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Sample records for acrylonitrile butadiene styrene

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

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Acrylonitrile/styrene copoly-mer modified with butadiene/styrene elastomer. 177.1050 Section 177.1050 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) INDIRECT FOOD ADDITIVES: POLYMERS Substances for Use as...

  2. 21 CFR 177.1050 - Acrylonitrile/styrene copoly-mer modified with butadiene/styrene elastomer.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Acrylonitrile/styrene copoly-mer modified with butadiene/styrene elastomer. 177.1050 Section 177.1050 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) INDIRECT FOOD ADDITIVES: POLYMERS Substances for Use as...

  3. 21 CFR 177.1050 - Acrylonitrile/styrene copoly-mer modified with butadiene/styrene elastomer.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Acrylonitrile/styrene copoly-mer modified with butadiene/styrene elastomer. 177.1050 Section 177.1050 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) INDIRECT FOOD ADDITIVES: POLYMERS Substances for Use as...

  4. 21 CFR 177.1030 - Acrylonitrile/butadiene/styrene/methyl methacrylate copolymer.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Acrylonitrile/butadiene/styrene/methyl methacrylate copolymer. 177.1030 Section 177.1030 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) INDIRECT FOOD ADDITIVES: POLYMERS Substances for Use as Basic Components...

  5. Simulations of the Interaction of Small Molecules with Styrene-Butadiene and Styrene-Butadiene-Acrylonitrile Polymer Thin Films

    NASA Astrophysics Data System (ADS)

    Natarajan, Upendra; Mattice, Wayne

    1997-03-01

    We have simulated atomistically the structure and energetics of Styrene-Butadiene(SB) and Styrene-Butadiene-Acrylonitrile(SBA) random copolymer thin films. The films attain bulk density in their interior region. The surface layer is about 5 ÅThe orientation of the backbone bonds is random in the interior region of the films, while orienting preferentially in the direction of the plane of the film at the surface. The surface energy for the SBA films is significantly higher than for the SB films and the reason was found to be the preferential location of Acrylonitrile groups on the surface. The comparison of density and surface energy with experimental data is very good. We studied the interaction of toluene, water and hexadecane with SB and SBA films. At small concentrations, toluene is found to wet the films and spread uniformly with random structural orientation. Hexadecane also wets the surface, its chains showing an extended conformation. The water molecules are seen to form drops and do not prefer the SB and SBA surfaces. We will present results of wetting and non-wetting interaction energies, surface coverage, and conformational characteristics of these molecules and low molecular weight surfactants at different concentrations of these molecules on the films.

  6. Denitrification with acrylonitrile as a substrate using pure bacteria cultures isolated from acrylonitrile-butadiene-styrene wastewater.

    PubMed

    Wang, C C; Lee, C M

    2001-04-01

    This study attempted to isolate and identify the denitrifying bacteria that utilize acrylonitrile as a substrate from acrylonitrile-butadiene-styrene (ABS) resin wastewater. The performance of the denitrifying bacteria for treating different initial acrylonitrile concentrations was also investigated under anoxic conditions. The results showed that seven strains of denitrifying bacteria that can use acrylonitrile or acrylic acid as a substrate were isolated from the denitrification tank of a wastewater treatment plant in a ABS resin manufacturing plant and a lab-scale anoxic granular activated carbon-fluidized bed. The bacteria strains Acidovorax facilis B and Pseudomonas nautica could utilize acrylonitrile up to 279 mg/l as a substrate for denitrification. For complete nitrate removal, an adequate supply of acrylonitrile was necessary. Under the assumption that the acrylic acid would be completely removed, the removal of 1 mg/l nitrate by A. facilis B or P. nautica, about 0.64-0.74 mg/l acrylonitrile or 0.87-1 mg/l acrylic acid was needed. Because strains A. facilis B and P. nautica could utilize acrylonitrile for denitrification, they are expected to play an important role in the treatment of acrylonitrile in the wastewater treatment plant (denitrification and nitrification processes) and lab-scale granular activated carbon-fluidized bed. PMID:11341291

  7. 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. PMID:26022280

  8. 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. PMID:25857992

  9. 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.

  10. 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.

  11. Carbon nanotube buckypaper reinforced acrylonitrile-butadiene-styrene composites for electronic applications.

    PubMed

    Díez-Pascual, Ana M; Gascón, David

    2013-11-27

    Novel acrylonitrile-butadiene-styrene (ABS) nanocomposites reinforced with pristine or functionalized single- or multiwalled carbon nanotube buckypaper (BP) sheets were manufactured via hot-compression and vacuum infiltration. Their morphology, thermal, mechanical, and electrical properties were comparatively investigated. Scanning electron microscopy and thermogravimetric analysis showed that the infiltration process leads to better BP impregnation than the hot-press technique. BPs made from functionalized or short nanotubes form compact networks that hamper the penetration of the matrix chains, whereas those composed of pristine tubes possess large pores that facilitate the polymer flow, resulting in composites with low degree of porosity and improved mechanical performance. Enhanced thermal and electrical properties are found for samples incorporating functionalized BPs since dense networks lead to more conductive pathways, and a stronger barrier effect to the diffusion of degradation products, thus better thermal stability. According to dynamic mechanical analysis these composites exhibit the highest glass transition temperatures, suggesting enhanced filler-matrix interactions as corroborated by the Raman spectra. The results presented herein demonstrate that the composite performance can be tailored by controlling the BP architecture and offer useful insights into the structure-property relationships of these materials to be used in electronic applications, particularly for EMI shielding and packaging of integrated circuits. PMID:24171494

  12. Environmentally benign electroless nickel plating using supercritical carbon-dioxide on hydrophilically modified acrylonitrile-butadiene-styrene

    NASA Astrophysics Data System (ADS)

    Tengsuwan, Siwach; Ohshima, Masahiro

    2014-08-01

    Electroless Ni-P plating using supercritical carbon dioxide (scCO2) in conjunction with copolymer-based hydrophilic modification was applied to an acrylonitrile-butadiene-styrene (ABS) substrate. The surface of ABS substrate was hydrophilically modified by blending with a multi-block copolymer, poly(ether-ester-amide)s (PEEA), in injection molding process. The substrate was then impregnated with Pd(II)-hexafluoroacetylacetonate, Pd(hfa)2, using scCO2, followed by the electroless plating reaction. ABS/PEEA substrates with different PEEA to ABS blend ratios and different volume ratios of butadiene to the styrene-acrylonitrile copolymer (SAN) matrix were prepared to investigate how the dispersed PEEA and butadiene domains affected the blend morphology and the adhesive strength of the plating metal-to-polymer contact. Increasing the PEEA copolymer to ABS blend ratio increased the mass transfer rate of the plating solution in the ABS substrate. Consequently, the metal-polymer composite layer became thicker, which increased the adhesive strength of the metal-to-polymer contact because of the anchoring effect. The butadiene domains appeared to attract the Pd catalyst precursor, and thus, the proportion of butadiene in the ABS matrix also affected the adhesive strength of the contact between the metal layer and the substrate. The ABS substrate was successfully plated with a Ni-P metal layer with an average adhesive strength of 9.1 ± 0.5 N cm-1 by choosing appropriate ABS/PEEA blend ratios and a Pd(hfa)2 concentration.

  13. 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... to 27 parts by weight of a grafted rubber consisting of (i) 16 to 20 parts of butadiene/styrene...) 5 to 10 parts by weight of a graft polymer having the same composition range as the matrix...

  14. 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

  15. 21 CFR 177.1050 - Acrylonitrile/styrene copoly-mer modified with butadiene/styrene elastomer.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... rubber consisting of (i) 8-12 parts of butadiene/styrene elastomer containing 77-82 parts by weight of... by the method titled, “Determination of β-Dodecyl-mercaptopropionitrile in NR-16 Polymer,” which is... infrared spectro-photo-metric method titled “Infrared Spectro-photo-metric Determination of...

  16. 21 CFR 177.1050 - Acrylonitrile/styrene copoly-mer modified with butadiene/styrene elastomer.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... parts by weight of a grafted rubber consisting of (i) 8-12 parts of butadiene/styrene elastomer...-mercaptopropionitrile in NR-16 Polymer,” which is incorporated by reference. Copies are available from the Center for... Determination of Polymer Extracted from Borex ® 210 Resin Pellets,” which is incorporated by reference....

  17. Surface discharge and tracking phenomena induced on acrylonitrile-butadiene-styrene polymer dielectric material by acid rain

    NASA Astrophysics Data System (ADS)

    Wang, X.; Yoshimura, N.

    1999-05-01

    The discharge and tracking phenomena induced on the polymer dielectric materials by acid rain are investigated by the accelerated aging of acrylonitrile-butadiene-styrene copolymer in artificial rainwater in this article. Based on the investigation of acid rain, the artificial rainwater is chosen to agree well with the actual ingredients of precipitation. The influence of hydrophobicity degradation on the surface discharge and tracking is studied. The relations among the surface discharge, tracking, hydrophobicity, and microchemical structure and physical morphology of material are furthermore discussed. Experimental results show that the polymer dielectric materials suffer a large attack and degradation from acid rain. The dielectric surface degrades and becomes rough, and the hydrophobicity decreases so that the surface discharge and tracking may occur on them.

  18. Analysis of acrylonitrile, 1,3-butadiene, and related compounds in acrylonitrile-butadiene-styrene copolymers for kitchen utensils and children's toys by headspace gas chromatography/mass spectrometry.

    PubMed

    Ohno, Hiroyuki; Kawamura, Yoko

    2010-01-01

    A headspace gas chromatography/mass spectrometry method was developed for the simultaneous determination of the residual levels of acrylonitrile (AN), 1,3-butadiene (1,3-BD), and their related compounds containing propionitrile (PN) and 4-vinyl-1-cyclohexene (4-VC) in acrylonitrile-butadiene-styrene (ABS) copolymers for kitchen utensils and children's toys. A sample was cut into small pieces, then N,N-dimethylacetamide and an internal standard were added in a sealed headspace vial. The vial was incubated for 1 h at 90 degrees C and the headspace gas was analyzed by gas chromatography/mass spectrometry. The recovery rates of the analytes were 93.3-101.8% and the coefficients of variation were 0.3-6.5%. In ABS copolymers, the levels were 0.3-50.4 microg/g for AN, ND-4.5 microg/g for PN, 0.06-1.58 microg/g for 1,3-BD, and 1.1-295 microg/g for 4-VC. The highest level was found for 4-VC, which is a dimer of 1,3-BD, and the next highest was for AN, which is one of the monomers of the ABS copolymer. Furthermore, the method was also applied to acrylonitrile-styrene (AS) copolymers and polystyrenes (PS) for kitchen utensils, and nitrile-butadiene rubber (NBR) gloves. In AS copolymers, AN and PN were detected at 16.8-54.5 and 0.8-6.9 microg/g, respectively. On the other hand, the levels in PS and NBR samples were all low. PMID:21313827

  19. Isolation of the epsilon-caprolactam denitrifying bacteria from a wastewater treatment system manufactured with acrylonitrile-butadiene-styrene resin.

    PubMed

    Wang, Chun-Chin; Lee, Chi-Mei

    2007-06-25

    epsilon-Caprolactam has high COD and toxicity, so its discharge to natural water and soil systems may lead to an adverse environmental effect on water quality, endangering public health and welfare. This investigation attempts to isolate epsilon-caprolactam denitrifying bacteria from a wastewater treatment system manufactured with acrylonitrile-butadiene-styrene (ABS) resin. The goal is to elucidate the effectiveness of isolated pure strain and ABS mixed strains in treating epsilon-caprolactam from synthetic wastewater. The results reveal that Paracoccus versutus MDC-3 was isolated from the wastewater treatment system manufactured with ABS resin. The ABS mixed strains and P. versutus MDC-3 can consume up to 1539mg/l epsilon-caprolactam to denitrify from synthetic wastewater. Complete epsilon-caprolactam removal depended on the supply of sufficient electron acceptors (nitrate). Strain P. versutus MDC-3, Hyphomicrobium sp. HM, Methylosinus pucelana and Magnetospirillum sp. CC-26 are related closely, according to the phylogenetic analyses of 16S rDNA sequences. PMID:17161908

  20. 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. PMID:25266156

  1. 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.

  2. 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... weight of methyl methacrylate; and (2) 21 to 27 parts by weight of a grafted rubber consisting of (i) 16... 28 parts by weight of styrene and (ii) 5 to 10 parts by weight of a graft polymer having the...

  3. 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... weight of methyl methacrylate; and (2) 21 to 27 parts by weight of a grafted rubber consisting of (i) 16... 28 parts by weight of styrene and (ii) 5 to 10 parts by weight of a graft polymer having the...

  4. 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... weight of methyl methacrylate; and (2) 21 to 27 parts by weight of a grafted rubber consisting of (i) 16... 28 parts by weight of styrene and (ii) 5 to 10 parts by weight of a graft polymer having the...

  5. SISTER CHROMATID EXCHANGE AND CHROMOSOME ABERRATION ANALYSES IN MICE AFTER IN VIVO EXPOSURE TO ACRYLONITRILE, STYRENE, OR BUTADIENE MONOXIDE

    EPA Science Inventory

    The use of polymers in plastic and rubber products has generated concern that monomers potentially active in biological systems may be eluted from these substances. The authors have evaluated two such monomers, acrylonitrile and styrene, for the induction of chromosome damage in ...

  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.../butadiene/sty-rene co-polymer. Acrylonitrile/butadiene/styrene copolymer identified in this section may be... of: (1) Eighty-four to eighty-nine parts by weight of a matrix polymer containing 73 to 78 parts...

  7. 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.../butadiene/sty-rene co-polymer. Acrylonitrile/butadiene/styrene copolymer identified in this section may be... of: (1) Eighty-four to eighty-nine parts by weight of a matrix polymer containing 73 to 78 parts...

  8. 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...

  9. 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...

  10. 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.

  11. 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. PMID:25413110

  12. 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

  13. Laser transmission welding of Acrylonitrile-Butadiene-Styrene (ABS) using a tailored high power diode-laser optical fiber coupled system

    NASA Astrophysics Data System (ADS)

    Rodríguez-Vidal, E.; Quintana, I.; Etxarri, J.; Otaduy, D.; González, F.; Moreno, F.

    2012-06-01

    Laser transmission welding (LTW) of polymers is a direct bonding technique which is already used in different industrial applications sectors such as automobile, microfluidic, electronic and biomedicine. This technique offers several advantages over conventional methods, especially when a local deposition of energy and minimum thermal distortions are required. In LTW one of the polymeric materials needs to be transparent to the laser wavelength and the second part needs to be designed to be absorbed in IR spectrum. This report presents a study of laser weldability of ABS (acrylonitrile/butadiene/styrene) filled with two different concentrations of carbon nanotubes (0.01% and 0.05% CNTs). These additives are used as infrared absorbing components in the laser welding process, affecting the thermal and optical properties of the material and, hence, the final quality of the weld seam. A tailored laser system has been designed to obtain high quality weld seams with widths between 0.4 and 1.0mm. It consists of two diode laser bars (50W per bar) coupled into an optical fiber using a non-imaging solution: equalization of the beam quality factor (M2) in the slow and fast axes by a pair of micro step-mirrors. The beam quality factor has been analyzed at different laser powers with the aim to guarantee a coupling efficiency to the multimode optical fiber. The power scaling is carried out by means of multiplexing polarization technique. The analysis of energy balance and beam quality is performed in two linked steps: first by means ray tracing simulations (ZEMAX®) and second, by validation. Quality of the weld seams is analyzed in terms of the process parameters (welding speed, laser power and clamping pressure) by visual and optical microscope inspections. The optimum laser power range for three different welding speeds is determinate meanwhile the clamping pressure is held constant. Additionally, the corresponding mechanical shear tests were carried out to analyze the

  14. Crude butadiene to styrene process

    SciTech Connect

    Dixit, R.S.; Murchison, C.B.

