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1

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

Code of Federal Regulations, 2010 CFR

...2009-04-01 true Acrylonitrile/styrene copoly-mer modified with butadiene/styrene elastomer...copoly-mer modified with butadiene/styrene elastomer. Acrylonitrile/styrene copolymer modified with butadiene/styrene...

2010-04-01

2

Effect of Acrylonitrile-Butadiene-Styrene High-Rubber Powder and Strain Rate on the Morphology and Mechanical Properties of Acrylonitrile-Butadiene-Styrene\\/Poly (Methyl Methacrylate) Blends  

Microsoft Academic Search

Acrylonitrile-butadiene-styrene (ABS) high-rubber powder (HRP) toughened acrylonitrile-butadiene-styrene (ABS)\\/polymethyl methacrylate (PMMA) blends were prepared in a co-rotating twin screw extruder. The effect of ABS HRP on mechanical and morphology properties of ABS\\/PMMA blends was studied. It is shown that the toughness of ABS\\/PMMA blends was improved effectively with the incorporation of ABS HRP, while the elastic modulus and tensile strength decrease

Aimin Zhang; Guoqun Zhao; Jun Gao; Yanjin Guan

2010-01-01

3

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

PubMed

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 ?g/g of styrene, respectively. The residual levels of 1,3-butadiene ranged from 0.06 to 1.7 ?g/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 ?g/g in ABS and from 19 to 180 ?g/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

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

2014-05-01

4

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

PubMed Central

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 ?g/g of styrene, respectively. The residual levels of 1,3-butadiene ranged from 0.06 to 1.7 ?g/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 ?g/g in ABS and from 19 to 180 ?g/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

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

2014-01-01

5

Curing Characteristics and Mechanical and Morphological Properties of Styrene Butadiene Rubber\\/Virgin Acrylonitrile-Butadiene Rubber (SBR\\/vNBR) and Styrene Butadiene Rubber\\/Recycled Acrylonitrile-Butadiene Rubber (SBR\\/rNBR) Blends  

Microsoft Academic Search

Curing characteristics and mechanical and morphological properties of styrene butadiene rubber\\/virgin acrylonitrile-butadiene rubber (SBR\\/vNBR) and styrene butadiene rubber\\/recycled acrylonitrile-butadiene rubber (SBR\\/rNBR) were investigated. Results indicated that the curing characteristics, such as scorch time, t2, and cure time, t90, of SBR\\/vNBR and SBR\\/rNBR blends decreased with increasing vNBR and rNBR content. At similar blend ratios, particularly up to 15 phr, SBR\\/rNBR blends

N. Z. Noriman; H. Ismail; Azura Rashid

2008-01-01

6

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

PubMed

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

Wang, C C; Lee, C M

2001-04-01

7

Microstructure-based multistage fatigue characterization and modeling of an acrylonitrile butadiene styrene copolymer  

NASA Astrophysics Data System (ADS)

In this work, fatigue experiments and observations are used to experimentally and computationally quantify fatigue structure-property relationships and then capture these effects through a microstructure-based MultiStage Fatigue (MSF) model for a thermoplastic Acrylonitrile Butadiene Styrene copolymer. Completely reversed fatigue experiments were conducted over a range of strain amplitudes at two frequencies (1 Hz and 10 Hz). Scanning electron microscopy of fatigue fracture surfaces was used to quantify the microstructural notch root or initiating particle size for structure-property relations. Results were then processed in an MSF model sensitive to microstructural effects to capture the fatigue lifetimes for the thermoplastic ABS copolymer.

Fountain, Jason Elvin

8

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

PubMed

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 (70wt%) 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

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

2015-07-10

9

The effects of electron beam irradiation on the thermal properties, fatigue life and natural weathering of styrene butadiene rubber\\/recycled acrylonitrile–butadiene rubber blends  

Microsoft Academic Search

The effects of electron beam (EB) irradiation on the thermal properties, fatigue life and natural weathering of styrene butadiene rubber\\/recycled acrylonitrile–butadiene rubber (SBR\\/NBRr) blends were investigated. The SBR\\/NBRr blends were prepared at 95\\/5, 85\\/15, 75\\/25, 65\\/35, or 50\\/50 blend ratios with and without the presence of a 3part per hundred rubber (phr) of polyfunctional monomer, trimethylolpropane triacrylate (TMPTA). Results indicate

N. Z. Noriman; H. Ismail

2011-01-01

10

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

DOEpatents

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.

Jody, Bassam J. (Chicago, IL); Arman, Bayram (Amherst, NY); Karvelas, Dimitrios E. (Downers Grove, IL); Pomykala, Jr., Joseph A. (Crest Hill, IL); Daniels, Edward J. (Oak Lawn, IL)

1997-01-01

11

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

NASA Astrophysics Data System (ADS)

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.

McCulley, Jonathan M.

12

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

PubMed

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

Díez-Pascual, Ana M; Gascón, David

2013-11-27

13

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

NASA Astrophysics Data System (ADS)

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.

Tengsuwan, Siwach; Ohshima, Masahiro

2014-08-01

14

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

Code of Federal Regulations, 2010 CFR

...true Acrylonitrile/butadiene/sty-rene co-polymer. 177.1020 Section 177...1020 Acrylonitrile/butadiene/sty-rene co-polymer. Acrylonitrile/butadiene...butadiene/styrene elastomer containing 72 to 77 parts by weight of butadiene and 23...

2010-04-01

15

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

Code of Federal Regulations, 2014 CFR

...false Acrylonitrile/butadiene/sty-rene co-polymer. 177.1020 Section 177...1020 Acrylonitrile/butadiene/sty-rene co-polymer. Acrylonitrile/butadiene...butadiene/styrene elastomer containing 72 to 77 parts by weight of butadiene and 23...

2014-04-01

16

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

Code of Federal Regulations, 2013 CFR

...false Acrylonitrile/butadiene/sty-rene co-polymer. 177.1020 Section 177...1020 Acrylonitrile/butadiene/sty-rene co-polymer. Acrylonitrile/butadiene...butadiene/styrene elastomer containing 72 to 77 parts by weight of butadiene and 23...

2013-04-01

17

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

Code of Federal Regulations, 2012 CFR

...false Acrylonitrile/butadiene/sty-rene co-polymer. 177.1020 Section 177...1020 Acrylonitrile/butadiene/sty-rene co-polymer. Acrylonitrile/butadiene...butadiene/styrene elastomer containing 72 to 77 parts by weight of butadiene and 23...

2012-04-01

18

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

Code of Federal Regulations, 2011 CFR

...false Acrylonitrile/butadiene/sty-rene co-polymer. 177.1020 Section 177...1020 Acrylonitrile/butadiene/sty-rene co-polymer. Acrylonitrile/butadiene...butadiene/styrene elastomer containing 72 to 77 parts by weight of butadiene and 23...

2011-04-01

19

Denitrification with acrylamide by pure culture of bacteria isolated from acrylonitrile-butadiene-styrene resin manufactured wastewater treatment system.  

PubMed

Acrylamide is widely used in industrial applications as cement binder and solidification agent. Due to its carcinogenicity and toxicity, discharge of acrylamide to the natural water and soil systems may lead to an adverse environmental impact on water quality and thus endanger public health and welfare. This study attempts to isolate and identify the denitrifying bacteria, which utilize acrylamide as the substrate from the acrylonitrile-butadiene-styrene resin manufactured wastewater treatment system. The performance of the denitrifying bacteria for treating different initial acrylamide concentrations was also investigated under aerobic and anaerobic conditions. The test results indicated that the Pseudomonas stutzeri could remove acrylamide at concentrations below 440 mg/l under aerobic conditions. The acrylic acid and ammonia intermediates were used as carbon and nitrogen sources, respectively. However, P. stutzeri did not show the capability of metabolizing acrylonitrile under aerobic conditions. Furthermore, the P. stutzeri could utilize both acrylamide and acrylic acid in the presence of nitrate (denitrification) and acrylamide could be removed completely from the wastewater. PMID:11513390

Wang, C C; Lee, C M

2001-08-01

20

Dynamics of phase separation in poly(acrylonitrile-butadiene-styrene)-modified epoxy/DDS system: kinetics and viscoelastic effects.  

PubMed

The dynamics of phase separation and final morphologies of poly(acrylonitrile-butadiene-styrene) (ABS)-modified epoxy system based on diglycidyl ether of bisphenol A (DGEBA) cured with 4,4'-diaminodiphenylsulfone (DDS) have been monitored in situ throughout the entire curing process by using optical microscopy (OM), differential scanning calorimetry (DSC), rheometry, and small-angle laser light scattering (SALLS). The evolution of phase separation and final morphologies with substructures were explored by OM. The final morphologies of the blend cured at 150 and 165 °C are of phase-inverted type and are quite different from the final morphologies of the same blend cured at 180 °C, in which the final morphologies are cocontinuous. AFM observations of the fully cured sample confirmed the existence of three different phases, the epoxy continuous phase, SAN (styrene/acrylonitrile) continuous phase, and PB droplets at the interface, with a strong tendency to stay at SAN continuous phase. Furthermore, the continuous epoxy phase contains SAN particles and the continuous SAN phase contains epoxy particles. Cure kinetics and rheological results correspond well with the viscoelastic phase separation revealed by OM. The SALLS results display clearly that the phase separation takes place according to nucleation and growth mechanism followed by spinodal decomposition. The development of light scattering patterns during the second stage phase separation follows the Cahn-Hilliard model of spinodal demixing. Furthermore, the evolution of the scattering vector follows a Maxwell-type relaxation equation establishing the viscoelastic behavior of phase separation. The relaxation time of phase separation can be described by the Williams-Landel-Ferry equation for viscoelasticity. As a whole, the dependence of phase separation on cure temperature and the development of final morphologies and the associated mechanisms were explored in detail for the complex epoxy/ABS system. PMID:20925346

Jyotishkumar, P; Özdilek, Ceren; Moldenaers, Paula; Sinturel, Christophe; Janke, Andreas; Pionteck, Jürgen; Thomas, Sabu

2010-10-28

21

An oxygen index evaluation of flammability for zinc hydroxystannate and zinc stannate as synergistic flame retardants for acrylonitrile–butadiene–styrene copolymer  

Microsoft Academic Search

This article describes a study on zinc hydroxystannate (ZHS) and zinc stannate (ZS) in combination with 1,2-bis(tribromophenoxy)ethane (BTBPE) for increasing flame retardancy and reduced smoke emission in an acrylonitrile-butadiene-styrene (ABS) copolymer. The combination between BTBPE, synergist and chlorinated polyethylene (CPE) yield a high value of LOI which for some proportions is higher than for commercial ABS.

A. Petsom; S. Roengsumran; A. Ariyaphattanakul; P. Sangvanich

2003-01-01

22

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

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

Ohno, Hiroyuki; Kawamura, Yoko

2010-01-01

23

Use of an acrylonitrile-butadiene-styrene (ABS) plastic ring as a matrix in the recovery of bite mark evidence.  

PubMed

Valuable forensic information can be obtained from analysis of human bite mark injuries after careful retrieval of such evidence from living or deceased victims. It is difficult, however, to maintain the anatomical configuration of the skin, especially where body contours complicate the recovery process. Transillumination of the injury pattern in the skin after removal and preservation of the tissue from a deceased victim can provide significant information in the investigation process. A dimensionally stable matrix is required to support the skin's anatomical configuration during and after its removal. The authors have developed a unique and convenient method of heating and contouring a ring of acrylonitrile-butadiene-styrene (ABS) plastic using table salt over a heat source. When this ring is applied to the deceased victim's skin, and a backing material is added for support, removal of the skin and the bite mark can be accomplished more predictably while maintaining the anatomical contour. It is important to record bite marks accurately as soon after discovery as possible; the authors believe that this technique will significantly aid recovery of such evidence either at the crime scene or in the laboratory. A method of inscribing appropriate anatomical markers and case numbers on the rings is also described. PMID:1955841

Sweet, D J; Bastien, R B

1991-09-01

24

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

PubMed

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

Wang, Chun-Chin; Lee, Chi-Mei

2007-06-25

25

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

PubMed

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

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

2014-12-01

26

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 ...

27

Comprehensive analysis of the toxic and refractory pollutants in acrylonitrile-butadiene-styrene resin manufacturing wastewater by gas chromatography spectrometry with a mass or flame ionization detector.  

PubMed

Acrylonitrile-butadiene-styrene (ABS) resin manufacturing wastewater is a complicated, toxic and refractory industrial wastewater. Comprehensive and accurate analysis of the typical pollutants in ABS resin manufacturing wastewater is critical to develop cost-effective wastewater treatment technologies. In this paper, a comprehensively qualitative analysis combined with three complementary methods has been developed for the detection of typical pollutants in ABS resin manufacturing wastewater from three production sections, and thirty-seven compounds had been detected and further confirmed by this analysis method with standards. Simultaneous chromatographic separation and quantification of seven representative pollutants, including three mononuclear aromatics, three acrylonitrile dimers and one acrylonitrile derivative, were achieved by GC-FID system. The detection limits of this method for seven representative pollutants were in the range of 0.007-0.89 mg/L. The within-day and between-day precisions of this method were less than 6.5% (RSD, n=6). The recoveries of the representative pollutants reached 90-120%. The ABS resin manufacturing wastewater from E zone was successfully determined by this method, with two mononuclear aromatics and three acrylonitrile dimers accounting for 57.73% and 40.63% of the selected seven compounds, respectively. These results reveal that the removal of mononuclear aromatics and acrylonitrile dimers is a key to treat this wastewater. PMID:22621884

Lai, Bo; Zhou, Yuexi; Yang, Ping; Wang, Ke

2012-06-29

28

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

PubMed

Synchrotron-based Fourier transform infrared micro-spectroscopy (SR-?FTIR) was used to map photo-oxidative degradation of acrylonitrile-butadiene-styrene (ABS) and to investigate the presence and the migration of additives in historical samples from important Italian design objects. High resolution (3×3 ?m(2)) molecular maps were obtained by FTIR microspectroscopy in transmission mode, using a new method for the preparation of polymer thin sections. The depth of photo-oxidation in samples was evaluated and accompanied by the formation of ketones, aldehydes, esters, and unsaturated carbonyl compounds. This study demonstrates selective surface oxidation and a probable passivation of material against further degradation. In polymer fragments from design objects made of ABS from the 1960s, UV-stabilizers were detected and mapped, and microscopic inclusions of proteinaceous material were identified and mapped for the first time. PMID:25150697

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

2014-09-16

29

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

PubMed Central

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

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

2014-01-01

30

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

PubMed

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/m(2). 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

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

2015-01-01

31

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)

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.

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

2014-08-01

32

Three-dimensional printed acrylonitrile butadiene styrene framework coated with Cu-BTC metal-organic frameworks for the removal of methylene blue.  

PubMed

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

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

2014-01-01

33

Ultrasonic degradation of butadiene, styrene and their copolymers.  

PubMed

Ultrasonic degradation of commercially important polymers, styrene-butadiene (SBR) rubber, acrylonitrile-butadiene (NBR) rubber, styrene-acrylonitrile (SAN), polybutadiene rubber and polystyrene were investigated. The molecular weight distributions were measured using gel permeation chromatography (GPC). A model based on continuous distribution kinetics approach was used to study the time evolution of molecular weight distribution for these polymers during degradation. The effect of solvent properties and ultrasound intensity on the degradation of SBR rubber was investigated using different pure solvents and mixed solvents of varying volatility and different ultrasonic intensities. PMID:21986515

Sathiskumar, P S; Madras, Giridhar

2012-05-01

34

Improvement in the etching performance of the acrylonitrile-butadiene-styrene resin by MnO2-H3PO4-H2SO4 colloid.  

PubMed

The present study aimed to evaluate the surface etching of the acrylonitrile-butadiene-styrene (ABS) resin in the MnO2-H3PO4-H2SO4 colloid. To enhance the soluble Mn(IV) ion concentration and improve the etching performance of ABS resin, H3PO4 was added as a complexing agent into the MnO2-H2SO4 etching system. The effects of the H2SO4 concentration and etching time on the surface topography, surface roughness, adhesion strength, and the surface chemistry of the ABS substrates were investigated. The optimal oxidation potentials of MnO2 in the colloids decreased from 1.426 to 1.369 V with the addition of H3PO4. Though the etching conditions changed from 70 °C for 20 min to 60 °C for 10 min, the adhesion strength between the ABS substrates and electroless copper film increased from 1.19 to 1.33 KN/m after etching treatment. This could be attributed to the significant increase of the soluble Mn(IV) ion concentration in the MnO2-H3PO4-H2SO4 colloid. The surface chemistry results demonstrated that the oxidation reaction of -C?C- bonds in the polybutadiene phase was accelerated in the etching process by the addition of H3PO4, and the abundant -COOH and -OH groups were formed rapidly on the ABS surface with the etching treatment. These results were in agreement with the results of surface scanning electron microscopic observations and adhesion strength measurement. The results suggested that the MnO2-H3PO4-H2SO4 colloid was an effective surface etching system for the ABS surface roughness. PMID:23611532

Zhao, Wenxia; Ding, Jie; Wang, Zenglin

2013-05-21

35

FUNCTIONAL POLYMERS. 63. EMULSION COPOLYMERIZATION OF MALEIMIDE TYPE MONOMERS WITH ACRYLONITRILE AND STYRENE IN ABS LATEXES  

Microsoft Academic Search

Copolymerization of maleimide-type monomers: N-phenyl-maleimide, N-(2,6-dimethylphenyl)-maleimide and maleimide-bound 2(2-hydroxyphenyl)2H-benzotriazole with acrylonitrile and styrene was successfully carried out in the presence of acrylonitrile-butadiene or styrene-butadiene latexes. A new type of polymerizable 2(2-hydroxyphenyl)-2H-benzotriazole UV stabilizer with a reactive maleimide group was prepared and gave modi-acrylonitrile-butadience-styrene (ABA) resins with improved thermomechanical properties and increased resistance to ultraviolet radiation. Functional Polymer 62: J. Bartus,

Jan Bartus; William J. Simonsick Jr; Otto Vogl

1999-01-01

36

Acrylic acid removal by acrylic acid utilizing bacteria from acrylonitrile-butadiene-styrene resin manufactured wastewater treatment system.  

PubMed

The aim of this study is to isolate the acrylic acid utilizing bacteria from the ABS resin manufactured wastewater treatment system. The bacteria should have the ability to remove acrylic acid and tolerate the acrylonitrile and acrylamide toxicity. The aim is also to understand the performance of isolated pure strain for treating different initial acrylic acid concentrations from synthetic wastewater. The results are: twenty strains were isolated from the ABS resin manufactured wastewater treatment system and twelve of them could utilize 600 mg/l acrylic acid for growth. Seven of twelve strains could tolerate the acrylonitrile and acrylamide toxicity, when the concentration was below 300 mg/l. Bacillus thuringiensis was one of the seven strains and the optimum growth temperature was 32 degrees C. Bacillus thuringiensis could utilize acrylic acid for growth, when the initial acrylic acid concentration was below 1,690.4 mg/l. Besides this, when the initial acrylic acid concentration was below 606.8 mg/l, the acrylic acid removal efficiency exceeded 96.3%. Bacillus thuringiensis could tolerate 295.7 mg/l acrylamide and 198.4 mg/l acrylonitrile toxicity but could not tolerate 297.3 mg/l epsilon-caprolactam. PMID:16749456

Wang, C C; Lee, C M

2006-01-01

37

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

NASA Astrophysics Data System (ADS)

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 mechanical properties of the weld seams. This work provides a detailed study concerning the effect of the material microstructure and laser beam quality on the final weld formation and surface integrity.

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

2012-06-01

38

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)

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 operations. As for the comparison of the treatments, it was determined that the treatments have statistically significant differences. It was also determined that there is a significant statistical difference between the processes where a surface treatment is performed and the process where no surface treatment is applied to the ETFE. The chemical treatment results in a higher tensile load at failure (tensile strength) of 276.6 N on average, the air ionization treatment has an average of 248.4 N, and the process with no treatment has the lower ultimate tensile strength average of 53 N. This comparison has demonstrated that the best treatment is the chemical treatment with sodium naphthenate under the conditions tested.

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

2014-09-01

39

29 CFR 1910.1051 - 1,3-Butadiene.  

Code of Federal Regulations, 2010 CFR

...2010-07-01 false 1,3-Butadiene. 1910.1051 Section 1910...used to manufacture styrene-butadiene rubber and Polybutadiene rubber...include: Polychloroprene rubber, acrylonitrile butadiene-stryene resins, nylon...

2010-07-01

40

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

Code of Federal Regulations, 2014 CFR

...limitations for styrene butadiene rubber by emulsion processes. 63.500 Section 63...limitations for styrene butadiene rubber by emulsion processes. (a) Owners or operators...producing styrene butadiene rubber using an emulsion process shall operate the process...

2014-07-01

41

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

Code of Federal Regulations, 2012 CFR

...limitations for styrene butadiene rubber by emulsion processes. 63.500 Section 63...limitations for styrene butadiene rubber by emulsion processes. (a) Owners or operators...producing styrene butadiene rubber using an emulsion process shall operate the process...

2012-07-01

42

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

Code of Federal Regulations, 2013 CFR

...limitations for styrene butadiene rubber by emulsion processes. 63.500 Section 63...limitations for styrene butadiene rubber by emulsion processes. (a) Owners or operators...producing styrene butadiene rubber using an emulsion process shall operate the process...

2013-07-01

43

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

Code of Federal Regulations, 2010 CFR

...limitations for styrene butadiene rubber by emulsion processes. 63.500 Section 63...limitations for styrene butadiene rubber by emulsion processes. (a) Owners or operators...producing styrene butadiene rubber using an emulsion process shall operate the process...

2010-07-01

44

Characterization and development of new hydrogenated acrylonitrile-butadiene rubber blends  

NASA Astrophysics Data System (ADS)

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

Severe, Geralda

45

CHARACTERIZATION OF SOY PROTEIN ISOLATE/STYRENE-BUTADIENE RUBBER COMPOSITES  

Technology Transfer Automated Retrieval System (TEKTRAN)

The use of renewable soy protein aggregates as a reinforcement network in Styrene-butadiene rubber composites is investigated by a dynamic mechanical method. The rigid nature of dry protein has a high shear elastic modulus of ~2 GPa and, therefore, is suitable as a reinforcement phase in rubber com...

46

Recycling of Chrome Tanned Leather Dust in Acrylonitrile Butadiene Rubber  

NASA Astrophysics Data System (ADS)

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.

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

2010-06-01

47

Chrome-tanned leather shavings as a filler of butadiene-acrylonitrile rubber.  

PubMed

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

Przepiórkowska, A; Chro?ska, K; Zaborski, M

2007-03-01

48

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

Code of Federal Regulations, 2011 CFR

...false Back-end process provisions-carbon disulfide limitations for styrene butadiene...500 Back-end process provisions—carbon disulfide limitations for styrene butadiene...shall operate the process such that the carbon disulfide concentration in each...

2011-07-01

49

Micromechanical modeling of the linear viscoelasticity of carbon-black filled styrene butadiene rubbers: the role  

E-print Network

Micromechanical modeling of the linear viscoelasticity of carbon-black filled styrene butadiene Micromechanics modeling of the linear viscoelasticity of carbon-black filled styrene butadiene rubbers (SBR for a bounded rubber layer coating the fillers, provides satisfactory estimates of the linear viscoelasticity

Paris-Sud XI, Université de

50

Study on the thermal stability of styrene butadiene rubber nanocomposites  

NASA Astrophysics Data System (ADS)

This study aims to investigate the thermal stability of the styrene butadiene rubber (SBR) nanocomposites containig surface modified calcium carbonate (MCC). All nanocomposites were produced at various nanofiller contents, utilizing a laboratory scale two-roll mill. The thermal stability parameters including initial decomposing temperature, temperature at maximum rate of weight loss, and char content of the MCC/SBR nanocomposites were then compared. It was found that by increasing the filler content, the decomposition temperature of MCC/SBR nanocomposites increases. Furthermore, the char content at high temperatures rises by increasing nanofiller content.

Saeb, M. R.; Chenari, T. N.; Parast, O. Yazdan; Jafari, B.; Asadi, H.; Safari, M. Arfavi; Holisaz, H.

2012-07-01

51

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

NASA Astrophysics Data System (ADS)

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).

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

2013-06-01

52

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...

53

Leukemia and cumulative exposure to butadiene, styrene and benzene among workers in the synthetic rubber industry  

Microsoft Academic Search

Retrospective, quantitative estimates of exposure to 1,3-butadiene, styrene and benzene were developed for a follow-up study of leukemia mortality among 16610 subjects employed at six North American styrene-butadiene rubber manufacturing plants (418846 person-years, 58 leukemia deaths). The estimation procedure entailed identifying work areas within each manufacturing process, historical changes in exposure potential and specific tasks involving exposure, and using mathematical

Maurizio Macaluso; Rodney Larson; Elizabeth Delzell; Nalini Sathiakumar; Mary Hovinga; Jim Julian; David Muir; Philip Cole

1996-01-01

54

Rheology of the miscible polymer blend poly(methyl methacrylate) and poly(styrene-co-acrylonitrile)  

SciTech Connect

The viscoelasticity of micible blends of PMMA and a copolymer of styrene and acrylonitrile has been investigated by means of oscillatory shear and compared to that of the pure components. The validity of the time-temperature superposition principle is discussed.

Pathak, J.A.; Colby, R.H. [Pennsylvania State Univ., University Park, PA (United States); Stadler, R. [Johannes Gutenberg Universitaet, Mainz (Germany)

1996-12-31

55

Butadiene production process overview.  

PubMed

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

White, Wm Claude

2007-03-20

56

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

NASA Astrophysics Data System (ADS)

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.

Nishimura, Shin; Fujiwara, Hirotada

2012-01-01

57

Acrylonitrile-Butadiene Rubber (NBR) Prepared via Living/Controlled Radical Polymerization (RAFT).  

PubMed

In the current work we present results on the controlled/living radical copolymerization of acrylonitrile (AN) and 1,3-butadiene (BD) via reversible addition fragmentation chain transfer (RAFT) polymerization techniques. For the first time, a solution polymerization process for the synthesis of nitrile butadiene rubber (NBR) via the use of dithioacetate and trithiocarbonate RAFT agents is described. It is demonstrated that the number average molar mass, $\\overline M _{\\rm n} $, of the NBR can be varied between a few thousand and 60?000?g?·?mol(-1) with polydispersities between 1.2 and 2.0 (depending on the monomer to polymer conversion). Excellent agreement between the experimentally observed and the theoretically expected molar masses is found. Detailed information on the structure of the synthesized polymers is obtained by variable analytical techniques such as infrared spectroscopy (IR), nuclear magnetic resonance (NMR) spectroscopy, differential scanning calorimetry, and electrospray ionization-mass spectrometry (ESI-MS). PMID:21567572

Kaiser, Andreas; Brandau, Sven; Klimpel, Michael; Barner-Kowollik, Christopher

2010-09-15

58

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

NASA Astrophysics Data System (ADS)

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.

