer via photo-initiated graft polymerization of poly(ethylene glycol)

    NASA Astrophysics Data System (ADS)

    Li, Xiaomeng; Luan, Shifang; Yang, Huawei; Shi, Hengchong; Zhao, Jie; Jin, Jing; Yin, Jinghua; Stagnaro, Paola

    2012-01-01

    Poly(styrene-b-(ethylene-co-butylene)-b-styrene) (SEBS) copolymer biomedical elastomer was covalently grafted with poly(ethylene glycol) methyl ether methacrylate (PEGMA) via a photo-initiated graft polymerization technique. The surface graft polymerization of SEBS with PEGMA was verified by ATR-FTIR and XPS. Effect of graft polymerization parameters, i.e., monomer concentration, UV irradiation time and initiator concentration on the grafting density was investigated. Comparing with the virgin SEBS film, the PEGMA-modified SEBS film presented an enhanced wettability and a larger surface energy. Besides, the surface grafting of PEGMA imparted excellent anti-platelet adhesion and anti-protein adsorption to the SEBS surface.

  8. Process for the recovery and separation of plastics

    DOEpatents

    Jody, Bassam J.; Daniels, Edward J.; Pomykala Jr., Joseph A.

    2003-07-29

    A method of separating a portion of acrylonitrile-butadiene-styrene (ABS) from a mixture containing ABS and for separating a portion of ABS and polycarbonate (PC) from a mixture of plastics containing ABS and PC is disclosed. The method includes shredding and/or granulating the mixture of plastics containing ABS and PC to provide a selected particle size; sequentially dispersing the shredded mixture of plastics in a series aqueous solutions having different specific gravities and separating the floating fraction until the desired separation is obtained. Surface tension and pH are also variable to be controlled.

  9. Production of super-smooth articles

    SciTech Connect

    Duchane, D.V.

    1983-03-15

    Super-smooth rounded or formed articles made of thermoplastic materials including various poly(Methyl methacrylate) or acrylonitrile-butadiene-styrene copolymers are produced by immersing the articles into a bath, the composition of which is slowly changed with time. The starting composition of the bath is made up of at least one solvent for the polymer and a diluent made up of at least one nonsolvent for the polymer and optional materials which are soluble in the bath. The resulting extremely smooth articles are useful as mandrels for laser fusion and should be useful for a wide variety of other purposes, for example lenses.

  10. Development of recycled plastic composites for structural applications from CEA plastics

    NASA Astrophysics Data System (ADS)

    Bhalla, Agrim

    Plastic waste from consumer electronic appliances (CEAs) such as computer and printer parts including Polystyrene (PS), Acrylonitrile Butadiene Styrene (ABS), Polystyrene (PS) and PC/ABS were collected using handheld FTIR Spectrophotometer. The blends of these plastics with High Density Polyethylene (HDPE) are manufactured under special processing conditions in a single screw compounding injection molding machine. The blends are thermoplastics have high stiffness and strength, which may enhance the mechanical properties of HDPE like tensile modulus, ultimate tensile strength, tensile break and tensile yield. These composites have a potential to be used for the future application of recycled plastic lumber, thus replacing the traditional wood lumber.

  11. Production of super-smooth articles

    DOEpatents

    Duchane, David V.

    1983-01-01

    Super-smooth rounded or formed articles made of thermoplastic materials including various poly(methyl methacrylate) or acrylonitrile-butadiene-styrene copolymers are produced by immersing the articles into a bath, the composition of which is slowly changed with time. The starting composition of the bath is made up of at least one solvent for the polymer and a diluent made up of at least one nonsolvent for the polymer and optional materials which are soluble in the bath. The resulting extremely smooth articles are useful as mandrels for laser fusion and should be useful for a wide variety of other purposes, for example lenses.

  12. Production of super-smooth articles

    SciTech Connect

    Duchane, D.V.

    1981-05-29

    Super-smooth rounded or formed articles made of thermoplastic materials including various poly(methyl methacrylate) or acrylonitrile-butadiene-styrene copolymers are produced by immersing the articles into a bath, the composition of which is slowly changed with time. The starting composition of the bath is made up of at least one solvent for the polymer and a diluent made up of at least one nonsolvent for the polymer and optional materials which are soluble in the bath. The resulting extremely smooth articles are useful as mandrels for laser fusion and should be useful for a wide variety of other purposes, for example lenses.

  13. Inhalation developmental toxicology studies of 1,3-butadiene in the rat: Final report

    SciTech Connect

    Hackett, P.L.; Sikov, M.R.; Mast, T.J.; Brown, M.G.; Buschbom, R.L.; Clark, M.L.; Decker, J.R.; Evanoff, J.J.; Rommereim, R.L.; Rowe, S.E.; Westerberg, R.B.