    1994-12-31

    One of the natural by-products of ethylene manufacture is a mixture of C4`s containing butadiene, butenes and butane. This C4 stream is the predominant feed stock for producing pure butadiene by an extraction process. The demand growth for ethylene far exceeds that for butadiene resulting in a world wide surplus of butadiene. The ethylene producer has a number of options available to process the crude C4 stream if the market price does not justify isolation of the pure butadiene. The first option is recycle the crude C4 stream back to the ethylene cracker and co-crack with fresh feed. A second option that has become popular in the last few years has been the partial or complete hydrogenation of the butadiene and butenes in the crude C4 stream. Partial or selective hydrogenation is preferred when there is a market for iso-butene which finds use in MTBE manufacture. Full hydrogenation is used when cracker feed stock is limited, there is excess hydrogen and no cost effective outlets exist for butenes. Full hydrogenation produces butanes that are excellent crack feed stock. Both selective and full hydrogenation require low to moderate capital expenditure. Both of these options are currently being practiced to remove excess butadiene from the market. The crude C4 to styrene process developed by Dow offers an attractive, high value alternative to an olefins producer. This process selectively upgrades butadiene in C4 streams to styrene monomer and produces raffinate-1 as a by-product. The process is currently being operated at the 18--40 lb/hr scale in a Dow Texas pilot plant.

  15. Heparinized styrene-butadiene-styrene elastomers.

    PubMed

    Goosen, M F; Sefton, M V

    1979-05-01

    A heparinized high-strength elastomer has been developed which is potentially useful as a nonthrombogenic vascular prosthesis. A surface hydroxylated styrene-butadiene-styrene (SBS) block copolymer with at least 40% extent of reaction after glow-discharge cleaning was coated with a 20% acetylated polyvinyl alcohol/heparin mixture containing glutaraldehyde and magnesium chloride. After curing at 80 degrees C for 100 min, the polyvinyl alcohol, heparin, and hydroxylated SBS were covalently bound to each other by acetal bridges. The effects of the various substrate and coating parameters were optimized to achieve very strong adhesion between the coating layer and the surface hydroxylated SBS. Heparin was not leached from the surface of the new material using 3M saline at pH 7.4 despite a detection limit of 10(-5) micrograms heparin/cm2 min. Prolonged partial thromboplastin times of greater than 1200 sec were observed (control: PTT = 120 sec). Preliminary ex vivo testing using a simple arteriovenous shunt in the leg of a rabbit showed good thromboresistance. The heparinized SBS shunt chamber remained patent for more than two hours without desorption of heparin. It was concluded that surface hydroxylated SBS heparinized by acetal coupling owed its thromboresistance to the heparin covalently bound to the surface and not to a microenvironment of heparin in solution at the blood/material interface. PMID:438224

  16. 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... Repeated Use Food Contact Surfaces § 177.1020 Acrylonitrile/butadiene/sty-rene co-polymer. Acrylonitrile... by weight of a matrix polymer containing 73 to 78 parts by weight of acrylonitrile and 22 to 27...

  17. 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

  18. Radiation grafting of styrene and acrylonitrile to cellulose and polyethylene

    NASA Astrophysics Data System (ADS)

    Hassanpour, S.

    1999-06-01

    Radiation induced graft polymerization is one of the best methods for obtaining material with new properties. In this work, radiation grafting of styrene, mixture of styrene and acrylonitrile to cellulose and polyethylene in the presence of methanol as a solvent by mutual method is discussed. At a low dose rate, high grafting yields were obtained from the two systems used, due to lesser termination of free radicals with the polymer growing radicals and recombination of primary radicals, resulting in a longer chain length of the grafted copolymer. In the system of styrene and acrylonitrile, comonomer technique was used and the styrene controlled the homopolymer formation during graft polymerization. Water uptake of cellulose decreased by increasing the grafting yields. Grafted cellulose can be molded to some extent and in a high percent of grafting, a new transparent material was obtained. By radiation grafting of styrene-acrylonitrile to low density polyethylene a high degree of crosslinking was observed.

  19. Inhalation exposure to 1,3-butadiene and styrene in styrene-butadiene copolymer production.

    PubMed

    Anttinen-Klemetti, Tiina; Vaaranrinta, Raija; Mutanen, Pertti; Peltonen, Kimmo

    2006-03-01

    This study assessed personal exposure to 1,3-butadiene (BD) and styrene in three plants manufacturing styrene-butadiene (SB) copolymers. Air samples were collected from the breathing zone of 28 workers over 4 months in three SB plants using diffusive samplers. The total number of samples was 885 with the number of samples per participant varying from 19 to 39. Samples were collected by use of 3M 3500 passive monitors and analyzed with a gas chromatograph (GC). Sampling proved to be simple and inexpensive and laboratory analysis of BD could detect 0.01 and 0.007 part per millions (ppm) of styrene in the 8h samples. In the case of BD, 624 samples were below the limit of quantification (LOQ), 240 samples were between the LOQ and 1 ppm, and 21 samples exceeded the threshold limit value (TLV). In the case of styrene 336 samples were below the LOQ, 548 samples were between the LOQ and 20 ppm. The TLV was exceeded once. The data gives a comprehensive picture of personal exposure of workers in modern SB latex manufacturing plants. The study illustrates also how the new TLV of BD is being implemented. PMID:16503301

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

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... temperature for 2 h.1 Minimum 10 pct solution viscosity at 25 °C (77 °F) is 10cP. 1 3. Acrylonitrile/styrene... average molecular weight, and solution viscosity, titled: “Determination of Residual Acrylonitrile and... 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. Chrome-tanned leather shavings as a filler of butadiene-acrylonitrile rubber.

    PubMed

    Przepiórkowska, A; Chrońska, K; Zaborski, M

    2007-03-01

    The noxious wastes from the tanning industry such as chrome-tanned leather shavings were used as the only filler of rubber mixes containing carboxylated butadiene-acrylonitrile rubber (XNBR) or butadiene-acrylonitrile rubber (NBR), and a dispersing agent Limanol PEV (Schill & Seilacher). The best form addition of leather powder to the rubber mixes is mixed the waste protein with zinc oxide. The leather powder added to the rubber mixes improves the mechanical properties: tensile strength (T(s)), elongation at break (epsilon(b)) and increase the cross-linking density of carboxylated XNBR and NBR rubber mixes. Satisfactory results of these studies are presented in this work. PMID:16942836

  3. Determination of microstructure and composition in butadiene and styrene-butadiene polymers by near-infrared spectroscopy

    SciTech Connect

    Miller, C.E.; Eichinger, B.E. ); Gurley, T.W.; Hermiller, J.G. )

    1990-09-01

    Transmission spectroscopy in the near-infrared region (1,100-2,500 nm) is used to determine the microstructure and the composition of poly(butadiene) (PBD) polymers and styrene-butadiene (SBR) copolymers in bulk and in carbon tetrachloride solution. The multivariate method of classical least squares (CLS) is used to analyze near-infrared spectra of polymers with NMR-determined microstructures and compositions. Although the near-infrared spectra of the pure analytes (cis-1,4-butadiene, trans-1,4-butadiene, 1,2-butadiene, and styrene) are highly overlapped, the CLS method provides accurate predictions of analyte concentrations, because all available spectral frequencies are used for quantitation. The sensitivity of near-infrared spectroscopy to intermolecular interactions and neighboring-group effects in these polymers is demonstrated.

  4. 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).

  5. Carbon nanotubes as reinforcement of styrene butadiene rubber

    NASA Astrophysics Data System (ADS)

    De Falco, Alejandro; Goyanes, Silvia; Rubiolo, Gerardo H.; Mondragon, Iñaki; Marzocca, Angel

    2007-10-01

    This study reports an easy technique to produce cured styrene-butadiene rubber (SBR)/multi-walled carbon nanotubes (MWCNT) composites with a sulphur/accelerator system at 150 °C. Significant improvement in Young's modulus and tensile strength were achieved by incorporating 0.66 wt% of filler without sacrificing SBR elastomer high elongation at break. A comparison with carbon black filled SBR was also made. Field emission scanning electron microscopy was used to investigate dispersion and fracture surfaces. Results indicated that the homogeneous dispersion of MWCNT throughout SBR matrix and strong interfacial adhesion between oxidized MWCNT and the matrix are responsible for the considerable enhancement of mechanical properties of the composite.

  6. The overgrowth of vaterite on functionalized styrene-butadiene copolymer

    NASA Astrophysics Data System (ADS)

    Dalas, E.; Koklas, S. N.

    2003-09-01

    The kinetics of vaterite crystallization on styrene (30% w/w)-butadiene copolymer (branched) containing -C(O)CH 3 functional groups was investigated by the constant composition method. The polymer along with the functional groups stabilizes this calcium carbonate polymorph which transforms slowly to calcite. The apparent order for the crystallization process was found to be 1.3±0.1 indicative of a surface diffusion control mechanism. The number of ions forming the critical nucleus was found to be n*=3. The surface energy of the growing phase was 45 mJ m -2. The formation of vaterite initiated through the interaction of Ca 2+ ions of the supersaturated solution with the negative end of the -CO bond.

  7. Aragonite crystallization on functionalized styrene-butadiene copolymer

    NASA Astrophysics Data System (ADS)

    Dalas, E.; Koklas, S. N.; Papakostas, V.

    2003-06-01

    A styrene (30% w/w)-butadiene copolymer (3-arm configuration), epoxidized and further functionalized with the -S(O) 2OH groups was found to be a substrate favoring the deposition of aragonite crystals from stable supersaturated solutions at pH 8.50 and 25°C. The crystallization was studied by the constant composition technique, thus making it possible for a relatively large amount of the overgrowths to be formed and to be identified exclusively as aragonite crystals. The apparent order found from kinetic analysis was n=7.2±0.8, thus suggesting a polynuclear mechanism. A surface energy of 44±5 mJ m -2 was calculated for the growing aragonite phase and a four-ion cluster forming the critical nucleus, according to the classical nucleation theory.

  8. 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.

  9. Diamino Telechelic Polybutadienes for Solventless Styrene-butadiene-styrene (SBS) Triblock Copolymer Formation.

    PubMed

    Ji, Shengxiang; Hoye, Thomas R; Macosko, Christopher W

    2008-11-10

    High molecular weight, high functionality diamino telechelic polybutadienes (TPBs) were synthesized by ring-opening metathesis polymerization (ROMP) of 1,5-cyclooctadiene (COD) in the presence of a chain transfer agent, 1,8-dicyano-4-octene, followed by lithium aluminum hydride reduction. Melt coupling of diamino TPB with anhydride-terminated polystyrene (PS-anh) resulted in the formation of styrene-butadiene-styrene (SBS) triblock copolymers; ca. 80% maximum conversion of PS-anh was achieved within 30 seconds. The results from SAXS, TEM, and rheological measurements of the coupling products confirmed the formation of SBS triblock copolymers having lamellar morphology. A fluororesent-labeled PS-anh was used to study the coupling kinetics by diluting the reactants by the addition of non-functional PS. PMID:19907636

  10. Ferromagnetic resonance investigations on styrene-butadiene-styrene barium ferrite nanocomposites.

    PubMed

    All, N; Chipara, M; Balascuta, S; Skomski, R; Sellmyer, D J

    2009-07-01

    FMR measurements on barium ferrite nanoparticles (with an average length of about 13 nm) dispersed within a block copolymer (styrene-butadiene-styrene) are reported. Resonance spectra have been successfully simulated by a convolution of a Dysonian line and a Lorentzian line. The temperature dependence of FMR spectra in the so called in-the-plane and out-of the-plane configurations is reported. The angular dependence of FMR spectra at room temperature is analyzed in detail and simulated within simple thermodynamic model that takes into account the competition between shape and magnetocrystalline anisotropies. FMR data revealed that the local magnetic field acting on uncoupled electronic spin is dominated by the magnetocrystalline contribution, which eventually includes surface effects. The strong connection between FMR spectra and hysteresis loop is demonstrated. PMID:19916470

  11. Surface hydroxylation of styrene-butadiene-styrene block copolymers for biomaterials.

    PubMed

    Sefton, M V; Merrill, E W

    1976-01-01

    This work pertains to the development of high strength elastomers potentially useful as nonthrombogenic cardiovascular prostheses. Triblock copolymers of the styrene-butadiene-styrene type have been subjected to surface hydroxylation which provide reactive sites at the surface for the subsequent coupling of heparin while retaining the unique mechanical properties of the SBS copolymers. Curves of hydroxyl content versus the copolymer film thickness demonstrate the effect of swelling in the surface region on the product distribution and on the time dependence of the hydroxylation process. In addition, the effect of time, temperature, and the composition of the reaction bath on the diffusion/reaction process is shown. Finally, the general applicability of this surface modification scheme to the development of biomaterials is discussed. PMID:1249089

  12. Diamino Telechelic Polybutadienes for Solventless Styrene-butadiene-styrene (SBS) Triblock Copolymer Formation

    PubMed Central

    Ji, Shengxiang; Hoye, Thomas R.; Macosko, Christopher W.

    2008-01-01

    High molecular weight, high functionality diamino telechelic polybutadienes (TPBs) were synthesized by ring-opening metathesis polymerization (ROMP) of 1,5-cyclooctadiene (COD) in the presence of a chain transfer agent, 1,8-dicyano-4-octene, followed by lithium aluminum hydride reduction. Melt coupling of diamino TPB with anhydride-terminated polystyrene (PS-anh) resulted in the formation of styrene-butadiene-styrene (SBS) triblock copolymers; ca. 80% maximum conversion of PS-anh was achieved within 30 seconds. The results from SAXS, TEM, and rheological measurements of the coupling products confirmed the formation of SBS triblock copolymers having lamellar morphology. A fluororesent-labeled PS-anh was used to study the coupling kinetics by diluting the reactants by the addition of non-functional PS. PMID:19907636

  13. 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...

  14. 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.

  15. 21 CFR 177.1040 - Acrylonitrile/styrene copoly-mer.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... deionized water or reagent grade n-heptane at reflux temperature for 2 h.1 Minimum 10 pct solution viscosity... viscosity, titled: “Determination of Residual Acrylonitrile and Styrene Monomers-Gas Chromatographic... Copolymers,” and “Analytical Method for 10% Solution Viscosity of Tyril,” which are incorproated by...

  16. 21 CFR 177.1040 - Acrylonitrile/styrene copoly-mer.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Acrylonitrile/styrene copoly-mer. 177.1040 Section 177.1040 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) INDIRECT FOOD ADDITIVES: POLYMERS Substances for Use as Basic Components of Single and Repeated Use...

  17. 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

  18. 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). PMID:17324391

  19. Morphology and Phase Transitions in Styrene-Butadiene-Styrene Triblock Copolymer Grafted with Isobutyl-Substituted Polyhedral Oligomeric Silsesquioxanes

    SciTech Connect

    Drazkowski, Daniel B.; Lee, Andre; Haddad, Timothy S.

    2008-10-03

    Two symmetric triblock polystyrene-butadiene-polystyrene (SBS) copolymers with different initial morphologies were grafted with varying amounts of isobutyl-substituted polyhedral oligomeric silsesquioxane (POSS) molecules. The POSS octamers, R{prime}R{sub 7}Si{sub 8}O{sub 12}, were designed to contain a single silane functional group, R{prime}, which was used to graft onto the dangling 1,2-butadienes in the polybutadiene block and seven identical organic groups, R = isobutyl (iBu). Morphology and phase transitions of these iBu-POSS-modified SBS were investigated using small-angle X-ray scattering and rheological methods. It was observed that when iBu-POSS was grafted to the butadiene segment, the long-range and local order of the morphology were preserved, and the d-spacing showed a small, systematic increase with increasing POSS content. These observations suggest that grafted iBu-POSS were well-distributed within the butadiene domains and did not interact with the styrene domains; effectively, grafting of iBu-POSS to butadiene did not affect the segregation between butadiene and styrene domains. However, addition of iBu-POSS reduces the overall polystyrene volume. Consequently, from a morphology standpoint, this modification effectively shifts the phase diagram to lower styrene content. This was supported with SAXS and transition temperatures measurements made from the different host morphologies.

  20. Detection of hydrogen dissolved in acrylonitrile butadiene rubber by 1H nuclear magnetic resonance

    NASA Astrophysics Data System (ADS)

    Nishimura, Shin; Fujiwara, Hirotada

    2012-01-01

    Rubber materials, which are used for hydrogen gas seal, can dissolve hydrogen during exposure in high-pressure hydrogen gas. Dissolved hydrogen molecules were detected by solid state 1H NMR of the unfilled vulcanized acrylonitrile butadiene rubber. Two signals were observed at 4.5 ppm and 4.8 ppm, which were assignable to dissolved hydrogen, in the 1H NMR spectrum of NBR after being exposed 100 MPa hydrogen gas for 24 h at room temperature. These signals were shifted from that of gaseous hydrogen molecules. Assignment of the signals was confirmed by quantitative estimation of dissolved hydrogen and peak area of the signals.