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

2013-12-01

59

Application of Lignin as Antioxidant in Styrene Butadiene Rubber Composite  

NASA Astrophysics Data System (ADS)

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.

Liu, Shusheng; Cheng, Xiansu

2010-11-01

60

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

NASA Astrophysics Data System (ADS)

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.

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

2014-05-01

61

Barrierity of hydrogenated butadiene-acrylonitrile rubber and butyl rubber after exposure to organic solvents.  

PubMed

Resistance of antichemical clothing primarily depends on the type of material it is made from, in particular on the type of polymer used for coating the fabric carrier. This paper reports on systematic investigations on the influence of the cross-linking density of an elastomer and the composition of a cross-linked elastomer on its resistance to permeation of selected organic solvents. Tests of barrier material samples made from nonpolar butyl rubber (IIR) and polar hydrogenated butadiene-acrylonitrile rubber (HNBR) showed that (a) in rubber-solvent systems with medium thermodynamic affinity, cross-linking density influenced resistance to permeation and (b) the polarity of the system had a significant influence on barrierity. PMID:21375953

Krzemi?ska, Sylwia; Rzymski, W?adys?aw M

2011-01-01

62

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

NASA Astrophysics Data System (ADS)

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).

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

2010-04-01

63

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

Microsoft Academic Search

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

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

1988-01-01

64

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...

65

On the degradation and stability of high abrasion furnace black (HAF)\\/acrylonitrile butadiene rubber (NBR) and high abrasion furnace black (HAF)\\/graphite\\/acrylonitrile butadiene rubber (NBR) under cyclic stress–strain  

Microsoft Academic Search

Acrylonitrile butadiene rubber (NBR) compounds filled with 40phr of high abrasion furnace black (HAF) and HAF (20phr)\\/graphite (20phr) were experimentally investigated. The stress–strain curves of the composites were studied, which are described by applying Ogden's model. The effect of cyclic fatigue and hysteresis was also examined. The dissipation energy that indicates the vibration damping capacity for all samples was determined.

Waleed E. Mahmoud; S. A. Mansour; M. Hafez; M. A. Salam

2007-01-01

66

Preparation of styrene\\/acrylonitrile copolymer microspheres and their composites with metal particles  

Microsoft Academic Search

Monodispersed poly(styrene-co-acrylonitrile) [P(St-co-AN)] microspheres were prepared by emulsifier-free emulsion copolymerization of St with AN. Fourier transform IR spectroscopy\\u000a and elemental analysis were used to measure the content of AN in the poly(St-co-AN) microspheres. X-ray photoelectron spectroscopy (XPS) measurements indicated the presence of an AN unit on the surface\\u000a of the microspheres. The combined results of the elemental analysis and the

P.-H. Wang; C.-Y. Pan

2000-01-01

67

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

NASA Technical Reports Server (NTRS)

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.

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

1984-01-01

68

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

PubMed

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(?-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. No bacterial transport was found. PMID:24268243

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

2014-01-01

69

Study of styrene butadiene rubber and sodium methyl cellulose as binder for negative electrodes in lithium-ion batteries  

Microsoft Academic Search

Graphite and nano-silicon-based negative electrodes in lithium-ion batteries with low binder content were evaluated. The effectiveness of styrene butadiene rubber (SBR) and various types of cellulose containing electrodes were compared to standard electrodes containing PVdF as binder. The cycling performance of lithium-based half cells in EC:DMC (1:1), 1M LiPF6 shows that styrene butadiene rubber (SBR), sodium carboxymethyl cellulose (Na-CMC), or

H. Buqa; M. Holzapfel; F. Krumeich; C. Veit; P. Novák

2006-01-01

70

Barrier properties of hydrogenated acrylonitrile-butadiene rubber composites containing modified layered aluminosilicates  

NASA Astrophysics Data System (ADS)

The resistance to permeation by the selected solvents of flat membranes made of cured hydrogenated acrylonitrile-butadiene rubber (HNBR) materials without any fillers and containing 5 phr of layered aluminosilicate nanofiller (bentonite), modified with various types of ammonium salts or N330 type carbon black, was investigated. The barrier properties were assessed on the basis of the breakthrough time of a liquid with low (cyclohexane) or average (butyl acetate) thermodynamic affinity to HNBR, determined according to EN 6529:2001, through a cured elastomer sample. The addition of bentonite, irrespectively of the method of modification of its particles, was found to increase the cured HNBR breakthrough time by 20 - 35 % in the case of slowly permeating non-polar cyclohexane, and by 50 - 130 % in the case of polar butyl acetate permeating more rapidly, in comparison with the barrier material containing no filler. The layered aluminosilicate nanofillers increased the breakthrough time of the material sample for both the tested solvents. In particular, the breakthrough time for polar butyl acetate was even longer than for conventional carbon black. Additionally, the increase of the breakthrough time was observed to depend on the modifier of bentonite particle surface.

Krzemi?ska, S.; Rzymski, W. M.

2011-12-01

71

Three-dimensional constitutive equations for Styrene Butadiene Rubber at high strain rates  

Microsoft Academic Search

Tensile stress–extension ratio and force–extension curves for Styrene Butadiene Rubber dumbbell and sheet specimens, respectively, were obtained from a Charpy tensile impact experiment and used to develop high rate-dependent constitutive equations for the rubber. The tensile tests were performed up to material failure and under constant strain rates ranging from 76s?1 to 450s?1. The rubber became stiffer with increasing strain

Michelle S. Hoo Fatt; Xin Ouyang

2008-01-01

72

Historical Estimation of Exposure to 1,3Butadiene, Styrene, and Dimethyldithiocarbamate Among Synthetic Rubber Workers  

Microsoft Academic Search

Quantitative estimates of exposure to 1,3-butadiene (BD), styrene (STY), and dimethyldithiocarbamate (DMDTC) were developed for a follow-up study of workers at six North American synthetic rubber plants. Procedures entailed identifying tasks and jobs involving exposure, identifying factors influencing historical changes in exposure potential, and using mathematical models to calculate job- and time-period-specific exposures. Exposure metrics included 8-hour time-weighted average (TWA)

Maurizio Macaluso; Rodney Larson; Jeremiah Lynch; Sydney Lipton; Elizabeth Delzell

2004-01-01

73

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

PubMed

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

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

2013-12-01

74

Investigation on the mechanisms of genotoxicity of butadiene, styrene and their combination in human lymphocytes using the Comet assay.  

PubMed

The toxicity of butadiene and styrene is exerted by their metabolites. Such metabolites have been extensively scrutinized at the in vitro level demonstrating evident genotoxic properties. In monitoring, a diverse range of outcomes has been produced. Additionally, epidemiological studies in rubber workers face difficulties of data interpretation due to the changeability and multiple exposures of the workers as well as to confounding factors inherent to the cohorts. Nevertheless, toxicity has been associated with a significant trend of increasing the risk of leukaemia in employees at the styrene-butadiene rubber industry. Thus, further effort must be made to distinguish the exposures to each chemical over time and to characterize their interrelationships. The present investigation focuses on the effects and mechanisms of damage of the mixture styrene-butadiene by examining its metabolites: styrene oxide (SO), butadiene monoepoxide (BME) and butadiene diepoxide (BDE) respectively. The in vitro Comet assay on frozen lymphocytes has been employed to ascertain the DNA damage patterns for the styrene-butadiene metabolites combined and on their own. Different patterns were observed for the mixture and each of its components. This study has also led to determining the mechanism of damage of the mixture and the compounds. With regard to the presence of reactive oxygen species (ROS), co-treatment with catalase does not modulate the genotoxicity of the mixture but it does modulate its components. The outcomes also indicate that the mixture induces cross-links and this is due to the influence of BDE in the mixture, being more evident as the concentration of BDE increases. An investigation on the sensitivity of lymphocytes from occupationally un/exposed subjects to in vitro exposure of the mixture and its components revealed that occupationally exposed subjects had a substantially higher background of DNA damage and a lower sensitivity to the metabolites of styrene, 1,3-butadiene and its mixture. PMID:19428383

Cemeli, Eduardo; Mirkova, Ekaterina; Chiuchiarelli, Giorgia; Alexandrova, Elena; Anderson, Diana

2009-05-12

75

Gas transport through nano and micro composites of natural rubber (NR) and their blends with carboxylated styrene butadiene rubber (XSBR) latex membranes  

Microsoft Academic Search

The gas permeability coefficient of nano and micro composites of natural rubber, carboxylated styrene butadiene rubber and 70:30 natural rubber\\/carboxylated styrene butadiene rubber blend membranes has been investigated with special reference to type of filler, gases, filler loading and pressure. The layered silicates such as sodium bentonite and sodium fluorohectorite were the nanofillers used and the conventional micro fillers were

Ranimol Stephen; C. Ranganathaiah; Siby Varghese; Kuruvilla Joseph; Sabu Thomas

2006-01-01

76

Morphology, Thermal and Mechanical Properties of Poly (Styrene-Acrylonitrile) (SAN)\\/Clay Nanocomposites from Organic-Modified Montmorillonite  

Microsoft Academic Search

Poly (styrene-acrylonitrile) (SAN)\\/clay nanocomposites have successfully been prepared by melt intercalation method. The hexadecyl triphenyl phosphonium bromide (P16) and cetyl pyridium chloride (CPC) are used to modify the montmorillonite (MMT). The structure and thermal stability property of the organic modified MMT are, respectively characterized by Fourier transfer infrared (FT-IR) spectra, X-ray diffraction (XRD) and thermogravimetric analysis (TGA). The results indicate

Yibing Cai; Yuan Hu; Junfeng Xiao; Lei Song; Weicheng Fan; Huaxia Deng; Xinglong Gong; Zuyao Chen

2007-01-01

77

Multicomponent blends based on polyamide 6 and styrenic polymers: Morphology and melt rheology  

Microsoft Academic Search

The role of each blend component on blend morphology and melt rheological properties was investigated for multicomponent compatibilized blends of polyamide 6 (PA6) and acrylonitrile-butadiene-styrene terpolymer (ABS). Blends with PA6 content of 50 wt% were prepared at similar processing conditions on a ZSK 30 twin screw extruder. PA6\\/styrene-acrylonitrile co-polymer (SAN) blends showed a dispersed morphology with PA6 as matrix. Addition

S.Ha Jafari; P. a c Pötschke; M. a Stephan; H. b Warth; H. b Alberts

2002-01-01

78

21 CFR 177.1010 - Acrylic and modified acrylic plastics, semirigid and rigid.  

Code of Federal Regulations, 2010 CFR

...occur when they are mixed: Butadiene-acrylonitrile copolymers. Butadiene-acrylonitrile-styrene copolymers. Butadiene-acrylonitrile-styrene-methyl methacrylic...Butadiene-styrene copolymers. Butyl rubber. Natural rubber....

2010-04-01

79

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

NASA Astrophysics Data System (ADS)

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 ?) 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.

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

2013-12-01

80

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...

81

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...

82

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

NASA Technical Reports Server (NTRS)

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.

Arenz, R. J.

1977-01-01

83

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...

84

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

SciTech Connect

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.

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

1988-02-01

85

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

NASA Astrophysics Data System (ADS)

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.

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

2012-01-01

86

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

NASA Astrophysics Data System (ADS)

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.

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

2015-01-01

87

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

NASA Astrophysics Data System (ADS)

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.

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

2010-04-01

88

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

PubMed

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

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

2012-01-01

89

Effect of methyl methacrylate-butadiene-styrene copolymer on the thermooxidation and biodegradation of LDPE\\/plasticized starch blends  

Microsoft Academic Search

The effect of methyl methacrylate-butadiene-styrene copolymer (MBS) on the thermooxidative degradation and biodegradation of low-density polyethylene (LDPE)\\/plasticized starch (PLST) blends was examined. Ethylene-co-acrylic acid (EAA) was used as compatibilizer and cobalt stearate as pro-oxidant. The thermooxidative degradation was followed by means of Fourier transform infra-red spectroscopy, gravimetric measurements and mechanical properties during incubation of the blends in an air oven

D. Bikiaris; J. Prinos; C. Panayiotou

1997-01-01

90

Effect of concentration and humidity on the formation of porous polymer films using Styrene Butadiene Co-Polymer  

NASA Astrophysics Data System (ADS)

Honeycomb structured porous materials from complex polymers are formed using water droplet templating method. In the present work microporous films were prepared from styrene butadiene rubber (SBR) using emulsion technique. The pore sizes can be easily tuned by changing the concentration and the humidity condition. The pore size is characterized by optical microscope and Scanning electron microscope (SEM). These films can be used for various applications in optoelectronics, photonics, catalysis, tissue engineering, bioanalytical purposes etc.

Jose, Renu; Sujith, A.; Predeep, P.

2011-10-01

91

Influence of fillers on free volume and gas barrier properties in styrene-butadiene rubber studied by positrons  

Microsoft Academic Search

The measurements of free-volume hole property by positron annihilation lifetime spectroscopy (PALS) have been carried out for polymer–clay nanocomposite materials that consist of styrene–butadiene rubber (SBR) and layered silicate clay of rectorite and conventional composite materials N326 (carbon black) \\/SBR. The PALS and differential scanning calorimeter (DSC) results show layered rectorite has a stronger effect on restraining polymer chain mobility

Z. F. Wang; B. Wang; N. Qi; H. F. Zhang; L. Q. Zhang

2005-01-01

92

24 CFR 3280.604 - Materials.  

Code of Federal Regulations, 2010 CFR

...Standard Specification Acrylonitrile-Butadiene-Styrene (ABS) Schedule...Standard Specification for Acrylonitrile-Butadiene-Styrene (ABS) Schedule...for Solvent Cement for Acrylonitrile-Butadiene-Styrene (ABS)...

2010-04-01

93

40 CFR 63.191 - Definitions.  

Code of Federal Regulations, 2010 CFR

...Methyl Methacrylate-Acrylonitrile-Butadiene-Styrene (MABS...methyl methacrylate, acrylonitrile, 1,3-butadiene, and styrene. The...methyl methacrylate- acrylonitrile-styrene and butadiene monomer. The...

2010-07-01

94

77 FR 1267 - National Emission Standards for Hazardous Air Pollutant Emissions: Group IV Polymers and Resins...  

Federal Register 2010, 2011, 2012, 2013, 2014

...defined here: ABS--Acrylonitrile Butadiene Styrene Resin ADAF...Resins Source Categories A. Acrylonitrile Butadiene Styrene Resin (ABS) B...Methacrylate- 325211 1317 Acrylonitrile-Butadiene-Styrene...

2012-01-09

95

Identification of alkylbenzene sulfonate surfactants leaching from an acrylonitrile butadiene rubber as novel inhibitors of calcineurin activity.  

PubMed

Calcineurin (CN) is a Ca(2+)/calmodulin (CaM) dependent serine/threonine protein phosphatase and plays important role in several cellular functions in both higher and lower eukaryotes. Here we report inhibition of CN by linear alkylbenzene sulfonate. The clue to the finding was obtained while identifying the inhibitory material leaching from acrylonitrile butadiene rubber used for packing. Using standard dodecylbenzene sulfonate (C12-LAS), we obtained strong inhibition of CN with a half maximal inhibitory concentration of 9.3 µM, whereas analogs such as p-octylbenzene sulfonate and SDS hardly or only slightly affected CN activity. Three alkaline phosphatases, derived from shrimp, bacteria, and calf-intestine, which exhibit similar enzymatic activities to CN, were not inhibited by C12-LAS at concentrations of up to 100 µM. Furthermore, C12-LAS did not inhibit Ca(2+)/CaM-dependent myosin light chain kinase activity when tested at concentrations of up to 36 µM. The results indicate that C12-LAS is a potent selective inhibitor of CN activity. PMID:23649261

Ito, Noboru; Shibuguchi, Nao; Ishikawa, Ryoki; Tanaka, Susumu; Tokita, Yoshiharu; Nakajima-Shimada, Junko; Hosaka, Kohei

2013-01-01

96

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

Code of Federal Regulations, 2014 CFR

...Paint Branch Pkwy., College Park, MD 20740...Food Safety and Applied Nutrition (HFS-200), Food...Paint Branch Pkwy., College Park, MD 20740...Food Safety and Applied Nutrition (HFS-200), Food...Paint Branch Pkwy., College Park, MD...

2014-04-01

97

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

Code of Federal Regulations, 2010 CFR

...Paint Branch Pkwy., College Park, MD 20740...Food Safety and Applied Nutrition (HFS-200), Food...Paint Branch Pkwy., College Park, MD 20740...Food Safety and Applied Nutrition (HFS-200), Food...Paint Branch Pkwy., College Park, MD...

2010-04-01

98

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

Code of Federal Regulations, 2011 CFR

...Paint Branch Pkwy., College Park, MD 20740...Food Safety and Applied Nutrition (HFS-200), Food...Paint Branch Pkwy., College Park, MD 20740...Food Safety and Applied Nutrition (HFS-200), Food...Paint Branch Pkwy., College Park, MD...

2011-04-01

99

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

Code of Federal Regulations, 2013 CFR

...Paint Branch Pkwy., College Park, MD 20740...Food Safety and Applied Nutrition (HFS-200), Food...Paint Branch Pkwy., College Park, MD 20740...Food Safety and Applied Nutrition (HFS-200), Food...Paint Branch Pkwy., College Park, MD...

2013-04-01

100

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

Code of Federal Regulations, 2012 CFR

...Paint Branch Pkwy., College Park, MD 20740...Food Safety and Applied Nutrition (HFS-200), Food...Paint Branch Pkwy., College Park, MD 20740...Food Safety and Applied Nutrition (HFS-200), Food...Paint Branch Pkwy., College Park, MD...

2012-04-01

101

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

NASA Astrophysics Data System (ADS)

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.

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

2012-11-01

102

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

NASA Astrophysics Data System (ADS)

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.

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

2012-08-01

103

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

NASA Astrophysics Data System (ADS)

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.

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

2011-03-01

104

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

Code of Federal Regulations, 2010 CFR

...Abstract Service Number. ABS = Acrylonitrile butadiene styrene resin. ASA/AMSAN = Acrylonitrile styrene resin/alpha methyl styrene...resin. MABS = methyl methacrylate acrylonitrile butadiene styrene resin. PET =...

2010-07-01

105

21 CFR 177.1040 - Acrylonitrile/styrene copoly-mer.  

Code of Federal Regulations, 2011 CFR

...for 2 h.1 Minimum 10 pct solution viscosity at 25 °C (77 °F) is 10cP. 1 ...average molecular weight, and solution viscosity, titled: “Determination of Residual Acrylonitrile...Analytical Method for 10% Solution Viscosity of Tyril,” which are...

2011-04-01

106

21 CFR 177.1040 - Acrylonitrile/styrene copoly-mer.  

Code of Federal Regulations, 2012 CFR

...for 2 h.1 Minimum 10 pct solution viscosity at 25 °C (77 °F) is 10cP. 1 ...average molecular weight, and solution viscosity, titled: “Determination of Residual Acrylonitrile...Analytical Method for 10% Solution Viscosity of Tyril,” which are...

2012-04-01

107

21 CFR 177.1040 - Acrylonitrile/styrene copoly-mer.  

Code of Federal Regulations, 2014 CFR

...for 2 h.1 Minimum 10 pct solution viscosity at 25 °C (77 °F) is 10cP. 1 ...average molecular weight, and solution viscosity, titled: “Determination of Residual Acrylonitrile...Analytical Method for 10% Solution Viscosity of Tyril,” which are...

2014-04-01

108

21 CFR 177.1040 - Acrylonitrile/styrene copoly-mer.  

Code of Federal Regulations, 2013 CFR

...for 2 h.1 Minimum 10 pct solution viscosity at 25 °C (77 °F) is 10cP. 1 ...average molecular weight, and solution viscosity, titled: “Determination of Residual Acrylonitrile...Analytical Method for 10% Solution Viscosity of Tyril,” which are...

2013-04-01

109

21 CFR 177.1040 - Acrylonitrile/styrene copoly-mer.  

Code of Federal Regulations, 2010 CFR

...for 2 h.1 Minimum 10 pct solution viscosity at 25 °C (77 °F) is 10cP. 1 ...average molecular weight, and solution viscosity, titled: “Determination of Residual Acrylonitrile...Analytical Method for 10% Solution Viscosity of Tyril,” which are...

2010-04-01

110

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

Code of Federal Regulations, 2012 CFR

...in the range of 17.7-19.8 percent. (2) Intrinsic viscosity of the matrix copolymer in butyrolactone is not less than 0...titled “Molecular Weight of Matrix Copolymer by Solution Viscosity,” which is incorporated by reference. Copies are...

2012-04-01

111

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

Code of Federal Regulations, 2013 CFR

...in the range of 17.7-19.8 percent. (2) Intrinsic viscosity of the matrix copolymer in butyrolactone is not less than 0...titled “Molecular Weight of Matrix Copolymer by Solution Viscosity,” which is incorporated by reference. Copies are...

2013-04-01

112

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

Code of Federal Regulations, 2011 CFR

...in the range of 17.7-19.8 percent. (2) Intrinsic viscosity of the matrix copolymer in butyrolactone is not less than 0...titled “Molecular Weight of Matrix Copolymer by Solution Viscosity,” which is incorporated by reference. Copies are...

2011-04-01

113

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

Code of Federal Regulations, 2014 CFR

...in the range of 17.7-19.8 percent. (2) Intrinsic viscosity of the matrix copolymer in butyrolactone is not less than 0...titled “Molecular Weight of Matrix Copolymer by Solution Viscosity,” which is incorporated by reference. Copies are...

2014-04-01

114

21 CFR 177.1480 - Nitrile rubber modified acrylonitrile-methyl acrylate copolymers.  

Code of Federal Regulations, 2010 CFR

...acrylate copolymers. Nitrile rubber modified acrylonitrile-methyl...of this section, nitrile rubber modified acrylonitrile-methyl...8-10 parts by weight of butadiene-acrylonitrile copolymers containing approximately...butadiene. (b) The nitrile rubber modified...

2010-04-01

115

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

NASA Astrophysics Data System (ADS)

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.

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

2011-05-01

116

Biomonitoring of 1,3-butadiene and related compounds.  

PubMed Central

The 1990 Clean Air Act Amendments list several volatile organic chemicals as hazardous air pollutants, including ethylene oxide, butadiene, styrene, and acrylonitrile. The toxicology of many of these compounds shares several common elements such as carcinogenicity in laboratory animals, genotoxicity of the epoxide intermediates, involvement of cytochrome P450 for metabolic activation (except ethylene oxide), and involvement of at least two enzymes for detoxication of the epoxides (e.g., hydrolysis or conjugation with glutathione). These similarities facilitate research strategies for identifying and developing biomarkers of exposure. This article reviews the current knowledge about biomarkers of butadiene. Butadiene is carcinogenic in mice and rats, which raises concern for potential carcinogenicity in humans. Butadiene is metabolized to DNA-reactive metabolites, including 1,2-epoxy-3-butene and diepoxybutane. These epoxides are thought to play a critical role in butadiene carcinogenicity. Butadiene and some of its metabolites (e.g., epoxybutene) are volatile. Exhalation of unchanged butadiene and excretion of butadiene metabolites in urine represent major routes of elimination. Therefore, biomonitoring of butadiene exposure could be based on chemical analysis of butadiene in exhaled breath, blood levels of butadiene epoxides, excretion of butadiene metabolites in urine, or adducts of butadiene epoxides with DNA or blood proteins. Mutation induction in specific genes (e.g., HPRT) following butadiene exposure can be potentially used as a biomarker. Excretion of 1,2-dihydroxy-4-(N-acetylcysteinyl-S)butane or the product of epoxybutene with N-7 in guanine in urine, epoxybutene-hemoglobin adducts, and HPRT mutation have been used as biomarkers in recent studies of occupational exposure to butadiene. Data in laboratory animals suggest that diepoxybutane may be a more important genotoxic metabolite than epoxybutene. Biomonitoring methods need to be developed for diepoxybutane and other putative reactive butadiene metabolites. With butadiene and related compounds, the ultimate challenge is to identify useful biomarkers of exposure in which quantitative linkages between exposure and internal dose of the important DNA-reactive metabolites are established. PMID:8933033

Osterman-Golkar, S; Bond, J A

1996-01-01

117

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

NASA Technical Reports Server (NTRS)

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.

Arenz, R. J.

1974-01-01

118

Acrylonitrile removal from synthetic wastewater and actual industrial wastewater with high strength nitrogen using a pure bacteria culture.  

PubMed

A gram-negative rod-shaped bacteria (strain AAS6), capable of utilizing acrylonitrile as the sole source of both carbon and nitrogen, was utilized to investigate the removal of acrylonitrile in ABS resin manufacturing wastewater. Both synthetic wastewater, containing a high concentration of acrylonitrile, and actual wastewater obtained from an ABS manufacturing factory were used. The result indicated that strain AAS6 was capable of completely removing acrylonitrile from synthetic wastewater containing less than 889 mg/l acrylonitrile and from actual industrial wastewater containing less than 400 mg/l acrylonitrile. Whether in synthetic wastewater or actual industrial wastewater, strain AAS6 showed approximately the same ability for acrylonitrile removal and used acrylic acid, a metabolic by-product of acrylonitrile, as the carbon source and ammonium as the nitrogen source. The bacteria could not directly metabolize other chemicals found in the actual industrial wastewater. However, its metabolic activities were not inhibited by the presence of compounds such as butadiene, styrene or acrylonitrile-styrene polymer. Thus, this strain is expected to play an important role in aeration tanks for treating ABS resin manufacturing wastewater. PMID:11380201

Wang, C C; Lee, C M; Cheng, P W

2001-01-01

119

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)

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.

Markovi?, G.; Marinovi?-Cincovi?, M.; Tanasi?, Lj.; Jovanovi?, V.; Samaržija-Jovanovi?, S.; Vuki?, N.; Budinski-Simendi?, J.