    1987-11-01

    Maternal toxicity, reproductive performance and developmental toxicology were evaluated in Sprague-Dawley-derived rats during and following 6 hours/day, whole-body, inhalation exposures to 0, 40, 200, and 1000 ppM of 1,3-butadiene. The female rats (Ns = 24 to 28), which had mated with unexposed males, were exposed to the chemical from 6 through 15 dg and sacrificed on 20 dg. Maternal animals were weighed prior to mating and on 0, 6, 11, 16 and 20 dg; the rats were observed for mortality, morbidity and signs of toxicity during exposure and examined for gross tissue abnormalities at necropsy. Live fetuses were weighed and subjected to external, visceral and skeletal examinations to detect growth retardation and morphologic anomalies. There were no significant differences among treatment groups in maternal body weights or extragestational weights of rats exposed to 1,3-butadiene concentrations of 40 or 200 ppM, but, in animals exposed to 1000 ppM, significantly depressed body weight gains were observed during the first 5 days of exposure and extragestational weight gains tended to be lower than control values. These results, and the absence of clinical signs of toxicity, were considered to indicate that there was no maternal toxicity at exposure levels of 200 ppM or lower. The percentage of pregnant animals and the number of litters with live fetuses were unaffected by treatment. Under the conditions of this exposure regimen, there was no evidence for a teratogenic response to 1,3-butadiene exposure.

  14. Pre-irradiation grafting of acrylonitrile onto chitin for adsorption of arsenic in water

    NASA Astrophysics Data System (ADS)

    Hanh, Truong Thi; Huy, Ha Thuc; Hien, Nguyen Quoc

    2015-01-01

    Radiation-induced grafting is an effective technique for preparation of novel materials. In this study, partially deacetylated chitin with deacetylation degree (DDA) of about 40% was graft-copolymerized with acrylonitrile (AN) by a γ-ray pre-irradiation method. The maximal grafting degree of AN onto pre-irradiated chitin at 25±1.2 kGy was 114% for AN concentration in dimethylformamide of 40% (v/v) at 70 °C for 8 h. The mixture ratio of 0.1 N NH2OH·HCl to 0.1 N NaOH was selected to be 7:3 (v/v) for amidoxime conversion of cyano-groups on grafted chitin (Chi-g-AN). The characteristics of modified chitin were depicted by the FT-IR spectra, BET area and SEM images. Adsorption equilibrium of As(III) onto Chi-g-AN converted amidoxime (Chi-g-AN-C) fits with the Langmuir model and the maximal adsorption capacity was 19.724 mg/g. The break-through times of As(III) on Chi-g-AN-C in column adsorption experiments increased with the increase in bed depths.

  15. 2-Cyanoethylmercapturic acid (CEMA) in the urine as a possible indicator of exposure to acrylonitrile.

    PubMed

    Jakubowski, M; Linhart, I; Pielas, G; Kopecký, J

    1987-12-01

    The aim of this study was to evaluate the efficiency of metabolism of acrylonitrile (ACN) to N-acetyl-S-(2-cyanoethyl)-L-cysteine (2-cyanoethylmercapturic acid (CEMA) in man, the kinetics of excretion of this metabolite, and the relation between the uptake of ACN and the excretion of CEMA in urine. Eleven experiments were performed on six male volunteers exposed for eight hours to ACN at concentrations of 5 or 10 mg/m3. The average respiratory retention of ACN was 52% and 21.8% of the retained ACN was excreted as CEMA in urine. Elimination approximated first order kinetics with half life of about eight hours. The best correlation between the uptake of ACN in the lungs and excretion of CEMA in urine was obtained when the concentration of CEMA in the urine fraction, collected between the sixth and eighth hours after the beginning of exposure, was adjusted to a specific gravity of 1.016 (y = 0.33x-13.3; r = 0.83). CEMA excretion, however, cannot be used as an individual index of exposure.

  16. Preirradiation grafting of acrylonitrile onto polypropylene monofilament for biomedical applications: I. Influence of synthesis conditions

    NASA Astrophysics Data System (ADS)

    Gupta, Bhuvanesh; Jain, Rachna; Anjum, Nishat; Singh, Harpal

    2006-01-01

    Graft polymerization of acrylonitrile onto polypropylene (PP) monofilament was carried out by a preirradiation method using a 60Co gamma radiation source. The influence of synthesis conditions, such as preirradiation dose, reaction time, monomer concentration, reaction temperature and additives was determined. The grafting was considerably influenced by the instantaneous swelling of the monofilament in the reaction mixture during the course of the grafting process. The order of dependence of the rate of grafting on monomer concentration was found to be 1.04. The nature of the medium of the grafting and the additives had profound influence over the grafting reaction. The accelerative effects of solvent medium on the grafting were higher in methylethyl ketone (MEK) and dimethylformamide (DMF) as compared to methanol. At the same time, partial replacement of DMF with water led to acceleration in the grafting with peak maxima at 20% solvent composition. The addition of a small amount of sulfuric acid to the reaction mixture also resulted in a significant acceleration of the degree of grafting.

  17. Cobalt-Mediated Radical Polymerization of Vinyl Acetate and Acrylonitrile in Supercritical Carbon Dioxide.

    PubMed

    Kermagoret, Anthony; Chau, Ngoc Do Quyen; Grignard, Bruno; Cordella, Daniela; Debuigne, Antoine; Jérôme, Christine; Detrembleur, Christophe

    2016-03-01

    Cobalt-mediated radical polymerization (CMRP) of vinyl acetate (VAc) is successfully achieved in supercritical carbon dioxide (scCO2). CMRP of VAc is conducted using an alkyl-cobalt(III) adduct that is soluble in scCO2. Kinetics studies coupled to visual observations of the polymerization medium highlight that the melt viscosity and PVAc molar mass (Mn) are key parameters that affect the CMRP in scCO2. It is noticed that CMRP is controlled for Mn up to 10 000 g mol(-1), but loss of control is progressively observed for higher molar masses when PVAc precipitates in the polymerization medium. Low molar mass PVAc macroinitiator, prepared by CMRP in scCO2, is then successfully used to initiate the acrylonitrile polymerization. PVAc-b-PAN block copolymer is collected as a free flowing powder at the end of the process although the dispersity of the copolymer increases with the reaction time. Although optimization is required to decrease the dispersity of the polymer formed, this CMRP process opens new perspectives for macromolecular engineering in scCO2 without the utilization of fluorinated comonomers or organic solvents.