  1. Chemical characterization of CTBN (carboxyl-terminated butadiene/acrylonitrile) and its epoxy adduct

    SciTech Connect

    Smith, R.E.

    1990-01-01

    This report describes the analysis of carbonxyl-terminated butadiene (CTB), carboxyl-terminated butadiene/acrylonitrile (CTBN), and a CTBN adduct prepared by reaction with Epon 828. Data from gel permeation chromatography, nuclear magnetic resonance spectroscopy, high performance liquid chromatography, and ion chromatography are presented and discussed. Quantitative methods based on carbon-13 and proton NMR for analyzing CTBN are described. Proton NMR was found to be useful in identifying lots that have an abnormal amount of CTBN protons. One such lot exhibited a phase separation of a polybutadiene impurity. Carbon-13 NMR was found to be capable of determining nitrile content directly. Carbon-13 NMR had a relative standard deviation of 8.3% and a proton NMR of 3.9%. Proton NMR was found to be useful in identifying lots that have 5% more CTBN protons than other lots. 3 refs., 11 figs., 4 tabs.

  2. Mortality of workers in styrene-butadiene polymer production

    SciTech Connect

    Matanoski, G.M.; Schwartz, L.

    1987-08-01

    A total of 13,920 males who had worked in eight styrene-butadiene rubber polymer manufacturing plants in the US and Canada for at least 1 year were followed for deaths from 1943 when the industry began to 1979. Mortality ratios standardized for age, race, and calendar time using US male rates as a comparison revealed no excess mortality in this population for any cause of death. The overall standardized mortality ratio (SMR) for all causes was 0.81. Only the SMR for arteriosclerotic heart disease among black males showed a significant excess (SMR = 1.28). Examination of risks by major work areas such as production, utilities, maintenance, and other jobs, as well as by salaried and hourly pay grade, revealed no significant differences in cancer mortality by specific sites. Because the ratios for selected digestive cancers were above the all-cause SMR, this group of neoplasms is under further investigation as is the exposure profile of specific jobs within the industry.

  3. 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.

  4. Evaluation of tri-steps modified styrene-butadiene-styrene block copolymer membrane for wound dressing.

    PubMed

    Yang, Jen Ming; Huang, Huei Tsz

    2012-08-01

    Tri-steps modified styrene-butadiene-styrene block copolymer (SBS) membrane was prepared with epoxidation, ring opening reaction with maleated ionomer and layer-by-layer assembled polyelectrolyte technique. The tri-steps modified SBS membrane was characterized by infrared spectroscopy and X-ray photoelectron spectroscope (XPS). The structures of the modified SBS membranes were identified with methylene blue and azocarmine G. The content of amino group on the surface of the modified membrane was calculated from uptake of an acid dye. The values of the contact angle, water absorption, water vapor transmission rate and the adsorption of fibronectin on the membranes were determined. To evaluate the biocompatibility of the tri-steps modified SBS membrane, the cytotoxicity, antibacterial and growth profile of the cell culture of 3T3 fibroblasts on the membrane were evaluated. The bactericidal activity was found on the modified SBS. From the cell culture of 3T3 fibroblasts on the membrane, it revealed that the cells not only remained viable but also proliferated on the surface of the tri-steps modified SBS membranes. As the membranes are sterile semipermeable with bactericidal activity and transparent allowing wound checks, they can be considered for shallow wound with low exudates. PMID:24364963

  5. 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. PMID:17544580

  6. 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.

  7. Recycling cycle of materials applied to acrylonitrile-butadiene-styrene/policarbonate blends with styrene-butadiene-styrene copolymer addition

    NASA Astrophysics Data System (ADS)

    Cândido, L. H. A.; Ferreira, D. B.; Júnior, W. Kindlein; Demori, R.; Mauler, R. S.

    2014-05-01

    The scope of this research is the recycling of polymers from mobile phones hulls discarded and the performance evaluation when they are submitted to the Recycling Cycle of Materials (RCM). The studied material was the ABS/PC blend in a 70/30 proportion. Different compositions were evaluated adding virgin material, recycled material and using the copolymer SBS as impact modifier. In order to evaluate the properties of material's composition, the samples were characterized by TGA, FTIR, SEM, IZOD impact strength and tensile strength tests. At the first stage, the presented results suggest the composition containing 25% of recycled material and 5% of SBS combines good mechanical performance to the higher content of recycled material and lower content of impact modifier providing major benefits to recycling plans. Five cycles (RCM) were applied in the second stage; they evidenced a decrease trend considering the impact strength. At first and second cycle the impact strength was higher than reference material (ABS/PC blend) and from the fourth cycle it was lower. The superiority impact strength in the first and second cycles can be attributed to impact modifier effect. The thermal tests and the spectrometry didn't show the presence of degradation process in the material and the TGA curves demonstrated the process stability. The impact surface of each sample was observed at SEM. The microstructures are not homogeneous presenting voids and lamellar appearance, although the outer surface presents no defects, demonstrating good moldability. The present work aims to assess the life cycle of the material from the successive recycling processes.

  8. Gloves against mineral oils and mechanical hazards: composites of carboxylated acrylonitrile-butadiene rubber latex.

    PubMed

    Krzemińska, Sylwia; Rzymski, Władysław M; Malesa, Monika; Borkowska, Urszula; Oleksy, Mariusz

    2016-09-01

    Resistance to permeation of noxious chemical substances should be accompanied by resistance to mechanical factors because the glove material may be torn, cut or punctured in the workplace. This study reports on glove materials, protecting against mineral oils and mechanical hazards, made of carboxylated acrylonitrile-butadiene rubber (XNBR) latex. The obtained materials were characterized by a very high resistance of the produced materials to oil permeation (breakthrough time > 480 min). The mechanical properties, and especially tear resistance, of the studied materials were improved after the addition of modified bentonite (nanofiller) to the XNBR latex mixture. The nanocomposite meets the requirements in terms of parameters characterizing tear, abrasion, cut and puncture resistance. Therefore, the developed material may be used for the production of multifunctional protective gloves. PMID:26757889

  9. 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).

  10. 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...

  11. A new polymer-based hydrogen getter. [Styrene-butadiene triblock copolymer

    SciTech Connect

    Gilliom, L.R.

    1987-01-01

    Styrene-butadiene triblock copolymer PS-PB-PS was hydrogenated in the bulk using the Crabtree catalyst (Ir(COD)(py)(tcyp))PF/sub 6/ (COD = 1,5-cyclooctadiene, py = pyridene, tcyp = tricyclohexylphosphine). Since this polymer/catalyst mixture reacts rapidly with hydrogen at ambient temperature and low hydrogen pressures, it should act as an effective hydrogen getter. 7 refs., 2 figs.

  12. 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

  13. Morphology and Dynamic Mechanical Properties of Diglycidyl Ether of Bisphenol-A Toughened with Carboxyl-Terminated Butadiene-Acrylonitrile

    NASA Technical Reports Server (NTRS)

    Hong, S. D.; Chung, S. Y.; Fedors, R. F.; Moacanin, J.; Gupta, A.

    1984-01-01

    The fracture toughness of an incorporation of a carboxyl-terminated butadiene acrylonitrile (CTBN) elastomer in diglycidyl ether bisphenol A (DGEBA) resin was investigated. Measurements of dynamic mechanical properties, scanning electron microscopy and small-angle X-ray scattering were carried out to characterize the state of cure, morphology and particle size and size distribution of the neat resins and their graphite fiber reinforced composites.

  14. 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.

  15. 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

    2015-09-01

    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. PMID:26005134

  16. Nanocomposites prepared from acrylonitrile butadiene rubber and organically modified montmorillonite with vinyl groups

    NASA Astrophysics Data System (ADS)

    Han, Mijeong; Kim, Hoonjung; Kim, Eunkyoung

    2006-01-01

    Nanocomposites were prepared from acrylonitrile-butadiene rubber (NBR), vinyl groups containing organically modified montmorillonite and additives, such as zinc oxide, stearic acid, and sulfur. The organically modified montmorillonites used in these nanocomposites were prepared by ion exchange reactions of N,N'-dimethylalkyl-(p-vinylbenzyl)-ammonium chlorides (DAVBAs, alkyl = octyl, dodecyl, and octadecyl) with sodium montmorillonite (Na+-MMT). NBR nanocomposites were obtained by controlling both the mixing and vulcanization conditions, by using a Brabender mixer and hot-press process. X-ray diffraction (XRD) analysis shows that, depending on the amount of montmorillonite that is added, both exfoliated and intercalated nanocomposite structures are formed. The NBR/DAVBA-MMT nanocomposites exhibit much higher mechanical properties (e.g., tensile strength, Young's modulus, 300% modulus, and hardness) as well as gas barrier properties as compared to NBR Na+-MMT or NBR composites generated from modified montmorillonites without vinyl groups. Consistent with the results of XRD, transmission electron microscopy (TEM) reveals that the intercalation and exfoliation structures of the nanocomposites coexist and that the DAVBA-MMT layers are well dispersed in NBR.

  17. 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

  18. 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. PMID:26644917

  19. Photocrosslinking of styrene-butadiene-styrene (SBS) networks formed by thiol-ene reactions and their influence on cell survival.

    PubMed

    Gidon, Dogan; Aydin, Derya; Kizilel, Seda

    2015-12-01

    Styrene-butadiene-styrene (SBS) triblock copolymer has been conventionally used as synthetic rubber. However, the potential of SBS for biomedical applications has only been considered in limited earlier reports. Here, we demonstrate an effective approach to designing a photocrosslinked SBS network. Rheological analysis has been conducted for the investigation of the storage modulus of the resultant network. Crosslinked SBS networks were synthesized and characterized through optical and electron microscope imaging. The crosslink density of the network, calculated from swelling experiments, was 643 mol m(-3), where higher swelling in a hydrophobic medium was observed compared to the swelling measured in water. Cell survival analysis with HeLa cells and NIH/3T3 fibroblasts revealed that these networks are non-toxic, and that they could be considered for a variety of biomedical applications. PMID:26526076

  20. 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

  1. 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. PMID:2653733

  2. Mechanical property modification and morphology of poly(styrene-b-hydrogenated butadiene-b-styrene)/poly(hydrogenated butadiene) blends

    SciTech Connect

    Baetzold, J.P.; Gancarz, I.; Quan, X.; Koberstein, J.T. )

    1994-09-12

    The mechanical properties and morphology of a series of triblock copolymer blends with midblock associating homopolymers of varying molecular weight (Mw) have been characterized. The symmetric triblock copolymer studied contains polystyrene endblocks and midblocks of hydrogenated poly(1,2-butadiene) and is mixed with hydrogenated poly (1,2-butadiene) homopolymers of Mw both below and above that of the copolymer midblock. The rubbery plateau modulus determined by dynamic mechanical spectroscopy increases with increasing Mw of the homopolymer at fixed overall homopolymer content. At fixed Mw, the composition dependence of the plateau modulus is complex and shows unusually synergistic behavior. For high Mw homopolymers the plateau modulus increases initially upon homopolymer addition. Small angle neutron scattering and TEM are employed to determine the morphological changes. In all cases, the blends exhibit a lamellar microphase structure, with homopolymer macrophases apparent at high homopolymer contents. The apparent homopolymer solubility limits are found to be inversely related to the homopolymer Mw. The results indicate that the lamellar repeat distance decreases upon addition of the lowest Mw homopolymer and that the microdomains swell in blends containing homopolymers with Mw similar to that of the midblock sequence and are unchanged for high Mw homopolymers with negligible solubility. The results suggest that the interesting mechanical response of the blends can be explained by consideration of the changes in their entanglement structure resulting from confinement of the homopolymer chains within the highly constrained environment of the midblock lamellae.

  3. 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

  4. Enhanced photorefractive performance in CdSe quantum-dot-dispersed poly(styrene-co-acrylonitrile) polymers

    SciTech Connect

    Li Xiangping; Embden, Joel van; Chon, James W. M.; Gu Min; Evans, Richard A.

    2010-06-21

    This paper reports on the enhanced photorefractive behavior of a CdSe quantum-dot-dispersed less expensive polymer of poly(styrene-co-acrylonitrile). The capability of CdSe quantum dots used as photosensitizers and the associated photorefractive performance are characterized through a photocurrent experiment and a two-beam coupling experiment, respectively. An enhanced two-beam coupling gain coefficient of 12.2 cm{sup -1} at 46 V/mum was observed owning to the reduced potential barrier. The photorefractive performance per CdSe quantum dot is three orders of magnitude higher than that in the sample sensitized by trinitrofluorenone in poly(styrene-co-acrylonitrile), and almost ten times higher than that in the CdSe quantum-dot-sensitized poly(N-vinylcarbazole) polymers.

  5. Magnetic properties of barium ferrite dispersed within polystyrene-butadiene-styrene block copolymers.

    PubMed

    Chipara, M; Skomski, R; Ali, N; Hui, D; Sellmyer, D J

    2009-06-01

    Magnetic properties of nanocomposite materials obtained by dispersing barium ferrite nanoparticles within polystyrene-butadiene-styrene block copolymer, in the temperature range, 300 to 500 K are reported. The temperature dependence of the magnetization at saturation, averaged uniaxial magnetocrystalline anisotropy, and coercive field of thick films are analyzed. A "matrix effect" was noticed within the glass transition range of the hard component (polystyrene) of the polymeric matrix. The reported modifications of the magnetic properties were assigned to the competition between the magnetic and mechanical reorientation of nanoparticles within the polymeric matrix. Such modifications were not observed in barium ferrite dispersed in cement. PMID:19504902

  6. Effect of crosslink density on some properties of electron beam-irradiated styrene-butadiene rubber

    NASA Astrophysics Data System (ADS)

    Wang, Qingguo; Wang, Fenlan; Cheng, Kuo

    2009-11-01

    Crosslink densities of electron beam (EB)-irradiated styrene-butadiene rubber (SBR) samples were measured by using a novel magnetic resonance crosslink density spectrometer (MRCDS). With 1,1,1-trimethylolpropane triacrylate (TMPTA) loading increasing, the crosslink density of EB-irradiated SBR increases up to a certain level, and then decreases in the irradiation dose range 50-200 kGy. Tensile strength, elongation at break, thermal stability and pyrolysis products of the EB-irradiated SBR samples with different crosslink densities were also studied in this paper.

  7. Conductivity of styrene-butadiene block copolymers upon continuous irradiation with fast electrons

    SciTech Connect

    Khatipov, S.A.; Edrisov, A.T.; Bol`bit, N.M.; Milinchuk, V.K.

    1995-03-01

    The time dependences of the density of radiation-induced current in polystyrene, polybutadiene, and styrene-butadiene block copolymers of various composition were studied upon varying the electric field strength and radiation dose rate. Significant deviations of the values of the radiation-induced conductivity constant A{sub m} and dispersion parameter {alpha} from those expected for additive contributions of each component into the radiation-induced conductivity were revealed. Conclusions on the charge carriers generated during irradiation transfer from polybutadiene to polystyrene microdomains were drawn.

  8. 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. PMID:24647801

  9. Continuous spin fractionation and characterization by size-exclusion chromatography for styrene-butadiene block copolymers.