2011-12-01

120

Compatibilization Efficiency of Styrene-Butadiene Block Copolymers as a Function of Their Block Number  

Microsoft Academic Search

Effect of block number in linear styrene-bu- tadiene (SB) block copolymers (BCs) on their compatibili- zation efficiency in blending polystyrene (PS) with polybu- tadiene (PB) was studied. Di-, tri-, or pentablocks of SB copolymers as well as their combinations were blended with the mentioned homopolymers; supramolecular struc- ture determined by small angle X-ray scattering method (SAXS), morphology using scanning electron

Nina Vranjes; Frantisek Lednicky; Josef Baldrian; Vesna Rek; Ivan Fortelny; Zdenek Horak

121

Synthesis and electrical conductivity studies of metal chloro and nitroxide group containing styrene butadiene rubber  

NASA Astrophysics Data System (ADS)

The introduction of different functional group in SBR was done by a simple reaction between sodium nitrite and mercuric chloride in the presence of phase transfer catalyst. The attachment of chlorine and NO2 functional group in the double bond of the butadiene was monitored by FTIR and UV spectroscopy. The structure and morphology of chloro nitro SBR was studied by SEM and XRD. Flame retardency studies revealed that the chemical modification imparts better flame resistance to chemically modified SBR. AC conductivity and dielectric properties of chloro- nitro SBR was higher than that of SBR and conductivity increases with the level of chemical modification.

Anilkumar, T.; Ramesan, M. T.

2014-10-01

122

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

PubMed Central

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

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

2012-01-01

123

21 CFR 177.1200 - Cellophane.  

Code of Federal Regulations, 2010 CFR

...by weight of finished packaging cellophane) Acrylonitrile-butadiene copolymer resins As the basic polymer. Acrylonitrile-butadiene-styrene copolymer resins Do. Acrylonitrile-styrene copolymer resins Do....

2010-04-01

124

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

PubMed Central

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

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

1990-01-01

125

21 CFR 178.3790 - Polymer modifiers in semirigid and rigid vinyl chloride plastics.  

Code of Federal Regulations, 2010 CFR

...following monomers: Acrylonitrile. Butadiene. a -Methylstyrene...units derived from butadiene-styrene copolymers...methylstyrene and acrylonitrile and may optionally...units derived from butadiene-styrene...

2010-04-01

126

21 CFR 175.125 - Pressure-sensitive adhesives.  

Code of Federal Regulations, 2010 CFR

...identified in this subparagraph and subject to the limitations provided: BHA. BHT. Butadiene-acrylonitrile copolymer. Butadiene-acrylonitrile-styrene copolymer. Butadiene-styrene copolymer. Butyl rubber. Butylated...

2010-04-01

127

Biomonitoring of 1,3-butadiene and related compounds  

SciTech Connect

The 1990 Clean Air Act Amendments list several volatile organic chemicals as hazardous air pollutants, including ethylene oxide, butadiene, styrene, and acrylonitrile. The toxicology of many of these compounds shares several common elements such as carcinogenicity in laboratory animals, genotoxicity of the epoxide intermediates, involvement of cytochrome P450 for metabolic activation (except ethylene oxide), and involvement of at least two enzymes for detoxication of the epoxides (e.g., hydrolysis or conjugation with glutathione). These similarities facilitate research strategies for identifying and developing biomarkers of exposure. This article reviews the current knowledge about biomarkers of butadiene. Butadiene is carcinogenic in mice and rats, which raises concern for potential carcinogenicity in humans. 85 refs., 1 fig., 2 tabs.

Osterman-Golkar, S. [Stockholm Univ. (Sweden); Bond, J.A. [Chemical Industry Institute of Toxicology, Research Triangle Park, NC (United States)

1996-10-01

128

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

PubMed Central

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

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

1999-01-01

129

Quadratic Electro-Optic Effect in the Nonconjugated Conductive Co-polymer Iodine-doped Styrene-Butadiene-Rubber Measured at 633 nm and 1550 nm  

NASA Astrophysics Data System (ADS)

The quadratic electro-optic effect in the nonconjugated conductive co-polymer film of styrene-butadiene-rubber (SBR) has been measured using field-induced birefringence method. Thin films of styrene-butadiene-rubber have been prepared on various substrates from a chloroform solution and characterized using optical absorption spectroscopy, FTIR and DSC before and after doping with iodine. The optical absorption spectrum at low doping shows two peaks: one at 4.27 eV and the other at 3.2 eV corresponding to the radical cation and charge-transfer transition. FTIR data indicate =C-H vibration bands (964 cm-1 and 910 cm-1) of polybutadiene decrease upon doping due to transformation of the double bonds into radical cations. The Kerr coefficients as measured at 633 nm and at 1550 nm are 3.1x10-10 m/V^2 and 1.3x10-10 m/V^2 respectively. These exceptionally large values have been attributed to the subnanometer metallic domains formed upon doping and charge-transfer involving isolated double-bonds.

Telang, Gurudutt; Thakur, Mrinal

2012-02-01

130

78 FR 73965 - Manufactured Home Construction and Safety Standards  

Federal Register 2010, 2011, 2012, 2013, 2014

...for Solvent Cement for Acrylonitrile-Butadiene-Styrene (ABS) Plastic...Standard Specification for Acrylonitrile- Butadiene-Styrene (ABS) Schedule...Standard Specification for Acrylonitrile- Butadiene-Styrene (ABS)...

2013-12-09

131

21 CFR 178.2010 - Antioxidants and/or stabilizers for polymers.  

Code of Federal Regulations, 2010 CFR

...weight of natural rubber, butadiene-acrylonitrile, butadiene-acrylonitrile-styrene, and butadiene-styrene...chapter, and of rubber articles complying...weight of natural rubber, butadiene-acrylonitrile,...

2010-04-01

132

Trans-stereospecific polymerization of butadiene and random copolymerization with styrene using borohydrido neodymium / magnesium dialkyl catalysts  

E-print Network

borohydrido neodymium / magnesium dialkyl catalysts A. Venturaa , T. Chenalb,c,d,e, *, M. Briab,f , F. Bonnetb neodymium and magnesium, and significant amounts of 1,2-units are observed. When considered for butadiene

Boyer, Edmond

133

Electrografting of copolymer of poly[ N-vinylcarbazole-co-styrene] and poly[ N-vinylcarbazole-co-acrylonitrile] onto carbon fiber: cyclovoltammetric (CV), spectroscopic (UV-Vis, FT-IR-ATR), and morphological study (SEM)  

Microsoft Academic Search

Random copolymers of poly(N-vinylcarbazole-styrene), P[NVCz-co-St], and poly(N-vinylcarbazole-acrylonitrile), P[NVCz-co-AN] were synthesized by the reaction of ceric ammonium nitrate (CAN) in acetonitrile. The resulting copolymers of P[NVCz-co-St], and P[NVCz-co-AN] were electrochemically coated (grafted) onto a few single carbon fiber microelectrodes. The electrocoated carbon fibers were characterized by cyclic voltammetry (CV), FT-IR-ATR, UV-Vis spectrophotometer, and scanning electron microscope (SEM). Polymer modified carbon fiber

A. Sezai Saraç; Yusuf Bardavit

2004-01-01

134

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

Federal Register 2010, 2011, 2012, 2013, 2014

...including ethylene, propylene, butadiene, benzene, toluene, xylene...ethylhexanol, acetic acid, acrylonitrile butadiene styrene, alachlor, ammonium...sulfur, sulfuric acid, styrene butadiene, toluene diisocyanate,...

2012-11-13

135

40 CFR 63.190 - Applicability and designation of source.  

Code of Federal Regulations, 2010 CFR

... (i) [Reserved] (ii) Methylmethacrylate-butadiene-styrene resins (MBS) (iii) Butadiene-furfural cotrimer, (iv) Methylmethacrylate-acrylonitrile-butadiene-styrene (MABS) resins, and (v) Ethylidene...

2010-07-01

136

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

PubMed

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

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

2012-10-01

137

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

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.

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

1984-06-18

138

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)

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.

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

2014-05-01

139

[Analytical method of volatile substances in styrene polymers by head-space gas chromatography using o-dichlorobenzene].  

PubMed

A quantitative analytical method for 8 volatile substances (such as styrene) in styrene polymers that are not soluble in tetrahydrofuran (THF) and dimethylformamide was developed. The sample was chopped finely and a 0.1 g portion was weighed in a head-space vial. To this was added 2 mL of o-dichlorobenzene (DCB) including 50 ?g/mL of internal standard. The vial was sealed and heated at 140? for 1 hour and then 1 mL of the head-space gas was injected into a gas chromatograph using an automatic sampler. Samples of syndiotactic polystyrene, styrene block copolymer and modified polyphenylenether were dissolved or dispersed in DCB. Separation and accuracy of the method were satisfactory. Recoveries were 95-113% at the spiked concentration of 300 ?g/g. The method was confirmed to be suitable for general styrene polymers that are soluble in THF. Equivalent results were obtained with this method and the method in "Specifications and Standards for Food, Food Additives, etc. " for general purpose polystyrene, high impact polystyrene, styrene/acrylonitrile resin and acrylonitrile/butadiene/styrene resin. PMID:24190292

Miyake, Daisuke; Hayakawa, Kenji; Nomura, Takakazu

2013-01-01

140

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...

141

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

PubMed Central

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

Morrow, N L

1990-01-01

142

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)

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.

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

2011-02-01

143

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...

144

40 CFR 52.2570 - Identification of plan.  

Code of Federal Regulations, 2010 CFR

...products; Mmanufacture of pneumatic rubber tires; Automobile and light duty...be used to manufacture styrene-butadiene-acrylonitrile latex. (i) Incorporation by...balance system for the styrene-butadiene-acrylonitrile latex manufacturing process,...

2010-07-01

145

24 CFR Appendix A to Part 200 - Standards Incorporated by Reference in the Minimum Property Standards for Housing (HUD Handbook...  

Code of Federal Regulations, 2010 CFR

...Fittings—3/28/80 78 Polyethylene (PE), Acrylonitrile-Butadiene-Styrene (ABS), Poly Vinyl Chloride (PVC...Domestic Cold Water Service—4/25/78 79a Acrylonitrile-Butadiene-Styrene (ABS) and Poly (Vinyl...

2010-04-01

146

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...

147

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

PubMed

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

Chronska, K; Przepiorkowska, A

2008-03-01

148

Polybenzoxazole-filled nitrile butadiene rubber compositions  

NASA Technical Reports Server (NTRS)

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.

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

2008-01-01

149

21 CFR 175.320 - Resinous and polymeric coatings for polyolefin films.  

Code of Federal Regulations, 2010 CFR

...with formaldehyde and butanol Butadiene-acrylonitrile copolymer Butadiene-acrylonitrile-styrene terpolymer Butyl rubber N,N ?-Diphenyl-p...this chapter. Blended with butyl rubber for use as a component of...

2010-04-01

150

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

PubMed

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

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

2014-11-20

151

Molecular Structure of Acrylonitrile  

NSDL National Science Digital Library

Acrylonitrile is an industrial chemical used to manufacture fibers, resins, plastics, and rubbers to produce various consumer goods. During its production, use, and disposal, it is mainly released to the air, due to a high evaporation rate, but also to soil and water. By inhalation, ingestion, or contact, acrylonitrile is toxic at high levels, severely affecting the nervous system, respiratory system, skin, and eyes. It causes cancer in animals and is a suspected human carcinogen. Although acrylonitrile is produced on a large scale, it reacts with chemicals and sunlight when released to the air, thus has a half-life less than 50 hrs. When released to soil or water, bacteria typically degrade it. Therefore, the environment is not permanently affected when the chemical is regulated.

2002-09-27

152

Carcinogenicity of 1,3-butadiene.  

PubMed Central

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

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

1993-01-01

153

Solubility parameter of poly(butadiene-co-acrylonitrile)  

NASA Astrophysics Data System (ADS)

This document is part of Subvolume D2 'Polymer Solutions - Physical Properties and their Relations I (Thermodynamic Properties: PVT -Data and miscellaneous Properties of polymer Solutions) of Volume 6 `Polymers' of Landolt-Börnstein - Group VIII `Advanced Materials and Technologies'.

Wohlfarth, Ch.

154

Second virial coefficient of poly(butadiene-co-acrylonitrile)  

NASA Astrophysics Data System (ADS)

This document is part of Subvolume D2 'Polymer Solutions - Physical Properties and their Relations I (Thermodynamic Properties: PVT -Data and miscellaneous Properties of polymer Solutions) of Volume 6 `Polymers' of Landolt-Börnstein - Group VIII `Advanced Materials and Technologies'.

Wohlfarth, Ch.

155

Fundamental Scratch Behavior of Styrene-Acrylonitrile Random Copolymers  

E-print Network

Software ................................... 20 3.2 Model PP and PVC Systems ................................................................ 21 3.3 Scratch Testing and Analysis ............................................................... 22... of model PP and PVC. (Resolution = 300 dpi) ................................................................................ 24 3.2 Summary of critical load values for visibility and plowing for model PP and PVC...

Browning, Robert Lee

2011-10-21

156

21 CFR 178.3400 - Emulsifiers and/or surface-active agents.  

Code of Federal Regulations, 2010 CFR

...potassium, and sodium salts For use only:1. In acrylonitrile-butadiene copolymers identified in § 177.2600(c)(4...to exceed 0.3 percent by weight of styrene-butadiene copolymer coatings for paper and paperboard...

2010-04-01

157

1,3-Butadiene  

Cancer.gov

Exposure to 1,3-butadiene mainly occurs among workers who breath contaminated air on the job. Other sources of exposure include automobile exhaust; tobacco smoke; and polluted air and water near chemical, plastic, or rubber facilities.

158

24 CFR Appendix A to Part 200 - Standards Incorporated by Reference in the Minimum Property Standards for Housing (HUD Handbook...  

Code of Federal Regulations, 2013 CFR

...Specification for Rigid Poly (Vinyl Chloride) (PVC) Siding ASTM E 72-80 Standard Methods...Acrylonitrile-Butadiene-Styrene (ABS), Poly Vinyl Chloride (PVC) and Polybutylene (PB) Plastic Piping for...Acrylonitrile-Butadiene-Styrene (ABS) and Poly (Vinyl Chloride) (PVC) Plastic Drain, Waste and Vent Pipe...

2013-04-01

159

24 CFR Appendix A to Part 200 - Standards Incorporated by Reference in the Minimum Property Standards for Housing (HUD Handbook...  

Code of Federal Regulations, 2014 CFR

...Specification for Rigid Poly (Vinyl Chloride) (PVC) Siding ASTM E 72-80 Standard Methods...Acrylonitrile-Butadiene-Styrene (ABS), Poly Vinyl Chloride (PVC) and Polybutylene (PB) Plastic Piping for...Acrylonitrile-Butadiene-Styrene (ABS) and Poly (Vinyl Chloride) (PVC) Plastic Drain, Waste and Vent Pipe...

2014-04-01

160

24 CFR Appendix A to Part 200 - Standards Incorporated by Reference in the Minimum Property Standards for Housing (HUD Handbook...  

Code of Federal Regulations, 2012 CFR

...Specification for Rigid Poly (Vinyl Chloride) (PVC) Siding ASTM E 72-80 Standard Methods...Acrylonitrile-Butadiene-Styrene (ABS), Poly Vinyl Chloride (PVC) and Polybutylene (PB) Plastic Piping for...Acrylonitrile-Butadiene-Styrene (ABS) and Poly (Vinyl Chloride) (PVC) Plastic Drain, Waste and Vent Pipe...

2012-04-01

161

24 CFR Appendix A to Part 200 - Standards Incorporated by Reference in the Minimum Property Standards for Housing (HUD Handbook...  

Code of Federal Regulations, 2011 CFR

...Specification for Rigid Poly (Vinyl Chloride) (PVC) Siding ASTM E 72-80 Standard Methods...Acrylonitrile-Butadiene-Styrene (ABS), Poly Vinyl Chloride (PVC) and Polybutylene (PB) Plastic Piping for...Acrylonitrile-Butadiene-Styrene (ABS) and Poly (Vinyl Chloride) (PVC) Plastic Drain, Waste and Vent Pipe...

2011-04-01

162

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...

163

Assessment of 1,3-butadiene epidemiology studies.  

PubMed Central

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

Ott, M G

1990-01-01

164

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,...

165

21 CFR 181.32 - Acrylonitrile copolymers and resins.  

Code of Federal Regulations, 2010 CFR

...acrylonitrile monomer extraction for finished food-contact articles, determined by using the method of analysis titled “Gas-Solid Chromatographic Procedure for Determining Acrylonitrile Monomer in Acrylonitrile-Containing Polymers and...

2010-04-01

166

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...

167

Gold catalyst Styrene Benzaldehyde Styrene oxide Acetophenone  

E-print Network

O O O + + O2 Gold catalyst Styrene Benzaldehyde Styrene oxide Acetophenone studies. However, the study by Turner et al.1 seems to be the first to use Au55 in the synthesis of supported gold catalysts attempts to relate structure to activity in gold catalysis. What, then, makes gold particles of this size

Rouyer, Francois

168

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...

169

Ion-Molecule Association in Acrylonitrile  

NASA Technical Reports Server (NTRS)

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.

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

1997-01-01

170

Disclosed dielectric and electromechanical properties of hydrogenated nitrile-butadiene dielectric elastomer  

NASA Astrophysics Data System (ADS)

This paper presents a comprehensive study of the effects of acrylonitrile content, crosslink density and plasticization on the dielectric and electromechanical performances of hydrogenated nitrile-butadiene dielectric elastomer. It was found that by increasing the acrylonitrile content of hydrogenated nitrile-butadiene dielectric elastomer, the dielectric constant will be improved accompanied with a sharp decrease of electrical breakdown strength leading to a small actuated strain. At a fixed electric field, a high crosslink density increased the elastic modulus of dielectric elastomer, but it also enhanced the electrical breakdown strength leading to a high actuated strain. Adding a plasticizer into the dielectric elastomer decreased the dielectric constant and electrical breakdown strength slightly, but reduced the elastic modulus sharply, which was beneficial for obtaining a large strain at low electric field from the dielectric elastomer. The largest actuated strain of 22% at an electric field of 30 kV mm-1 without any prestrain was obtained. Moreover, the hydrogenated nitrile-butadiene dielectric actuator showed good history dependence. This proposed material has great potential to be an excellent dielectric elastomer.

Yang, Dan; Tian, Ming; Dong, Yingchao; Liu, Haoliang; Yu, Yingchun; Zhang, Liqun

2012-03-01

171

Molecular Structure of Styrene  

NSDL National Science Digital Library

Styrene is a colorless to yellowish, oily liquid with a sweet, floral odor in the pure form but usually contains aldehydes that produce an extremely penetrating smell, that is sharp and unpleasant. The styrene monomer can be manufacture in many different techniques for commercial production but the most important are dehydrogenation of ethylbezene and the oxidation of ethylbenzene to ethylbenzene hydroperoxide. Styrene is used in the manufacture of plastics, synthetic rubber, polymer resins and protective coatings as insulators. Styrene is also used as a dilutant to reduce viscosity of uncured resin systems. In addition, it is used in dental fillings, as a component in agricultural products, as stabilizing agent and as a chemical intermediate. Styrene polymer is used in the manufacture of photocopier toner. Styrene will corrode copper and copper alloys.

2004-11-11

172

Radiation-induced graft copolymerization of styrene with vinylic monomers at high dose rates  

NASA Astrophysics Data System (ADS)

Radiation-induced graft copolymerization of the following monomer pairs: styrene-acrylonitrile (AN), styrene-methyl methacrylate (MMA), styrene-2-methyl-5-vinylpyridine (MVP) and styrene- acrylic acid (AA) onto polyethylene film was studied at room temperature in the range of dose rates 8.10 -2-6.10 3 Gy/s. The grafted copolymer compositions were determined and copolymerization reactivity ratios were calculated. At high dose rates the contribution of the ionic mechanism is proved by the change of the copolymer compositions obtained at essential different dose rates and by different influence of the donor and acceptor solvents on this process. It is established that transition from radical mechanism to ionic one begins in the interval of dose rates 10 2-10 3 Gy/s for styrene-AN, styrene-MMA, styrene-MVP systems but occurs in the interval of dose rates 10 3-6.10 3 Gy/s for styrene-AA system. The formation of the grafted polymer compositions, obtained at high dose rates, must be described by the kinetics which takes into account the presence of ionic process.

Kabanov, V. Ya.; Aliev, R. E.

173

Reinforcement of hydrogenated carboxylated nitrile-butadiene rubber by multi-walled carbon nanotubes  

NASA Astrophysics Data System (ADS)

Hydrogenated carboxylated acrylonitrile-butadiene rubber (HXNBR) and multi-walled carbon nanotubes (MWCNT) composites were prepared. The dispersion of MWCNT in HXNBR matrix was evaluated by field emission scanning electron microscopy. HXNBR/MWCNT composite had shorter scorch time and optimum curing time compared with that of unfilled HXNBR. The tensile strength and modulus of HXNBR/MWCNT composites increased with increasing MWCNT content. Mooney-Rivlin equation was used to describe the stress-strain behavior of unfilled HXNBR and the strain amplification factor was taken into account for HXNBR/MWCNT composites. The Mullins effect and dynamic mechanical properties of HXNBR/MWCNT composite were also investigated.

Lu, Lan; Zhai, Yinghao; Zhang, Yong; Ong, Christopher; Guo, Sharon

2008-12-01

174

Electron impact ionization of acrylonitrile  

NASA Astrophysics Data System (ADS)

An electron impact (EI) ion source and a double focusing sector field mass spectrometer were used to investigate ionization processes of acrylonitrile C3H3N. The ionization and appearance energies for observed singly CxHyNz+ (x = 1-3; y = 0, 1, 3; z = 0, 1) and doubly C3H3N2+ and C3HN2+ charged ions were determined by using the non-linear least-square fitting procedure to the raising set of the data points. In the case of ions: C2HN+/C3H3+, C2N+/C3H2+, C3H+, C3+, CH2N+, CHN+/C2H3+, C2H+, C2+, H2N+, HN+/CH3+, CH2+/N+, CH+, C+, C3H3N2+ and C3HN2+ these energies were obtained for the first time.

Gluch, Krzysztof; Cytawa, Jan; Michalak, Leszek

2008-11-01

175

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...

176

STATUS ASSESSMENT OF TOXIC CHEMICALS: ACRYLONITRILE  

EPA Science Inventory

This report identifies the services and effects of environmental contaminators by acrylonitrile, as well as the health hazards resulting from such contamination. The present manufacturing processes, uses, control technologies, and regulatory actions are described, and areas requi...

177

Computational Investigation of the Competition between the Concerted Diels-Alder Reaction and Formation of Diradicals in Reactions of Acrylonitrile with Non-Polar Dienes  

PubMed Central

The energetics of the Diels-Alder cycloaddition reactions of several 1,3-dienes with acrylonitrile, and the energetics of formation of diradicals, were investigated with density functional theory (B3LYP and M06-2X) and compared to experimental data. For the reaction of 2,3-dimethyl-1,3-butadiene with acrylonitrile, the concerted reaction is favored over the diradical pathway by 2.5 kcal/mol using B3LYP/6-31G(d); experimentally this reaction gives both cycloadduct and copolymer. The concerted cycloaddition of cyclopentadiene with acrylonitrile is preferred computationally over the stepwise pathway by 5.9 kcal/mol; experimentally, only the Diels-Alder adduct is formed. For the reactions of (E)-1,3-pentadiene and acrylonitrile, both cycloaddition and copolymerization were observed experimentally; these trends were mimicked by the computational results, which showed only a 1.2 kcal/mol preference for the concerted pathway. For the reactions of (Z)-1,3-pentadiene and acrylonitrile, the stepwise pathway is preferred by 3.9 kcal/mol, in agreement with previous experimental findings that only polymerization occurs. M06-2X is known to give more accurate activation and reaction energetics but the energies of diradicals are too high. PMID:23758325

James, Natalie C.; Um, Joann M.; Padias, Anne B.; Hall, H. K.; Houk, K. N.

2013-01-01

178

Computational investigation of the competition between the concerted Diels-Alder reaction and formation of diradicals in reactions of acrylonitrile with nonpolar dienes.  

PubMed

The energetics of the Diels-Alder cycloaddition reactions of several 1,3-dienes with acrylonitrile, and the energetics of formation of diradicals, were investigated with density functional theory (B3LYP and M06-2X) and compared to experimental data (Hall et al., J. Org. Chem.1993, 58, 7049-7058). For the reaction of 2,3-dimethyl-1,3-butadiene with acrylonitrile, the concerted reaction is favored over the diradical pathway by 2.5 kcal/mol using B3LYP/6-31G(d); experimentally, this reaction gives both cycloadduct and copolymer. The concerted cycloaddition of cyclopentadiene with acrylonitrile is preferred computationally over the stepwise pathway by 5.9 kcal/mol; experimentally, only the Diels-Alder adduct is formed. For the reactions of (E)-1,3-pentadiene and acrylonitrile, both cycloaddition and copolymerization were observed experimentally; these trends were mimicked by the computational results, which showed only a 1.2 kcal/mol preference for the concerted pathway. For the reactions of (Z)-1,3-pentadiene and acrylonitrile, the stepwise pathway is preferred by 3.9 kcal/mol, in agreement with previous experimental findings that only polymerization occurs. M06-2X is known to give more accurate activation and reaction energetics (Pieniazek, et al., Angew. Chem. Int.2008, 47, 7746-7749), but the energies of diradicals are too high. PMID:23758325

James, Natalie C; Um, Joann M; Padias, Anne B; Hall, H K; Houk, K N

2013-07-01

179

24 CFR 3280.803 - Power supply.  

Code of Federal Regulations, 2014 CFR

...manufactured home floor. The raceway may be rigid conduit, electrical metallic tubing or polyethylene (PE), poly-vinylchloride (PVC) or acrylonitrile-butadiene-styrene (ABS) plastic tubing having a minimum wall thickness of nominal 1/8 inch....

2014-04-01

180

24 CFR 3280.803 - Power supply.  

Code of Federal Regulations, 2012 CFR

...manufactured home floor. The raceway may be rigid conduit, electrical metallic tubing or polyethylene (PE), poly-vinylchloride (PVC) or acrylonitrile-butadiene-styrene (ABS) plastic tubing having a minimum wall thickness of nominal 1/8 inch....

2012-04-01

181

24 CFR 3280.803 - Power supply.  

Code of Federal Regulations, 2013 CFR

...manufactured home floor. The raceway may be rigid conduit, electrical metallic tubing or polyethylene (PE), poly-vinylchloride (PVC) or acrylonitrile-butadiene-styrene (ABS) plastic tubing having a minimum wall thickness of nominal 1/8 inch....