  18. Adsorptive removal of acrylonitrile by commercial grade activated carbon: kinetics, equilibrium and thermodynamics.

    PubMed

    Kumar, Arvind; Prasad, B; Mishra, I M

    2008-04-01

    The potential of activated carbons--powdered (PAC) and granular (GAC), for the adsorption of acrylonitrile (AN) at different initial AN concentrations (50

  19. Modification of fiber properties through grafting of acrylonitrile to rayon by chemical and radiation methods.

    PubMed

    Kaur, Inderjeet; Sharma, Neelam; Kumari, Vandna

    2013-11-01

    Fibrous properties of rayon has been modified through synthesis of graft copolymers of rayon with acrylonitrile (AN) by chemical method using ceric ammonium nitrate (CAN/HNO3) as a redox initiator and gamma radiation mutual method. Percentage of grafting (Pg) was determined as a function of initiator concentration, monomer concentration, irradiation dose, temperature, time of reaction and the amount of water. Maximum percentage of grafting (160.01%) using CAN/HNO3 was obtained at [CAN] = 22.80 × 10(-3) mol/L, [HNO3] = 112.68 × 10(-2) mol/L and [AN] = 114.49 × 10(-2) mol/L in 20 mL of water at 45 °C within 120 min while in case of gamma radiation method, maximum Pg (90.24%) was obtained at an optimum concentration of AN of 76.32 × 10(-2) mol/L using 10 mL of water at room temperature with total dose exposure of 3.456 kGy/h. The grafted fiber was characterized by FTIR, SEM, TGA and XRD studies. Swelling behavior of grafted rayon in different solvents such as water, methanol, ethanol, DMF and acetone was studied and compared with the unmodified rayon. Dyeing behavior of the grafted fiber was also investigated.

  20. Hg(II) adsorption using amidoximated porous acrylonitrile/itaconic copolymers prepared by suspended emulsion polymerization.

    PubMed

    Ji, Chunnuan; Qu, Rongjun; Chen, Hou; Liu, Xiguang; Sun, Changmei; Ma, Caixia

    2016-01-01

    Initially, porous acrylonitrile/itaconic acid copolymers (AN/IA) were prepared by suspended emulsion polymerization. Successively, the cyano groups in AN/IA copolymers were converted to amidoxime (AO) groups by the reaction with hydroxylamine hydrochloride. The structures of the AN/IA and amidoximated AN/IA (AO AN/IA) were characterized by infrared spectroscopy, scanning electron microscopy, and porous structural analysis. The adsorption properties of AO AN/IA for Hg(II) were investigated. The results show that AO AN/IA has mesopores and macropores, and surface area of 11.71 m(2) g(-1). It was found that AO AN/IA has higher affinity for Hg(II), with the maximum adsorption capacity of 84.25 mg g(-1). The AO AN/IA also can effectively remove Hg(II) from different binary metal ion mixture systems. Furthermore, the adsorption kinetics and thermodynamics were studied in detail. The adsorption equilibrium can quickly be achieved in 4 h determined by an adsorption kinetics study. The adsorption process is found to belong to the second-order model, and can be described by the Freundlich model.

  1. Nanostructured synthetic carbons obtained by pyrolysis of spherical acrylonitrile/divinylbenzene copolymers.

    PubMed

    Malik, Danish J; Trochimczuk, Andrzej W; Ronka, Sylwia

    2012-01-01

    Novel carbon materials have been prepared by the carbonization of acrylonitrile (AN)/divinylbenzene (DVB) suspension porous copolymers having nominal crosslinking degrees in the range of 30-70% and obtained in the presence of various amounts of porogens. The carbons were obtained by pre-oxidation of AN/DVB copolymers at 250-350°C in air followed by pyrolysis at 850°C in an N(2) atmosphere. Both processes were carried out in one furnace and the resulting material needed no further activation. Resulting materials were characterized by XPS and low temperature nitrogen adsorption/desorption. It was found that maximum pyrolysis yield was ca. 50% depending on the oxidation conditions but almost independent of the crosslinking degree of the polymers. Porous structure of the carbons was characterized for the presence of micropores and macropores, when obtained from highly crosslinked polymers or polymers oxidized at 350°C and meso- and macropores in all other cases. The latter pores are prevailing in the structure of carbons obtained from less porous AN/DVB resins. Specific surface area (BET) of polymer derived carbons can vary between 440 m(2)/g and 250 m(2)/g depending on the amount of porogen used in the synthesis of the AN/DVB polymeric precursors.