    PubMed

    Xiong, Xiaopeng; Eckelt, John; Wolf, Bernhard A; Zhang, Zhengjun; Zhang, Lina

    2006-03-31

    Linear and star-shaped styrene-butadiene block copolymers synthesized by anionic polymerization of butadiene and styrene were fractionated by applying a newly developed large-scale fractionation technique, named continuous spin fractionation (CSF). Their molecular weight and polydispersity index (d=M(w)/M(n)) were measured with size-exclusion chromatography and static light scattering. For the linear triblock copolymer a fractionation via temperature variation turned out to be better suited than the usual isothermal procedure. The star-shaped polymer with the d value of 1.33 was fractionated in two CSF steps to get the targeted sample, which has a considerably more uniform structure and a narrower molecular weight distribution (d=1.11). The corresponding starting linear diblock copolymer was fractionated in one step reducing d from 1.68 to 1.17. With one set of simple laboratory equipment, 1kg polymer can be fractionated per day. Utilizing CSF, for the first time, we fractionated successfully the block copolymers. PMID:16466731

  10. Optical properties of polycarbonate/styrene-co-acrylonitrile blends: effects of molecular weight of the matrix.

    PubMed

    Yi, Ping; Xiong, Ying; Guo, Shaoyun

    2015-12-01

    In this paper, the effects of the molecular weight of a polycarbonate (PC) matrix on the phase morphology and optical properties of a PC/styrene-co-acrylonitrile (SAN) blend were investigated. A scanning electron microscope is used to analyze the phase morphology of the blends, and Mie scattering theory is used to analyze the changing laws of the optical properties of PC/SAN blends with the increasing of PC molecular weight. Results show that the average particle diameter is not strongly changed with different PC molecular weight because the values of the viscosity ratios are very close to each other. But it is obvious that the number of large particles gradually reduced while small particles (especially d<2  μm) significantly increased with the increasing of PC molecular weight. And the increase in small particles will result in an increase in backward scattering so the transmittance of PC/SAN blends decreases with the increase of PC molecular weight. However, the balance of the scattering coefficients and the number concentration of particles eventually lead to the haze of the blends being very close, despite having different PC molecular weights. Meanwhile, the photographs of scattering patterns indicate that the PC/SAN blends whose component weight ratios are fixed at 70:30 have excellent antiglare properties, despite the changes in molecular weight of the PC matrix. PMID:26836652

  11. 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.

  12. 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.

  13. DYNAMIC MECHANICAL PROPERTIES OF STYRENE-BUTADIENE COMPOSITES REINFORCED BY DEFATTED SOY FLOUR AND CARBON BLACK CO-FILLER

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Carboxylated styrene-butadiene (SB) composites reinforced by a mixture of defatted soy flour (DSF) and carbon black (CB) were investigated in terms of their dynamic mechanical properties. DSF is an abundant renewable commodity and has a lower cost than CB. DSF contains soy protein, soy carbohydrat...

  14. EFFECT OF PH ON THE COMPOSITE MODULUS OF SOY PROTEIN AGGREGATES AND CARBOXYLATED STYRENE-BUTADIENE LATEX

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soy protein isolate (SPI) has been reported to have a significant reinforcement effect in styrene-butadiene composites prepared under alkaline condition. SPI is a soy product that remains after soybean oil and soy carbohydrates (both soluble and insoluble) are removed from soybean flakes. SPI is a...

  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. 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...

  17. 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...

  18. 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.

  19. The influence of mechanical properties in the electrical breakdown in poly-styrene-ethylene-butadiene-styrene thermoplastic elastomer

    NASA Astrophysics Data System (ADS)

    Kollosche, Matthias; Melzer, Michael; Becker, Andre; Stoyanov, Hristian; McCarthy, Denis N.; Ragusch, Hülya; Kofod, Guggi

    2009-03-01

    Dielectric elastomer actuators (DEA) are a class of eletro-active polymers with promising properties for a number of applications, however, such actuators are prone to failure. One of the leading failure mechanisms is the electrical breakdown. It is already well-known that the electro-mechanical actuation properties of DEA are strongly influenced by the mechanical properties of the elastomer and compliant electrodes. It was recently suggested that also the electrical breakdown in such soft materials is influenced by the mechanical properties of the elastomer. Here, we present stress-strain measurements obtained on two tri-block thermoplastic elastomers (SEBS 500040 and SEBS 500120, poly-styrene-ethylene-butadiene-styrene), with resulting large differences in mechanical properties, and compare them to measurements on the commonly used VHB 4910. Materials were prepared by either direct heat-pressing of the raw material, or by dissolving in toluene, centrifuging and drop-casting. Experiments showed that materials prepared with identical processing steps showed a difference in stiffness of about 20%, where centrifuged and drop-casted films were seen to be softer than heat-pressed films. Electric breakdown measurements showed that for identically processed materials, the stiffness seemed to be a strong indicator of the electrical breakdown strength. It was therefore found that processing leads to differences in both stiffness and electrical breakdown strength. However, unexpectedly, the softer drop-cast films had a much higher breakdown strength than the heatpressed films. We attribute this effect to impurities still present in the heat-pressed films, since these were not purified by centrifuging.

  20. Direct pyrolysis mass spectrometry of acrylonitrile-cellulose graft copolymer prepared by radiation-induced graft polymerization in presence of styrene as homopolymer suppressor

    NASA Astrophysics Data System (ADS)

    Badawy, Sayed M.; Dessouki, Ahmad M.; Nizam El-Din, Horia M.

    2001-05-01

    Graft polymerization of acrylonitrile onto cellulosic filter paper competing with the homopolymerization by mutual irradiation technique was studied in the presence of homopolymer suppressors. Addition of FeCl 3 decreased both homopolymerization and graft polymerization, whereas inclusion of a low ratio of styrene monomer with acrylonitrile leads to successful grafting of acrylonitrile with little homopolymer formation. Chemical structure and thermal behavior of the produced graft copolymers were investigated by gradual heating in the solid probe of a mass spectrometer equipped with a GCMS data system. The resulting total ion current (TIC) showed that the degradation of graft copolymers follows two-step pyrolysis. The presence of a low ratio of styrene comonomer increased thermal stability of the prepared acrylonitrile-cellulose graft copolymer. The pyrolysis products have mass spectra characteristic of the copolymer composition; they contain the repeating unit of the oligomers. Total ion current and spectrum subtractions were used to separate and measure spectra of graft copolymers at distinctly different temperatures.

  1. 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.

  2. Correlation of mass fractal dimension and cluster size of silica in styrene butadiene rubber composites.

    PubMed

    Schneider, Gerald Johannes; Vollnhals, V; Brandt, K; Roth, S V; Göritz, D

    2010-09-01

    The morphology of the precipitated silica VN3 filled in styrene butadiene rubber was studied as a function of the volume fraction Φ by means of small-angle X-ray scattering experiments. The wide q-range of 0.008 nm(-1)

  3. Environmental epidemiologic investigations in the styrene-butadiene rubber production industry.

    PubMed Central

    Lemen, R A; Meinhardt, T J; Crandall, M S; Fajen, J M; Brown, D P

    1990-01-01

    A review of the literature and an update that is in progress of a previous retrospective cohort mortality study of the styrene-1,3-butadiene industry are discussed. The follow-up has now been extended from April 1, 1976, through December 31, 1981, for plant B and December 31, 1982, for plant A. The person-years at risk of death have gone from 34,187 to 43,341 in plant A and from 19,742 to 26,314 in plant B. Among the death certificates received to date, observed deaths have increased in both plants, with increases in cancers of the trachea, bronchus and lung and in lymphosarcomas, reticulosarcomas, and cancers of the overall lymphatic and hematopoietic system. PMID:2205482

  4. Laser heating effect on Raman spectra of styrene-butadiene rubber/multiwalled carbon nanotube nanocomposites

    NASA Astrophysics Data System (ADS)

    Yan, Xinlei; Kitahama, Yasutaka; Sato, Harumi; Suzuki, Toshiaki; Han, Xiaoxia; Itoh, Tamitake; Bokobza, Liliane; Ozaki, Yukihiro

    2012-01-01

    The laser heating effect on MWCNTs in styrene-butadiene rubber/multiwalled carbon nanotube (SBR/MWCNT) composites were studied by Raman spectra. The intensity ratio of the D band to G band (ID/IG) of SBR/MWCNT composites largely decreased with temperature. This indicates the self-rearranging behavior of MWCNTs in the SBR/MWCNTs system during temperature increase. In addition, the temperature-dependent downward shift of the G band of SBR/MWCNT composites was smaller than that of MWCNTs samples. The self-rearrangement of MWCNTs in SBR/MWCNT composites and a mechanical compression were explained as two possible reasons for the different behavior of the G band shift.

  5. Charge transfer in the low-temperature radiolysis of styrene-butadiene block copolymers

    SciTech Connect

    Khatipov, S.A.; Edrisov, A.T.; Milinchuk, V.K.

    1995-05-01

    Radiation-induced conductivity of polystyrene, polybutadiene, and styrene-butadiene block copolymers, resulting from irradiation of the samples with fast electrons of 75 keV energy under vacuum at 100 K, was studied. A negative deviation of the radiation-induced conductivity constant A{sub m} from the corresponding additive values was detected upon varying the composition of block copolymers. It is concluded that the interfacial charge transfer from polystyrene to polybutadiene microdomains occurs in the block copolymers. This conclusion is confirmed by the results of investigations of drift mobility of the charge carriers and effects of donor-acceptor admixtures on the radiation-induced conductivity of the polymers studied.

  6. Effect of strain on the electrical conductivity of a styrene-butadiene rubber

    NASA Astrophysics Data System (ADS)

    Kim, Young Hee; Lim, Jee Young; Jose, Jobin; Kim, Jae Young; Lee, Gi-Bbeum; Gent, Alan N.; Nah, Changwoon

    2010-04-01

    When the carbon black-filled rubbers are stretched, the electrical resistivity increases at lower extension ranges, and then it decreases with further extension. This complex behavior is attributed to the morphology changes of carbon black particles during extension, i.e., breaking and forming conducting paths. In this study, highly conductive carbon blacks were compounded with high styrene content SBR matrix with contents varying from 5phr, 10phr, 15phr and 20phr. All the compounds measured the electrical resistance at room temp., 40°C, 80°C, respectively. The electrical resistances are decreased as the conductive carbon blacks are higher and temperature is increased. The electrical resistivity and tensile behaviors were investigated as a function of stretching at 80°C. The conductive carbon black-filled a styrene-butadiene rubber vulcanizate showed much higher conductivity and the electrical resistivity is more stable by increase of contents. In tensile behaviors, as the contents of conductive carbon blacks increase, it shows the increase of strength.

  7. Molecular characterization of solution styrene-butadiene rubber: thermal field-flow fractionation/multi-angle light scattering studies.

    PubMed

    Choi, You Jin; Kim, Sun Tae; Lee, Seung Hwa; Kim, A-Ju; Kwag, Gwanghoon; Lee, Seungho

    2013-11-01

    Solution styrene-butadiene rubber (SSBR) is mainly constituted of a random copolymer of styrene and butadiene. SSBR usually contains microgels, having ultrahigh molecular weight (M>10(7)g/mol), affecting rheological properties of the rubber. Thus, determinations of M and size distribution of these microgels are critical in performance evaluation and control for SSBR. We employ thermal field-flow fractionation (ThFFF), combined with online multi-angle light scattering (MALS), as most suited for characterization of solutions containing the microgels since they can be characterized in toto without removing the microgels from the solution. ThFFF-MALS was applied for characterization of linear and branched SBR materials from various commercial sources, and the results were compared to those from size-exclusion chromatography (SEC). ThFFF provides higher resolution than SEC for high molecular fractions and allowed gel content to be measured. The gel content was determined by subtracting the amount of sol from total injection mass, and was measured to be 10-15%. We infer from the characterization results that the microgel content may not be correlated to the microstructure, the styrene and vinyl content of butadiene but to the fraction of high molecular weight in SSBR. Finally, the macromolecular structure and the content of microgel (larger than about 100nm) were found to significantly affect various rheological parameters such as viscosity, mechanical and dynamic properties. PMID:24063984

  8. Application of Composite Powders Recycled from Graphite Tailings in Styrene-Butadiene Rubber

    NASA Astrophysics Data System (ADS)

    Hai, Yun; Liao, Libing; Lv, Guocheng; Qin, Faxiang; Mei, Lefu; Wei, Yaozu

    2015-11-01

    With styrene-butadiene rubber (SBR) as matrix and composite powders recycled from graphite tailings as fillers, the influence of the particle size and content of the composite powders on the tensile strength and electrical conductivity of the composite powder-filled SBR were studied. The results showed that composite powder recycled from graphite tailings could reinforce SBR, whose tensile strength was significantly increased with reducing the particle size of the composite powder, but it had little effect on the conductivity of the system. With composite powders as fillers in conjunction with conductive carbon black, the tensile strength and electrical conductivity of the system were greatly improved. The maximum tensile strength of the SBR filled with composite powder and conductive carbon black increased by 47% compared to that of the single composite powder-filled SBR. When the filling content of conductive carbon black was 10 phr and that of composite powder was above 30 phr, the volume resistivity of SBR showed a sharp decline, reaching a minimum about 106 Ω cm at 40 phr. All the results indicated that composite powder recycled from graphite tailings can be applied effectively as filler in SBR. It has great economic and environmental benefits.

  9. 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.

  10. 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.

  11. 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. PMID:23218267

  12. Styrene-butadiene rubber/halloysite nanotubes nanocomposites modified by methacrylic acid

    NASA Astrophysics Data System (ADS)

    Guo, Baochun; Lei, Yanda; Chen, Feng; Liu, Xiaoliang; Du, Mingliang; Jia, Demin

    2008-12-01

    Methacrylic acid (MAA) was used to improve the performance of styrene-butadiene rubber (SBR)/halloysite nanotubes (HNTs) nanocomposites by direct blending. The detailed interaction mechanisms of MAA and the in situ formed zinc methacrylate (ZDMA) were revealed by X-ray diffraction (XRD), surface area and porosity analysis, X-ray photoelectron spectroscopy (XPS) together with crosslink density determination. The strong interfacial bonding between HNTs and rubber matrix is resulted through ZDMA and MAA intermediated linkages. ZDMA connects SBR and HNTs via grafting/complexation mechanism. MAA bonds SBR and HNTs through grafting/hydrogen bonding mechanism. Significantly improved dispersion of HNTs in virtue of the interactions between HNTs and MAA or ZDMA was achieved. Effects of MAA content on the vulcanization behavior, morphology and mechanical properties of the nanocomposites were investigated. Promising mechanical properties of MAA modified SBR/HNTs nanocomposites were obtained. The changes in vulcanization behavior, mechanical properties and morphology were correlated with the interactions between HNTs and MAA or ZDMA and the largely improved dispersion of HNTs.

  13. 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.

  14. Tear energy and strain-induced crystallization of natural rubber/styrene-butadiene rubber blend

    NASA Astrophysics Data System (ADS)

    Noguchi, F.; Akabori, K.; Yamamoto, Y.; Kawazura, T.; Kawahara, S.

    2009-08-01

    Strain-induced crystallization of natural rubber (NR), dispersed in styrene-butadiene rubber (SBR), was investigated in relation to dimensional feature of a dispersoid and crosslink density of NR by measuring tear energy (G) of crosslinked NR/SBR blends. The crosslinked NR/SBR blends in ratios of 1/9 and 3/7 by weight were prepared by mixing masticated NR and SBR with an internal mixer at a rotor speed of 30 rpm, followed by crosslinking with dicumyl peroxide on a hot press at 444 K for 60 min. The G, measured in wide-ranges of temperature and tear rate, was superposed into a master curve with a Williams-Landel-Ferry shift factor. The G of the NR/SBR(3/7) blend abruptly decreased to a level comparable to that of SBR at about melting temperature of NR crystals formed on straining. The temperature, at which the dramatic decrease in the G occurred, was associated with the dimensional feature of the NR dispersoid and the crosslink density.

  15. Cavitation in Filled Styrene-butadiene Rubber: A Real Time SAXS Observation

    NASA Astrophysics Data System (ADS)

    Zhang, Huan; Scholz, Arthur K.; Vion-Loisel, Fabien; Kramer, Edward J.; Creton, Costantino

    2011-03-01

    Cavitation of filled and unfilled elastomers under confinement at the macroscopic scale has been experimentally reported and theoretically modeled. However, cavitation occurring at the nanometer length scale has not yet been demonstrated conclusively in rubbers. Real time SAXS with synchrotron radiation was employed to probe the structure changes in carbon black filled styrene-butadiene rubber (SBR) under uniaxial loading. The scattering invariant was calculated and increased sharply at a critical extension depending on both filler content and crosslinking density around q = 0.1 nm-1, which we attributed to the formation of voids. At very large strains, a sharp and wide streak developed perpendicular to the tensile axis in reciprocal space, suggesting the deformation of the voids in elliptical voids along the tensile direction. In step cycle test, we observed that voids only appeared when the current strain exceeded the maximum historical strain (Mullins effect) and attributed the increase of the scattering invariant outside the Mullins region to the creation of new voids rather than to the reopening of old ones.