2013-04-01

182

24 CFR 3280.803 - Power supply.  

Code of Federal Regulations, 2011 CFR

...manufactured home floor. The raceway may be rigid conduit, electrical metallic tubing or polyethylene (PE), poly-vinylchloride (PVC) or acrylonitrile-butadiene-styrene (ABS) plastic tubing having a minimum wall thickness of nominal 1/8 inch....

2011-04-01

183

24 CFR 3280.803 - Power supply.  

Code of Federal Regulations, 2010 CFR

...raceway may be rigid conduit, electrical metallic tubing or polyethylene (PE), poly-vinylchloride (PVC) or acrylonitrile-butadiene-styrene (ABS) plastic tubing having a minimum wall thickness of nominal 1/8 inch. (j)...

2010-04-01

184

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

...holes, cavities, or air bubbles) if the balls are made of materials other than those materials (such as ABS (acrylonitrile butadiene styrene), nylon, and high-impact polystyrene) that are injection-molded and possess high-impact...

2010-01-01

185

75 FR 39871 - Manufactured Home Construction and Safety Standards  

Federal Register 2010, 2011, 2012, 2013, 2014

...Materials for the spring-operated mechanical vents must be as follows: (A) Cap and housing must be listed acrylonitrile-butadiene-styrene, DWV grade; (B) Stem must be DWV grade nylon or acetal; (C) Spring must be stainless...

2010-07-13

186

77 FR 74006 - Polychlorinated Biphenyls (PCBs); Recycling Plastics From Shredder Residue  

Federal Register 2010, 2011, 2012, 2013, 2014

...PP), polyethylene (PE), polyurethane (PU), and polyvinyl chloride (PVC). ISRI also mentions acrylonitrile styrene butadiene (ABS) and high-impact polystyrene (HIPS) as additional types of automotive plastics found in...

2012-12-12

187

24 CFR 3280.611 - Vents and venting.  

Code of Federal Regulations, 2010 CFR

...5) Materials for the anti-siphon trap vent shall be as follows: (i) Cap and housing shall be listed acrylonitrile-butadiene-styrene, DWV grade; (ii) Stem shall be DWV grade nylon or acetal; (iii) Spring shall be...

2010-04-01

188

40 CFR 1065.170 - Batch sampling for gaseous and PM constituents.  

Code of Federal Regulations, 2010 CFR

...Cassettes must be made of one of the following materials: DelrinTM , 300 series stainless steel, polycarbonate, acrylonitrile-butadiene-styrene (ABS) resin, or conductive polypropylene. We recommend that you keep filter cassettes...

2010-07-01

189

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

PubMed

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

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

2014-05-01

190

40 CFR 86.1310-2007 - Exhaust gas sampling and analytical system for gaseous emissions from heavy-duty diesel-fueled...  

Code of Federal Regulations, 2010 CFR

...In addition to the specified Delrin TM material, 302, 303, or 304 stainless steel, polycarbonate or acrylonitrile/butadiene/styrene (ABS) resin, or a combination of these materials may also be used. (B) A bevel...

2010-07-01

191

75 FR 55067 - Energy Conservation Program: Test Procedures for Walk-In Coolers and Walk-In Freezers  

Federal Register 2010, 2011, 2012, 2013, 2014

...suggested. 2. In paper [2], Wilkes et al. measured the LTTR of 2-inch-thick foam samples faced with either Acrylonitrile Butadiene Styrene (ABS) or High Impact Polystyrene (HIPS) plastic. The edges of the samples were covered with...

2010-09-09

192

Investigating New Polymers for a Chlorine Tolerant RO Membrane Southwest Center for Education and the Natural Environment (SCENE)  

E-print Network

. Five Polymers Acrylonitrile Butadiene Styrene (ABS): Strong and rigid, resistant), NOT for high temperatures Polyvinylidene Fluoride (PVDF): Strong, very tough, resistant to abrasion, acids, bases, etc. Polytetrafluoroethylene/Teflon (PTFE): Maximum chemical

Hall, Sharon J.

193

21 CFR 181.32 - Acrylonitrile copolymers and resins.  

Code of Federal Regulations, 2014 CFR

... PRIOR-SANCTIONED FOOD INGREDIENTS Specific Prior-Sanctioned Food Ingredients § 181.32 Acrylonitrile...used with fresh fruits, vegetables, and fish. (iii) Acrylonitrile...heptane or an appropriate oil or fat. (c)...

2014-04-01

194

21 CFR 181.32 - Acrylonitrile copolymers and resins.  

Code of Federal Regulations, 2013 CFR

... PRIOR-SANCTIONED FOOD INGREDIENTS Specific Prior-Sanctioned Food Ingredients § 181.32 Acrylonitrile...used with fresh fruits, vegetables, and fish. (iii) Acrylonitrile...heptane or an appropriate oil or fat. (c)...

2013-04-01

195

21 CFR 181.32 - Acrylonitrile copolymers and resins.  

Code of Federal Regulations, 2012 CFR

... PRIOR-SANCTIONED FOOD INGREDIENTS Specific Prior-Sanctioned Food Ingredients § 181.32 Acrylonitrile...used with fresh fruits, vegetables, and fish. (iii) Acrylonitrile...heptane or an appropriate oil or fat. (c)...

2012-04-01

196

21 CFR 181.32 - Acrylonitrile copolymers and resins.  

Code of Federal Regulations, 2011 CFR

... PRIOR-SANCTIONED FOOD INGREDIENTS Specific Prior-Sanctioned Food Ingredients § 181.32 Acrylonitrile...used with fresh fruits, vegetables, and fish. (iii) Acrylonitrile...heptane or an appropriate oil or fat. (c)...

2011-04-01

197

Species differences in metabolism of 1,3-butadiene  

SciTech Connect

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.

Henderson, R.F.

1995-02-01

198

Stereochemical aspects of styrene biotransformation  

Microsoft Academic Search

Urine of rats dosed with styrene (240 mg\\/kg), R-, S- and racemic styrene oxide (150 mg\\/kg) was analysed for mandelic acid enantiomers and for regioisomers and diastereomers of mercapturic acids by NMR spectrometry. Enantiomers of mandelic acid were converted to diastereomeric Mosher's derivatives prior to analysis. R- and S-styrene oxide yielded predominantly R- and S-mandelic acid, respectively, racemic styrene oxide

Igor Linhart; Jaroslav Šmejkal; Ivana Mládková

1998-01-01

199

SOURCE ASSESSMENT: ACRYLONITRILE MANUFACTURE (AIR EMISSIONS)  

EPA Science Inventory

The report gives results of an analysis of atmospheric emissions from propylene-based acrylonitrile manufacturing plants. Uncontrolled and controlled emission factors are given for each species emitted to the atmosphere from each source within a typical plant, based on field samp...

200

EVALUATION OF THE POTENTIAL CARCINOGENICITY OF ACRYLONITRILE  

EPA Science Inventory

Acrylonitrile is a probable human carcinogen, classified as weight-of-evidence Group Bl under the EPA Guidelines for Carcinogen Risk Assessment. vidence, on potential carcinogenicity from animal studies is "Sufficient," and the evidence from human studies is @'Limited." he potenc...

201

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

PubMed

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)(?(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

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

2015-04-24

202

Improved Dipole Moments for Acrylonitrile and Propionitrile  

NASA Astrophysics Data System (ADS)

Previous determinations of the electric dipole moment of acrylonitrile, while in agreement on the total dipole moment, showed an appreciable difference in the value of the smaller ?_b component. The value of this component is important for intensity considerations in the THz spectrum of this molecule, which is dominated by b-type transitions. We decided to update the dipole moment determination of acrylonitrile, and also of propionitrile (ethyl cyanide) by making Stark measurements in supersonic expansion. We used the Stark electrode arrangement developed in our laboratory and the program QSTARK for fitting Stark measurements on resolved nuclear quadrupole hyperfine structure. The results for acrylonitrile show a further, significant difference in the value of ?_b, while those for propionitrile, while more precise, are essentially consistent with previous values. The evidence from ab initio calculations and from relative intensity measurements supporting the current dipole moment determinations is presented. W.S.Wilcox, J.H.Goldstein, J.W.Simmons, J.Chem.Phys., 22, 516 (1954) M.Stolze, D.H.Sutter, Z.Naturforsch., 40a, 998 (1985) Z.Kisiel, L.Pszczó?kowski, B.J.Drouin, C.S.Brauer, S.Yu, J.C.Pearson, J. Mol. Spectrosc. 258, 26 (2009). Z.Kisiel, J.Kosarzewski, B.A.Pietrewicz, L.Pszczó?kowski, Chem.Phys.Lett. 325, 523 (2000). H.M.Heise, H.Lutz, H.Dreizler, Z.Naturforsch., 29a, 1345 (1974)

Kisiel, Zbigniew; Kra?nicki, Adam

2011-06-01

203

Selective real-time measurement of styrene vapor using a surface-acoustic-wave sensor with a regenerable organoplatinum coating.  

PubMed

The performance of a coated surface-acoustic-wave (SAW) sensor for monitoring styrene vapor is investigated. The effects of several organic co-contaminants and atmospheric humidity are described, and regeneration of the sensor coating is demonstrated. The dual-SAW delay-line oscillator employs a reagent coating of trans-PtCl2(ethylene)(pyridine) to trap styrene via ethylene substitution. The rate of change of the sensor frequency is used to provide real-time measurement of styrene vapor concentrations. No effect on the response to styrene is observed upon simultaneous exposure to each of several olefin and non-olefin solvent vapors used with styrene in industrial processes. Butadiene, however, presents a reversible negative interference by successfully competing with styrene for reaction with the trapping agent. The response to styrene exhibits a moderate positive humidity dependence. Following prolonged exposure, the original complex can be regenerated in situ by exposure to ethylene gas, permitting repeated use of the sensor. An emphasis is placed on the application of the sensor to workplace air monitoring. PMID:2372126

Zellers, E T; Hassold, N; White, R M; Rappaport, S M

1990-07-01

204

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...

205

1,3-Butadiene: I. Review of metabolism and the implications to human health risk assessment.  

PubMed

1,3-Butadiene (BD) is a multisite carcinogen in laboratory rodents following lifetime exposure, with mice demonstrating greater sensitivity than rats. In epidemiology studies of men in the styrene-butadiene rubber industry, leukemia mortality is associated with butadiene exposure, and this association is most pronounced for high-intensity BD exposures. Metabolism is an important determinant of BD carcinogenicity. BD is metabolized to several electrophilic intermediates, including epoxybutene (EB), diepoxybutane (DEB), and epoxybutane diol (EBD), which differ considerably in their genotoxic potency (DEB >> EB > EBD). Important species differences exist with respect to the formation of reactive metabolites and their subsequent detoxification, which underlie observed species differences in sensitivity to the carcinogenic effects of BD. The modes of action for human leukemia and for the observed solid tumors in rodents are both likely related to the genotoxic potencies for one or more of these metabolites. A number of factors related to metabolism can also contribute to nonlinearity in the dose-response relationship, including enzyme induction and inhibition, depletion of tissue glutathione, and saturation of oxidative metabolism. A quantitative risk assessment of BD needs to reflect these species differences and sources of nonlinearity if it is to reflect the current understanding of the disposition of BD. PMID:20868266

Kirman, Christopher R; Albertini, Richard J; Sweeney, Lisa M; Gargas, Michael L

2010-10-01

206

Uptake, Disposition, and Persistence of Acrylonitrile in Rainbow Trout  

Microsoft Academic Search

Uptake, Disposition, and Persistence of Acrylonitrile in Rainbow Trout, Lech, J. J., Waddell, W. J., Friedman, M. A., and Johnson, L. R. (1995). Fundam. Appl. Toxicol. 27, 291-294.The uptake and disposition of [2,3-14C]acrylonitrile-derived 14 C were studied in rainbow trout by water exposure. Trout were exposed to [14C]ACN at 5.3 ?g\\/liter and sampled at various times during a 24-hr uptake

John J. Lech; William J. Waddell; Marvin A. Friedman; Lawrence Johnson

1995-01-01

207

Biological Monitoring of Styrene: A Review  

Microsoft Academic Search

Recent literature about the biological monitoring of styrene-exposed workers is reviewed. Styrene primarily exhibits its toxicity on the central and peripheral nervous systems, although its mutagenicity and chromosome damaging ability also may be relevant. Uptake, transformation and excretion of styrene show that beside the usual biological indicators, such as urinary mandelic and phenylglyoxylic acids (main metabolites), other indicators also may

M. P. GUILLEMIN; M. BERODE

1988-01-01

208

Mechanism of Selective Ammoxidation of Propene to Acrylonitrile on Bismuth Molybdates from Quantum Mechanical Calculations  

E-print Network

Mechanism of Selective Ammoxidation of Propene to Acrylonitrile on Bismuth Molybdates from Quantum ammoxidation of propene to acrylonitrile by bismuth molybdates, we report quantum mechanical studies (using stages of this industry, acrylonitrile was produced by propene on simple bismuth and molybdenum oxide

Goddard III, William A.

209

Assessment of 1,3-butadiene exposure in polymer production workers using HPRT mutations in lymphocytes as a biomarker.  

PubMed Central

1,3-Butadiene (BD), which is used to make styrene-butadiene rubber, is a potent carcinogen in mice and a probable carcinogen, associated with leukemia, in humans. We have previously used HPRT mutation as a biomarker to evaluate exposures to BD in a monomer production plant. We now report on a study of 49 workers in a styrene-butadiene rubber plant in which we used the concentration of the BD metabolite 1,2-dihydroxy-4-(N-acetylcysteinyl-S)-butane (M1) in urine as a biomarker of exposure and the frequency of HPRT variant (mutant) lymphocytes (Vf) as a biomarker of effect. Workers were assigned to high- and low-exposure groups based on historical information about work areas and jobs. Personal exposure to BD for one work shift was measured using a passive badge dosimeter. Each participant provided a urine specimen and blood sample at the end of the work shift and completed a questionnaire providing information on lifestyle, health, and work activities. The average BD exposures in the high- and low-exposure groups were significantly different, even after excluding two extreme values, (high 1.48 ppm; low 0.15 ppm, p < 0.002). This study was done in 1994 and 1995 before the establishment, in 1996, of the new permissible exposure limit of 1 ppm. Both the mean M1 and the HPRT Vf were more than three times greater in the high-exposure group than in the low-exposure group (p < 0.0005). The three end points correlated with each other, with sample correlation coefficients between 0.4 and 0.6. The correlations among BD exposure and the biomarkers of internal exposure and genotoxicity suggest that occupational exposure to BD, in the range of 1-3 ppm, may be associated with adverse biological effects. PMID:11748032

Ammenheuser, M M; Bechtold, W E; Abdel-Rahman, S Z; Rosenblatt, J I; Hastings-Smith, D A; Ward, J B

2001-01-01

210

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

NASA Astrophysics Data System (ADS)

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

Jayasree, T. K.; Manuvel, Jayan

2013-06-01

211

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

PubMed

Morphology and vulcanizate properties of EPDM/SBR blends were investigated. AAHR (a mixture of aliphatic and aromatic hydrocarbon resins) was used as a compatibilizer and bis(3-triethoxysilylpropyl)tetrasulfide (TESPT) was used as a coupling agent. The vulcanizate properties and the morphological studies revealed that EPDM and SBR were incompatible, and the addition of AAHR was very effective to enhance the compatibility between EPDM and SBR. The weight percent of bound rubbers was increased with increasing SBR contents. The addition of an AAHR increased the amounts of bound rubbers, and hence the vulcanizate properties such as tear strength and fatigue resistance of the EPDM/SBR blends were improved. The dynamic mechanical analysis and the morphological studies revealed that the addition of TESPT increased the weight of bound rubbers and provided better dispersion of carbon black, resulting in good mechanical properties such as tear strength and fatigue resistance of the vulcanized EPDM/SBR blends. The smaller particle of zinc oxide (i.e., 50 nm > 100 nm > 1000 nm) yielded to the better blending properties of the polymer blend. PMID:20359035

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

2010-05-01

212

Styrene metabolism in Exophiala jeanselmei and involvement of a cytochrome P-450-dependent styrene monooxygenase.  

PubMed Central

The yeast-like fungus Exophiala jeanselmei degrades styrene via initial oxidation of the vinyl side chain to phenylacetic acid, which is subsequently hydroxylated to homogentisic acid. The initial reactions are catalyzed by a NADPH- and flavin adenine dinucleotide-dependent styrene monooxygenase, a styrene oxide isomerase, and a NAD(+)-dependent phenylacetaldehyde dehydrogenase. The reduced CO-difference spectrum of microsomal preparations of styrene-grown cells shows a characteristic absorption maximum at 450 nm, which strongly suggests the involvement of a cytochrome P-450-dependent styrene monooxygenase. Inhibition of styrene monooxygenase activity in cell extracts by cytochrome P-450 inhibitors SKF-525-A, metyrapone, and CO confirms this assumption. PMID:8919815

Cox, H H; Faber, B W; Van Heiningen, W N; Radhoe, H; Doddema, H J; Harder, W

1996-01-01

213

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

NASA Astrophysics Data System (ADS)

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.

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

2014-10-01

214

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

PubMed

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

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

2014-07-14

215

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

Code of Federal Regulations, 2011 CFR

...2011-10-01 false Butadiene or vinyl chloride: Refrigeration system. 154.1750 Section 154.1750...154.1750 Butadiene or vinyl chloride: Refrigeration system. A refrigeration system for butadiene or vinyl chloride...

2011-10-01

216

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

Code of Federal Regulations, 2012 CFR

...2012-10-01 false Butadiene or vinyl chloride: Refrigeration system. 154.1750 Section 154.1750...154.1750 Butadiene or vinyl chloride: Refrigeration system. A refrigeration system for butadiene or vinyl chloride...

2012-10-01

217

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

Code of Federal Regulations, 2013 CFR

...2013-10-01 false Butadiene or vinyl chloride: Refrigeration system. 154.1750 Section 154.1750...154.1750 Butadiene or vinyl chloride: Refrigeration system. A refrigeration system for butadiene or vinyl chloride...

2013-10-01

218

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

Code of Federal Regulations, 2014 CFR

...2014-10-01 false Butadiene or vinyl chloride: Refrigeration system. 154.1750 Section 154.1750...154.1750 Butadiene or vinyl chloride: Refrigeration system. A refrigeration system for butadiene or vinyl chloride...

2014-10-01

219

IRIS Toxicological Review of Acrylonitrile (2011 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...

220

Review and meta-analysis of studies of acrylonitrile workers.  

PubMed

Twenty-five epidemiologic studies of acrylonitrile workers were reviewed and subjected to meta-analytic techniques in this study to assess the findings for 10 cancer sites. The analyses indicate that workers with acrylonitrile exposure have essentially null findings for most cancers, including lung [meta-relative risk (mRR) 0.9, 95% confidence interval (95% CI) 0.9-1.1], brain (mRR 1.2, 95% CI 0.8-1.7), and prostate (mRR 1.0, 95% CI 0.7-1.4) cancers. Bladder cancer rates were elevated (mRR 1.8, 95% CI 1.0-3.4), but the excess was not dose-related and was limited to plants with aromatic amines. Therefore, the bladder cancer excess is unlikely to be related to acrylonitrile exposure. Some evidence of publication bias was found in the examined literature, but the bias did not have a significant impact on risk estimates for individual cancers. It was concluded that the available studies do not support a causal relation between acrylonitrile exposure and cancer. PMID:9714515

Collins, J J; Acquavella, J F

1998-01-01

221

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...

222

40 CFR Appendix Vii to Part 261 - Basis for Listing Hazardous Waste  

Code of Federal Regulations, 2010 CFR

...3-butadiene, hexachloro-1,3-butadiene, hexachlorocyclopentadiene...Dichloropropene; 2-Chloro-1,3-butadiene; Hexachloro-1,3-butadiene; Hexachlorocyclopentadiene...chloroacetaldehyde. K011 Acrylonitrile, acetonitrile,...

2010-07-01

223

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

Code of Federal Regulations, 2014 CFR

...false Modified styrene, divinylbenzene polymer (generic). 721.10151 Section...10151 Modified styrene, divinylbenzene polymer (generic). (a) Chemical substance...generically as modified styrene, divinylbenzene polymer (PMN P-07-642) is subject to...

2014-07-01

224

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

Code of Federal Regulations, 2012 CFR

...false Modified styrene, divinylbenzene polymer (generic). 721.10151 Section...10151 Modified styrene, divinylbenzene polymer (generic). (a) Chemical substance...generically as modified styrene, divinylbenzene polymer (PMN P-07-642) is subject to...

2012-07-01

225

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

Code of Federal Regulations, 2013 CFR

...false Modified styrene, divinylbenzene polymer (generic). 721.10151 Section...10151 Modified styrene, divinylbenzene polymer (generic). (a) Chemical substance...generically as modified styrene, divinylbenzene polymer (PMN P-07-642) is subject to...

2013-07-01

226

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

Code of Federal Regulations, 2010 CFR

...false Modified styrene, divinylbenzene polymer (generic). 721.10151 Section...10151 Modified styrene, divinylbenzene polymer (generic). (a) Chemical substance...generically as modified styrene, divinylbenzene polymer (PMN P-07-642) is subject to...

2010-07-01

227

High Concentrations of Butadiene Epoxides in Livers and Lungs of Mice Compared to Rats Exposed to 1,3Butadiene  

Microsoft Academic Search

1,3-Butadiene (BD) is carcinogenic in B6C3F1 mice and Sprague-Dawley rats, and mice are more sensitive than rats. This study measured the concentrations of the putative DNA-reactive BD metabolites, butadiene monoxide (BMO) and butadiene diepoxide (BDE), in lung and liver of male Sprague-Dawley rats and B6C3F1 mice exposed to BD by inhalation. Samples (n = 3-6) of lung and liver were

M. W. Himmelstein; B. Asgharian; J. A. Bond

1995-01-01

228

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

PubMed

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 1,3-butadiene, with the deadline for compliance being brought forward to 31/12/2003. The UK Hydrocarbon Monitoring Network provides continuous hourly measurements of 1,3-butadiene at 13 sites, and has been operational since 1993. The dataset that is available allows spatial and temporal trends to be evaluated, and has proved to be invaluable in characterising the current ambient levels of 1,3-butadiene in the UK. Hourly maximum concentrations of 1,3-butadiene of up to 10 ppb (1 ppb=1 ppb, i.e. 1 vol. of 1,3-butadiene in 1,000,000,000 vol. of air. 1 ppb of 1,3-butadiene is ca. equal to 2.25 microg m(-3) at 20 degrees C) may be measured for several hours at the sites. Monthly mean concentrations are typically 0.1-0.4 ppbv. At most sites, these levels are driven by emissions from motor vehicles. Occasionally emissions of 1,3-butadiene from industrial sources may elevate 1,3-butadiene concentrations to several tens of ppb. Trend analysis of the data suggests that ambient concentrations of 1,3-butadiene in the UK are declining at about 10% per year. PMID:11397390

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

2001-06-01

229

Analysis of butadiene, butadiene monoxide, and butadiene dioxide in blood by gas chromatography/gas chromatography/mass spectroscopy.  

PubMed

A new method was developed to quantify the levels of 1,3-butadiene (BD), butadiene monoxide (BDO), and butadiene diepoxide (BDO2) in blood. The method was based on vacuum distillation of tissues followed by analysis of the distillates using multidimensional GC/MS. Metabolites isolated from blood by vacuum distillation were condensed into a cold trap. After warming the traps to room temperature, BD and BDO were sampled from the trap vapor phase. BDO2 was extracted from the codistilled water phase using ethyl acetate. Samples were analyzed using a multidimensional GC system equipped with a custom-built interface. The method was validated by analysis of 0.75-mL aliquots of mouse blood spiked with 5.0, 3.4, and 0.55 nmol of BD, BDO, and BDO2, respectively. The recoveries of analytes were 96 +/- 18%, 125 +/- 15%, and 98 +/- 12%, respectively (mean +/- SD, n = 6). Kinetic studies indicated no loss of BDO and BDO2 in blood held at room temperature in closed containers for up to 1 h. The method was applied to blood samples from B6C3F1 mice and Sprague-Dawley rats exposed by inhalation (nose-only) to 100 ppm BD for 4 h. Blood levels of BD and BDO in exposed rats were 4.1 +/- 1.0 and 0.10 +/- 0.06 microM, respectively (mean +/- SD, n = 6). Levels of BDO2 were below the limits of detection (0.01 nmol/mL). Blood levels of BD, BDO, and BDO2 in mice exposed to 100 ppm BD for 4 h were 2.9 +/- 1.3, 0.38 +/- 0.14, and 0.33 +/- 0.19 microM, respectively (mean +/- SD, n = 6).(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7766800

Bechtold, W E; Strunk, M R; Thornton-Manning, J R; Henderson, R F

1995-03-01

230

Assessment of exposure to butadiene in the process industry  

Microsoft Academic Search

Occupational exposure levels to 1,3-butadiene (BD) are variable but generally below 1 ppm in the European process industry. A preliminary analysis showed that hemoglobin adduct levels of butadiene monoxide (BMO) were increased among the worker groups with higher potential exposure to BD (process work, bomb voiding, repair duties) than among less exposed workers in maintenance and laboratory or control persons.

M. Sorsa; S. Osterman-Golkar; K. Peltonen; S. T. Saarikoski; R. Šram

1996-01-01

231

Butadiene from acetylene-ethylene cross-metathesis.  

PubMed

Acetylene to butadiene direct synthesis, via enyne cross-metathesis, is demonstrated with commercial ruthenium carbene catalysts. Using excess of ethylene, yields greater than 50% are obtained. High activity is observed in the first minute of the reaction (TOF > 800 h(-1) based on butadiene). Catalyst reusability and poisoning are discussed. PMID:25811306

Trotu?, Ioan-Teodor; Zimmermann, Tobias; Duyckaerts, Nicolas; Geboers, Jan; Schüth, Ferdi

2015-04-01

232

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...

233

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...

234

Styrene  

MedlinePLUS

... of Information Act Office of Inspector General Web Policies & Notices Contact Us Department of Health & Human Services USA.gov National Institute of Environmental Health Sciences 111 T.W. Alexander Drive Research Triangle Park, ...

235

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

NASA Astrophysics Data System (ADS)

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

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

2014-04-01

236

Preparation and characterization of magnetic thermoplastic-based nanocomposites  

NASA Astrophysics Data System (ADS)

We developed a facile method for the preparation of magnetic nanocomposites based on the popular thermoplastic, acrylonitrile butadiene styrene (ABS). The nanocomposites were produced by liquid blending of ABS and Ni nanorods (NRs), followed by solvent evaporation. The characterizations showed that the nanocomposites were magnetic and Ni NRs were uniformly distributed in polymer matrix.