  2. Differential response to acrylonitrile toxicity in rat primary astrocytes and microglia

    PubMed Central

    Caito, Samuel; Yu, Yingchun; Aschner, Michael

    2016-01-01

    Acrylonitrile (ACN) is a widely used chemical in the production of plastics, resins, nitriles, acrylic fibers, synthetic rubber and acrylamide. While acute high level exposures to ACN are known to be lethal, chronic low dose exposures causes glial cell tumors in rats. Recently, these glial tumors have been characterized as microglial in origin. While effects of ACN on astrocytes, the more numerous glial cell, have been investigated, the effects on microglia are unknown. This study was conducted to compare the responses of astrocytes and microglia to ACN treatment in vitro to address differential sensitivities and adaptive responses to this toxic chemical. Cell viability, ACN uptake, lipid peroxidation byproducts (F2-isoprostanes), glutathione (GSH) levels and expression of NF-E2-related factor 2 (Nrf2) were evaluated in primary rat microglia and astrocytes following ACN treatment. Results indicate that microglia are more sensitive to ACN than astrocytes, accumulating less ACN while demonstrating higher F2-isoprostane levels. GSH levels were up-regulated in both cell types, as a protective mechanism against ACN-induced oxidative stress, while Nrf2 levels were only induced in microglia. Our data suggest that microglia and astrocytes exhibit different sensitivities and responses to ACN, which are linked to the intracellular thiol status inherent to each of these cell types. PMID:23628792

  3. Induction of oxidative stress and oxidative damage in rat glial cells by acrylonitrile.

    PubMed

    Kamendulis, L M; Jiang, J; Xu, Y; Klaunig, J E

    1999-08-01

    Chronic treatment of rats with acrylonitrile (ACN) resulted in a dose-related increase in glial cell tumors (astrocytomas). While the exact mechanism(s) for ACN-induced carcinogenicity remains unresolved, non-genotoxic and possibly tumor promotion modes of action appear to be involved in the induction of glial tumors. Recent studies have shown that ACN induced oxidative stress selectively in rat brain in a dose-responsive manner. The present study examined the ability of ACN to induce oxidative stress in a rat glial cell line, a target tissue, and in cultured rat hepatocytes, a non-target tissue of ACN carcinogenicity. Glial cells and hepatocytes were treated for 1, 4 and 24 h with sublethal concentrations of ACN. ACN induced an increase in oxidative DNA damage, as evidenced by increased production of 8-hydroxy-2'-deoxyguanosine (8-OH-dG) in glial cells but not in rat hepatocytes. Hydroxyl radical formation following ACN treatment was also selectively increased in glial cells. Following 1 and 4 h of ACN exposure, the levels of the non-enzymatic antioxidant glutathione, as well as the activities of the enzymatic antioxidants catalase and superoxide dismutase were significantly decreased in the rat glial cells. Lipid peroxidation and the activity of glutathione peroxidase were not affected by ACN treatment in rat glial cells. No changes in any of these biomarkers of oxidative stress were observed in hepatocytes treated with ACN. These data indicate that ACN selectively induced oxidative stress in rat glial cells.

  4. Weight-of-the-evidence review of acrylonitrile reproductive and developmental toxicity studies.

    PubMed

    Neal, Barbara H; Collins, James J; Strother, Dale E; Lamb, James C

    2009-01-01

    Risk assessment of acrylonitrile (AN) toxicity to humans has focused on potential carcinogenicity and acute toxicity. Epidemiological studies from China reported reproductive and developmental effects in AN workers, including infertility, birth defects, and spontaneous abortions. A weight-of-the-evidence (WoE) evaluation of the AN database assessed study strength, characterized toxicity, and identified no-observed-adverse-effect levels (NOAELs). The epidemiological studies do not demonstrate causality and are not sufficiently robust to be used for risk assessment. Rodent developmental studies showed fetotoxicity and malformations at maternally toxic levels; there was no unique developmental susceptibility. NOAELs for oral and inhalation exposures were 10 mg/kg/day and 12 ppm (6 h/day), respectively. Drinking-water and inhalation reproductive toxicity studies showed no clear effects on reproductive performance or fertility. Maternally toxic concentrations caused decreased pup growth. The drinking-water reproductive NOAEL was 100 ppm (moderate confidence due to study limitations). The inhalation exposure reproductive and neonatal toxicity high confidence NOAEL was 45 ppm (first generation 90 ppm) (6 h/day). The inhalation reproductive toxicity study provides the most robust data for risk assessment. Based on the WoE evaluation, AN is not expected to be a developmental or reproductive toxicant in the absence of significant maternal toxicity.

  5. Design, synthesis, and anti-melanogenic effects of (E)-2-benzoyl-3-(substituted phenyl)acrylonitriles

    PubMed Central

    Yun, Hwi Young; Kim, Do Hyun; Son, Sujin; Ullah, Sultan; Kim, Seong Jin; Kim, Yeon-Jeong; Yoo, Jin-Wook; Jung, Yunjin; Chun, Pusoon; Moon, Hyung Ryong

    2015-01-01

    Background Tyrosinase is the most prominent target for inhibitors of hyperpigmentation because it plays a critical role in melaninogenesis. Although many tyrosinase inhibitors have been identified, from both natural and synthetic sources, there remains a considerable demand for novel tyrosinase inhibitors that are safer and more effective. Methods (E)-2-Benzoyl-3-(substituted phenyl)acrylonitriles (BPA analogs) with a linear β-phenyl-α,β-unsaturated carbonyl scaffold were designed and synthesized as potential tyrosinase inhibitors. We evaluated their effects on cellular tyrosinase activity and melanin biosynthesis in murine B16F10 melanoma cells and their ability to inhibit mushroom tyrosinase activity. Results BPA analogs exhibited inhibitory activity against mushroom tyrosinase. In particular, BPA13 significantly suppressed melanin biosynthesis and inhibited cellular tyrosinase activity in B16F10 cells in a dose-dependent manner. A docking study revealed that BPA13 had higher binding affinity for tyrosinase than kojic acid. Conclusion BPA13, which possesses a linear β-phenyl-α,β-unsaturated carbonyl scaffold, is a potential candidate skin-whitening agent and treatment for diseases associated with hyperpigmentation. PMID:26347064