  16. Radiation chemical effects on polybutadiene polymers, styrene-butadiene block copolymers, and isotactic polypropylene

    SciTech Connect

    Basheer, R.A.

    1981-01-01

    Electron spin resonance (ESR) of the free radical structure resulting from high energy gamma LNT irradiation of the polymers revealed the presence of allylic free radicals of the type approx. CH.CH = CH.CH/sub 2/ approx. The presence of chemically trapped electrons in polybutadiene and styrene-butadiene (SB) block copolymers irradiated in the absence of light at LNT was determined by ESR measurements, and the trapping sites were shown to be impurities or additive molecules which were imbedded in between the polymer chains and which had not been completely removed by purification. Reaction kinetic studies of free radical decay indicated that the decay followed the equation derived for the case in which some free radicals decay by a second order mechanism in the presence of nondecaying free radicals. The same reaction scheme was found to describe the kinetics of alkyl free radical decay in LNT irradiated quenched and annealed isotactic polypropylene with the decay rate of quenched samples being higher than for annealed samples. Results of studies of radiation-induced crosslinking of the elastomers are also included. (BLM)

  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. 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%.

  19. Improved mechanical properties and ozone resistance of radiation-cured SBR. Final report, Dec 88-Jun 91. [Styrene Butadiene Rubber

    SciTech Connect

    Basfar, A.A.; Silverman, J.

    1991-08-01

    This report is a continuation and extension of the work of the earlier Army contract, where the superiority of the electron beam cured styrene butadiene rubber (SBR) tank pads to the sulfur cured pads was demonstrated. The focus of the present study is the investigation of the extraordinary ozone resistance of our radiation cured SBR, and also on possible alternatives for SBR, butadiene rubber (BR) in particular, as a tank pad compound. Base formulations of a fully sulfur cured system were established with 5% reproducibility, and results were confirmed by mechanical properties measurements on identical formulations from Belvoir Research Development and Engineering Center (BRDEC). Constant mechanical properties as a function of exposure to ozone indicate either competitive cross-linking and scissioning reactions or a 'protective' effect caused by higher terminal vinyl concentrations in the radiation cured formulations.

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

    PubMed

    Khabaz, Fardin; Khare, Rajesh

    2015-11-01

    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. PMID:26451630

  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. 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.

  3. 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.

  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. Quantitative characterizations of styrene butadiene core shell latexes by TOF-SIMS and pyrolysis GC/MS

    NASA Astrophysics Data System (ADS)

    Maekawa, Toshihiko

    2006-07-01

    We have established a characterization method of a 100 nm sized core-shell latexes composed of styrene-butadiene co-polymer. The core-shell structure was revealed by TEM observation of the latex film after modification with OsO 4 vapor. Pyrolysis gas chromatography combined with mass spectrometry (Py-GC/MS) of the latexes showed the average chemical composition of the core-shell latexes. TOF-SIMS of the latex film gave the characteristic peak for styrene and butadiene. The peak intensities changed in accordance with the chemical composition of the latexes. Surface composition of the latex film, which corresponds to the composition of the shell part of the latexes, was estimated from this peak intensity ratio. From the combined analysis of Py-GC/MS and TOF-SIMS of the latexes, we successfully evaluated the chemical composition of both the core part and the shell part of latexes individually. As the results of characterization of some core-shell latex, it was revealed that the high degree of cross-linking is needed to synthesize the tailored core-shell latex.

  6. Analysis of recycled poly (styrene-co-butadiene) sulfonation: a new approach in solid catalysts for biodiesel production.

    PubMed

    Aguilar-Garnica, Efrén; Paredes-Casillas, Mario; Herrera-Larrasilla, Tito E; Rodríguez-Palomera, Felicia; Ramírez-Arreola, Daniel E

    2013-01-01

    The disposal of solid waste is a serious problem worldwide that is made worse in developing countries due to inadequate planning and unsustainable solid waste management. In Mexico, only 2% of total urban solid waste is recycled. One non-recyclable material is poly (styrene-co-butadiene), which is commonly used in consumer products (like components of appliances and toys), in the automotive industry (in instrument panels) and in food services (e.g. hot and cold drinking cups and glasses). In this paper, a lab-scale strategy is proposed for recycling poly (styrene-co-butadiene) waste by sulfonation with fuming sulfuric acid. Tests of the sulfonation strategy were carried out at various reaction conditions. The results show that 75°C and 2.5 h are the operating conditions that maximize the sulfonation level expressed as number of acid sites. The modified resin is tested as a heterogeneous catalyst in the first step (known as esterification) of biodiesel production from a mixture containing tallow fat and canola oil with 59% of free fatty acids. The preliminary results show that esterification can reach 91% conversion in the presence of the sulfonated polymeric catalyst compared with 67% conversion when the reaction is performed without catalyst. PMID:24098857

  7. Volume shrinkage and rheological studies of epoxidised and unepoxidised poly(styrene-block-butadiene-block-styrene) triblock copolymer modified epoxy resin-diamino diphenyl methane nanostructured blend systems.

    PubMed

    George, Sajeev Martin; Puglia, Debora; Kenny, Josè M; Parameswaranpillai, Jyotishkumar; Vijayan P, Poornima; Pionteck, Jűrgen; Thomas, Sabu

    2015-05-21

    Styrene-block-butadiene-block-styrene (SBS) copolymers epoxidised at different epoxidation degrees were used as modifiers for diglycidyl ether of the bisphenol A-diamino diphenyl methane (DGEBA-DDM) system. Epoxy systems containing modified epoxidised styrene-block-butadiene-block-styrene (eSBS) triblock copolymer with compositions ranging from 0 to 30 wt% were prepared and the curing reaction was monitored in situ using rheometry and pressure-volume-temperature (PVT) analysis. By controlling the mole percent of epoxidation, we could generate vesicles, worm-like micelles and core-shell nanodomains. At the highest mole percent of epoxidation, the fraction of the epoxy miscible component in the triblock copolymer (epoxidised polybutadiene (PB)) was maximum. This gave rise to core-shell nanodomains having a size of 10-15 nm, in which the incompatible polystyrene (PS) becomes the core, the unepoxidised PB becomes the shell and the epoxidised PB interpenetrates with the epoxy phase. On the other hand, the low level of epoxidation gave rise to bigger domains having a size of ∼1 μm and the intermediate epoxidation level resulted in a worm-like structure. This investigation specifically focused on the importance of cure rheology on nanostructure formation, using rheometry. The reaction induced phase separation of the PS phase in the epoxy matrix was carefully explored through rheological measurements. PVT measurements during curing were carried out to understand the volume shrinkage of the blend, confirming that shrinkage behaviour is related to the block copolymer phase separation process during curing. The volume shrinkage was found to be maximum in the case of blends with unmodified SBS, where a heterogeneous morphology was observed, while a decrease in the shrinkage was evidenced in the case of SBS epoxidation. It could be explained by two effects: (1) solubility of the epoxidised block copolymer in the DGEBA leads to the formation of nanoscopic domains upon

  8. 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.

  9. Use of Ultra Small Angle X-Ray Scattering to Measure Grain Size of Styrene-Butadiene Block Copolymers

    NASA Astrophysics Data System (ADS)

    Cohen, Robert E.; Myers, Randall T.; Bellare, Anuj

    1998-03-01

    Simultaneous determination of the lamellar morphological length scale and the grain size of several commercial heterogeneous styrene - butadiene block copolymers was accomplished through the use of ultra small angle x-ray scattering measurements. NIST's X23A3 ultra SAXS beamline at the Brookhaven National Laboratory provided a range of scattering vector q from 0.0004 to 0.1 ÅThe grain dimension was determined by analysis of both the Bragg peaks and the Porod region coupled with the invarient assosciated with the scattering intensities at very low values of q. Grain size was controlled in a given block copolymer by the choice of evaporation solvent and temperature as well as annealing time and temperature. Conventional 2-dimensional SAXS and transmission electron microscopy corroborated the ultra SAXS analysis.

  10. Time-resolved small-angle x-ray-scattering study of ordering kinetics in diblock styrene-butadiene

    NASA Astrophysics Data System (ADS)

    Singh, M. A.; Harkless, C. R.; Nagler, S. E.; Shannon, R. F., Jr.; Ghosh, S. S.

    1993-04-01

    A detailed study of the kinetics of phase transformations of the diblock copolymer, styrene-butadiene, is reported. The technique of in situ time-resolved small-angle x-ray scattering with the use of synchrotron radiation has been used to study the first-order phase transitions of microphase separation and microdomain ordering. These transitions occur following a rapid, thermal quench from the homogeneous, disordered state to temperatures below the transition point. The isothermal ordering process is discussed in the context of classical theories of nucleation and growth. Anomalous temporal oscillations in the ordered-volume fraction are observed following quenches to temperatures just below the ordering transition. These results are reported and qualitatively discussed.

  11. 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.

  12. Time-resolved small-angle x-ray-scattering study of ordering kinetics in diblock styrene-butadiene

    SciTech Connect

    Singh, M.A. ); Harkless, C.R. ); Nagler, S.E. ); Shannon, R.F. Jr.; Ghosh, S.S. )

    1993-04-01

    A detailed study of the kinetics of phase transformations of the diblock copolymer, styrene-butadiene, is reported. The technique of [ital in] [ital situ] time-resolved small-angle x-ray scattering with the use of synchrotron radiation has been used to study the first-order phase transitions of microphase separation and microdomain ordering. These transitions occur following a rapid, thermal quench from the homogeneous, disordered state to temperatures below the transition point. The isothermal ordering process is discussed in the context of classical theories of nucleation and growth. Anomalous temporal oscillations in the ordered-volume fraction are observed following quenches to temperatures just below the ordering transition. These results are reported and qualitatively discussed.

  13. 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.

  14. 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...

  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. 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.

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

    PubMed Central

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

    2014-01-01

    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. PMID:24936293

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

    PubMed

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

    2015-09-21

    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. PMID:26395734

  19. The filler-rubber interface in styrene butadiene nanocomposites with anisotropic silica particles: morphology and dynamic properties.

    PubMed

    Tadiello, L; D'Arienzo, M; Di Credico, B; Hanel, T; Matejka, L; Mauri, M; Morazzoni, F; Simonutti, R; Spirkova, M; Scotti, R

    2015-05-28

    Silica-styrene butadiene rubber (SBR) nanocomposites were prepared by using shape-controlled spherical and rod-like silica nanoparticles (NPs) with different aspect ratios (AR = 1-5), obtained by a sol-gel route assisted by a structure directing agent. The nanocomposites were used as models to study the influence of the particle shape on the formation of nanoscale immobilized rubber at the silica-rubber interface and its effect on the dynamic-mechanical behavior. TEM and AFM tapping mode analyses of nanocomposites demonstrated that the silica particles are surrounded by a rubber layer immobilized at the particle surface. The spherical filler showed small contact zones between neighboring particles in contact with thin rubber layers, while anisotropic particles (AR > 2) formed domains of rods preferentially aligned along the main axis. A detailed analysis of the polymer chain mobility by different time domain nuclear magnetic resonance (TD-NMR) techniques evidenced a population of rigid rubber chains surrounding particles, whose amount increases with the particle anisotropy, even in the absence of significant differences in terms of chemical crosslinking. Dynamic measurements demonstrate that rod-like particles induce stronger reinforcement of rubber, increasing with the AR. This was related to the self-alignment of the anisotropic silica particles in domains able to immobilize rubber. PMID:25899456

  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. Deformation of Inclusions and Lamellae during Melt Elongation of Blends of a Styrene-Butadiene Block Copolymer with Polystyrene

    NASA Astrophysics Data System (ADS)

    Handge, U. A.; Buschnakowski, M.; Michler, G. H.

    2008-07-01

    In this study, we investigated the development of the morphology in melt extension of blends of a linear styrene-butadiene block copolymer (LN3) and polystyrene (PS 158K). After melt mixing, PS 158K and LN3 formed two-phase polymer blends. The block copolymer was arranged in a lamellar phase. Our rheological experiments in shear and elongation clearly showed that the complex modulus, the transient extensional viscosity and the recovered stretch of the blends mainly resulted from a superposition of the properties of the neat blend components. The melt elongation experiments revealed that pure LN3 started to crumble at a small elongational strain. At our test parameters, the deformation of the PS 158K/LN3 blends was associated with an anisotropic Poisson ratio. Morphological investigations using transmission electron microscopy revealed that the PS 158K and LN3 inclusions in the LN3 and PS 158K matrix, respectively, were deformed into a filament-like shape in melt extension. Furthermore, the alignment of the lamellae of the block copolymer also increased with applied elongational strain. In relaxation after melt elongation the alignment of the lamellae persisted, whereas in recovery the alignment of the lamellae decreased.

  3. Radiation-induced graft polymerization of maleic acid and maleic anhydride onto ultra-fine powdered styrene butadiene rubber (UFSBR)

    NASA Astrophysics Data System (ADS)

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

    2007-11-01

    The functionalization of ultra-fine powdered styrene-butadiene rubber (UFSBR) was carried out using gamma radiation-induced graft polymerization of maleic acid (MA) and maleic anhydride (MAH), respectively. It was found that the graft yield of MA onto UFSBR increased rapidly up to the peak and then decreased with increasing MA content. Moreover, the peak shifted to the direction of lower MA content with increasing absorbed dose. Similarly, there was the peak of graft yield with increasing MAH content for grafting of MAH onto UFSBR, whereas the peak of graft yield was achieved at 10 wt% MAH content at different absorbed doses. On the other hand, increasing absorbed dose and decreasing monomer contents are useful to improve the graft efficiency of MA and MAH. At high dose and low monomer content, the graft yield of MAH onto UFSBR is higher than that of MA. FTIR spectra confirmed that both MA and MAH can be grafted successfully onto the UFSBR under gamma irradiation, respectively. Comparing with maleation of rubber by melt grafting, the graft yield of MAH on UFSBR is higher, which can be attributed to the network structure and nanometer size of UFSBR as well as high energy provided by radiation.

  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. Kinetics of thermal decomposition of styrene-butadiene rubber at low heating rates in nitrogen and oxygen

    SciTech Connect

    Chen, K.S.; Yeh, R.Z.; Chang, Y.R.

    1997-03-01

    The kinetics of thermal decomposition of styrene-butadiene rubber have been investigated thermogravimetrically under various heating rates either in nitrogen or mixed with 5--25% oxygen in nitrogen. The results show that in pure nitrogen the reaction involves only one stage, with an initial reaction temperature of 622--661 K and an apparent activation energy at 211 {+-} 15 kJ/mol. The initial reaction temperature decreases, but the reaction rate and its temperature range increase when the heating rate is increased. When oxygen is present, the reaction involves two parallel steps. The fractional conversion at the end of the first reaction is 0.83--0.87, depending on the oxygen concentration. Although the presence of oxygen somewhat delays the start of the initial reaction, the activation energy is reduced significantly, so that its rate becomes faster once reaction commences. The complete rate equation for both stages of reaction was obtained by summing the individual weighted rate equations; the weighting factors were determined from the fractional conversion at the end of the first reaction.

  6. 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.

  7. 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

  8. 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.

  9. 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.

  10. Infrared thermochromic behaviour of a composite Sm0.65Ca0.35MnO3-poly(styrene-co-acrylonitrile) film

    NASA Astrophysics Data System (ADS)

    Ammar, M. R.; Napierala, C.; Laffez, P.

    2009-05-01

    Samarium calcium perovskite manganite Sm0.65Ca0.35MnO3 was dispersed homogeneously in a solution of poly(styrene-co-acrylonitrile). A thin film was deposited on (100) oriented silicon substrate by spin-coating and the optical thermochromic behaviour in the infrared range was studied. In the wavelength range 8-14 µm, the optical transmittance of the thermochromic composite coating exhibited a large variation between 173 and 343 K due to a semiconductor-metal first-order transition at Tc = 250 K. The thermochromic behaviour of the composite coatings was optimized. The contrast in the transmittance first increased with pigment content, then reached a maximum value.

  11. 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

  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. 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 )

  14. Effects of copolymer composition on the formation of ionic species, hydrogen evolution, and free-radical reaction in el-irradiated styrene-butadiene random and block copolymers

    SciTech Connect

    Basheer, R.; Dole, M.