Thu, T. V.; Takamura, T.; Tsetserukou, D.; Sandhu, A.

2014-02-01

237

Effect of molecular weight between cross-links on the abrasion behavior of rubber by a blade abrader  

Microsoft Academic Search

The effect of molecular weight between cross-links on the abrasion behavior of rubber was investigated using acrylonitrile–butadiene rubber (NBR), styrene–butadiene rubber (SBR), and natural rubber (NR) with a blade abrader. The rate of abrasion was found to be almost constant irrespective of the cross-link density of rubber at low frictional input work, whereas it decreased to a minimum and increased

Kilwon Cho; Daeho Lee

2000-01-01

238

Styrene Purification and Recovery Using Freeze Crystallization  

E-print Network

, in place of conventional distillation columns, with substantial reductions in energy consumption. The impact on plant energy balances for a typical styrene plant will be presented, along with the results from lab testing....

Heist, J. A.; Wrobel, P. J.

239

Effect of mixing on polymerization of styrene  

E-print Network

on Polymerization of Styrene. (August 1977) Michael Norris Treybig, B. S, , Texas Tech University Chairman of Advisory Committee: Dr. R. G. Anthony Styrene was polymerized in a 50 ml bench scale constant flow stirred tank reactor (CFSTR). The polymerization... degrees of mixing in the reactor. To simulate the performance of the laboratory reactor and to determine the effect of mixing on the molecular weight distribution (MWD), mathematical models were developed based on the concepts of micromixing and total...

Treybig, Michael Norris

1977-01-01

240

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

SciTech Connect

Highlights: •Cytochrome c peroxidase (CcP) binds acrylonitrile in a pH-independent fashion. •The spectrum of the CcP/acrylonitrile complex is that of a 6c–ls ferric heme. •The acrylonitrile/CcP complex has a K{sub D} value of 1.1 ± 0.2 M. •CcP compound I oxidizes acrylonitrile with a maximum turnover rate of 0.61 min{sup ?1}. -- Abstract: Ferric heme proteins bind weakly basic ligands and the binding affinity is often pH dependent due to protonation of the ligand as well as the protein. In an effort to find a small, neutral ligand without significant acid/base properties to probe ligand binding reactions in ferric heme proteins we were led to consider the organonitriles. Although organonitriles are known to bind to transition metals, we have been unable to find any prior studies of nitrile binding to heme proteins. In this communication we report on the equilibrium and kinetic properties of acrylonitrile binding to cytochrome c peroxidase (CcP) as well as the oxidation of acrylonitrile by CcP compound I. Acrylonitrile binding to CcP is independent of pH between pH 4 and 8. The association and dissociation rate constants are 0.32 ± 0.16 M{sup ?1} s{sup ?1} and 0.34 ± 0.15 s{sup ?1}, respectively, and the independently measured equilibrium dissociation constant for the complex is 1.1 ± 0.2 M. We have demonstrated for the first time that acrylonitrile can bind to a ferric heme protein. The binding mechanism appears to be a simple, one-step association of the ligand with the heme iron. We have also demonstrated that CcP can catalyze the oxidation of acrylonitrile, most likely to 2-cyanoethylene oxide in a “peroxygenase”-type reaction, with rates that are similar to rat liver microsomal cytochrome P450-catalyzed oxidation of acrylonitrile in the monooxygenase reaction. CcP compound I oxidizes acrylonitrile with a maximum turnover number of 0.61 min{sup ?1} at pH 6.0.

Chinchilla, Diana, E-mail: Diana_Chinchilla@yahoo.com; Kilheeney, Heather, E-mail: raindropszoo@yahoo.com; Vitello, Lidia B., E-mail: lvitello@niu.edu; Erman, James E., E-mail: jerman@niu.edu

2014-01-03

241

Photodegradation mechanisms of tetraphenyl butadiene coatings for liquid argon detectors  

E-print Network

We report on studies of degradation mechanisms of tetraphenyl butadiene (TPB) coatings of the type used in neutrino and dark matter liquid argon experiments. Using gas chromatography coupled to mass spectrometry we have ...

Jones, Benjamin James Poyner

242

MTBE from butadiene-rich C/sub 4/s  

SciTech Connect

Methyl tert-butyl ether (MTBE), is made by reacting methanol with isobutylene. The preferred source of isobutylene is a steam cracker C/sub 4/ cut from which butadiene has been removed. However, moving the MTBE synthesis upstream of the butadiene extraction will improve the extraction step. The following is a review of conditions imposed on the MTBE unit's design and operation when placed in this new location.

Ancillotti, F.; Pescarollo, E.; Szatmari, E.; Lazar, L.

1987-12-01

243

Aspects of the synthesis of poly(styrene-b-isobutylene-b-styrene) block copolymer  

SciTech Connect

Poly(styrene-b-isobutylene-b-styrene) block copolymers were synthesized by the addition of a solution of styrene to living polyisobutylene chains produced from a dicumyl chloride/TiCl{sub 4}/pyridine initiating system. The effect of the time of the styrene addition was investigated with respect to product polymer composition. Styrene addition at an isobutylene reaction time far exceeding the time necessary for complete isobutylene consumption was found to result in a very rapid polymerization of styrene, some of which was blocked properly and some of which was not. Conversely, premature addition of styrene (at intermediate isobutylene conversion) resulted in retardation of the polymerization and possible creation of a transitional random copolymer block. The appropriate time for styrene addition seems to be at an isobutylene conversion which corresponds to the point of departure from linearity of a plot of {minus}ln1{minus}(DP{sub n}[I]{sub o}/[M]{sub o}) vs time. Linearity of this plot ensures the absence of chain transfer and termination, and for the isobutylene polymerization system under investigation, the point of departure from linearity has been determined to be an approximately 90% conversion.

Storey, R.F.; Chisholm, B.J. [Univ. of Southern Mississippi, Hattiesburg, MI (United States)

1993-12-31

244

Incorporation of carbon nanotubes into the biomedical polymer poly(styrene-?-isobutylene-?-styrene)  

Microsoft Academic Search

Poly(styrene-?-isobutylene-?-styrene) (SIBS) is a block copolymer that has been used extensively as a coating for medical devices in which it acts as a carrier for therapeutics. In this study the incorporation of carbon nanotubes (CNTs) into SIBS coatings was investigated as a means of modifying both the electrical conductivity and the surface characteristics of the SIBS coatings in order to

Kerry J. Gilmore; Simon E. Moulton; Gordon G. Wallace

2007-01-01

245

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

SciTech Connect

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

Matsumoto, Morihiko; Ichino, Toshihiro; Rutt, J.S.; Nishi, Shiro (Nippon Telegraph and Telephone Corp., Tokyo (Japan). NTT Interdisciplinary Research Lab.)

1993-10-01

246

Occupational exposure of workers to 1,3-butadiene.  

PubMed Central

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

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

1990-01-01

247

Occupational exposure of workers to 1,3-butadiene.  

PubMed

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

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

1990-06-01

248

Degradation of chlorinated butenes and butadienes in granular iron columns.  

PubMed

Manufacturing facilities for production of chlorobutyl rubber have the potential to release a mixture of at least 5 chlorinated butenes and butadienes including trans-1,4-dichlorobutene-2 (1,4-DCB-2), 3,4-dichlorobutene-1 (3,4-DCB-1), 2,3,4-trichlorobutene-1 (TCB), 2-chlorobutadiene-1,3 (chloroprene) and 2,3-dichlorobutadiene-1,3 (DCBD) into groundwater environment. To evaluate the potential of using granular iron in the remediation of the above contaminants, a series of column experiments were conducted. Degradation of all 5 compounds followed pseudo-first-order kinetics. The three chlorinated butenes degraded much faster (surface area normalized half-lives, t(1/2)', ranged from 1.6 to 5.2 min m2/mL) than the 2 chlorinated butadienes (t(1/2)' ranged from 102 to 197 min m2/mL). All contaminants fully dechlorinated by granular iron to 1,3-butadiene as a common reaction intermediate that then degraded to a mixture of relatively non-harmful end products consisting of 1-butene, cis-2-butene, trans-2-butene and n-butane. Based on the kinetic data, product distributions, and chlorine mass balances, reaction pathways for these compounds are proposed. For the chlorinated butenes, 3,4-DCB-1 and TCB, undergo reductive beta-elimination reactions resulting in 1,3-butadiene and chloroprene intermediates. Dechlorination of 1,4-DCB-2 to 1,3-butadiene occurs through a reductive elimination similar to reductive beta-elimination. For dechlorination of the two chlorinated butadienes, chloroprene and DCBD, dechlorination occurs through a hydrogenolysis pathway. The common non-chlorinated intermediate, 1,3-butadiene, undergoes catalytic hydrogenation resulting in a mixture of butane isomers and n-butane. The results suggest that granular iron is an effective material for treatment of groundwater contaminated with these compounds. PMID:19847707

Hughes, Rodney; Gui, Lai; Gillham, Robert W

2009-10-01

249

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

PubMed Central

Ferric heme proteins bind weakly basic ligands and the binding affinity is often pH dependent due to protonation of the ligand as well as the protein. In an effort to find a small, neutral ligand without significant acid/base properties to probe ligand binding reactions in ferric heme proteins we were led to consider the organonitriles. Although organonitriles are known to bind to transition metals, we have been unable to find any prior studies of nitrile binding to heme proteins. In this communication we report on the equilibrium and kinetic properties of acrylonitrile binding to cytochrome c peroxidase (CcP) as well as the oxidation of acrylonitrile by CcP compound I. Acrylonitrile binding to CcP is independent of pH between pH 4 and 8. The association and dissociation rate constants are 0.32 ± 0.16 M?1s?1 and 0.34 ± 0.15 s?1, respectively, and the independently measured equilibrium dissociation constant for the complex is 1.1 ± 0.2 M. We have demonstrated for the first time that acrylonitrile can bind to a ferric heme protein. The binding mechanism appears to be a simple, one-step association of the ligand with the heme iron. We have also demonstrated that CcP can catalyze the oxidation of acrylonitrile, most likely to 2-cyanoethylene oxide in a “peroxygenase”-type reaction, with rates that are similar to rat liver microsomal cytochrome P450-catalyzed oxidation of acrylonitrile in the monooxygenase reaction. CcP compound I oxidizes acrylonitrile with a maximum turnover number of 0.61 min?1 at pH 6.0. PMID:24291498

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

2013-01-01

250

21 CFR 177.1820 - Styrene-maleic anhydride copolymers.  

Code of Federal Regulations, 2011 CFR

...Specifications: Styrene-maleic copolymers Molecular weight (minimum number average) Residual styrene...prescribed in this section are as follows: (1) Molecular weight. Molecular weight shall be determined by membrane...

2011-04-01

251

21 CFR 177.1820 - Styrene-maleic anhydride copolymers.  

Code of Federal Regulations, 2010 CFR

...Specifications: Styrene-maleic copolymers Molecular weight (minimum number average) Residual styrene...prescribed in this section are as follows: (1) Molecular weight. Molecular weight shall be determined by membrane...

2010-04-01

252

21 CFR 177.1820 - Styrene-maleic anhydride copolymers.  

Code of Federal Regulations, 2013 CFR

...Specifications: Styrene-maleic copolymers Molecular weight (minimum number average) Residual styrene...prescribed in this section are as follows: (1) Molecular weight. Molecular weight shall be determined by membrane...

2013-04-01

253

21 CFR 177.1820 - Styrene-maleic anhydride copolymers.  

Code of Federal Regulations, 2012 CFR

...Specifications: Styrene-maleic copolymers Molecular weight (minimum number average) Residual styrene...prescribed in this section are as follows: (1) Molecular weight. Molecular weight shall be determined by membrane...

2012-04-01

254

BIOMARKERS IN CZECH WORKERS EXPOSED TO 1,3-BUTADIENE: A TRANSITIONAL EPIDEMIOLOGIC STUDY  

EPA Science Inventory

All the biomarkers of exposure were correlated with the measurements of butadiene recorded by the air samplers. Although the correlation between hemoglobin adducts and exposure levels was strongest, urinary metabolites were also found to be very useful measures of butadiene...

255

Morphologies in Sulfonated Styrenic Pentablock Copolymer Membranes  

NASA Astrophysics Data System (ADS)

Membranes of pentablock and triblock copolymers consisting of poly(tert-butyl styrene) (TBS), hydrogenated polyisoprene (HI), and partially sulfonated poly(styrene-ran-styrene sulfonate) (SS) were studied using small angle X-ray scattering (SAXS) and transmission electron microscopy (TEM). The TBS-HI-SS-HI-TBS pentablock and TBS-HI-SS triblock copolymer membranes exhibit anisotropic microphase separated morphologies. Because the pentablock and triblock copolymers can be expected to have complex morphologies, thermal annealing was conducted to promote well-defined morphologies. The annealed membranes exhibit stronger peaks and more high order reflections in SAXS patterns, as well as better defined microstructures in the TEM. Electron microcopy studies with various staining protocols are underway to establish the morphology of the pentablock copolymer membranes including the size and shape of the three microdomains (TBS, HI and SS). We gratefully acknowledge Kraton Polymers, Inc. for materials.

Choi, Jae-Hong; Bramson, Matt; Winey, Karen I.

2010-03-01

256

Styrene-induced hepatotoxicity in mice depleted of glutathione.  

PubMed

In mice depleted of glutathione (GSH) by pretreatment with an inhibitor of GSH synthesis, buthionine sulfoximine (BSO; 1 hr before styrene, 2 mmol/kg or higher doses, ip), styrene (0.96-5.76 mmol/kg, po) produced hepatotoxicity characterized by an increase in serum alanine transaminase activity and cetrilobular necrosis of hepatocytes. Treatment with inhibitors of hepatic cytochrome P-450-dependent monooxygenases such as carbon disulfide, methoxsalen, piperonyl butoxide, and SKF-525A prevented or tended to reduce the hepatotoxic effect of styrene given in combination with BSO. Styrene 7,8-oxide (3.84 mmol/kg, po), a known metabolite of styrene, in combination with BSO caused an earlier and larger increase in SALT than that caused by an equimolar dose of styrene in combination with BSO. These results suggest that metabolism of styrene, possibly to styrene 7,8-oxide, is a necessary step in styrene-induced hepatotoxicity in GSH-depleted mice. Before the onset of hepatotoxicity, styrene in combination with BSO produced a larger and more prolonged depletion of hepatic GSH than that seen after the sole treatment with BSO or prolonged depletion of hepatic GSH than that seen after the sole treatment with BSO or styrene, but no depletion of hepatic protein sulfhydryls was induced by styrene in combination with BSO. PMID:7712112

Mizutani, T; Irie, Y; Nakanishi, K

1994-12-01

257

Influence of occupational styrene exposure on memory and attention  

SciTech Connect

Short-term memory, perceptual speed, attention and psychomotor function were studied in 55 workers professionally exposed to styrene. The subjects were grouped according to their urinary styrene metabolites. Those with higher styrene exposure showed a significant impairment of short-term memory only.

Schoenhuber, R.; Gentilini, M. (Universita degli Studi, Modena (Italy))

1989-11-01

258

Neurobehavioral effects of acute styrene exposure in fiberglass boatbuilders  

Microsoft Academic Search

A field investigation of the effects of acute exposure to styrene among fiberglass boatbuilders was performed. Personal samples of styrene in breathing zone air and postshift urinary mandelic acid were collected for 105 workers exposed and not exposed to styrene in 6 fiberglass boatbuilding companies in New England. Three tests from the computerized Neurobehavioral Evaluation System (NES) were performed by

R. Letz; F. C. Mahoney; D. L. Hershman; S. Woskie; T. J. Smith

1990-01-01

259

The Iodochlorination of Styrene: An Experiment that Makes a Difference  

ERIC Educational Resources Information Center

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

Amiet, R. Gary; Urban, Sylvia

2008-01-01

260

Sulfonation and characterization of poly(styrene-isobutylene-styrene) triblock copolymers at high ion-exchange capacities  

Microsoft Academic Search

In this study, a triblock copolymer, poly(styrene-isobutylene-styrene), was sulfonated to eight different levels ranging from 0.36 to 2.04mequiv.\\/g (13 to 82mol% of styrene; styrene is 19mol% of the unsulfonated block copolymer). These sulfonated polymers were characterized with elemental analysis and infrared spectroscopy to confirm sulfonation and determine accurate sulfonation levels. Infrared analysis revealed four additional stretching vibrations as a result

Yossef A Elabd; Eugene Napadensky

2004-01-01

261

HEALTH ASSESSMENT DOCUMENT FOR 1,3-BUTADIENE (EXTERNAL REVIEW DRAFT)  

EPA Science Inventory

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

262

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

Code of Federal Regulations, 2014 CFR

...2014-07-01 false Measurement methods for benzene and 1,3-butadiene. 80.55 Section...Gasoline § 80.55 Measurement methods for benzene and 1,3-butadiene. (a) Sampling for benzene and 1,3-butadiene must be...

2014-07-01

263

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

Code of Federal Regulations, 2010 CFR

...2010-07-01 false Measurement methods for benzene and 1,3-butadiene. 80.55 Section...Gasoline § 80.55 Measurement methods for benzene and 1,3-butadiene. (a) Sampling for benzene and 1,3-butadiene must be...

2010-07-01

264

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

Code of Federal Regulations, 2011 CFR

...2011-07-01 false Measurement methods for benzene and 1,3-butadiene. 80.55 Section...Gasoline § 80.55 Measurement methods for benzene and 1,3-butadiene. (a) Sampling for benzene and 1,3-butadiene must be...

2011-07-01

265

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

Code of Federal Regulations, 2012 CFR

...2012-07-01 false Measurement methods for benzene and 1,3-butadiene. 80.55 Section...Gasoline § 80.55 Measurement methods for benzene and 1,3-butadiene. (a) Sampling for benzene and 1,3-butadiene must be...

2012-07-01

266

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

Code of Federal Regulations, 2013 CFR

...2013-07-01 false Measurement methods for benzene and 1,3-butadiene. 80.55 Section...Gasoline § 80.55 Measurement methods for benzene and 1,3-butadiene. (a) Sampling for benzene and 1,3-butadiene must be...

2013-07-01

267

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

Federal Register 2010, 2011, 2012, 2013, 2014

...EPA-HQ-OPP-2010-0033; FRL-8827-4] 2-Propenoic acid polymer, with 1,3-butadiene and ethenylbenzene...tolerance for residues of 2-propenoic acid polymer, with 1,3- butadiene and ethenylbenzene...permissible level for residues of 2-propenoic acid polymer, with 1,3-butadiene and...

2010-06-04

268

Vapor-liquid equilibria of copolymer + solvent and homopolymer + solvent binaries: New experimental data and their correlation  

SciTech Connect

Sixty-four isothermal data sets for vapor-liquid equilibria (VLE) for polymer + solvent binaries have been obtained using a gravimetric sorption technique, in the range of 23.5--80 C. Solvents studied were acetone, acetonitrile, 1-butanol, 1,2-dichloroethane, chloroform, cyclohexane, hexane, methanol, octane, pentane, and toluene. Copolymers studied were poly(acrylonitrile-co-butadiene), poly(styrene-co-acrylonitrile), poly(styrene-co-butadiene), poly(styrene-co-butyl methacrylate), poly(vinyl acetate-co-ethylene), and poly(vinyl acetate-co-vinyl chloride). All copolymers were random copolymers. Some homopolymers were also studied: polyacrylonitrile, polybutadiene, poly(butyl methacrylate), poly(ethylene oxide), polystyrene, and poly(vinyl acetate). The composition of the copolymer may have a surprising effect on VLE. Normally, deviation from ideal behavior lies between those of the constituent homopolymers, according to the copolymer composition, as observed for cyclohexane + poly(ethylene-co-vinyl acetate) and chloroform + poly(styrene-co-butyl methacrylate). However, the strong nonideal behavior observed for systems containing hydrocarbons and poly(butadiene-co-acrylonitrile) shows that the effect of acrylonitrile is in excess of that expected form the copolymer composition. The perturbed hard-sphere chain (PHSC) equation of state was used to represent VLE of the copolymer solutions studied here.

Gupta, R.B.; Prausnitz, J.M. [Lawrence Berkeley Lab., CA (United States)

1995-07-01

269

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

Federal Register 2010, 2011, 2012, 2013, 2014

...Styrenics, LLC-Marietta Plant a Subsidiary of Americas...LP Including On-Site Leased Workers From...Styrenics LLC- Marietta plant, a subsidiary of...LLC, including on- site leased workers from...Styrenics LLC-Marietta Plant, a subsidiary of...LP, including on-site leased workers...

2010-03-02

270

SINGLE LABORATORY VALIDATION OF EPA (ENVIRONMENTAL PROTECTION AGENCY) METHOD 8030: ACROLEIN, ACRYLONITRILE, AND ACETONITRILE  

EPA Science Inventory

USEPA Method 8030 was modified and evaluated with revised chromatographic conditions for the determination of acrolein, acrylonitrile, and acetonitrile in groundwater, solid, and organic liquid matrices. Groundwater was analyzed by the heated purge-and-trap method; a solid waste ...

271

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

EPA Science Inventory

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

272

Medical applications of poly(styrene- block-isobutylene- block-styrene) (“SIBS”)  

Microsoft Academic Search

Poly(Styrene-block-IsoButylene-block-Styrene) (“SIBS”) is a biostable thermoplastic elastomer with physical properties that overlap silicone rubber and polyurethane. Initial data collected with SIBS stent-grafts and coatings on metallic stents demonstrate hemocompatibility, biocompatibility and long-term stability in contact with metal. SIBS has been used successfully as the carrier for a drug-eluting coronary stent; specifically Boston Scientific's TAXUS® stent, and its uses are being

Leonard Pinchuk; Gregory J. Wilson; James J. Barry; Richard T. Schoephoerster; Jean-Marie Parel; Joseph P. Kennedy

2008-01-01

273

Styrene exposure during the manufacturing of reinforced fiberglass pipe  

SciTech Connect

Considering the large number of employees exposed to airborne styrene during the manufacturing of reinforced fiberglass pipe and the absence of appropriate information to define airborne styrene exposure and the resulting levels of urinary mandelic acid, it was necessary that these parameters be evaluated in an actual industrial setting in order to appropriately monitor and control health hazards in the work place. Styrene measurements were collected at eight work stations over a 5-year period at the world's largest manufacturer of styrenated reinforced fiberglass pipe. Pre- and post-shift urinary mandelic acid was measured for 16 employees for 3-consecutive days. The data obtained were statistically analyzed to determine the mean styrene exposure at each work station and the relationship between airborne styrene and pre-and post-shift urinary mandelic acid. The results of this study indicated that both the pre- and post-shift urinary mandelic acid measurements can be utilized to confirm human exposure to styrene. Post-shift measurements are more reflective of daily variations in styrene exposure, whereas pre-shift urinary mandelic acid was found to correlate best to the long-term airborne styrene concentrations (r = 0.787). The prediction equations of NIOSH and ACGIH for the arithmetic mean airborne styrene concentration from post-shift mandelic acid were not valid for the low levels of styrene exposure and urinary mandelic acid concentrations found in this study. Significant changes in the post-shift to pre-shift urinary mandelic acid concentrations were observed.

Anderson, K.E.

1986-01-01

274

40 CFR Appendix A to Part 414 - Non-Complexed Metal-Bearing Waste Streams and Cyanide-Bearing Waste Streams  

Code of Federal Regulations, 2010 CFR

...propylene via acrolein Acrylonitrile/Propylene ammoxidation...Direct cyanation of butadiene Alkyl amines/Amination...Acrylic fiber (85% acrylonitrile)/Solution polymerization...and wet spinning Acrylonitrile/Ammoxidation of propylene Adiponitrile/Butadiene + Hydrogen...

2010-07-01

275

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

Technology Transfer Automated Retrieval System (TEKTRAN)

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

276

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

Technology Transfer Automated Retrieval System (TEKTRAN)

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

277

CARBOXYLATED STYRENE-BUTADIENE RUBBER COMPOSITES REINFORCED BY DEFATTED SOY FLOUR AND CARBON BLACK CO-FILLER  

Technology Transfer Automated Retrieval System (TEKTRAN)

The rubber composites reinforced by a mixture of defatted soy flour (DSF) and carbon black (CB) are investigated in terms of their dynamic shear modulus. DSF is an inexpensive and plentiful renewable material from soybean after soybean oil is removed. DSF contains soy protein and soy carbohydrate....

278

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

NASA Astrophysics Data System (ADS)

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

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

2011-01-01

279

HEALTH AND ENVIRONMENTAL EFFECTS PROFILE FOR 1,3-BUTADIENE  

EPA Science Inventory

The Health and Environmental Effects Profile for 1,3-Butadiene was prepared by the Office of Health and Environmental Assessment, Environmental Criteria and Assessment Office, Cincinnati, OH for the Office of Solid Waste to support listings of hazardous constituents of a wide ran...

280

Chemocatalytic conversion of ethanol into butadiene and other bulk chemicals.  

PubMed

The development of new and improved processes for the synthesis of bio-based chemicals is one of the scientific challenges of our time. These new discoveries are not only important from an environmental point of view, but also represent an important economic opportunity, provided that the developed processes are selective and efficient. Bioethanol is currently produced from renewable resources in large amounts and, in addition to its use as biofuel, holds considerable promise as a building block for the chemical industry. Indeed, further improvements in production, both in terms of efficiency and feedstock selection, will guarantee availability at competitive prices. The conversion of bioethanol into commodity chemicals, in particular direct 'drop-in' replacements is, therefore, becoming increasingly attractive, provided that the appropriate (catalytic) technology is in place. The production of green and renewable 1,3-butadiene is a clear example of this approach. The Lebedev process for the one-step catalytic conversion of ethanol to butadiene has been known since the 1930s and has been applied on an industrial scale to produce synthetic rubber. Later, the availability of low-cost oil made it more convenient to obtain butadiene from petrochemical sources. The desire to produce bulk chemicals in a sustainable way and the availability of low-cost bioethanol in large volumes has, however, resulted in a renaissance of this old butadiene production process. This paper reviews the catalytic aspects associated with the synthesis of butadiene via the Lebedev process, as well as the production of other, mechanistically related bulk chemicals that can be obtained from (bio)ethanol. PMID:23703747

Angelici, Carlo; Weckhuysen, Bert M; Bruijnincx, Pieter C A

2013-09-01

281

Is styrene planar in liquid phases?  