  6. Effects of acrylonitrile on lymphocyte lipid rafts and RAS/RAF/MAPK/ERK signaling pathways.

    PubMed

    Li, X J; Li, B; Huang, J S; Shi, J M; Wang, P; Fan, W; Zhou, Y L

    2014-09-26

    Acrylonitrile (ACN) is a widely used chemical in the production of plastics, resins, nitriles, acrylic fibers, and synthetic rubber. Previous epidemiological investigations and animal studies have confirmed that ACN affects the lymphocytes and spleen. However, the immune toxicity mechanism is unknown. Lipid rafts are cell membrane structures that are rich in cholesterol and involved in cell signal transduction. The B cell lymophoma-10 (Bcl10) protein is a joint protein that is important in lymphocyte development and signal pathways. This study was conducted to examine the in vitro effects of ACN. We separated lipid rafts, and analyzed Bcl10 protein and caveolin. Western blotting was used to detect mitogen-activated protein kinase (MAPK) and phosphorylated MAPK levels. The results indicated that with increasing ACN concentration, the total amount of Bcl10 remained stable, but was concentrated mainly in part 4 to part 11 in electrophoretic band district which is high density in gradient centrifugation. Caveolin-1 was evaluated as a lipid raft marker protein; caveolin-1 content and position were relatively unchanged. Western blotting showed that in a certain range, MAPK protein was secreted at a higher level. At some ACN exposure levels, MAPK protein secretion was significantly decreased compared to the control group (P < 0.05). These results indicate that ACN can cause immune toxicity by damaging lipid raft structures, causing Bcl10 protein and lipid raft separation and restraining Ras-Raf-MAPK-extracellular signal-regulated kinase signaling pathways.

  7. Acrylonitrile induced apoptosis via oxidative stress in neuroblastoma SH-SY5Y cell.

    PubMed

    Watcharasit, Piyajit; Suntararuks, Sumitra; Visitnonthachai, Daranee; Thiantanawat, Apinya; Satayavivad, Jutamaad

    2010-10-01

    Acrylonitrile (ACN) is a chemical that is widely used in the production of plastics, acrylic fibers, synthetic rubbers and resins. It has been reported that ACN can cause oxidative stress, a condition which is well recognized as an apoptotic initiator; however, information regarding ACN-induced apoptosis is limited. This present study investigated whether ACN induces apoptosis in human neuroblastoma SH-SY5Y cells, and whether its apoptotic induction involves oxidative stress. The results showed that ACN caused activation of caspase-3, a key enzyme involved in apoptosis, in a dose- and time-dependent manner. Detection of sub-G1 apoptotic cell death and apoptotic nuclear condensation revealed that ACN caused an increase in the number of apoptotic cells indicating ACN induces apoptosis in SH-SY5Y cells. ACN dose- and time-dependently increased the level of proapoptotic protein, Bax. Pretreatment with N-acetylcysteine (NAC), an antioxidant, attenuated caspase-3 activation by ACN, as evidenced by a reduction in proteolysis of PARP, a known caspase-3 substrate, as well as in the number of sub-G1 apoptotic cells. Moreover, induction of Bax by ACN was abolished by NAC. Taken together, the results indicate that ACN induces apoptosis in SH-SY5Y cells via a mechanism involving generation of oxidative stress-mediated Bax induction.

  8. Differential response to acrylonitrile toxicity in rat primary astrocytes and microglia.

    PubMed

    Caito, Samuel; Yu, Yingchun; Aschner, Michael

    2013-07-01

    Acrylonitrile (ACN) is a widely used chemical in the production of plastics, resins, nitriles, acrylic fibers, synthetic rubber and acrylamide. While acute high level exposures to ACN are known to be lethal, chronic low dose exposures causes glial cell tumors in rats. Recently, these glial tumors have been characterized as microglial in origin. While effects of ACN on astrocytes, the more numerous glial cell, have been investigated, the effects on microglia are unknown. This study was conducted to compare the responses of astrocytes and microglia to ACN treatment in vitro to address differential sensitivities and adaptive responses to this toxic chemical. Cell viability, ACN uptake, lipid peroxidation byproducts (F2-isoprostanes), glutathione (GSH) levels and expression of NF-E2-related factor 2 (Nrf2) were evaluated in primary rat microglia and astrocytes following ACN treatment. Results indicate that microglia are more sensitive to ACN than astrocytes, accumulating less ACN while demonstrating higher F2-isoprostane levels. GSH levels were up-regulated in both cell types, as a protective mechanism against ACN-induced oxidative stress, while Nrf2 levels were only induced in microglia. Our data suggest that microglia and astrocytes exhibit different sensitivities and responses to ACN, which are linked to the intracellular thiol status inherent to each of these cell types.