    1984-01-01

    Block and random copolymers of butadiene and styrene as well as polybutadiene and polystyrene homopolymers have been investigated with respect to formation of trapped electrons, contribution of ionic species to crosslinking, and hydrogen gas evolution due to el radiation. The decay kinetics of the disubstituted benzyl radical has also been studied. The yields of electron trapping G(e ) are measured. The G(e ) increase linearly with increased polystyrene content in block polymers, while in random copolymer a deviation from a linear relation is observed. The contribution of ionic reactions to crosslinking is about 25-35% of the total crosslinking yield. Hydrogen production in block copolymers is approximately a linear function of the weight-fraction additivity of the yield of hydrogen formation in polystrene and polybutadiene homopolymers. Energy transfer from butadiene units to styrene units in random copolymers resulted in a deviation from such an additivity relation. The decay of the disubstituted benzyl free radical in block copolymers is a second-order reaction. In random copolymer, the decay is best interpreted in terms of equation based on a second-order decay mechanism of a fraction of the free radicals decaying in the presence of other nondecaying free radicals. 24 references, 11 figures, 3 tables.

  15. 1,3-Butadiene, styrene and lymphohematopoietic cancer among male synthetic rubber industry workers--Preliminary exposure-response analyses.

    PubMed

    Sathiakumar, Nalini; Brill, Ilene; Leader, Mark; Delzell, Elizabeth

    2015-11-01

    We updated the mortality experience of North American synthetic rubber industry workers to include follow-up from 1944 through 2009, adding 11 years of mortality data to previous investigations. The present analysis used Cox regression to examine the exposure-response relationship between 1,3-butadiene (BD) and styrene (STY) parts per million (ppm)-years and leukemia (N = 114 deaths), non-Hodgkin lymphoma (NHL) (N = 89) and multiple myeloma (MM) (N = 48). A pattern of largely monotonically increasing rate ratios across deciles of BD ppm-years and a positive, statistically significant exposure-response trend were observed for BD ppm-years and leukemia. Using continuous, untransformed BD ppm-years the regression coefficient (β) adjusted only for age was 2.6 × 10(-4) (p < 0.01); the regression coefficient adjusted for age, year of birth, race and plant was 2.9 × 10(-4) (p < 0.01). STY ppm-years also displayed a positive exposure-response association with leukemia. STY and BD were strongly correlated, and the separate effects of these two agents could not be estimated. For NHL, a pattern of approximately monotonically increasing rate ratios across deciles of exposure was seen for STY but not for BD; the test of trend was statistically significant in one of five models that used different STY exposure metrics and adjusted for age and other covariates. BD ppm-years and STY ppm-years were not associated with MM. The present analyses indicated a positive exposure-response relationship between BD cumulative exposure and leukemia. This result along with other research and biological information support an interpretation that BD causes leukemia in humans. STY exposure also was positively associated with leukemia, but its independent effect could not be delineated because of its strong correlation with BD, and there is no external support for a STY-leukemia association. STY, but not BD, was associated positively with NHL. The interpretation of this result is

  16. Effect of thermally reduced graphene sheets on the phase behavior, morphology, and electrical conductivity in poly[(α-methyl styrene)-co-(acrylonitrile)/poly(methyl-methacrylate) blends.

    PubMed

    Vleminckx, Giovanni; Bose, Suryasarathi; Leys, Jan; Vermant, Jan; Wübbenhorst, Michael; Abdala, Ahmed A; Macosko, Chris; Moldenaers, Paula

    2011-08-01

    The effects of thermally reduced graphene sheets (TRG) on the phase separation in poly[(α-methyl styrene)-co-(acrylonitrile)]/poly(methyl-methacrylate) blends were monitored using melt rheology, conductivity spectroscopy, and electron microscopic techniques. The TRG were incorporated in the single-phase material by solution mixing. The composite samples were then allowed to phase separate in situ. The thermodynamics of phase separation have been investigated by monitoring the evolution of the storage modulus (G') as a function of temperature as the system passes through the binodal and the spinodal lines of the phase diagram. The phase separation kinetics were probed by monitoring the evolution of G' as a function of time at a quench depth well in the spinodal region. It was observed that TRG significantly influenced the phase separation temperature, the shape of the phase diagram and the rate of phase separation. The state of dispersion of TRG in the blends was assessed using electron microscopy and conductivity spectroscopy measurements. Interestingly, the composite samples (monophasic) were virtually insulators at room temperature, whereas highly conducting materials were obtained as a result of phase separation in the biphasic materials. PMID:21749102

  17. Observations made during stretching, tearing and failure of NR (natural rubber) and SBR (styrene-butadiene rubber) loaded with various amounts of carbon black

    SciTech Connect

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

    1988-02-01

    In order to effectively utilize fractography as an aid in identifying the influence of material and service (or test) parameters on material properties, one must first understand the origin of the morphological features developed during the tearing and fracturing of these elastomers. At our laboratory, we have made extensive fractographic studies while evaluating the effects of material formulations, temperature, and loading rates on the loading response, tearing energy, induced damage, and tearing phenomena in SBR (Styrene Butadiene Rubber) containing different amounts of CB (Carbon Black) filler. We have also examined failures in tank track pads, as well as laboratory-tested samples cut from new track pads. In this paper we report on observations made during the actual stretching, tearing and failure of elastomeric samples pulled in tension at a constraint stroke-diplacement rate. 15 refs., 12 figs.

  18. Biochemical markers in butadiene-exposed workers

    SciTech Connect

    Bechtold, W.E.; Hayes, R.B.; Thornton-Manning, J.R.; Henderson, R.F.

    1994-11-01

    1,3-Butadiene (BD) is used to manufacture a wide range of polymers and copolymers including styrene-butadiene rubber, polybutadiene, and acrylonitrile-butadiene-syrene resins. The carcinogenicity of BD has been determined in life-span inhalation studies in both Sprague-Dawley rats and B6C3F{sub 1} mice. Results suggest a marked species difference in the carcinogenic effects of BD. For example, female mice exposed to as low as 6.25 ppm BD exhibited increased alveolar/bronchiolar neoplasms. In contrast, BD was only a weak carcinogen in Sprague-Dawley rats. Rats were observed to have an increase only in mammary tumors after exposure to 1000 ppm. A biochemical study of highly exposed BD workers and unexposed controls is providing valuable information on BD metabolism in humans, and how this relates to the development of intermediate biologic effects. A group of heavily exposed workers were identified in a BD production facility in China. The purpose of this paper is to report the initial results from the sampling trip in the first quarter of 1994.

  19. 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. PMID:11863549

  20. Damage development during low cycle fatigue of carbon-black loaded SBR. [Styrene butadiene rubber containing 0, 15, 25, and 35 wt % carbon black

    SciTech Connect

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

    1984-06-18

    Fatigue of elastomers is a subject that has received considerable study over the years. This paper explores the problem of damage accumulation in a series of styrene butadiene rubber (SBR) based compounds containing 0, 15, 25, and 35 wt % carbon-black under conditions in which a limited number of higher stress cycles have been applied to the material (referred to here as low cycle fatigue). Damage development in elastomers can take many forms. Generally speaking, one can classify the degradation as mechanical or chemical in origin. The most obvious form of mechanical damage is flaw or cut growth, while typical examples of chemical damage include chain scission or thermal oxidation. The fatigue crack growth relationship given in Equation 1 obviously only applies to flaw growth. However, it does an excellent job of following the data and exhibits the threshold behavior observed in both SBR and SBR-35 at room temperature. At higher temperatures, the damaged material shows an increasing deviation from threshold behavior. The obvious implication is that some thermally activated damage mechanism is degrading the material. In previous work, carbon-black loaded SBR subjected to a high temperature, high stress environment was shown to undergo a thermal-mechanical oxidation process. Certainly, this process is a candidate for a damage mechanism in these studies. 6 references, 14 figures, 1 table.

  1. Comparative study of the effect of untreated, silanized and grafted alumina nanoparticles on thermal and dynamic mechanical properties of the styrene-butadiene rubber

    NASA Astrophysics Data System (ADS)

    Sushko, Rymma; Baller, Joerg; Filimon, Marlena; Sanctuary, Roland

    2014-05-01

    Elastomers filled with hard nanoparticles are of great technical importance for the rubber industry. In general, fillers improve mechanical properties of polymer materials, e.g. elastic moduli, tensile strength etc. The smaller the size of the particles the larger is the interface where interactions between polymer molecules and fillers can generate new properties. Using Temperature Modulated Differential Scanning Calorimetry (TMDSC) and Dynamic Mechanical Analysis (DMA), we investigated the properties of the pure styrene-butadiene rubber (SBR), SBR/ alumina nanoparticles, SBR/silanized alumina and SBR/alumina grafted to polymer chains. Beside a general reinforcement effect seen in the complex elastic moduli, the studies revealed that: i) small concentrations of nanoparticles (of 1.5-2 wt%) lead to a minimum in the glass transition temperature as a function of nanoparticle content; ii) for the grafted nanocomposites increasing the nanoparticle concentration beyond 4 wt% yields an increase of Tg by 4 K; iii) DMA mastercurves showed that in case of untreated and silanized alumina mechanical behaviour of the composite systems is rather near to the one of the SBR matrix, but the grafting of elastomer molecules to the silanized fillers induces a quasi-solid like response of the system in the low frequency regime.

  2. 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.

  3. 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

    2012-10-01

    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. PMID:22950720

  4. HEALTH ASSESSMENT OF 1,3-BUTADIENE

    EPA Science Inventory

    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...

  5. 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

  6. Modeling the low-cycle fatigue behavior of visco-hyperelastic elastomeric materials using a new network alteration theory: Application to styrene-butadiene rubber

    NASA Astrophysics Data System (ADS)

    Ayoub, G.; Zaïri, F.; Naït-Abdelaziz, M.; Gloaguen, J. M.

    2011-02-01

    Although several theories were more or less recently proposed to describe the Mullins effect, i.e. the stress-softening after the first load, the nonlinear equilibrium and non-equilibrium material response as well as the continuous stress-softening during fatigue loading need to be included in the analysis to propose a reliable design of rubber structures. This contribution presents for the first time a network alteration theory, based on physical interpretations of the stress-softening phenomenon, to capture the time-dependent mechanical response of elastomeric materials under fatigue loading, and this until failure. A successful physically based visco-hyperelastic model is revisited by introducing an evolution law for the physical material parameters affected by the network alteration. The general form of the model can be basically represented by two parallel networks: a nonlinear equilibrium response and a time-dependent deviation from equilibrium, in which the network parameters become functions of the damage rate (defined as the ratio of the applied cycle over the applied cycle to failure). The mechanical behavior of styrene-butadiene rubber was experimentally investigated, and the main features of the constitutive response under fatigue loading are highlighted. The experimental results demonstrate that the evolution of the normalized maximum stress only depends on the damage rate endured by the material during the fatigue loading history. The average chain length and the average chain density are then taken as functions of the damage rate in the proposed network alteration theory. The new model is found to adequately capture the important features of the observed stress-strain curves under loading-unloading for a large spectrum of strain and damage levels. The model capabilities to predict variable amplitude tests are critically discussed by comparisons with experiments.

  7. 21 CFR 177.1820 - Styrene-maleic anhydride copolymers.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... units by weight and not more than 20 percent styrene-butadiene and/or butadiene rubber units by weight... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Styrene-maleic anhydride copolymers. 177.1820... copolymers. Styrene-maleic anhydride copolymers identified in paragraph (a) of this section may be...

  8. 21 CFR 177.1820 - Styrene-maleic anhydride copolymers.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... units by weight and not more than 20 percent styrene-butadiene and/or butadiene rubber units by weight... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Styrene-maleic anhydride copolymers. 177.1820... copolymers. Styrene-maleic anhydride copolymers identified in paragraph (a) of this section may be...

  9. 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

  10. 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

    2016-01-01

    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

  11. 21 CFR 177.1820 - Styrene-maleic anhydride copolymers.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... sieve No. 20. 2. Styrene-maleic anhydride copolymer modified with butadiene, (CAS Reg. No. 27288-99-9... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Styrene-maleic anhydride copolymers. 177.1820... Use Food Contact Surfaces § 177.1820 Styrene-maleic anhydride copolymers. Styrene-maleic...

  12. CASE-COHORT STUDY OF STYRENE EXPOSURE AND ISCHEMIC HEART DISEASE INVESTIGATORS

    EPA Science Inventory

    Investigators examined workers exposed to styrene while working in styrene-butadiene polymer manufacturing plants between 1943 and 1982. Workers who had died from ischemic heart disease were compared to a subgroup of all men employed in two styrene-butadiene polymer manufac...

  13. 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.

  14. 21 CFR 181.32 - Acrylonitrile copolymers and resins.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...) Acrylonitrile/butadiene copolymer blended with vinyl chloride-vinyl acetate (optional at level up to 5 percent by weight of the vinyl chloride resin) resin—for use only in contact with oleomargarine. (iv... with polyvinyl chloride resins—for use only on paper and paperboard in contact with meats and lard....

  15. SAMPLING AND ANALYSIS OF BUTADIENE AT A SYNTHETIC RUBBER PLANT

    EPA Science Inventory

    Butadiene emission samples were collected from the process vent stream of a plant manufacturing synthetic rubber from styrene and butadiene. Samples were collected by modification of the evacuated container sampling procedure, outlined in Section 7.1.1 of EPA Method 18. On-site a...

  16. 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. PMID:17629616

  17. 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.

  18. Thermal cracking of butadiene

    SciTech Connect

    Duisters, H.A.M. )

    1994-01-01

    This paper presents experimental data on the thermal cracking of butadiene in a pilot plant, under conditions representative of industrial operation. The product distribution of pure-butadiene cracking is shown. Results from cocracking experiments in naphtha and C[sub 4]-raffinate are also presented. It is shown that butadiene cracking can be an interesting outlet for the increasing butadiene overcapacity in steam crackers. Some aspects of coke formation during butadiene pyrolysis are addressed as well.

  19. Preparation of candidate reference materials for the determination of phosphorus containing flame retardants in styrene-based polymers.

    PubMed

    Roth, Thomas; Urpi Bertran, Raquel; Latza, Andreas; Andörfer-Lang, Katrin; Hügelschäffer, Claudia; Pöhlein, Manfred; Puchta, Ralph; Placht, Christian; Maid, Harald; Bauer, Walter; van Eldik, Rudi

    2015-04-01

    Candidate reference materials (RM) for the analysis of phosphorus-based flame retardants in styrene-based polymers were prepared using a self-made mini-extruder. Due to legal requirements of the current restriction for the use of certain hazardous substances in electrical and electronic equipment, focus now is placed on phosphorus-based flame retardants instead of the brominated kind. Newly developed analytical methods for the first-mentioned substances also require RMs similar to industrial samples for validation and verification purposes. Hence, the prepared candidate RMs contained resorcinol-bis-(diphenyl phosphate), bisphenol A bis(diphenyl phosphate), triphenyl phosphate and triphenyl phosphine oxide as phosphorus-based flame retardants. Blends of polycarbonate and acrylonitrile-co-butadiene-co-styrene as well as blends of high-impact polystyrene and polyphenylene oxide were chosen as carrier polymers. Homogeneity and thermal stability of the candidate RMs were investigated. Results showed that the candidate RMs were comparable to the available industrial materials. Measurements by ICP/OES, FTIR and NMR confirmed the expected concentrations of the flame retardants and proved that analyte loss and degradation, respectively, was below the uncertainty of measurement during the extrusion process. Thus, the candidate RMs were found to be suitable for laboratory use. PMID:25410641

  20. 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

  1. [Migrants from disposable gloves and residual acrylonitrile].

    PubMed

    Wakui, C; Kawamura, Y; Maitani, T

    2001-10-01

    Disposable gloves made from polyvinyl chloride with and without di(2-ethylhexyl) phthalate (PVC-DEHP, PVC-NP), polyethylene (PE), natural rubber (NR) and nitrile-butadiene rubber (NBR) were investigated with respect to evaporation residue, migrated metals, migrants and residual acrylonitrile. The evaporation residue found in n-heptane was 870-1,300 ppm from PVC-DEHP and PVC-NP, which was due to the plasticizers. Most of the PE gloves had low evaporation residue levels and migrants, except for the glove designated as antibacterial, which released copper and zinc into 4% acetic acid. For the NR and NBR gloves, the evaporation residue found in 4% acetic acid was 29-180 ppm. They also released over 10 ppm of calcium and 6 ppm of zinc into 4% acetic acid, and 1.68-8.37 ppm of zinc di-ethyldithiocarbamate and zinc di-n-butyldithiocarbamate used as vulcanization accelerators into n-heptane. The acrylonitrile content was 0.40-0.94 ppm in NBR gloves. PMID:11775358

  2. 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

  3. 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.