Microsoft Academic Search

The proton NMR spectra of two 13C-labeled isotopomers of styrene dissolved in two liquid crystalline solvents have been obtained and analyzed to yield four sets each of 24 dipolar couplings. These couplings were then used to investigate the structure of the ring and the ene fragments of the molecule, and the position of the maximum, phi0, in the ring-ene bond

Giorgio Celebre; Giuseppina de Luca; Marcello Longeri; Giuseppe Pileio; James W. Emsley

2004-01-01

282

Simple Replica Micromolding of Biocompatible Styrenic Elastomers†  

PubMed Central

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

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

2013-01-01

283

Simple replica micromolding of biocompatible styrenic elastomers.  

PubMed

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

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

2013-07-21

284

Exposure to styrene and mortality from nonmalignant respiratory diseases.  

PubMed Central

A cohort of 34,560 men and 6128 women employed in 660 European factories manufacturing reinforced plastic products, followed up originally to assess the risk of cancer, was used to assess the risk of non-malignant respiratory diseases associated with exposure to styrene. Mortality from pneumonia was associated with intensity of exposure to styrene, but this may have been due to chance. Mortality from bronchitis, emphysema, and asthma was not associated with styrene exposure. PMID:8704877

Welp, E; Partanen, T; Kogevinas, M; Andersen, A; Bellander, T; Biocca, M; Coggon, D; Gennaro, V; Kolstad, H; Lundberg, I; Lynge, E; Spence, A; Ferro, G; Saracci, R; Boffetta, P

1996-01-01

285

CNS tumors and exposure to acrylonitrile: inconsistency between experimental and epidemiology studies.  

PubMed

Acrylonitrile is a potent CNS tumorigen in rats leading to concern that it may be a tumorigen in humans. There have been 12 epidemiology studies of 37,352 workers exposed to acrylonitrile which evaluate CNS cancers. We summarize and evaluate these epidemiology studies for CNS cancers using the methods of meta-analysis. Our analyses indicate that workers with acrylonitrile exposure have null findings for CNS cancer (relative risk = 1.1, 95% confidence interval 0.8-1.5), which are in stark contrast to the projected risk to humans using the rat findings (relative risk = 3.5, 95% confidence interval 3.0-4.0). We discuss several explanations for the inconsistency between animal and human findings, including the possibility that the acrylonitrile-induced rat CNS tumors may not be relevant to humans. Given the rarity of CNS tumors in humans and a lack of understanding of the causal mechanisms of these tumors in rats, however, a more definitive conclusion will have to await additional experimental and observational data. Nevertheless, the epidemiology evidence indicates that acrylonitrile is not a potent CNS tumorigen. PMID:11550315

Collins, J J; Strother, D E

1999-07-01

286

CNS tumors and exposure to acrylonitrile: inconsistency between experimental and epidemiology studies.  

PubMed Central

Acrylonitrile is a potent CNS tumorigen in rats leading to concern that it may be a tumorigen in humans. There have been 12 epidemiology studies of 37,352 workers exposed to acrylonitrile which evaluate CNS cancers. We summarize and evaluate these epidemiology studies for CNS cancers using the methods of meta-analysis. Our analyses indicate that workers with acrylonitrile exposure have null findings for CNS cancer (relative risk = 1.1, 95% confidence interval 0.8-1.5), which are in stark contrast to the projected risk to humans using the rat findings (relative risk = 3.5, 95% confidence interval 3.0-4.0). We discuss several explanations for the inconsistency between animal and human findings, including the possibility that the acrylonitrile-induced rat CNS tumors may not be relevant to humans. Given the rarity of CNS tumors in humans and a lack of understanding of the causal mechanisms of these tumors in rats, however, a more definitive conclusion will have to await additional experimental and observational data. Nevertheless, the epidemiology evidence indicates that acrylonitrile is not a potent CNS tumorigen. PMID:11550315

Collins, J. J.; Strother, D. E.

1999-01-01

287

40 CFR 721.10389 - Styrene, copolymer with acrylic acid, salt with alkoxylated alkenylamine (generic).  

Code of Federal Regulations, 2012 CFR

...Styrene, copolymer with acrylic acid, salt with alkoxylated alkenylamine (generic...Styrene, copolymer with acrylic acid, salt with alkoxylated alkenylamine (generic...styrene, copolymer with acrylic acid, salt with alkoxylated alkenylamine (PMN...

2012-07-01

288

40 CFR 721.6920 - Butyl acrylate, polymer with substituted methyl styrene, methyl methacrylate, and substituted...  

Code of Federal Regulations, 2014 CFR

...2014-07-01 false Butyl acrylate, polymer with substituted methyl styrene, methyl...Substances § 721.6920 Butyl acrylate, polymer with substituted methyl styrene, methyl...substance identified as butyl acrylate, polymer with substituted methyl styrene,...

2014-07-01

289

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

Code of Federal Regulations, 2013 CFR

...2013-07-01 2013-07-01 false Polymers of styrene, cyclohexyl methacrylate...Chemical Substances § 721.9492 Polymers of styrene, cyclohexyl methacrylate...chemical substances identified generically as polymers of styrene, cyclohexyl...

2013-07-01

290

40 CFR 721.6920 - Butyl acrylate, polymer with substituted methyl styrene, methyl methacrylate, and substituted...  

Code of Federal Regulations, 2013 CFR

...2013-07-01 false Butyl acrylate, polymer with substituted methyl styrene, methyl...Substances § 721.6920 Butyl acrylate, polymer with substituted methyl styrene, methyl...substance identified as butyl acrylate, polymer with substituted methyl styrene,...

2013-07-01

291

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

Code of Federal Regulations, 2012 CFR

...2012-07-01 2012-07-01 false Polymers of styrene, cyclohexyl methacrylate...Chemical Substances § 721.9492 Polymers of styrene, cyclohexyl methacrylate...chemical substances identified generically as polymers of styrene, cyclohexyl...

2012-07-01

292

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

Code of Federal Regulations, 2014 CFR

...2014-07-01 2014-07-01 false Polymers of styrene, cyclohexyl methacrylate...Chemical Substances § 721.9492 Polymers of styrene, cyclohexyl methacrylate...chemical substances identified generically as polymers of styrene, cyclohexyl...

2014-07-01

293

40 CFR 721.3700 - Fatty acid, ester with styrenated phenol, ethylene oxide adduct.  

Code of Federal Regulations, 2010 CFR

... 2010-07-01 false Fatty acid, ester with styrenated phenol, ethylene oxide...Substances § 721.3700 Fatty acid, ester with styrenated phenol, ethylene oxide...substance identified generically as fatty acid, ester with styrenated phenol, ethylene...

2010-07-01

294

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

Code of Federal Regulations, 2010 CFR

...2010-07-01 2010-07-01 false Polymers of styrene, cyclohexyl methacrylate...Chemical Substances § 721.9492 Polymers of styrene, cyclohexyl methacrylate...chemical substances identified generically as polymers of styrene, cyclohexyl...

2010-07-01

295

40 CFR 721.6920 - Butyl acrylate, polymer with substituted methyl styrene, methyl methacrylate, and substituted...  

Code of Federal Regulations, 2010 CFR

...2010-07-01 false Butyl acrylate, polymer with substituted methyl styrene, methyl...Substances § 721.6920 Butyl acrylate, polymer with substituted methyl styrene, methyl...substance identified as butyl acrylate, polymer with substituted methyl styrene,...

2010-07-01

296

Morphology and physical properties of poly(styrene- b-isobutylene- b-styrene) block copolymers  

Microsoft Academic Search

A series of linear and three-arm star poly(styrene-b-isobutylene-b-styrene) (PS-PIB-PS) block copolymers with varying block compositions was synthesized via living carbocationic polymerization using the initiation system 1,3-di(2-chloro-2-propyl)-5-tert-butylbenzene (or 1,3,5-tris-(2-chloro-2-propyl)benzene)\\/TiCl4\\/pyridine\\/2,6-di-tert-butylpyridine in a 6040 (v\\/v) hexane\\/MeCl solvent mixture at ?80°C. High resolution gel permeation chromatography showed that the compositions of the copolymers were complex, consisting of higher molecular weight coupled products, and products

Michael A. Masse

1996-01-01

297

Mutagenic activity of ultraviolet-irradiated mixtures of nitrogen dioxide and propene or butadiene  

Microsoft Academic Search

The mutagenic activities of mixtures of nitrogen dioxide and 1,3-butadiene or propene were investigated after uv-irradiation in a small, laboratory-bench scale flow-through gas exposure system. The tester organism was Salmonella typhimurium, principally strain TA100. The photoreaction products from 1,3-butadiene and nitrogen dioxide were more mutagenic than those from propene and nitrogen dioxide. Approximately 0.25 ppm butadiene, compared to 100 ppm

K. Victorin; M. Stahlberg

1989-01-01

298

Copolymerization of carbon dioxide and butadiene via a lactone intermediate  

NASA Astrophysics Data System (ADS)

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

Nakano, Ryo; Ito, Shingo; Nozaki, Kyoko

2014-04-01

299

Otoacoustic emission sensitivity to exposure to styrene and noise.  

PubMed

The ototoxic effect of the exposure to styrene is evaluated, also in the presence of simultaneous exposure to noise, using otoacoustic emissions as biomarkers of mild cochlear damage. Transient-evoked and distortion product otoacoustic emissions were recorded and analyzed in a sample of workers (15 subjects) exposed to styrene and noise in a fiberglass manufacturing facility and in a control group of 13 non-exposed subjects. Individual exposure monitoring of the airborne styrene concentrations was performed, as well as biological monitoring, based on the urinary concentration of two styrene metabolites, the Mandelic and Phenylglyoxylic acids. Noise exposure was evaluated using wearable phonometers, and hearing loss with pure tone audiometry. Due to their different job tasks, one group of workers was exposed to high noise and low styrene levels, another group to higher styrene levels, close to the limit of 20?ppm, and to low noise levels. A significant negative correlation was found between the otoacoustic emission levels and the concentration of the styrene urinary metabolites. Otoacoustic emissions, and particularly distortion products, were able to discriminate the exposed workers from the controls, providing also a rough estimate of the slope of the dose-response relation between otoacoustic levels and styrene exposure. PMID:24180784

Sisto, R; Cerini, L; Gatto, M P; Gherardi, M; Gordiani, A; Sanjust, F; Paci, E; Tranfo, G; Moleti, A

2013-11-01

300

76 FR 22565 - National Emission Standards for Hazardous Air Pollutant Emissions: Group I Polymers and Resins...  

Federal Register 2010, 2011, 2012, 2013, 2014

...dissolved in an organic solvent, or the emulsion process, where monomers are dispersed...10) Styrene Butadiene Rubber by Emulsion; and (11) Styrene Butadiene Latex...styrene butadiene rubber produced by the emulsion process, polybutadiene rubber and...

2011-04-21

301

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

NASA Astrophysics Data System (ADS)

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

Czader, Beata H.; Rappenglück, Bernhard

2015-02-01

302

Bioconversion of acrylonitrile to acrylic acid by rhodococcus ruber strain AKSH-84.  

PubMed

A new versatile acrylonitrile-bioconverting strain isolated from a petroleum-contaminated sludge sample and identified as Rhodococcus ruber AKSH-84 was used for optimization of medium and biotransformation conditions for nitrilase activity to produce acrylic acid. A simple and rapid HPLC protocol was optimized for quantification of acrylic acid, acrylamide, and acrylonitrile. The optimal medium conditions for nitrilase activity were pH of 7.0, temperature of 30degreesC, agitation of 150 rpm, and inoculum level of 2%. Glycerol as a carbon source and sodium nitrate as the nitrogen source provided good nutritional sources for achieving good biotransformation. Nitrilase activity was constitutive in nature and was in the exponential growth phase after 24 h of incubation under optimal conditions without addition of any inducer. The substrate preference was acrylonitrile and acetonitrile. The present work demonstrates the biotransformation of acrylonitrile to acrylic acid with the new strain, R. ruber AKSH-84, which can be used in green biosynthesis of acrylic acid for biotechnological processes. The nitrilase produced by the isolate was purified and characterized. PMID:21301190

Kamal, Ahmed; Kumar, M Shiva; Kumar, C Ganesh; Shaik, Thokhir

2011-01-01

303

GRAFT POLYMERIZATION OF ACRYLONITRILE ONTO STARCH-COATED POLYETHYLENE FILM SURFACES  

Technology Transfer Automated Retrieval System (TEKTRAN)

When starch-coated polyethylene (PE) films were allowed to react with acrylonitrile in the presence of ceric ammonium nitrate initiator, graft polymerization occurred to produce starch-polyacrylonitrile (PAN) coatings that contained about 25% grafted PAN, by weight. The graft copolymer coatings adh...

304

Structural and electronic effects on the reactivity of carbamoylsilanes towards acrylonitrile addition  

Microsoft Academic Search

The effect of substituents on Si and N on t1\\/2 values in the addition of carbamoylsilanes to acrylonitrile was explored. After examination of steric and structural parameters, the best correlation was found to be that rates increased with a decrease in the ionization potential of the carbamoylsilane.

Robert F. Cunico; Adalie R. Motta

2006-01-01

305

Insights into the toxicokinetics and toxicodynamics of 1,3-butadiene.  

PubMed

1,3 Butadiene (BD) is a colorless gas used in the production of synthetic rubber and plastics. BD is carcinogenic in rats and mice, however, there are striking species differences in cancer potency and spectrum of tumors, with mice being more susceptible to tumor induction than rats. Epidemiology studies suggest an excess incidence of leukemia in workers in the styrene-butadiene rubber industry. Consideration of mechanisms of BD carcinogenicity can provide insights into differences in cancer potency between rodents and serve to elucidate the extent to which BD exposure may cause cancer in humans. Mechanistic research in the areas of biochemical toxicology, molecular biology, molecular dosimetry, and susceptibility factors can impact BD cancer risk assessment for humans. This research has focused on quantitating species differences in the metabolism of BD and BD epoxides, defining molecular lesions produced by BD epoxides, identifying biomarkers for BD exposure to explore metabolic pathways in humans, and determining potential risk factors for sensitive subpopulations. BD is activated by P450 isozymes, including CYP2E1, to at least two genotoxic metabolites, epoxybutene (EB) and diepoxybutane (DEB). Dosimetry data from several laboratories on EB and DEB following inhalation exposure to BD indicate that blood concentrations of EB were four-eight-fold higher in mice compared with rats and that blood concentrations of DEB were 25-100-fold higher in mice than in rats. The higher levels of these two DNA-reactive metabolites in mice compared with rats probably contribute to the species differences in carcinogenic effects of BD between mice and rats. In vitro metabolism studies of BD in rats, mice, and human tissues indicate that there are significant quantitative species differences in the metabolic activation of BD to EB and DEB and the detoxication of EB and DEB. Activation/detoxication ratios calculated using in vitro kinetic constants reveal that ratios in mice were greater than in both rats and humans. In vitro data are consistent with in vivo dosimetry data and cancer potency for rodents, and suggest that humans may be at a decreased risk. Data on mutagenicity and mutational spectra of BD epoxides show mechanistic differences between EB- and DEB-induced mutational events suggesting involvement of DEB in the development of cancer. Concentrations of DEB that are genotoxic in vitro are within the range of concentrations measured in mice in vivo, whereas concentrations of EB that are genotoxic in vitro are ten-100-fold greater than concentrations observed in vivo. Characterization of molecular events indicate that EB-induced genotoxicity is due to point mutations and small deletions, while DEB induces point mutations, small deletions, and large-scale deletions involving many base pairs. The extent to which epoxybutanediol is involved in BD carcinogenesis is not known. Molecular dosimetry studies in rodents and humans have focused on urinary metabolites and DNA and hemoglobin adducts. Data from these studies are consistent with in vivo and in vitro metabolism data providing further support for the differences in metabolic activation and deactivation of BD and BD epoxides across species and the role of DEB in tumor development. Research on potential susceptibility factors points to other P450 isozymes, in addition to CYP2E1, that are involved in both the metabolic activation and mutagenicity of BD. Taken together, mechanistic data on BD toxicokinetics and toxicodynamics provide an integrated insight into critical steps in initiation of cancer, metabolites responsible for cancer, sensitive biomarkers for exposure, and potential risk factors for individual susceptibility. Available evidence suggests that BD is unlikely to be a human carcinogen at the low exposure concentrations currently encountered in the environment or workplace. PMID:11397415

Bond, J A; Medinsky, M A

2001-06-01

306

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

Code of Federal Regulations, 2013 CFR

...2013-07-01 2013-07-01 false Benzene ethenyl-, polymer with 1,3-butadiene...Chemical Substances § 721.10280 Benzene ethenyl-, polymer with 1,3-butadiene...The chemical substance identified as benzene ethenyl-, polymer with...

2013-07-01

307

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

Code of Federal Regulations, 2014 CFR

...2014-07-01 2014-07-01 false Benzene ethenyl-, polymer with 1,3-butadiene...Chemical Substances § 721.10280 Benzene ethenyl-, polymer with 1,3-butadiene...The chemical substance identified as benzene ethenyl-, polymer with...

2014-07-01

308

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

PubMed Central

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

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

1990-01-01

309

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

EPA Science Inventory

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

310

Neurobehavioral effects of acute styrene exposure in fiberglass boatbuilders  

SciTech Connect

A field investigation of the effects of acute exposure to styrene among fiberglass boatbuilders was performed. Personal samples of styrene in breathing zone air and postshift urinary mandelic acid were collected for 105 workers exposed and not exposed to styrene in 6 fiberglass boatbuilding companies in New England. Three tests from the computerized Neurobehavioral Evaluation System (NES) were performed by the subjects in the morning before exposure to styrene, near midday, and at the end of the work day. Duration of exposure averaged 2.9 years (SD = 4.6), 8-hour TWA styrene exposure averaged 29.9 ppm (SD = 36.2), and urinary mandelic acid averaged 347 mg/g creatinine (SD = 465). Regression analyses indicated a statistically significant relationship between postshift performance on the Symbol-Digit test and both acute styrene exposure and mandelic acid. Other analyses comparing workers exposed to less than 50 ppm and greater than 50 ppm styrene also showed a significant effect on Symbol-Digit performance. All three NES tests showed test-retest correlation coefficients above .80, and ease of use for collection of neurobehavioral data under field conditions was demonstrated.

Letz, R.; Mahoney, F.C.; Hershman, D.L.; Woskie, S.; Smith, T.J. (Mount Sinai School of Medicine, New York, NY (USA))

1990-11-01

311

Using metallic resin and aluminum alloy molds to manufacture propellers with RP\\/RT technique  

Microsoft Academic Search

Purpose – This purpose of this study is to investigate an effective method to manufacture propellers. Design\\/methodology\\/approach – The investment casting process and injection molding process have been applied separately to the rapid prototyping\\/rapid tooling (RP\\/RT) to obtain metal (Al-Si alloy) propellers and plastic (Acrylonitrile butadiene styrene – ABS) propellers. The two different manufacturing processes were compared following the same

C. Y. Hsu; C. K. Huang; G. J. Tzou

2008-01-01

312

Morphological, mechanical and thermal properties of nylon 6\\/ABS blends using glycidyl methacrylate-methyl methacrylate copolymers  

Microsoft Academic Search

Nylon6 is an attractive polymer for engineering applications because it has reactive functionality through amine and carboxyl end groups that are capable of reacting. For this reason, it has been used a lot in polymeric blends. Blends of nylon6\\/ABS (acrylonitrile-butadiene-styrene) were produced using glycidyl methacrylate-methyl methacrylate (GMA-MMA) copolymers as compatibilizer. The binary blends were immiscible and exhibited poor mechanical properties

E. M. Araú Jo; E. Hage; A. J. F. Carvalho

2005-01-01

313

Synergistic Effect of Montmorillonite and Intumescent Flame Retardant on Flame Retardance Enhancement of ABS  

Microsoft Academic Search

The synergistic effects of organic montmorillonite (OMMT) and intumescent flame retardant (IFR) based on the ammonium polyphosphate (APP) and pentaerythritol (PER) on flame retardant enhancement of acrylonitrile-butadiene-styrene copolymer (ABS) were investigated by using the limiting oxygen index (LOI), the UL-94 (vertical flame) test, thermogravimetric analysis (TGA), x-ray diffractometry (XRD) and scanning electron microscopy (SEM). The LOI data and vertical flame

Ying Xia; Xi-gao Jian; Jian-feng Li; Xin-hong Wang; Yan-yan Xu

2007-01-01

314

The development of an intelligent Web-based rapid prototyping manufacturing system  

Microsoft Academic Search

A rapid prototyping (RP) machine system which combines a PC-based controller with the thermal-extrusion method is presented. The proposed RP system offers a three-axis platform, an extrusion head, a temperature controller, and a PC-based control system. Low-cost acrylonitrile-butadiene-styrene (ABS) pellets\\/powder are used for thermal extrusion, although the system is easily adapted to other not-too-dissimilar materials. In order to improve the

Ren C. Luo; Jyh Hwa Tzou

2004-01-01

315

Dynamic mechanical, thermal, and morphological study of ABS\\/textile fiber composites  

Microsoft Academic Search

In this work, acrylonitrile–butadiene–styrene ABS terpolymer was mixed with acrylic fiber, cotton fiber, and waste textile\\u000a fiber (WTF) (50\\/50 wt% cotton\\/acrylic fiber) with 10 and 30 wt% of fiber content in a batch mixer. The composites with 30 wt%\\u000a of acrylic fiber showed the highest stabilized torque, while the compositions with 30 wt% of cotton were situated at the lowest\\u000a values in torque rheometry.

Johnny N. MartinsTobias; Tobias G. Klohn; Otavio Bianchi; Rudinei Fiorio; Estevão Freire

2010-01-01

316

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

NASA Technical Reports Server (NTRS)

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

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

1978-01-01

317

Toxicity of Pyrolysis Gases from Elastomers  

NASA Technical Reports Server (NTRS)

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

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

1977-01-01

318

Modification of ABS Membrane by PEG for Capturing Carbon Dioxide from CO2\\/N2 Streams  

Microsoft Academic Search

Carbon dioxide capture and storage (CCS) has been propounded as an important issue in greenhouse gas emissions control. In this connection, in the present article, the advantages of using polymeric membrane for separation of carbon dioxide from CO2\\/N2 streams have been discussed. A novel composition for fabrication of a blend membrane prepared from acrylonitrile-butadiene-styrene (ABS) terpolymer and polyethylene glycol (PEG)

Abtin Ebadi Amooghin; Hamidreza Sanaeepur; Abdolreza Moghadassi; Ali Kargari; Davood Ghanbari; Zahra Sheikhi Mehrabadi

2010-01-01

319

Clinical studies of styrene workers: initial findings.  

PubMed Central

Styrene monomer is a high volume chemical used chiefly in production of polystyrene. A clinical survey of 493 production workers was undertaken at the oldest and largest monomer production, polymerization, and extrusion facility in the U.S. Relative exposure durations and levels were obtained from occupational histories. Significant differences between the high and low exposure groups were found with regard to history of acute prenarcotic symptoms, acute lower respiratory symptoms, prevalence of FEV 1/FV less than 75 per cent, and elevated GCTP. Other liver function tests, chest x-ray, FVC less than 80 per cent, and hematological parameters showed no distinct pattern. A concomitant mortality study has been mounted and is in progress. PMID:1026403

Lorimer, W V; Lilis, R; Nicholson, W J; Anderson, H; Fischbein, A; Daum, S; Rom, W; Rice, C; Selikoff, I J

1976-01-01

320

21 CFR 177.1820 - Styrene-maleic anhydride copolymers.  

Code of Federal Regulations, 2014 CFR

...at specified temperatures, times, and particle size 1. Styrene-maleic anhydride copolymers containing not more than 15 pct maleic anhydride units by weight; for use as articles or as components of articles that contact food of Types I, II,...

2014-04-01

321

Air Oxidative Radical Hydroxysulfurization of Styrenes Leading to ?-Hydroxysulfides.  

PubMed

Air oxidative radical hydroxysulfurization of styrenes initiated by 0.5 mol % of tert-butyl hydroperoxide with arylthiols is described, and a new type of difunctionalization of alkenes was achieved. PMID:25752231

Zhou, Shao-Fang; Pan, Xiangqiang; Zhou, Zhi-Hao; Shoberu, Adedamola; Zou, Jian-Ping

2015-04-01

322

78 FR 6213 - Styrene-2-Ethylhexyl Acrylate Copolymer; Tolerance Exemption  

Federal Register 2010, 2011, 2012, 2013, 2014

...2-propenoic acid, 2-ethylhexyl ester, polymer with ethenylbenzene; also known as styrene-2-ethylhexyl...2-propenoic acid, 2-Ethylhexyl Ester, Polymer with Ethenylbenzene on food or feed commodities...2-propenoic acid, 2-ethylhexyl ester, polymer with ethenylbenzene; CAS No....

2013-01-30

323

40 CFR 116.4 - Designation of hazardous substances.  

Code of Federal Regulations, 2010 CFR

...acrylaldehyde, acraldehydeAcrylonitrile 107131Cyanoethylene, Fumigrain... 787952-methyl-1,3-butadiene Isopropanolamine dodecylbenzenesulfonate...107051Allyl chloride 107131Acrylonitrile 107153Ethylenediamine...

2010-07-01

324

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

NASA Technical Reports Server (NTRS)

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

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

1977-01-01

325

Choice Reaction Time in Workers Exposed to Styrene Vapour  

Microsoft Academic Search

1 Behavioural effects of occupational exposure to vapour from styrene-based resin were investigated in 10 female workers with a portable test of choice reaction time. Testing was carried out both at the beginning and end of the day's shift.2 Uptake and metabolism of styrene were assessed by monitoring post-shift urinary mandelic acid excretion rates. By using these data workers were

C. J. Mackay; G. R. Kelman

1986-01-01

326

Emission modeling of styrene from vinyl ester resins  

Microsoft Academic Search

The use of vinyl ester (VE) resins in the composites industry has increased in the last decade, and the trend is projected\\u000a to continue. Styrene is a commonly used co-monomer in VE resins, which acts as a reactive diluent and is required in many\\u000a liquid molding methods to reduce viscosity and increase gel time. The emission rate of styrene from

John J. La Scala; Chad A. Ulven; Joshua A. Orlicki; Rahul Jain; Giuseppe R. Palmese; Uday K. Vaidya; James M. Sands

2007-01-01

327

Simultaneous determination of aromatic acid metabolites of styrene and styrene-oxide in rat urine by gas chromatography -flame ionisation detection  

E-print Network

into styrene glycol. This compound is then metabolized into mandelic acid (MA) and further to phenylglyoxylic1 Simultaneous determination of aromatic acid metabolites of styrene and styrene-oxide in rat urine and reliable gas chromatographic method was developed for the simultaneous determination of six aromatic acid

Paris-Sud XI, Université de

328

Sequence of reactions in thermooxidative degradation of polyacrylonitrile and of acrylonitrile-methyl acrylate copolymer  

SciTech Connect

Despite the considerable number of studies of thermooxidative degradation of polyacrylonitrile (PAN), the question of the sequence of reactions involved is not completely clear. The mechanism of action of comonomer units on the course of degradation in acrylonitrile copolymers has been studied very little, apart from initiation of degradation by comonomer units of the carboxylic acid type. The question of participation of comonomer units of the acrylate, methyl acrylate, etc., types remains open. Since most commercially available PAN fibers contain units of this type, study of the thermal stability of acrylonitrile-methyl acrylate (AN/MA) copolymer is of considerable practical importance. Accordingly, the purpose of the present work was to establish the sequence of thermooxidative degradation reactions and to elucidate the influence of comonomer units of the ester type on the course of these reactions.