  9. Differential inflammatory response to acrylonitrile in rat primary astrocytes and microglia.

    PubMed

    Caito, Samuel W; Yu, Yingchun; Aschner, Michael

    2014-05-01

    Acrylonitrile (ACN) is extensively used in the production of plastics, resins, nitriles and other commercial products. Chronic low dose exposures to ACN cause glial cell tumors in rats, primarily microglial in origin. Recently it has been determined that astrocytes and microglia respond to ACN-induced oxidative stress differently, which may influence cell-specific activation of inflammatory and carcinogenic pathways. This study was conducted to compare the inflammatory responses of astrocytes and microglia following ACN treatment in vitro to further characterize differential sensitivities and adaptive responses in these cell types. Nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) and p53 levels were measured along with levels of 12 different cytokines and chemokines in primary rat microglia and astrocytes. Additionally levels of cytochrome P450 2E1 (CYP2E1) were measured to evaluate the cells' ability to metabolize ACN. Results indicate that while both cells upregulate p53 and NF-κB, the cytokines and chemokines produced differ between the cell types. Astrocytes, but not microglia, upregulated CYP2E1 in response to ACN, which may be due to the astrocytes accumulating more ACN than the microglia. Altogether our data implicate the inflammatory response as an important event in ACN-induced neurotoxicity.

  10. Phenomena affecting morphology of microporous poly(acrylonitrile) prepared via phase separation from solution

    SciTech Connect

    Legasse, R.R.; Weagley, R.J.; Leslie, P.K.; Schneider, D.A.

    1990-01-01

    This paper is concerned with controlling the morphology of microporous polymers prepared via thermal demixing of solutions. 2 wt % solutions of poly(acrylonitrile) in maleic anhydride, a poor solvent, are first cooled to produce separated polymer-rich and solvent-rich phases. Removing the solvent by freeze drying then produces a microporous material having a density of 33 mg/cm{sup 3}, a void fraction of 97%, and a pore size of about 10 {mu}m. We find that the morphology cannot be explained by existing models, which focus on phase diagrams and kinetics of phase transformations during cooling of the solution. In conflict with those models, we find that two radically different morphologies can be produced even when the polymer concentration and cooling path are held strictly constant. A hypothesis that polymer degradation causes the different morphologies is not supported by GPC, {sup 13}C NMR, and FTIR experiments. Instead, we offer evidence that the different microporous morphologies are caused by different polymer conformations in solutions having the same concentration and temperature. 11 refs., 3 figs.

  11. Destruction of Gaseous Styrene with a Low-Temperature Plasma Induced by a Tubular Multilayer Dielectric Barrier Discharge

    NASA Astrophysics Data System (ADS)

    Zhang, Jiahui; Liu, Juanjuan; Zhang, Renxi; Hou, Huiqi; Chen, Shanping; Zhang, Yi

    2015-01-01

    The destruction of gaseous styrene was studied using a low-temperature plasma induced by tubular multilayer dielectric barrier discharge (DBD). The results indicate that the applied voltage, gas flow rate, inlet styrene concentration and reactor configuration play important roles in styrene removal efficiency (ηstyrene) and energy yield (EY). Values of ηstyrene and EY reached 96% and 15567 mg/kWh when the applied voltage, gas flow rate, inlet styrene concentration and layers of quartz tubes were set at 10.8 kV, 5.0 m/s, 229 mg/m3 and 5 layers, respectively. A qualitative analysis of the byproducts and a detailed discussion of the reaction mechanism are also presented. The results could facilitate industrial applications of the new DBD reactor for waste gas treatment.

  12. Association of the blood/air partition coefficient of 1,3-butadiene with blood lipids and albumin.

    PubMed

    Lin, Yu-Sheng; Smith, Thomas J; Wypij, David; Kelsey, Karl T; Sacks, Frank M

    2002-02-01

    Pulmonary gas uptake is a function of the blood solubility of a vapor, indicated by the blood/air partition coefficient. We hypothesized that blood lipid compositions are associated with the blood/air partition coefficients of lipophilic toxic vapors such as 1,3-butadiene. Our goal was to investigate cross-sectional and longitudinal relationships of blood triglycerides, total cholesterol, and albumin to the blood/air partition coefficient of butadiene. We collected blood samples from 24 subjects at three time points: a fasting baseline and 2 and 4 hr after drinking a standardized high-fat milk shake (107 g fat, 80 g sugar, and 27 g protein). The blood/air partition coefficient was determined using the closed vial-equilibrium technique. Triglycerides and total cholesterol were analyzed by an enzymatic method, and albumin was analyzed with an immunoassay technique. We used multiple linear regression and general linear models to examine the cross-sectional and longitudinal relationship, respectively. The results showed that the blood/air partition coefficient of butadiene was cross-sectionally associated only with triglycerides at baseline, and longitudinally related to baseline triglycerides, total cholesterol, and the change in triglycerides over time. The blood/air partition coefficient of butadiene increased, on average, by approximately 20% and up to 40% for subjects with borderline higher triglyceride levels after ingestion of a standardized milk shake. In addition, a time factor beyond lipids was also significant in predicting the blood/air partition coefficient of butadiene. This may represent the effects of other unmeasured parameters related to time or time of day on the blood/air partition coefficient of butadiene. Because the blood/air partition coefficient is a major determinant of gas uptake, ingestion of a high fat meal before this type of exposure may significantly increase an individual's absorbed dose, possibly increasing the risk of adverse effects.