  4. Morphology and Dynamic Mechanical Properties of Styrene Containing Tri-Block Copolymers for Electromagnetic Wave Interaction Applications

    NASA Astrophysics Data System (ADS)

    Peddini, S.; Mauritz, K.; Nikles, D.; Weston, J.

    2008-03-01

    Styrene containing triblock copolymers, namely poly(styrene-ethylene/butylene-styrene) (SEBS) and poly(styrene-butadiene-styrene)] (SBS), were selectively modified by attaching polar groups to facilitate the in-growth of an inorganic component. In case of SEBS, the styrene block was sulfonated, and in SBS, the butadiene block was hydroxylated. The extent of modification was determined by analytical and spectroscopic methods. This presentation shows the morphology and dynamical mechanical properties of both block copolymers before and after modification. Nanocomposites of these block copolymers were prepared by inclusion of magnetic metal oxides via an in-situ precipitation and self assembly processes and their morphology and dynamical mechanical properties were studied. Magnetic properties of these polymers filled with iron oxide nanoparticles were measured using an alternating gradient magnetometer (AGM) at room temperature to observe the magnetic hysteresis.

  5. 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. PMID:25750055

  6. Health Assessment Document for Acrylonitrile (Final Report)

    EPA Science Inventory

    Acute acrylonitrile intoxication in humans, like many volatile organic compounds, results in irritation of the eyes and nose, weakness, labored breathing, dizziness, impaired judgement, cyanosis, nausea, and convulsions. Unlike many of these other organics, acrylonitrile causes s...

  7. 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

  8. Design and Characterization of Styrene-Based Proton Exchange Membranes

    NASA Astrophysics Data System (ADS)

    Ebrasu, D.; Petreanu, I.; Patularu, L.; Stefanescu, I.; Valeanu, M.

    This paper deals with preparation of PEM, based on commercial block copolymer of the styrene-butadiene. The copolymer was structurally changed by sulfonation followed by cross linking, in order to design a Proton Exchange Membrane for Fuel Cells. The membranes were structural tested by FTIR Spectroscopy and Scanning Electron Microscopy. Ionic Exchange Capacity (IEC) and thermal behavior by Differential Scanning Calorimetry (DSC) were measured too.

  9. ACRYLONITRILE PLANT AIR POLLUTION CONTROL

    EPA Science Inventory

    Based on available literature, the report identifies and ranks (in terms of efficiency, cost, and energy requirements) air pollution control technologies for each of four major air pollutant emission sources in acrylonitrile plants. The sources are: (1) absorber vent gas streams,...

  10. 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

  11. Charcoal byproducts as potential styrene-butadiene rubber composte filler

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Carbon black, a byproduct of the petroleum industry, is the world's most predominant filler for rubber composites. In this study, various renewable charcoals in the form of pyrolyzed agricultural byproducts were evaluted as potential carbon-based filler for rubber composites made with carboxylated s...

  12. 21 CFR 180.22 - Acrylonitrile copolymers.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... ADDITIVES PERMITTED IN FOOD OR IN CONTACT WITH FOOD ON AN INTERIM BASIS PENDING ADDITIONAL STUDY Specific Requirements for Certain Food Additives § 180.22 Acrylonitrile copolymers. Acrylonitrile copolymers may be... uses subject to the denial are thereafter unapproved food additives and consequently unlawful. (3)...

  13. 40 CFR 721.505 - Halogenated acrylonitrile.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... CONTROL ACT SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.505 Halogenated acrylonitrile. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as halogenated acrylonitrile, (PMN P-90-299)...

  14. 40 CFR 721.505 - Halogenated acrylonitrile.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... CONTROL ACT SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.505 Halogenated acrylonitrile. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as halogenated acrylonitrile, (PMN P-90-299)...

  15. 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.

  16. HEALTH ASSESSMENT DOCUMENT FOR ACRYLONITRILE (REVISED DRAFT)

    EPA Science Inventory

    Acrylonitrile is readily absorbed in animals following ingestion or inhalation, while dermal absorption is poor (1%) compared to that of the lungs. Acrylonitrile is metabolized to cyanide, which is transformed to thiocyanic acid and by cyanoethylation of sulfhydryl groups to S-(2...

  17. Lowest Vibrational States of Acrylonitrile

    NASA Astrophysics Data System (ADS)

    Kisiel, Zbigniew; Martin-Drumel, Marie-Aline; Pirali, Olivier

    2015-06-01

    Recent studies of the broadband rotational spectrum of acrylonitrile, H_2C=CHC≡N, revealed the presence of multiple resonances between rotational levels in different vibrational states. The resonances affect even the ground state transitions and their analysis allowed determination of vibrational term values for the first three excited states above the ground state and of vibrational energy differences in several polyads above these states. At that time there was no infrared data of sufficient resolution to assess the reliability of the resonance based vibrational energy determinations. We presently report results based on a 40-700 cm-1 high-resolution spectrum of acrylonitrile recorded at the AILES beamline of the SOLEIL synchrotron. This spectrum was reduced by using the AABS packagea, and allowed assignment of vibration-rotation transitions in four fundamentals, five hot bands, and one overtone band. The infrared data and previous measurements made with microwave techniques have been combined into a single global fit encompassing over 31000 measured transitions. Precise vibrational term values have been determined for the eight lowest excited vibrational states. The new results validate the previous estimates from rotational perturbations and are also compared with results of ab~initio anharmonic force field calculations. Z. Kisiel, et al., J. Mol. Spectrosc. 280 134 (2012). A. López, et al., Astron. & Astrophys. 572, A44 Z. Kisiel, et al., J. Mol. Spectrosc. 233 231 (2005).

  18. 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

  19. HEALTH AND ENVIRONMENTAL EFFECTS PROFILE FOR ACRYLONITRILE

    EPA Science Inventory

    The Health and Environmental Effects Profile for acrylonitrile was prepared by the Office of Health and Environmental Assessment, Environmental Criteria and Assessment Office, Cincinnati, OH for the Office of Solid Waste and Emergency Response to support listings of hazardous con...

  20. [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. PMID:12846157

  1. 16 CFR 1500.86 - Exemptions from classification as a banned toy or other banned article for use by children.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... (acrylonitrile butadiene styrene), nylon, and high-impact polystyrene) that are injection-molded and possess high..., or high-impact polystyrene) though exempt from the requirements that there be no internal voids,...

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

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 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...

  3. 40 CFR 721.8965 - 1H-Pyrole-2, 5-dione, 1-(2,4,6-tribromophenyl)-.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 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...

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

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 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...

  5. 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. PMID:24695435

  6. 16 CFR 1500.86 - Exemptions from classification as a banned toy or other banned article for use by children.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... materials other than those materials (such as ABS (acrylonitrile butadiene styrene), nylon, and high-impact... characteristics (such as injection-molded balls made of ABS, nylon, or high-impact polystyrene) though exempt...

  7. Analysis of butadiene monoepoxide and butadiene diepoxide in various tissues of sprague-dawley rats and B6C3F{sub 1} mice following low-level exposures to 1,3-butadiene

    SciTech Connect

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

    1994-11-01

    1,3-Butadiene (BD) is used extensively in the production of styrene-butadiene rubber, polybutadiene elastomers, and other polymers. Occupational exposures of workers in areas with concentrations of up to 374 ppm BD have been documented in U.S. plants. Additionally, BD is present in cigarette smoke, gasoline vapors, and automobile exhaust resulting in exposures of this chemical to most of the U.S. population. Epidemiological studies have revealed increased incidences of mortality due to lymphatic and hematopoietic cancers among rubber industry workers exposed to BD. However, because these workers were most likely exposed to a wide variety of potentially harmful compounds, the contribution of BD to increased carcinogenic risk is uncertain. The purpose of the present investigation was to examine the production and disposition of BDO and BDO{sub 2} in several target tissues in rats and mice during and following 4-h exposures to a low-level (62.5 ppm) of BD.

  8. 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 ...

  9. 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.

  10. New modified hydrocarbon resins; An alternative to styrenated terpene resins in hot melts

    SciTech Connect

    Carper, J.D. )

    1990-06-01

    This paper reports on the development of two hydrocarbon-based resin formulations that could be used with different thermoplastic block copolymers to formulate pressure-sensitive adhesives. Results are examined with one of these resins in formulations with styrene-isoprene-styrene (SIS) and styrene-butadiene (SB) compounds. The new modified hydrocarbon resin, with a softening point of 98{degrees} C, matches the adhesive performance of a terpene resin with a softening point of 105{degrees} C. The resin performs as well as the modified terpene in SIS-, SB-, and EVA-based adhesives. The new hydrocarbon resin is especially well suited for hot-melt adhesives. It exhibits low volatility, good color stability, and excellent melt viscosity stability. Since the new resin is based on petroleum hydrocarbon feedstocks, it should be available at moderate, stable prices. The other hydrocarbon resin, with a softening point of 85{degrees} C, produced comparable results.

  11. Organic chemistry. A rhodium catalyst for single-step styrene production from benzene and ethylene.

    PubMed

    Vaughan, Benjamin A; Webster-Gardiner, Michael S; Cundari, Thomas R; Gunnoe, T Brent

    2015-04-24

    Rising global demand for fossil resources has prompted a renewed interest in catalyst technologies that increase the efficiency of conversion of hydrocarbons from petroleum and natural gas to higher-value materials. Styrene is currently produced from benzene and ethylene through the intermediacy of ethylbenzene, which must be dehydrogenated in a separate step. The direct oxidative conversion of benzene and ethylene to styrene could provide a more efficient route, but achieving high selectivity and yield for this reaction has been challenging. Here, we report that the Rh catalyst ((Fl)DAB)Rh(TFA)(η(2)-C2H4) [(Fl)DAB is N,N'-bis(pentafluorophenyl)-2,3-dimethyl-1,4-diaza-1,3-butadiene; TFA is trifluoroacetate] converts benzene, ethylene, and Cu(II) acetate to styrene, Cu(I) acetate, and acetic acid with 100% selectivity and yields ≥95%. Turnover numbers >800 have been demonstrated, with catalyst stability up to 96 hours. PMID:25908817

  12. 29 CFR 1915.1045 - Acrylonitrile.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 7 2010-07-01 2010-07-01 false Acrylonitrile. 1915.1045 Section 1915.1045 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR (CONTINUED) OCCUPATIONAL SAFETY AND HEALTH STANDARDS FOR SHIPYARD EMPLOYMENT Toxic and Hazardous...

  13. 40 CFR 721.505 - Halogenated acrylonitrile.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... reporting. (1) The chemical substance identified generically as halogenated acrylonitrile, (PMN P-90-299) is... specified in § 721.125 (a) through (h). (2) Limitations or revocation of certain notification requirements... Section 721.505 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC...

  14. 40 CFR 721.505 - Halogenated acrylonitrile.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... reporting. (1) The chemical substance identified generically as halogenated acrylonitrile, (PMN P-90-299) is... specified in § 721.125 (a) through (h). (2) Limitations or revocation of certain notification requirements... Section 721.505 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC...

  15. 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. PMID:27060197

  16. 21 CFR 181.32 - Acrylonitrile copolymers and resins.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Acrylonitrile copolymers and resins. 181.32 Section 181.32 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) PRIOR-SANCTIONED FOOD INGREDIENTS Specific Prior-Sanctioned Food Ingredients § 181.32 Acrylonitrile copolymers and resins. (a)...

  17. 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...

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

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... exposed to distilled water and 3 pct acetic acid for 10 d at 66 °C (150 °F)The extracted copolymer shall not exceed 0.001 mg/in 2 surface area of the food contact article when exposed to distilled water and... 2 surface area of the food contact article when exposed to distilled water and 3 pct acetic acid...

  19. Quantitative analysis of (styrene/acrylonitrile/methyl methacrylate) co-polymer systems by infrared resonance spectroscopy

    NASA Astrophysics Data System (ADS)

    Jalbout, Abraham F.; Jiang, Tao; Fengqi, Liu; Ding, C.; Darwish, Abdalla M.

    2002-02-01

    A detailed careful analysis of the infrared resonance (IR) spectra of polystyrene (PSt), polymethyl methacrylate (PMMA), polyacrylonitrile (PAN) and their co-mixtures were performed. Through this study the absorption peak area to weight ratios as well as working curves were obtained to test for their reliability as well as their suitability. Satisfactory results were achieved and these working curves were then used to measure the polymerized components of binary and ternary co-polymers. By investigating the acquired data we conclude that the monomer preferential polymeric sequence is St>MMA>AN. A quantitative method to measure P (St/AN/MMA) concentrations by IR spectroscopy is proposed in this work.

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

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... exposed to distilled water and 3 pct acetic acid for 10 d at 66 °C (150 °F)The extracted copolymer shall not exceed 0.001 mg/in 2 surface area of the food contact article when exposed to distilled water and... 2 surface area of the food contact article when exposed to distilled water and 3 pct acetic acid...

  1. Characterization of the thermodynamics and deformation behavior of styrene-butadiene-styrene grafted with polyhedral oligomeric silsesquioxanes

    NASA Astrophysics Data System (ADS)

    Drazkowski, Daniel B.

    This research study uses a model nanostructure-copolymer system in order to develop a fundamental understanding of how polymers are affected by functionalized nanostructures. For this study, polyhedral oligomeric silsesquioxanes (POSS) was chosen as the model nanostructure and polystyrene-block-polybutadiene-block-polystyrene copolymer (SBS) as the model polymer host. The choice of materials and chemical reaction scheme for grafting the SBS-POSS copolymers allows for reproducible products with the opportunity for wide selection of nanostructure grafting fractions. In order to examine the effects that the nanostructure's electronic properties have on the host polymer, the organic group of the POSS nanostructures was varied. To facilitate a rigorous comparison, four sterically similar, yet electronically different POSS derivatives were selected (cyclopentyl (Cp), cyclopenyl (Cy), cyclohexenyl (Cye), and phenyl (Ph)). Ph-POSS results in the greatest changes relative to the ungrafted SBS block copolymer because its chemistry has the largest contrast to the block in which it is grafted while simultaneously having the largest affinity toward the ungrafted block. All four of the cyclic POSS were found to have some affinity toward the polystyrene phase, so iBu-POSS was investigated in order to observe the effects of incorporating a noninteracting nanostructure. Two host morphologies were examined in order to compare noninteracting (iBu) and strongly interacting (Ph) POSS nanostructures. The morphology and phase behavior observed for noninteracting POSS is consistent with simply changing polystyrene content with no noticeable change in chi. Furthermore, local and long-ranged order of the morphology is well-preserved. The interacting nanostructures reduce chi substantially and disrupt the local order of the morphology, which is equivalent to a compatibilizing effect. Deformation was studied to supplement the previous findings regarding the equilibrium morphology, and give further information on the nature of the interactions between POSS-polymer and POSS-POSS interactions. The mechanical properties for both the grafted copolymers inherently drop because nanostructure grafting reduces the polystyrene content. For the noninteracting iBu-POSS, the reduction in mechanical properties was consistent with the fraction of polystyrene because the nanostructures are noninteracting with the polystyrene block and do not qualitatively change the morphology. This was observed at both low (30°C) and high (70°C) temperatures. The interacting Ph-POSS behavior is more complex. With increasing Ph-POSS, the morphology becomes more disrupted which should result in an additional drop in mechanical properties. However, there is reinforcement at larger concentrations of Ph-POSS. The disrupted morphology of the 10% and 20% Ph-POSS results in a smaller grain size, which together with the presence of POSS crystallites reinforce, or network, the morphology. Low strain reinforcement is more prominent at lower temperatures. At high temperatures (but still below Tg,PS), the drop in mechanical properties from the disrupted morphology order outweighs the low strain reinforcement effects. Some reinforcement is still observed at these higher temperatures due to POSS-POSS effects.