Grebenkin, A.N.; Romanova, E.P.; Kol'tsov, A.I.; Firsov, E.I.

1986-02-10

329

Chemiluminescence from poly(styrene- b-ethylene- co-butylene- b-styrene) (SEBS) block copolymers  

Microsoft Academic Search

A detailed analysis of the chemiluminescence emission (CL) from poly(styrene-b-ethylene-co-butylene-b-styrene), SEBS, was carried out. A phenol–phosphite stabilization system based on Irgafos 168 and Irganox 1330, was studied. The kinetic analysis of the CL profile under nitrogen shows a first-order reaction for the decay of chemiluminescence. The activation energy shows different values as a function of temperature, showing that different reactions

Carmen Peinado; Teresa Corrales; M Jesús García-Casas; Fernando Catalina; Valentín Ruiz Santa Quiteria; M Dolores Parellada

2006-01-01

330

Transport Properties of Sulfonated Poly(styrene- b -isobutylene- b -styrene) Triblock Copolymers at High Ion-Exchange Capacities  

Microsoft Academic Search

Transport properties of sulfonated poly(styrene-b-isobutylene-b-styrene) (S-SIBS) triblock copoly- mers were examined as a function of ion-exchange capacity (IEC), specifically at high IECs (up to 2 mequiv\\/ g). The proton conductivity of S-SIBS was 1 order of magnitude higher than sulfonated polystyrene at similar IECs and 3-fold higher than Nafion 117 at an IEC of 2 mequiv\\/g. However, all polymers in

Yossef A. Elabd; Eugene Napadensky; Charles W. Walker; Karen I. Winey

2006-01-01

331

Dodecagonal Quasicrystalline Morphology in a Poly(styrene-b-isoprene-b-styrene-b-ethylene oxide) Tetrablock Terpolymer  

Microsoft Academic Search

A dodecagonal quasicrystalline (QC) morphology is identified in a poly(styrene-b-isoprene-b-styrene-b-ethylene oxide) (SISO) tetrablock terpolymer based on evidence provided by transmission electron microscopy (TEM), small-angle X-ray scattering, and dynamic mechanical spectroscopy measurements. The QC state occurs at temperatures between those associated with simple hexagonal order (HEX) and the Ï-phase (P4â\\/mnm), T{sub HEX} < T{sub QC} < T{sub Ï} < T{sub ODT},

Jingwen Zhang; Frank S. Bates

2012-01-01

332

Enhanced electromechanical performance of carbon nano-fiber reinforced sulfonated poly(styrene-b-[ethylene\\/butylene]-b-styrene) actuator  

Microsoft Academic Search

In this paper, the carbon nano-fibers (CNFs) were used to improve the performance of sulfonated poly(styrene-b-[ethylene\\/butylene]-b-styrene) (SSEBS) composite actuator. The SSEBS actuator, which was developed in our previous study, does not have good electromechanical performance because the SSEBS ionic polymer is too flexible and soft. CNFs as a reinforcement for the polymer membranes greatly increased the bending performance of the

Xuan-Lun Wang; Il-Kwon Oh; Jin-Bong Kim

2009-01-01

333

One-step preparation of ultrafine poly(acrylonitrile) fibers containing silver nanoparticles  

Microsoft Academic Search

A simple one-step method of preparing of ultrafine poly(acrylonitrile) (PAN) fibers containing Ag nanoparticles was developed. Ag+ ions in a PAN solution were directly reduced to produce Ag nanoparticles and the resulting solution was electrospun into ultrafine PAN fibers. N,N-dimethylformamide (DMF) was used as a solvent for PAN as well as a reducing agent for the Ag+ ions. The numbers

Hwang Kyu Lee; Eun Hwan Jeong; Chi Kyoung Baek; Ji Ho Youk

2005-01-01

334

Catalytic synthesis of N-alkylacrylamide from acrylonitrile and alcohol with solid acids  

Microsoft Academic Search

Catalytic synthesis of N-alkylacrylamides, which are useful monomers for functional polymers, from acrylonitrile and alcohols, such as 1-adamantanol, tert-butyl alcohol, and isopropyl alcohol has been studied using various solid acids including heteropoly compounds and zeolites. For the reaction with 1-adamantanol or tert-butyl alcohol, a heteropoly compound, Cs2.5H0.5PW12O40, exhibited a high catalytic performance and water-tolerance. On the other hand, for the

Toshio Okuhara; Xin Chen; Hideho Matsuda

2000-01-01

335

Biomonitoring following a chemical incident with acrylonitrile and ethylene in 2008.  

PubMed

The analytical determination of hemoglobin adducts was used as an effective biomonitoring tool after a fire outbrake at a chemical plant close to Cologne/Germany in 2008. More than 1000 people (e.g. fire-men, police officers, and workers) were potentially exposed to acrylonitrile and ethylene. Air monitoring in the surrounding was performed, and acrylonitrile was measured in concentrations up to 20 ppm, the mean value being 7 ppm (time range: 8 h). As many people were concerned about their individual body burden, biomonitoring was recommended for all people involved. 816 persons took advantage of this opportunity and came for blood sampling to the occupational health department of our company. Regarding the lifespan of erythrocytes up to 3 months, it was possible to analyze hemoglobin adducts of acrylonitrile and ethylene during and after the accident. In case of acrylonitrile the hemoglobin adduct N-(2-cyanoethyl) valine and regarding ethylene, N-(2-hydroxyethyl) valine was determined. As a result, the body burden was in nearly all cases within our internal adduct reference values (CyEtVal<15 ?g/L blood or <612 pmol/g globin; HyEtVal<15 ?g/L blood or 646 pmol/g globin). In about 1% of the cases, the adduct concentrations were slightly above these reference values. This means that the body burden measured by biomonitoring turned out to be far lower than the one expected from the air data. Therefore, following chemical incidents, in case biomonitoring is meaningful, it is highly recommended beside of air monitoring. PMID:24960063

Leng, Gabriele; Gries, Wolfgang

2014-12-15

336

Acrylonitrile-based copolymer membranes containing reactive groups: Surface modification by the immobilization of biomacromolecules  

Microsoft Academic Search

Asymmetric membranes fabricated from poly(acrylonitrile-co-maleic acid) (PANCMA) were immobilized with heparin and\\/or insulin to improve their surface properties. These biomacromolecule-immobilized PANCMA membranes were prepared by the amination of the membrane surface with ethylenediamine, followed by the reaction of the amino groups with heparin and\\/or insulin in the presence of 1-ethyl-3-(3-dimethyl amidopropyl) carbodiimide. The surface-modified membranes were analyzed by X-ray photoelectron

Ai-Fu Che; Fu-Qiang Nie; Xiao-Dan Huang; Zhi-Kang Xu; Ke Yao

2005-01-01

337

Improvement of the water purification capability of poly(acrylonitrile) ultrafiltration membranes  

Microsoft Academic Search

Ultrafiltration membranes used for drinking water treatment need to have high rejection for microbial species. The effect of various inorganic halides added to a casting solution of poly(acrylonitrile) in N,N-dimethyl formamide was examined by measuring changes in the intrinsic viscosity, concentrated solution viscosity and the ternary phase boundary. Both mono- and divalent salts decreased polymer–solvent affinity; the higher viscosity in

M. H Shinde; S. S Kulkarni; D. A Musale; S. G Joshi

1999-01-01

338

Vibrational Energies for Acrylonitrile from Mm-Wave to Thz Rotational Spectra  

NASA Astrophysics Data System (ADS)

The THz rotational spectrum of acrylonitrile has recently been studied in detail. The coverage of the ground state rotational transitions has been extended up to J=128, K_a=29 and it was found that at very high-J there are multiple manifestations of a perturbation between the ground state and the lowest vibrationally excited state, V11=1. The perturbation has been successfully fitted and the excited state energy determined at 228.29991(2) Cm-1, which turns out to be the largest energy difference between any two neighboring vibrational states of acrylonitrile. Extensive broadband rotational spectra of acrylonitrile have been recorded at JPL and at OSU and provide coverage from the mm-wave region up to well into the THz. The analysis of these spectra performed with the AABS package allowed identification of a ladder of pairwise perturbations extending from the ground state and connecting all successive low lying vibrational states. A global fit of all of the observed effects is expected to deliver accurate energies for the lowest vibrational states from only the rotational spectrum. The progress made towards achieving this goal is described. Z.Kisiel, L.Pszczó?kowski, B.J.Drouin, C.S.Brauer, S.Yu, J.C.Pearson, J. Mol. Spectrosc., 258, 26 (2009). Z.Kisiel, L.Pszczó?kowski, I.R.Medvedev, M.Winewisser, F.C.De Lucia, E.Herbst, J. Mol. Spectrosc., 233, 231 (2005).

Kisiel, Zbigniew; Pszczó?kowski, Lech; Drouin, Brian J.; Brauer, Carolyn S.; Yu, Shanshan; Pearson, John C.; Medvedev, Ivan R.; Fortman, Sarah; Neese, Christopher

2011-06-01

339

Urinary excretion of the acrylonitrile metabolite 2-cyanoethylmercapturic acid is correlated with a variety of biomarkers of tobacco smoke exposure and consumption  

PubMed Central

Acrylonitrile is an IARC class 2B carcinogen present in cigarette smoke. Urinary 2-cyanoethylmercapturic acid (CEMA) is an acrylonitrile metabolite and a potential biomarker for acrylonitrile exposure. The objective of this work was to study the dose response of CEMA in urine of non-smokers and smokers of different ISO tar yield cigarettes. We observed that smokers excreted >100-fold higher amounts of urinary CEMA than non-smokers. The CEMA levels in smokers were significantly correlated with ISO tar yield, daily cigarette consumption, and urinary biomarkers of smoke exposure. In conclusion, urinary CEMA is a suitable biomarker for assessing smoking-related exposure to acrylonitrile. PMID:21108560

Minet, Emmanuel; Cheung, Francis; Errington, Graham; Sterz, Katharina; Scherer, Gerhard

2011-01-01

340

Laboratory accelerated and natural weathering of styrene–ethylene–butylene–styrene (SEBS) block copolymer  

Microsoft Academic Search

Indoor accelerated and outdoor weathering of polystyrene-b-(ethylene-co-butylene)-b-styrene (SEBS) was studied by infrared spectroscopy. Accelerated conditions involved simultaneous exposure of specimens to ultraviolet–visible radiation between 295 nm and 450 nm and each of four temperature\\/relative humidity (RH) environments, i.e., (a) 30 °C ± 1 °C at <1% RH, (b) 30 °C ± 1 °C at 80% RH, (c) 55 °C ± 1 °C at <1% RH, and (d) 55 °C ± 1 °C at 80% RH. Outdoor exposure was conducted

C. C. White; K. T. Tan; D. L. Hunston; T. Nguyen; D. J. Benatti; J. W. Chin

2011-01-01

341

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

PubMed

Occupational noise exposure can damage workers' hearing, particularly when combined with exposure to cochleotoxic chemicals such as styrene. Although styrene-induced cochlear impairments only become apparent after a long incubation period, the pharmacological impact of styrene on the central nervous system (CNS) can be rapidly measured by determining the threshold of the middle-ear acoustic reflex (MER) trigger. The aim of the study was to evaluate the effects of a noise (both continuous and impulse), and a low concentration of styrene [300ppm<(threshold limit value×10) safety factor] on the peripheral auditory receptor, and on the CNS in rats. The impact of the different conditions on hearing loss was assessed using distortion product oto-acoustic emissions, and histological analysis of cochleae. Although the LEX,8h (8-hour time-weighted average exposure) of the impulse noise was lower (80dB SPL sound pressure level) than that of the continuous noise (85dB SPL), it appeared more detrimental to the peripheral auditory receptors. A co-exposure to styrene and continuous noise was less damaging than exposure to continuous noise alone. In contrast, the traumatic effects of impulse noise on the organ of Corti were enhanced by co-exposure to styrene. The pharmacological effects of the solvent on the CNS were discussed to put forward a plausible explanation of these surprising results. We hypothesize that CNS effects of styrene may account for this apparent paradox. Based on the present results, the temporal structure of the noise should be reintroduced as a key parameter in hearing conservation regulations. PMID:24929234

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

2014-01-01

342

Photodegradation Mechanisms of Tetraphenyl Butadiene Coatings for Liquid Argon Detectors  

E-print Network

We report on studies of degradation mechanisms of tetraphenyl butadiene (TPB) coatings of the type used in neutrino and dark matter liquid argon experiments. Using gas chromatography coupled to mass spectrometry we have detected the ultraviolet-blocking impurity benzophenone (BP). We monitored the drop in performance and increase of benzophenone concentration in TPB plates with exposure to ultraviolet (UV) light, and demonstrate the correlation between these two variables. Based on the presence and initially exponential increase in the concentration of benzophenone observed, we propose that TPB degradation is a free radical-mediated photooxidation reaction, which is subsequently confirmed by displaying delayed degradation using a free radical inhibitor. Finally we show that the performance of wavelength-shifting coatings of the type envisioned for the LBNE experiment can be improved by 10-20%, with significantly delayed UV degradation, by using a 20% admixture of 4-tert-Butylcatechol.

B. J. P. Jones; J. K. VanGemert; J. M. Conrad; A. Pla-Dalmau

2012-11-30

343

Aging studies on thin tetra-phenyl butadiene films  

NASA Astrophysics Data System (ADS)

Tetra-Phenyl Butadiene (TPB) is the most commonly used compound to wave-shift the 128 nm scintillation light of liquid Argon down to the visible spectrum. We present a study on the loss of conversion efficiency of thin TPB films evaporated on reflective foils when exposed to light and atmosphere. The efficiency of the films is measured and monitored with a dedicated set-up that uses gaseous Argon excited by alpha particles to produce 128 nm photons and working at room temperature. In particular we performed a two years long exposure of the samples to lab diffuse light and atmosphere. We also performed more controlled aging tests to investigate the effect of storing samples in a inert atmosphere.

Acciarri, R.; Canci, N.; Cavanna, F.; Segreto, E.; Szelc, A. M.

2013-10-01

344

Impact of copolymer ratio on drug distribution in styrene-isobutylene-styrene block copolymers.  

PubMed

Drug-polymer composite coatings, composed of styrene-isobutylene-styrene (SIBS) tri-block copolymers, are frequently used in controlled drug release biomedical device applications. In this work, we used atomic force microscopy to characterize the effects of different drug loadings and polymer chemistries (i.e., block copolymer ratio) on the variation of surface structures and compositions of SIBS-tetracycline (SIBS-TC) cast composites including tetracycline (TC) drug amount, drug phase size distribution, and drug and polymer phase morphologies. We tested the structural variations by fabricating and characterizing two types of composite specimens, that is, SIBS15 and SIBS30, composed of 15 and 30 Wt % of polystyrene (PS), respectively. The differences in the distribution of TC drug, PS, and polyisobutylene (PIB) polymer phase structures observed in SIBS15 and SIBS30 resulted in more drug at the surface of SIBS30 compared to SIBS15. To support the experimental findings, we have determined the Hildebrand solubility parameter of TC using molecular dynamics (MD) computation and compared it to the polymer components, PS and PIB. The MD results show that the solubility parameter of TC is much closer to that of PS than PIB, which demonstrates a higher thermodynamic stability of TC-PS mixtures. PMID:23564439

McDermott, Martin K; Kim, Chang-Soo; Saylor, David M; Patwardhan, Dinesh V

2013-10-01

345

Palladium-Catalyzed Telomerization of Butadiene with Polyols: From Mono to Polysaccharides  

Microsoft Academic Search

\\u000a The telomerization of butadiene with alcohols is an elegant way to synthesize ethers with minimal environmental impact since\\u000a this reaction is 100% atom efficient. Besides telomerization of butadiene with methanol and water that is industrially developed,\\u000a the modification of polyols is still under development. Recently, a series of new substrates has been involved in this reaction,\\u000a including diols, pure or

Sandrine Bouquillon; Jacques Muzart; Catherine Pinel; Franck Rataboul

2010-01-01

346

78 FR 55644 - Styrene, Copolymers with Acrylic Acid and/or Methacrylic Acid; Tolerance Exemption  

Federal Register 2010, 2011, 2012, 2013, 2014

...FRL-9396-9] Styrene, Copolymers with Acrylic Acid and/or Methacrylic Acid; Tolerance Exemption AGENCY: Environmental Protection...for residues of styrene, copolymers with acrylic acid and/or methacrylic acid, with none and/or...

2013-09-11

347

Behavior of benzene and 1,3-butadiene concentrations in the urban atmosphere of Tokyo, Japan  

NASA Astrophysics Data System (ADS)

Benzene and 1,3-butadiene concentration profiles in the urban ambient air were generated to investigate their levels at two specified sampling locations, roadside and residential, in Tokyo, Japan. Air monitoring data for benzene and 1,3-butadiene were obtained from the Air Quality Monitoring Information of the Tokyo Metropolitan Government. Air samples were continuously obtained and analyzed every hour for volatile organic compounds (VOCs) using an automated GC-MS system. The diurnal variations in benzene and 1,3-butadiene concentrations showed bi-modal patterns, which were considered to be related to the increasing and decreasing trends of vehicle emissions and vertical mixing depths in a day. The frequencies of occurrence of various benzene and 1,3-butadiene concentrations were examined. The results of each concentration showed log-normal forms with almost straight lines. The frequency distributions of both pollutants were confirmed to have a log-normal, rather than a simple normal, form. The relationship between benzene and 1,3-butadiene concentrations at both the roadside and residential site were examined. Separate observations of day and night trends revealed that photochemical decomposition showed a greater influence on the data in the residential site than that in the roadside site. These results were considered as direct evidences of photochemical decomposition of 1,3-butadiene in the atmosphere.

Laowagul, Wanna; Yoshizumi, Kunio

348

Review of old chemistry and new catalytic advances in the on-purpose synthesis of butadiene.  

PubMed

Increasing demand for renewable feedstock-based chemicals is driving the interest of both academic and industrial research to substitute petrochemicals with renewable chemicals from biomass-derived resources. The search towards novel platform chemicals is challenging and rewarding, but the main research activities are concentrated on finding efficient pathways to produce familiar drop-in chemicals and polymer building blocks. A diversity of industrially important monomers like alkenes, conjugated dienes, unsaturated carboxylic acids and aromatic compounds are thus targeted from renewable feedstock. In this context, on-purpose production of 1,3-butadiene from biomass-derived feedstock is an interesting example as its production is under pressure by uncertainty of the conventional fossil feedstock. Ethanol, obtained via fermentation or (biomass-generated) syngas, can be converted to butadiene, although there is no large commercial activity today. Though practised on a large scale in the beginning of the 20th century, there is a growing worldwide renewed interest in the butadiene-from-ethanol route. An alternative route to produce butadiene from biomass is through direct carbohydrate and gas fermentation or indirectly via the dehydration of butanediols. This review starts with a brief discussion on the different feedstock possibilities to produce butadiene, followed by a comprehensive summary of the current state of knowledge regarding advances and achievements in the field of the chemocatalytic conversion of ethanol and butanediols to butadiene, including thermodynamics and kinetic aspects of the reactions with discussions on the reaction pathways and the type of catalysts developed. PMID:24993100

Makshina, Ekaterina V; Dusselier, Michiel; Janssens, Wout; Degrève, Jan; Jacobs, Pierre A; Sels, Bert F

2014-11-21

349

Comparative studies on the removal of heavy metals ions onto cross linked chitosan-g-acrylonitrile copolymer.  

PubMed

The graft copolymerization of acrylonitrile onto cross linked chitosan was carried out using ceric ammonium nitrate as an initiator. The prepared cross linked chitosan-g-acrylonitrile copolymer was characterized using FT-IR and XRD studies. The adsorption behavior of chromium(VI), copper(II) and nickel(II) ions from aqueous solution onto cross linked chitosan graft acrylonitrile copolymer was investigated through batch method. The efficiency of the adsorbent was identified from the varying the contact time, adsorbent dose and pH. The results evident that the adsorption of metal ions increases with the increase of shaking time and metal ion concentration. An optimum pH was found to be 5.0 for both Cr(VI) and Cu(II), whereas the optimum pH is 5.5 for the adsorption of Ni(II) onto cross linked chitosan-g-acrylonitrile copolymer. The Langmuir and Freundlich adsorption models were applied to describe the isotherms and isotherm constants. Adsorption isothermal data could be well interpreted by the Freundlich model. The kinetic experimental data properly correlated with the second-order kinetic model. From the above results it was concluded that the cross linked chitosan graft acrylonitrile copolymer was found to be the efficient adsorbent for removing the heavy metals under optimum conditions. PMID:24680901

Shankar, P; Gomathi, Thandapani; Vijayalakshmi, K; Sudha, P N

2014-06-01

350

21 CFR 177.2600 - Rubber articles intended for repeated use.  

Code of Federal Regulations, 2011 CFR

...Elastomers. Acrylonitrile-butadiene copolymer. Brominated isobutylene-isoprene copolymers complying with § 177.1210. Butadiene-acrylonitrile-ethylene...Barr Harbor Dr., West Conshohocken, PA 19428-2959. Isobutylene-isoprene copolymer. Polyamide/polyether block...

2011-04-01

351

21 CFR 177.2600 - Rubber articles intended for repeated use.  

Code of Federal Regulations, 2012 CFR

...Elastomers. Acrylonitrile-butadiene copolymer. Brominated isobutylene-isoprene copolymers complying with § 177.1210. Butadiene-acrylonitrile-ethylene...Barr Harbor Dr., West Conshohocken, PA 19428-2959. Isobutylene-isoprene copolymer. Polyamide/polyether block...

2012-04-01

352

21 CFR 177.2600 - Rubber articles intended for repeated use.  

Code of Federal Regulations, 2013 CFR

...Elastomers. Acrylonitrile-butadiene copolymer. Brominated isobutylene-isoprene copolymers complying with § 177.1210. Butadiene-acrylonitrile-ethylene...Barr Harbor Dr., West Conshohocken, PA 19428-2959. Isobutylene-isoprene copolymer. Polyamide/polyether block...

2013-04-01

353

21 CFR 177.2600 - Rubber articles intended for repeated use.  

Code of Federal Regulations, 2014 CFR

...Elastomers. Acrylonitrile-butadiene copolymer. Brominated isobutylene-isoprene copolymers complying with § 177.1210. Butadiene-acrylonitrile-ethylene...Barr Harbor Dr., West Conshohocken, PA 19428-2959. Isobutylene-isoprene copolymer. Polyamide/polyether block...

2014-04-01

354

21 CFR 177.2600 - Rubber articles intended for repeated use.  

Code of Federal Regulations, 2010 CFR

...the preparation of rubber articles include the...be safely used in rubber articles, subject...177.1210. Butadiene-acrylonitrile-ethylene glycol...4-hexadiene. Hydrogenated butadiene/acrylonitrile copolymers (CAS Reg...1991, by Polysar Rubber Corp., 1256...

2010-04-01

355

Preparation of periodic mesoporous silica-included divacant Keggin units for the catalytic oxidation of styrene to synthesize styrene oxide  

NASA Astrophysics Data System (ADS)

Periodic mesoporous composite catalysts, [( n-C 4H 9) 4N] 4[?-SiW 10O 34(H 2O) 2]/SBA-15 (TBA-1*/SBA-15, where TBA-1* = [( n-C 4H 9) 4N] 4[?-SiW 10O 34(H 2O) 2]), with TBA-1* loadings of 4.3-14.8% were prepared by simultaneous hydrolysis and co-condensation of the tetraethoxysilane (TEOS) in the presence of divacant Keggin-type polyoxometalate and triblock copolymer surfactant (P123) followed by hydrothermal treatment process. Structure integrity of the Keggin unit in as-prepared composites was studied by Fourier transform infrared spectroscopy (FT-IR), Raman scattering spectra, and 29Si magic-angle spinning (MAS) NMR. Periodic mesoporous structure of the composites was evaluated by low-angle X-ray powder diffraction (LXRD) patterns, nitrogen porosimetry, and transmission electron microscope (TEM) measurements. As-prepared TBA-1*/SBA-15 was used as an heterogeneous oxidation catalyst for the styrene epoxidation reaction to synthesize styrene oxide in the presence of dilute H 2O 2 (30%), and influences of solvent, molar ratio of styrene to H 2O 2, TBA-1* loading on the styrene conversion, styrene oxide yield and selectivity were considered.

Yu, Xiaodan; Xu, Leilei; Yang, Xia; Guo, Yingna; Li, Kexin; Hu, Jianglei; Li, Wei; Ma, Fengyan; Guo, Yihang

2008-05-01

356

Determination of urinary mandelic and phenylglyoxylic acids in styrene exposed workers and a control population  

Microsoft Academic Search

Styrene is rapidly metabolized in humans to mandelic () and phenylglyoxylic acids (P) which are excreted in urine. The present study investigates a gas chromatographic technique for measuring urinary concentrations of MA and PGA of workers exposed to styrene, compares the urinary concentrations of metabolites with time-weighted average air exposures to styrene and determines the levels of these metabolites in

VICTOR J. ELIA; LOREN A. ANDERSON; TIMOTHY J. MACDONALD; ARCH CARSON; C. RALPH BUNCHER; STUART M. BROOKS

1980-01-01

357

Microemulsion polymerization of styrene initiated with gamma ray  

NASA Astrophysics Data System (ADS)

The styrene microemulsion with high monomer content was stabilized with a specially designed emulsifier with a branch in lipophilic head. In order to keep the microemulsion stable during polymerization, the microemulsion was initiated with gamma ray at room temperature. It was observed that there was an apparent plateau of polymerization rate during polymerization. It was the number of growing polymer particles instead of the total polymer particles being kept constant during the plateau. The polymerization kinetics showed some similarity to that in styrene microemulsion stabilized with SDS and n-pentanol.