  13. Mortality study of workers in 1,3-butadiene production units identified from a chemical workers cohort.

    PubMed Central

    Ward, E M; Fajen, J M; Ruder, A M; Rinsky, R A; Halperin, W E; Fessler-Flesch, C A

    1995-01-01

    The International Agency for Research on Cancer has given the designations of "sufficient evidence" of carcinogenicity of 1,3-butadiene in experimental animals and "limited evidence" of carcinogenicity in humans. To investigate the carcinogenic effect in humans, we conducted a cohort mortality study among 364 men who were assigned to any of three 1,3-butadiene production units located within several chemical plants in the Kanawha Valley of West Virginia, including 277 men employed in a U.S. Rubber Reserve Plant which operated during World War II. The butadiene production units included in this study were selected from an index developed by the Union Carbide Corporation, which listed for each chemical production unit within their South Charleston, West Virginia and Institute, West Virginia, plants all products, by-products, and reactants. Departments included in the study were those where butadiene was a primary product and neither benzene nor ethylene oxide was present. A total of 185 deaths were observed; the standardized mortality ratio (SMR) for all causes of death was 91, reflecting lower mortality among the study population than the U.S. population. The study found a significantly elevated standardized mortality ratio (SMR) for lymphosarcoma and reticulosarcoma based on four observed cases (SMR = 577; 95% CI = 157-1480), which persisted in an analysis using county referent rates. An excess of lymphosarcoma and reticulosarcoma among all workers and among workers with routine exposure to 1,3-butadiene was also observed in the only other cohort of 1,3-butadiene production workers previously studied.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7556014

  14. Measurements of environmental 1,3-butadiene with pumped and diffusive samplers using the sorbent Carbopack X

    NASA Astrophysics Data System (ADS)

    Martin, Nicholas A.; Duckworth, Philippa; Henderson, Malcolm H.; Swann, Nigel R. W.; Granshaw, Simon T.; Lipscombe, Robert P.; Goody, Brian A.

    Studies with the sorbent Carbopack X in pumped and diffusive samplers, of the Perkin-Elmer-type, have been carried out using a controlled atmosphere test facility (CATFAC) to generate 1,3-butadiene, together with benzene, at environmental levels. The 7-day and 14-day 1,3-butadiene diffusive uptake rates for this sorbent have been determined to be respectively (1.24±0.16) ng ppm -1 min -1 ((0.55±0.07) cm 3 min -1)) and (1.02±0.12) ng ppm -1 min -1 ((0.45±0.05) cm 3 min -1)) under a wide range of concentrations at 20 °C, 50% relative humidity and a wind speed of 1 m s -1. Preliminary studies indicate that this sorbent may also be useful in radial diffusive samplers for short-term monitoring over a few hours. A pumped sampling method has been developed to measure both 1,3-butadiene and benzene simultaneously over a period of 14-days using two Perkin-Elmer-type devices coupled to an in-house developed controlled flow air sampler. The 1,3-butadiene safe sampling volume for Carbopack X has been measured yielding a value of ⩽82 litre g -1. Tests carried out with calibrated amounts of 1,3-butadiene (50 ng and 150 ng) on Carbopack X indicate that samplers should be stored in a refrigerator prior to thermal desorption in order to achieve a recovery of effectively 100%. Ambient ozone does not appear to react with 1,3-butadiene adsorbed in the samplers.

  15. Adsorption of 2-methylpropene and 1,3-butadiene on activated carbon

    SciTech Connect

    Olivier, M.G.; Berlier, K.; Bougard, J. . Service de Thermodynamique)

    1994-10-01

    Four adsorption isotherms at 278, 288, 293, and 303 K of 2-methylpropene and 1, 3-butadiene on activated carbon are given. The results at pressures up to 0.8P/P[sub s] are measured using an automated apparatus and correlated by the vacancy solution model of Cochran and Danner. This work aims at determining the influence of a double bond and a branched structure on the adsorption capacity. For their industrial separation by an adsorption process, it is important to have equilibrium data on the same adsorbent and at different temperatures.

  16. Heat of Combustion of the Product Formed by the Reaction of Diborane with 1,3-Butadiene

    NASA Technical Reports Server (NTRS)

    Tannenbaum, Stanley; Allen, Harrison, Jr.

    1953-01-01

    The net heat of combustion of the product formed by the reaction of diborane with 1,3-butadiene was found to be 18,700+/-150 Btu per pound for the reaction of liquid fuel to gaseous carbon dioxide, gaseous water, and solid boric oxide. The measurements were made in a Parr oxygen-bomb calorimeter, and the combustion was believed to be 98 percent complete. The estimated net heat of combustion for complete combustion would therefore be 19,075+/-150 Btu per pound. Since this value is approximately the same as the heat of combustion of butadiene, it seems certain that the material is partially oxidized.

  17. Temporal trends and weekend-weekday differences for benzene and 1,3-butadiene in Houston, Texas

    NASA Astrophysics Data System (ADS)