  2. A Molecular orbital study of the rotation about the CC bond in styrene

    NASA Astrophysics Data System (ADS)

    Bock, Charles W.; Trachtman, Mendel; George, Philip

    1985-03-01

    The geometry and energy of styrene have been calculated using the 6-31G basis set as a function of the C βC 2C 1C 2 dihedral angle-Φ = 0°(cis), 15°, 30°, 60° and 90° — assuming that the vinyl and phenyl groups remain planar, but otherwise with full geometry optimization. Similar calculations have been carried out for 1,3-butadiene and 3-methylene-1,4-pentadiene (MPD) where rotation about 180° generates a different and not the same conformer. The torsional potential energy curve for styrene has a very flat minimum Φ = 0, i.e. the cis structure is the most stable, whereas butadiene and MPD have minima in the region Φ = 37° to 40°, indicative of more stable gauche structures. For styrene the barrier height Φ = 90° is 131.1 KJ mol -1. These results provide strong support for the potential function obtained by Hollas and Ridley from single level vibronic fluorescence and other spectroscopic data. The distortion of the benzene ring brought about the vinyl group substitution is discussed, also the variation of the C/C and H/C bond lenghts with Φ and the change in charge on the vinyl group and the polarity of the various bonds in the conversion of the cis into the 90° gauche conformer. The stabilization energy for styrene relative to that for benzene has been evaluated according to various criteria, and, in addition, the energy associated with the distortion of the ring.

  3. Gas-phase photocatalytic oxidation of acrylonitrile.

    PubMed

    Krichevskaya, Marina; Jõks, Svetlana; Kachina, Anna; Preis, Sergei

    2009-05-01

    Photocatalytic oxidation (PCO) of acrylonitrile (AN) on titanium dioxide in the gaseous phase was studied. AN readily undergoes photocatalytic degradation in a gas-solid system by using TiO(2) Degussa P25. The AN PCO volatile products, visible in the infrared spectra, included nitrogen dioxide, nitrous oxide, carbon dioxide, water, hydrogen cyanide and carbon monoxide. Longer contact time resulted in deeper oxidation of AN with decreasing hydrogen cyanide and increasing nitrogen dioxide content. The effect of temperature increasing from 60 to 130 degrees C was observed to be slightly negative in terms of AN degradation rate. However, the effect of increased temperature was noticeable in terms of the character and yields of the PCO products: HCN peaks diminished with growing peaks of NO(2). PMID:19424531

  4. 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.

  5. 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...

  6. Facilities, testing, and continuing studies on carbon-black loaded styrene-butadiene rubber

    SciTech Connect

    Goldberg, A.; Sanchez, R.J.; LeMay, J.D.; Patt, J.

    1988-09-15

    The Lawrence Livermore National Laboratory (LLNL) has been involved with investigations dealing with the response of the rubber in tank track pads to various loading scenarios, both in the field and in the laboratory. In the laboratory, numerous studies were also performed on a number of other rubber formulations primarily involving a range of carbon-black loadings in SBR and NR. Reference is made to reports and papers addressing each of the studies involved in this program. Work performed during the final stages of this program is described. These studies were directed primarily at developing an understanding of the effects of cycling and notching histories, notch radius, notch depth, and specimen thickness on the deformation behavior, strain distributions, hysteresis, and residual strength of SBR containing various amounts of carbon black. Significant improvements were realized in our testing methodology, computer-controlled facilities, and data-acquisition system, and in our ability to obtain continuous photomicrographic documentation in ''real time'' of the tearing improvements, as they relate to the various studies, are detailed in this document. Results obtained in these studied involve (1) the fabrication and testing of thick tensile specimens, (2) the effect of notching under load on the residual strength, (3) the effect of cycling on residual strength of notched and notch-free specimens, (4) the effect of cycling on hysteresis, (5) the effect of notch radius for various notch depths on loss of strength, and (6) evaluation of strain at a notch tip and remote from the notch tip at various specimen extensions by analyzing the specimen grid markings, which were obtained with the microscope-video-Polaroid system. 15 refs., 27 figs.

  7. 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 ...

  8. 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 ...

  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 (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...

  10. Acrylonitrile characterization and high energetic photochemistry at Titan temperatures

    NASA Astrophysics Data System (ADS)

    Toumi, A.; Piétri, N.; Chiavassa, T.; Couturier-Tamburelli, I.

    2016-05-01

    Laboratory infrared spectra of amorphous and crystalline acrylonitrile (C2H3CN) ices were recorded between 4000 and 650 cm-1. Heating up the acrylonitrile sample to 160 K shows details on the transition between amorphous and crystalline ice at ∼94 K. This molecule can be used as an indicator of the surface temperature of Titan since it is known also to be ∼94 K. The desorption energy of acrylonitrile was determined using two methods (IRTF and mass spectrometries) to be around 35 kJ mol-1. Solid phase acrylonitrile was irradiated with vacuum ultraviolet (VUV) light at low temperatures (20, 70, 95 and 130 K) using a microwave-discharge hydrogen flow lamp. Isoacrylonitrile, cyanoacetylene (HC3N), isocyanoacetylene (HC2NC), acetylene (C2H2) and hydrogen cyanide (HCN) were identified as photoproducts by using FTIR spectroscopy. The branching ratio of each pathway has been calculated for the different temperatures. We have estimated the acrylonitrile, HCN and HC3N νCtbnd N stretching band strengths to be respectively A = 3.98 ×10-18 , A = 1.38 ×10-18 and A = 2.92 ×10-18cmmolecule-1 .

  11. 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.

  12. Styrene toxicity: an ecotoxicological assessment.

    PubMed

    Gibbs, B F; Mulligan, C N

    1997-12-01

    Although other aromatic compounds (e.g., benzene, toluene, polycyclic aromatic hydrocarbons (PAH), etc.) have been thoroughly studied over the years, styrene has been given little attention probably due to its lower rate of industrial use. In addition, it is less toxic than benzene and PAH, proven carcinogens. However, it is classified as a mutagen and thus potentially carcinogenic. Its main use is in the production of the polymer polystyrene and in the production of plastics, rubber, resins, and insulators. Entry into the environment is mainly through industrial and municipal discharges. In this review, the toxicological effects of styrene on humans, animals, and plants are discussed. Its mode of entry and methods of monitoring its presence are examined. Although its effects on humans and aquatic life have been studied, the data on short- or long-term exposures to plants, birds, and land animals are insufficient to be conclusive. Since exposure to workers can result in memory loss, difficulties in concentration and learning, brain and liver damage, and cancer, development of accurate methods to monitor its exposure is essential. In addition, the review outlines the present state of styrene in the environment and suggests ways to deal with its presence. It might appear that the quantities are not sufficient to harm humans, but more data are necessary to evaluate its effect, especially on workers who are regularly exposed to it. PMID:9469867

  13. 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. PMID:24852137

  14. 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.

  15. 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) FOOD FOR HUMAN CONSUMPTION (CONTINUED) PRIOR-SANCTIONED FOOD INGREDIENTS Specific Prior-Sanctioned...

  16. 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...

  17. 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 (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) PRIOR-SANCTIONED FOOD INGREDIENTS Specific Prior-Sanctioned Food Ingredients § 181.32...

  18. DEVELOPMENT AND VALIDATION OF A TEST METHOD FOR ACRYLONITRILE EMISSIONS

    EPA Science Inventory

    Acrylonitrile (AN) has been identified as a suspected carcinogen and may be regulated in the future as a hazardous air pollutant under Section 112 of the Clean Air Act. A method was validated that utilizes a midget impinger containing methanol for trapping AN vapors followed by a...

  19. Ambient concentrations of 1,3-butadiene in the UK.

    PubMed

    Dollard, G J; Dore, C J; Jenkin, M E

    2001-06-01

    This paper assesses the current knowledge of 1,3-butadiene as an atmospheric pollutant, considers measurement techniques and reviews available data on 1,3-butadiene monitoring and emissions estimates. Atmospheric chemistry, sources of emission, current legislation, measurement techniques and monitoring programmes for 1,3-butadiene are reviewed. There have been comparatively few studies of the products of oxidation of 1,3-butadiene in the atmosphere. However, on the basis of the available information, and by analogy with the oxidation mechanism for the widely-studied and structurally similar natural hydrocarbon isoprene (2-methyl-1,3-butadiene), it is possible to define some features of the likely oxidation pathways for 1,3-butadiene. The total UK 1,3-butadiene emission to the atmosphere for 1996 has been estimated at 10.60 kTonnes. 1,3-Butadiene is a product of petrol and diesel combustion; consequently this total is dominated by road transport exhaust emissions (accounting for some 68% of the total). Off-road vehicles and machinery are responsible for 14% of the total UK emission. 1,3-Butadiene is used in the manufacture of numerous rubber compounds, and consequently emissions arise from both the manufacture and use of 1,3-butadiene in industrial processes. Emissions from the chemical industry account for 18% of the UK total emission- 8% from 1,3-butadiene manufacture and 10% from 1,3-butadiene use. The United Kingdom Expert Panel on Air Quality Standards (EPAQS) has published a report on 1,3-butadiene, and recommended a national air quality standard of 1.0 ppb (expressed as an annual rolling mean). This was adopted by the Government as part of the National Air Quality Strategy (NAQS) in 1997, and a target of compliance by 2005 was set. Work conducted for the review of the NAQS (1999) indicated that it was likely that all locations would be compliant with the national standard by the end of 2003. As a result, the review updated the air quality objective for 1

  20. Metabolism of styrene oxide and 2-phenylethanol in the styrene-degrading Xanthobacter strain 124X

    SciTech Connect

    Hartmans, S.; Smits, J.P.; Van Der Werf, M.J.; Volkering, F.; De Bont, J.A.M. )

    1989-11-01

    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.

  1. 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...

  2. MUTAGENICITY AND CARCINOGENICITY ASSESSMENT OF 1,3-BUTADIENE

    EPA Science Inventory

    1,3-Butadiene has been shown to be an indirect mutage in bacteria. Two of its potential metabolites, 3,4- epoxybutene and diepoxybutane, are genotoxic in prokaryote as well as eukaryote test systems. Exposure of rodents to 1,3-butadiene results in ovarian tumors in mice and testi...

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

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 29 Labor 6 2012-07-01 2012-07-01 false 1,3-Butadiene. = 1910.1051 Section 1910.1051 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR (CONTINUED) OCCUPATIONAL SAFETY AND HEALTH STANDARDS (CONTINUED) Toxic and Hazardous Substances § 1910.1051 1,3-Butadiene.= (a) Scope and...

  4. SAMPLING AND ANALYSIS OF BUTADIENE AT A NEOPRENE PLANT

    EPA Science Inventory

    This document details a field study to validate a method for the sampling and analysis of butadiene emissions from a plant manufacturing neoprene from butadiene/chlorine mixtures. aseous samples were collected from the process vent of one such plant using a modification of the ev...

  5. Industrial emissions of 1,3-butadiene.

    PubMed Central

    Mullins, J A

    1990-01-01

    Sources of industrial emissions of 1,3-butadiene are discussed both by process (production, consumers) and type (equipment leaks, point sources). Quantification of the emissions are presented, as reported by the U.S. Environmental Protection Agency in 1986. The reported emissions attributed to equipment leaks (also known as fugitive emissions) range from about 50 to 95% of the total, depending on the specific production process used. The methods by which these emissions were estimated are discussed, with particular emphasis on the fugitive sources. Industry studies to better quantify the fugitive emissions are described. PMID:2401277

  6. Styrene Aziridination by Iron(IV) Nitrides.

    PubMed

    Muñoz, Salvador B; Lee, Wei-Tsung; Dickie, Diane A; Scepaniak, Jeremiah J; Subedi, Deepak; Pink, Maren; Johnson, Michael D; Smith, Jeremy M

    2015-09-01

    Thermolysis of the iron(IV) nitride complex [PhB(tBuIm)3Fe≡N] with styrene leads to formation of the high-spin iron(II) aziridino complex [PhB(tBuIm)3Fe-N(CH2CHPh)]. Similar aziridination occurs with both electron-rich and electron-poor styrenes, while bulky styrenes hinder the reaction. The aziridino complex [PhB(tBuIm)3Fe-N(CH2CHPh)] acts as a nitride synthon, reacting with electron-poor styrenes to generate their corresponding aziridino complexes, that is, aziridine cross-metathesis. Reaction of [PhB(tBuIm)3Fe-N(CH2CHPh)] with Me3SiCl releases the N-functionalized aziridine Me3SiN(CH2CHPh) while simultaneously generating [PhB(tBuIm)3FeCl]. This closes a synthetic cycle for styrene azirdination by a nitride complex. While the less hindered iron(IV) nitride complex [PhB(MesIm)3Fe≡N] reacts with styrenes below room temperature, only bulky styrenes lead to tractable aziridino products. PMID:26179563

  7. Testosterone in sera of workers exposed to acrylonitrile.

    PubMed

    Ivănescu, M; Berinde, M; Simionescu, L

    1990-01-01

    Testosterone was measured through three consecutive years in sera from young and adult male subjects working in a chemical factory exposed to some complex chemical noxae, the major exposure being acrylonitrile (vinylcyanid). In the first yr, (group A), the blood was collected on May 1975 (no 39), the II-nd yr (group B) on March (no 109) and the III-rd yr (group C) on May (no 149). The exposure time varied in each group between 6 mos and 7-10 yrs. For comparison, blood samples were collected from 145 men of comparable age grouped in nonexposed: blood donors (no 37) (group a), new workers (no 23) (group b) and exposed to other chemical noxae in the same factory: Na cyanid (group c, no 23), cyan derivatives (group d, no 22) and pyrolysis (group no 39). The seasonal testosterone variations being considered, the Student's 't' test applied to the hormonal levels in acrylonitrile groups A, B and C showed non significant differences. However, the comparison of the testosterone concentrations in sera of the groups A, B and C vs the control groups investigated during the same month of the year showed much lower levels of the hormone in the first groups (p less than 0.001). These data are suggesting that the exposure to acrylonitrile either by direct participation to the technological chain or by working in the same noxious environment may influence the testosterone synthesis and/or secretion. PMID:2103974

  8. 40 CFR 721.8965 - 1H-Pyrole-2, 5-dione, 1-(2,4,6-tribromophenyl)-.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...), (g)(2)(iii), (g)(2)(iv)( use chemical goggles), (g)(3)(ii), (g)(4)(i), (g)(4)(iii) (except the dewatering step during polymerization of acrylonitrile/butadiene/styrene), and (g)(5). (iii) Industrial... § 721.185 apply to this significant new use rule. (3) Determining whether a specific use is subject...

  9. Ototoxic effects of occupational exposure to styrene and co-exposure to styrene and noise.

    PubMed

    Sliwińska-Kowalska, Mariola; Zamyslowska-Szmytke, Ewa; Szymczak, Wieslaw; Kotylo, Piotr; Fiszer, Marta; Wesolowski, Wiktor; Pawlaczyk-Luszczynska, Malgorzata

    2003-01-01

    Ototoxicity of styrene and the synergistic action of styrene and noise have been shown in rats. The respective data in humans are scarce and equivocal. This study evaluated the effects of occupational exposure to styrene and combined exposures to styrene and noise on hearing. The study group, comprised of 290-yacht yard and plastic factory workers, was exposed to a mixture of organic solvents, having styrene as its main compound. The reference group, totaling 223 subjects, included (1) white-collar workers, exposed neither to solvents nor noise and (2) metal factory workers, exposed exclusively to noise. All subjects were assessed by means of a detailed questionnaire and underwent otorhinolaryngological and audiometric examinations. Multiple logistic regression analysis revealed almost a 4-fold (or 3.9; 95% CI = 2.4-6.2) increase in the odds of developing hearing loss related to styrene exposure. The factors adjusted for were: age, gender, current occupational exposure to noise, and exposure to noise in the past. In cases of the combined exposures to styrene and noise, the odds ratios were two to three times higher than the respective values for styrene-only and noise-only exposed subjects. The mean hearing thresholds--adjusted for age, gender, and exposure to noise--were significantly higher in the solvent-exposed group than in the unexposed reference group at all frequencies tested. A positive linear relationship existed between an averaged working life exposure to styrene concentration and a hearing threshold at the frequencies of 6 and 8 kHz. This study provides the epidemiological evidence that occupational exposure to styrene is related to an increased risk of hearing loss. Combined exposures to noise and styrene seem to be more ototoxic than exposure to noise alone. PMID:12553175

  10. 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.