    Reiss, Richard

    Temporal trends and weekend-weekday differences in benzene and 1,3-butadiene concentrations were investigated at a number of sites in the Houston, Texas area using monitoring data collected by the Texas Commission on Environmental Quality (TCEQ). The dataset included two networks, the Community Air Toxics Monitoring Network (CATMN), which has 24-h measurements every six days, and the Photochemical Assessment Monitoring System (PAMS), which includes hourly measurements. The period for data analysis was 1997-2004. The CATMN network had the larger number of stations. Over this time period, the network average benzene concentration at the CATMN stations was 0.93 ppb with individual stations ranging within a factor of about two of this network average. The network average 1,3-butadiene concentration was 0.57 ppb with most individual stations ranging within a factor of about six of this network average. These ranges suggest more spatial variability for 1,3-butadiene concentrations compared to benzene concentrations. Variations in meteorology can influence benzene and 1,3-butadiene concentrations making it difficult to examine the true concentration trends. Therefore, a generalized additive model (GAM) was used in a time-series analysis to adjust the benzene and 1,3-butadiene concentrations for variations caused by daily differences in meteorology. The analysis revealed very little difference in the weekend-weekday concentrations, except for a block of time during the morning rush hour where weekday concentrations were slightly higher. The GAM analysis showed that there was a significant decrease in the benzene and 1,3-butadiene concentrations throughout the trend period of 1997-2004. The average annual percent decrease across the sites was 1.7% for benzene for a meteorologically adjusted model (MA model) and 3.2% for a model without meteorological adjustment (raw trend or RT model). For 1,3-butadiene, there was a 3.7% annual decrease for MA model and 5.1% annual decrease

  18. Controlled Release of Imidacloprid from Poly Styrene-Diacetone - Nanoformulation

    NASA Astrophysics Data System (ADS)

    Qian, Kun; Guo, Yanzhen; He, Lin

    2012-01-01

    Imidacloprid is a neonicotinoids insecticide, which is important for the cash crops such as tomato, rape and so on. The conventional formulation does not only increase the loss of pesticide but also leads to environmental pollution. Controlled-release formulations of pesticide are highly desirable not only for attaining the most effective utilization of the pesticide, but also for reducing environmental pollution. Pesticide imidacloprid was incorporated in poly (styrene-diacetone crylamide)-based formulation to obtain controlled release properties, and the imidacloprid nanocontrolled release formulation was characterized by infrared (IR) and field emission scanning electron microscope (FESEM). Factors related to loading efficiency, swelling and release behaviors of the formulation were investigated. It showed that the loading efficiency could reach about 40% (w/w). The values for the diffusion exponent "n" were in the range of 0.31-0.58, which indicated that the release of imidacloprid was diffusion-controlled. The time taken for 50% of the active ingredient to be released into water, T50, was also calculated for the comparison of formulations in different conditions. The results showed that the formulation with higher temperature and more diacetone crylamide had lower value of T50, which means a quicker release of the active ingredient. This study highlighted some pieces of evidence that improved pesticide incorporation and slower release were linked to potential interactions between the pesticide and the polymer.

  19. Aqueous-based immobilization of initiator and surface-initiated ATRP to construct hemocompatible surface of poly (styrene-b-(ethylene-co-butylene)-b-styrene) elastomer.

    PubMed

    Hou, Jianwen; Shi, Qiang; Stagnaro, Paola; Ye, Wei; Jin, Jing; Conzatti, Lucia; Yin, Jinghua

    2013-11-01

    Surface-initiated atom transfer radical polymerization (SI-ATRP) is a versatile tool for surface functionalization in a well-controlled manner. However, surface modification of styrenic thermoplastic elastomers (STPEs) faces a great challenge because immobilization of typical ATRP initiators onto STPEs needs to be carried out in organic solvent, which dissolves and destroys the STPEs film. In this work, a simple aqueous-based route is developed to immobilize ATRP initiators, Br, onto the surface of styrene-b-(ethylene-co-butylene)-b-styrene elastomer (SEBS), chosen as a model copolymer of STPEs. In such a way, functional polymer brushes of ethylene glycol methyl ether methacrylate (OEGMA) are successfully prepared from the surface of SEBS. Kinetic investigations show an approximately linear relationship between grafting density and reaction time, indicating the growth of chains is coincident with a "controlled" process. CBr bonds directly connected to benzene rings on the SEBS-Br surfaces are demonstrated to be effective initiation sites for SI-ATRP. The even coverage of the surface by well-defined P(OEGMA) brushes enable SEBS films to exhibit excellent resistance to protein adsorption and platelet adhesion as well as low hemolysis ratio. This work not only manipulates the SEBS surface to substantially improve its biocompatibility, but paves a way to facilitate SI-ATRP on the surface of styrene-based block copolymers (SBCs).

  20. Kinetics of styrene in workers from a plastics industry after controlled exposure: a comparison with subjects not previously exposed.

    PubMed Central

    Löf, A; Lundgren, E; Nordqvist, M B

    1986-01-01

    Eight male workers from a glass reinforced plastics industry were experimentally exposed for 2 hours to 2.84 mmol/m3 (296 mg/m3) styrene during light physical exercise (50 W). About 63% of the amount supplied (4.6 mmol styrene) was taken up in the body. The arterial blood concentration of styrene reached a relatively stable level of 15 mumol/l at the end of exposure which was about 70% of the blood concentration in a group of volunteers with no previous exposure to solvents. The apparent blood clearance was significantly higher in the occupationally exposed subjects 2.01/h X kg compared with 1.51/h X kg. Contrary to the relatively stable level of styrene at the end of exposure the concentration of non-conjugated styrene glycol increased throughout the exposure and reached about 3 mumol/l in both groups. Like styrene, the non-conjugated styrene glycol seemed to be eliminated faster from the occupationally exposed workers. The blood concentration of styrene-7,8-oxide was low and seldom exceeded the detection limit of 0.02 mumol/l. The results show that long term exposure in a glass reinforced plastics industry may facilitate the metabolism of styrene. PMID:3730303