Mangling, Xu; Xuewu, Ge; Zhicheng, Zhang; Zhichao, Wu; Manwei, Zhang

1997-04-01

358

New styrene-b-isobutylene-b-styrene (SIBS) glaucoma drainage implant  

NASA Astrophysics Data System (ADS)

Purpose: To design and test the Miami-InnFocus Drainage Implant (MiDi) as a glaucoma shunt that is biocompatible, flexible, and significantly smaller than existing commercial implants in order to prevent postoperative hypotony, inflammation, scarring, erosion, and extrusion. Methods: A new biomaterial composed of styrene-b-isobutylene-b-styrene (SIBS) was used in a novel design for a glaucoma drainage implant. The implant consists of a tube 11mm long with an inner diameter of 70, 100, and 150 ?m and outer diameter of 250 ?m with a 1mm2 tab located 4.5mm from the proximal tip to prevent migration. The device was implanted in 15 New Zealand White rabbits for biocompatibility and efficacy testing. A similarly designed implant made of polydimethylsiloxane was implanted in 6 other animals as a pseudo-control. Typical GDI implantation technique was modified for this device. The proximal end of the new SIBS implant was inserted 2mm into the anterior chamber and the distal end placed in a subconjunctival space created by the surgeon. Biocompatibility of the device was studied by slit-lamp follow-up and intraocular pressure (IOP) measurements recorded periodically. Results: Biocompatibility of the MiDi was excellent. A low and diffuse bleb was observed with these devices. All SIBS tubes were patent 9 months after insertion. Immunostaining demonstrated non-continuous deposition of collagen with virtually no encapsulation. No macrophages or myofibroblast were visible around the SIBS polymer which was found more bioinert than the control PDMS. Conclusion: This newly designed glaucoma implant is clinically biocompatible in the rabbit model and maintained 100% patency at 9 months.

Orozco, Marcia A.; Acosta, Ana C.; Espana, Edgar M.; Pinchuk, Leonard; Weber, Bruce; Davis, Stewart; Arrieta, Esdras; Dubovy, Sander; Fantes, Francisco; Aly, Mohamed; Zhou, Yonghua; Parel, Jean-Marie

2006-02-01

359

Nonwoven fabric supported poly(acrylonitrile-vinyl acetate) gel electrolyte for lithium ion battery use  

Microsoft Academic Search

This paper reported on a new gel polymer electrolyte (GPE) based on polyethylene (PE) non-woven fabric supported poly(acrylonitrile-vinyl\\u000a acetate) (P(AN-VAc)\\/PE) membrane for lithium ion battery use. The preparation and performances of the P(AN-VAc)\\/PE membrane\\u000a and its GPE based on 1 M LiPF6 in dimethyl carbonate\\/diethylene carbonate\\/ethylene carbonate (1:1:1 in volume) were investigated with a comparison of the\\u000a unsupported P(AN-VAc) membrane. It

Xiaoping Li; Mumin Rao; Youhao Liao; Weishan Li; Mengqing Xu

2010-01-01

360

Nitrogen-doped carbon nanoparticles derived from acrylonitrile plasma for electrochemical oxygen reduction.  

PubMed

Nitrogen-doped carbon nanoparticles were synthesized via a solution plasma process, with acrylonitrile as a single-source precursor, followed by a post-thermal annealing process. The nitrogen-bonding states can be tuned by varying the annealing temperature. The best electrocatalytic activity for oxygen reduction reaction (ORR) in terms of both onset potential and limiting current density can be achieved for the catalyst annealed at an optimal temperature of 800 °C because of the high content of graphitic-N catalytic sites and a large specific surface area. PMID:25661238

Panomsuwan, Gasidit; Saito, Nagahiro; Ishizaki, Takahiro

2015-02-18

361

Estimating ambient concentration and cancer risk for 1,3-butadiene in Japan.  

PubMed

A detailed assessment of 1,3-butadiene exposure was performed for the purpose of risk assessment in Japan. The concentration of 1,3-butadiene and the 1,3-butadiene-exposure-related lifetime excess cancer risk in the general environment and in the vicinity of industrial point sources were estimated using two different types of diffusion models: the National Institute of Advanced Industrial Science and Technology-atmospheric dispersion model for exposure and risk assessment (AIST-ADMER) model ver. 1.0 for the estimation of regional scale concentrations and the Ministry of Economy, Trade and Industry - low rise industrial source dispersion (METI-LIS) model ver. 2.01 for the estimation of local concentrations near industrial sources. The calculated results indicate that the annual mean concentrations of 1,3-butadiene in residential areas are generally less than 0.5 microg/m(3), but in a few area near industrial point sources they exceed 1.7 microg/m(3), corresponding to a lifetime excess cancer risk of 10(-5). Using data on exposure concentrations and cancer unit risk, the lifetime excess cancer risk for persons exposed to 1,3-butadiene in Japan was evaluated. The results indicate that an extremely small number of people have a risk of developing 1,3-butadiene-exposure-related cancer that is greater than 10(-5), while that of most of the population in Japan is between 10(-5) and 10(-6). The total 1,3-butadiene-exposure-related cancer risk in Japan was calculated as 2.0 cases/year. A large proportion of the cancer risk was associated with general environmental areas. However, the individual risks of the population living in the vicinity of industrial point sources were significantly higher than those of the population living in the general environment. PMID:16685248

Mita, Kazuaki; Higashino, Haruyuki; Yoshikado, Hiroshi; Nakanishi, Junko

2006-01-01

362

Gold-loaded carbon nanoparticles from poly(vinyl alcohol)-b-poly(acrylonitrile) non-shell-cross-linked micelles.  

PubMed

Herein we show that a new amphiphilic poly(vinyl alcohol)-b-poly(acrylonitrile) block copolymer dispersed in water can be easily loaded with gold nanoparticles by addition of chlorauric acid followed by reduction by sodium borohydride. After deposition of the so-loaded micelles onto a silicon wafer, followed by an appropriate thermal treatment, the poly(acrylonitrile) core of the micelles is carbonized, while the poly(vinyl alcohol) shell is completely decomposed and volatilized, leading to gold encapsulated in carbon nanoparticles. The morphology of the micelles is maintained during thermal treatment without requiring shell-cross-linking of the micelles prior to pyrolysis. PMID:19557781

Bryaskova, Rayna; Willet, Nicolas; Duwez, Anne-Sophie; Debuigne, Antoine; Lepot, Laurent; Gilbert, Bernard; Jérôme, Christine; Jérôme, Robert; Detrembleur, Christophe

2009-08-01

363

Cloning and characterization of styrene catabolism genes from Pseudomonas fluorescens ST  

SciTech Connect

Styrene is used in large quantities in the manufacturing of plastics, synthetic rubber, and resins. Styrene-utilizing microorganisms have been isolate in consideration of their potential applications as biocatalysts in the removal of styrene in industrial wastes. However, data conserving styrene catabolism in bacteria are not abundant. In this paper the isolated of the Pseudomonas fluorescens ST genes involved in the first steps of styrene degradation are reported as well as the identification of the intermediates accumulated by single recombinant clones. 33 refs., 5 figs., 1 tab.

Marconi, A.M.; Solinas, F. [La Sapienza Univ. of Rome (Italy); Galli, E.; Bestetti, G. [Univ. of Milan (Italy)] [and others

1996-01-01

364

40 CFR 268.40 - Applicability of treatment standards.  

Code of Federal Regulations, 2010 CFR

...NA 9.7140NAAcrylonitrile107-13-1 0.24...NA2-Chloro-1,3-butadiene 126-99-80.057...stripper in the production of acrylonitrile.AcetonitrileAcrylonitrile...column in the production of acrylonitrile....

2010-07-01

365

16 CFR 303.7 - Generic names and definitions for manufactured fibers.  

Code of Federal Regulations, 2010 CFR

...35 percent by weight of acrylonitrile units EC29SE91.005...substance is a copolymer of acrylonitrile and a diene (such as butadiene) composed of not more...10 percent by weight of acrylonitrile units...

2010-01-01

366

High performance light-colored nitrile-butadiene rubber nanocomposites.  

PubMed

High mechanical performance nitrile-butadiene rubber (NBR) with light color was fabricated by the method of in situ formation of zinc disorbate (ZDS) or magnesium disorbate (MDS). The in situ formed ZDS and its polymerization via internal mixing was confirmed by X-ray diffaraction. The mechanical properties, ageing resistance, morphology and the dynamic mechanical analysis were fully studied. It was found that with increasing loading of metallic disorbate both the curing rate and the ionic crosslink density was largely increased. The modulus, tensile strength and tear strength were largely increased. With a comparison between internal mixing and opening mixing, the mechanical performance for the former one was obviously better than the latter one. The high performance was ascribed to the finely dispersion nano domains with irregular shape and obscure interfacial structures. Except for the NBR vulcanizate with a high loading of MDS, the others' ageing resistance with incorporation of these two metallic disorbate was found to be good. Dynamic mechanical analysis (DMA) showed that, with increasing loading of metallic disorbate, the highly increased storage modulus above -20 degrees C, the up-shifted glass transition temperature (Tg) and the reduced mechanical loss were ascribed to strengthened interfacial interactions. PMID:22408977

Lei, Yanda; Guo, Baochun; Chen, Feng; Zhu, Lixin; Zhou, Wenyou; Jia, Demin

2011-12-01

367

Bioaccumulation factors for chlorinated benzenes, chlorinated butadienes and hexachloroethane  

SciTech Connect

A field study was performed that measured bioaccumulation factors (BAFs) for chlorinated benzenes, chlorinated butadienes, and hexachloroethane in four species, Fundulus heteroclitus (mummichog), Callinectes sapidus (blue crabs), Brevoortia patronus (gulf menhaden), and Micropoganias undulatus (Atlantic croaker). The measured BAFs were not significantly different among the fishes. The measured BAFs for the C. sapidus were in good agreement with those measured for the fishes except for hexachloroethane (HCE), E- and Z-1,1,2,3,4-pentachlorobuta-1,3-diene (E-and Z-PeCBD), and hexachlorobuta-1,3-diene (HCBD). Their measured BAFs were approximately an order of magnitude smaller than those measured for the fishes. The measured BAFs were also in good agreement with BAFs reported/derived from the literature and to BAFs predicted using two methods of the Environmental Protection Agency (EPA) except for HCE, E- and Z-PeCBD, and HCBD in the C. sapidus. These BAFs were much smaller than the reported/derived and predicted BAFs. The smaller BAFs for HCE, E- and Z-PeCBD, and HCBD were consistent with the metabolism abilities for the C. sapidus, and metabolism processes are believed to be the cause for the smaller BAFs. The predicted BAFs were within a factor of five of the measured BAFs for 90% (n = 48) and 94% (n = 32) using the two methods of the EPA.

Burkhard, L.P. [Environmental Protection Agency, Duluth, MN (United States). National Health and Environmental Effects Research Lab.; Sheedy, B.R. [AScI Corp., Duluth, MN (United States); McCauley, D.J.; DeGraeve, G.M. [Battelle-Great Lakes Environmental Center, Traverse City, MI (United States)

1997-08-01

368

Acute behavioral effects of styrene exposure: a further analysis  

Microsoft Academic Search

Studies were carried out on two groups to styrene-based resin. Early morning urinary mandelic acid concentrations after two days without exposure correlated with reaction time measured on arrival at work. Men were found to differ considerably in their rate of clearance of mandelic acid-those with slow reaction times. After some months at reduced exposure, a small group of men with

N Cherry; B Rodgers; H Venables; H A Waldron; G G Wells

1981-01-01

369

Assessment of the potential risk to workers from exposure to 1,3-butadiene.  

PubMed Central

The available epidemiologic data provide equivocal evidence that 1,3-butadiene is carcinogenic in humans; some available studies suggest that the lymphopoietic system is a target, but there are inconsistencies among studies in the types of tumors associated with 1,3-butadiene exposure, and there is no evidence of a relationship between length of exposure and cancer risk, as one might expect if there was a true causal relationship between 1,3-butadiene exposure and cancer risk. The available chronic animal studies, however, show an increase in tumor incidence associated with exposure to high concentrations of 1,3-butadiene. In addition to the general uncertainty of the relevance of animal data to humans, there are several additional reasons why the National Toxicology Program's mouse study may not be appropriate for assessing possible human risks. These include: a) the possible involvement of a species-specific tumor virus (MuLV) in the response in mice; b) apparent differences between mice and humans in the rate of metabolism of 1,3-butadiene to reactive epoxides that may be proximate carcinogens; c) use of high dose levels that caused excess early mortality; and d) exposure of animals to 1,3-butadiene for only about half their lifetime. While recognizing the uncertainty in using the available animal data for risk assessment, we have performed low-dose extrapolation of the data to examine the implications of the data if humans were as sensitive as rats or mice to 1,3-butadiene, and to examine how the predictions of the animal data compare to that observed in the epidemiologic studies. With the mouse data, because the study was of less than lifetime duration, we have used the Hartley-Sielken time-to-tumor model to permit estimation of lifetime risk from the less than lifetime exposure of the study. With the rat data, we have used three plausible models for assessing low-dose risk: the multistage model, the Weibull model, and the Mantel-Bryan probit model. With both the rat and mouse data, we used information on how much 1,3-butadiene is retained by animals exposed to various concentrations of the chemical. This improves the accuracy of the low-dose extrapolation. When extrapolated to low-dose levels, mice appear to be at greater risk (by a factor of 5-fold to 40-fold) than rats. Some of this difference (a factor 3-fold to 5-fold) may be due to the faster rate of metabolism of 1,3-butadiene to, and higher blood levels of, epoxide derivatives in mice than in rats.(ABSTRACT TRUNCATED AT 400 WORDS) PMID:2205486

Turnbull, D; Rodricks, J V; Brett, S M

1990-01-01

370

Stable-Isotope-Based Labeling of Styrene-Degrading Microorganisms in Biofilters†  

PubMed Central

Deuterated styrene ([2H8]styrene) was used as a tracer in combination with phospholipid fatty acid (PLFA) analysis for characterization of styrene-degrading microbial populations of biofilters used for treatment of waste gases. Deuterated fatty acids were detected and quantified by gas chromatography-mass spectrometry. The method was evaluated with pure cultures of styrene-degrading bacteria and defined mixed cultures of styrene degraders and non-styrene-degrading organisms. Incubation of styrene degraders for 3 days with [2H8]styrene led to fatty acids consisting of up to 90% deuterated molecules. Mixed-culture experiments showed that specific labeling of styrene-degrading strains and only weak labeling of fatty acids of non-styrene-degrading organisms occurred after incubation with [2H8]styrene for up to 7 days. Analysis of actively degrading filter material from an experimental biofilter and a full-scale biofilter by this method showed that there were differences in the patterns of labeled fatty acids. For the experimental biofilter the fatty acids with largest amounts of labeled molecules were palmitic acid (16:0), 9,10-methylenehexadecanoic acid (17:0 cyclo9-10), and vaccenic acid (18:1 cis11). These lipid markers indicated that styrene was degraded by organisms with a Pseudomonas-like fatty acid profile. In contrast, the most intensively labeled fatty acids of the full-scale biofilter sample were palmitic acid and cis-11-hexadecenoic acid (16:1 cis11), indicating that an unknown styrene-degrading taxon was present. Iso-, anteiso-, and 10-methyl-branched fatty acids showed no or weak labeling. Therefore, we found no indication that styrene was degraded by organisms with methyl-branched fatty fatty acids, such as Xanthomonas, Bacillus, Streptomyces, or Gordonia spp. PMID:11571187

Alexandrino, Maria; Knief, Claudia; Lipski, André

2001-01-01

371

Metabolism of styrene by Rhodococcus rhodochrous NCIMB 13259.  

PubMed Central

Rhodococcus rhodochrous NCIMB 13259 grows on styrene, toluene, ethylbenzene, and benzene as sole carbon sources. Simultaneous induction tests with cells grown on styrene or toluene showed high rates of oxygen consumption with toluene cis-glycol and 3-methylcatechol, suggesting the involvement of a cis-glycol pathway. 3-Vinylcatechol accumulated when intact cells were incubated with styrene in the presence of 3-fluorocatechol to inhibit catechol dioxygenase activity. Experiments with 18O2 showed that 3-vinylcatechol was produced following a dioxygenase ring attack. Extracts contained a NAD-dependent cis-glycol dehydrogenase, which converted styrene cis-glycol to 3-vinylcatechol. Both catechol 1,2- and 2,3-dioxygenase activities were present, and these were separated from each other and from the activities of cis-glycol dehydrogenase and 2-hydroxymuconic acid semialdehyde hydrolase by ion-exchange chromatography of extracts. 2-Vinylmuconate accumulated in the growth medium when cells were grown on styrene, apparently as a dead-end product, and extracts contained no detectable muconate cycloisomerase activity. 3-Vinylcatechol was cleaved by catechol 2,3-dioxygenase to give a yellow compound, tentatively identified as 2-hydroxy-6-oxoocta-2,4,7-trienoic acid, and the action of 2-hydroxymuconic acid semialdehyde hydrolase on this produced acrylic acid. A compound with the spectral characteristics of 2-hydroxypenta-2,4-dienoate was produced by the action of 2-hydroxymuconic acid semialdehyde hydrolase on the 2,3-cleavage product of 3-methylcatechol. Extracts were able to transform 2-hydroxypenta-2,4-dienoate and 4-hydroxy-2-oxopentanoate into acetaldehyde and pyruvate.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:8017910

Warhurst, A M; Clarke, K F; Hill, R A; Holt, R A; Fewson, C A

1994-01-01

372

Discovery and optimization of sulfonyl acrylonitriles as selective, covalent inhibitors of protein phosphatase methylesterase-1.  

PubMed

The serine hydrolase protein phosphatase methylesterase-1 (PME-1) regulates the methylesterification state of protein phosphatase 2A (PP2A) and has been implicated in cancer and Alzheimer's disease. We recently reported a fluorescence polarization-activity-based protein profiling (fluopol-ABPP) high-throughput screen for PME-1 that uncovered a remarkably potent and selective class of aza-?-lactam (ABL) PME-1 inhibitors. Here, we describe a distinct set of sulfonyl acrylonitrile inhibitors that also emerged from this screen. The optimized compound, 28 (AMZ30), selectively inactivates PME-1 and reduces the demethylated form of PP2A in living cells. Considering that 28 is structurally unrelated to ABL inhibitors of PME-1, these agents, together, provide a valuable set of pharmacological probes to study the role of methylation in regulating PP2A function. We furthermore observed that several serine hydrolases were sensitive to analogues of 28, suggesting that more extensive structural exploration of the sulfonyl acrylonitrile chemotype may result in useful inhibitors for other members of this large enzyme class. PMID:21639134

Bachovchin, Daniel A; Zuhl, Andrea M; Speers, Anna E; Wolfe, Monique R; Weerapana, Eranthie; Brown, Steven J; Rosen, Hugh; Cravatt, Benjamin F

2011-07-28

373

REPRODUCTIVE EFFECTS ASSESSMENT GROUP'S REPORT ON THE MUTAGENICITY OF 1.3-BUTADIENE AND ITS REACTIVE METABOLITES  

EPA Science Inventory

A major data gap for assessing heritable risk from exposure to 1,3-butadiene is the lack of mammalian mutagenicity data. The data base on the mutagenic potential of 1,3-butadiene is limited to three bacterial studies from the same laboratory. Two of these studies were positive on...

374

PRODUCTS OF THE GAS-PHASE REACTIONS OF 1,3-BUTADIENE WITH OH AND NO3 RADICALS. (R825252)  

EPA Science Inventory

1,3-Butadiene is emitted into the atmosphere from a number of sources including combustion sources and is listed in the United States as a hazardous air pollutant. In the atmosphere, 1,3-butadiene reacts with OH radicals, NO3 radicals, and O3 ...

375

Structure-toxicity relationship study of para-halogenated styrene analogues in CYP2E1 transgenic cells  

PubMed Central

Styrene is one of the most important industrial intermediates consumed in the world and is mainly used as a monomer for reinforced plastics and rubber. Styrene has been found to be hepatotoxic and pneumotoxic in humans and experimental animals. The toxicity of styrene is suggested to be metabolism-dependent. Styrene-7,8-oxide has been considered as the major metabolite responsible for styrene-induced cytotoxicity. The objective of the study was to investigate the correlation between cytotoxicity of styrene and chemical and biochemical properties of the vinyl group of styrene by development of structure activity relationships (SAR). 4-Fluorostyrene, 4-chlorostyrene and 4-bromostyrene were selected for the SAR study. Cytotoxicity of styrene and the halogenated styrene derivatives with an order of 4-bromostyrene > 4-chlorostyrene > 4-fluorostyrene ? styrene was observed in CYP2E1 transgenic cells. Similar orders in the efficiency of the metabolism of styrene and the halogenated styrene analogues to their oxides and in the electrophilicity of the corresponding oxides were observed. Additionally, the order of the potency of cellular glutathione depletion and the degree of protein adduction induced by styrene and the halogenated styrenes were consistent with that of their cytotoxicities. The wild-type cells were less susceptible to the toxicity of the corresponding model compounds than CYP2E1 cells. The present study provided insight into the roles of the biochemical and chemical properties of styrene in its cytotoxicity. PMID:22366341

Chung, Jou-Ku; Shen, Shuijie; Jiang, Zhiteng; Yuan, Wei; Zheng, Jiang

2012-01-01

376

Significance of 1,3-butadiene to the US air toxics regulatory effort.  

PubMed

Because of its prevalence, particularly as a combustion by-product, 1,3-butadiene is a particularly important air toxic. It plays a significant role in all air toxics regulatory efforts in the US. The various requirements of the Federal Clean Air Act (CAA) dealing with air toxics are reviewed and the significance of 1,3-butadiene in each area is discussed in light of what is known about its emissions and health effects. The impacts of the changes in the understanding of 1,3-butadiene cancer potency over the past 15 years demonstrates the possible impact of such benchmarks and the importance of using the best science in understanding public health risks. PMID:11397386

Morrow, N L

2001-06-01

377

Ultrasonic velocity and absorption study of binary mixtures of cyclohexane with acrylonitrile by interferometric method at different frequencies  

NASA Astrophysics Data System (ADS)

The ultrasonic velocity (u), absorption (?), density (?), and viscosity (?) has been measured at different frequencies (1MHz to 10MHz) in the binary mixtures of cyclohexane with acrylonitriile over the entire range of composition at temperature 303K. Vander Waal's constant (b), adiabatic compressibility (?a), acoustic impedance (Z), molar volume (V), free length (Lf), free volume, internal pressure, intermolecular radius and relative association have been also calculated. A special application for acrylonitrile is in the manufacture of carbon fibers. These are produced by paralysis of oriented poly acrylonitrile fibers and are used to reinforce composites for high-performance applications in the aircraft, defense and aerospace industries. Other applications of acrylonitrile are in the production of fatty amines, ion exchange resins and fatty amine amides used in cosmetics, adhesives, corrosion inhibitors and water-treatment resins. Cyclohexane derivatives can be used for the synthesis of pharmaceuticals, dyes, herbicides, plant growth regulator, plasticizers, rubber chemicals, nylon, cyclamens and other organic compounds. In the view of these extensive applications of acrylonitrile and cyclohexane in the engineering process, textile and pharmaceutical industries present study provides qualitative information regarding the nature and strength of interaction in the liquid mixtures through derive parameters from ultrasonic velocity and absorption measurement.

Pawar, N. R.; Chimankar, O. P.; Bhandakkar, V. D.; Padole, N. N.

2012-12-01

378

Synergistic effects of superbasic catalysts on the selective formation of acrylonitrile via oxidative methylation of acetonitrile with methane  

SciTech Connect

The oxidative methylation of acetonitrile with methane to acrylonitrile occurs more actively and selectively over bialkali promoted CaO catalysts than over any monoalkali promoted system. The most effective catalytic systems are obtained with LiA + CsA, NaA + CsA, or KA + CsA (A = SO[sup 2[minus

Ruckenstein, E.; Khan, A.Z. (State Univ. of New York, Buffalo, NY (United States))

1994-02-01

379

Studies on photodissociation dynamics of butadiene monoxide at 193 nm.  

PubMed

Butadiene monoxide (BMO) undergoes the S(0)-->S(1) transition, involving the excitation of both pi and n electrons to pi(*) orbital, at 193 nm. After relaxing to the ground electronic state via internal conversion, BMO molecules undergo intramolecular rearrangement and subsequently dissociate to form unexpected OH radicals, which were detected state selectively by laser-induced fluorescence technique, and the energy state distribution was measured. OH is produced vibrationally cold, OH(nu(")=0,J(")), with the rotational population characterized by a rotational temperature of 456+/-70 K. The major portion (approximately 60%) of the available energy is partitioned into internal degrees of the photofragments, namely, vibration and rotation. A considerable portion (25%-35%) also goes to the relative translation of the products. The Lambda doublet and spin-orbit ratios of OH were measured to be nearly unity, implying statistical distribution of these states and, hence, no preference for any of the Lambda doublet (Lambda+ and Lambda-) and spin-orbit (Pi(3/2) and Pi(1/2)) states. Formation time of the nascent OH radical was measured to be <100 ns. Different products, such as crotonaldehyde and methyl vinyl ketone, were detected by gas chromatography as stable products of photodissociation. A reaction mechanism for the formation of all these photoproducts, transient and stable, is proposed. The multiple pathways by which these products can be formed have been theoretically optimized, and energies have been calculated. Absorption cross section of BMO at 193 nm was measured, and quantum yield of OH generation channel was also determined. PMID:18205452

Sengupta, Sumana; Indulkar, Yogesh; Kumar, Awadhesh; Naik, Prakash D; Bajaj, Paramanand

2008-01-14

380

Enantioselective C-H crotylation of primary alcohols via hydrohydroxyalkylation of butadiene.  

PubMed

The direct, by-product-free conversion of basic feedstocks to products of medicinal and agricultural relevance is a broad goal of chemical research. Butadiene is a product of petroleum cracking and is produced on an enormous scale (about 12 × 10(6) metric tons annually). Here, with the use of a ruthenium catalyst modified by a chiral phosphate counterion, we report the direct redox-triggered carbon-carbon coupling of alcohols and butadiene to form products of carbonyl crotylation with high levels of anti-diastereoselectivity and enantioselectivity in the absence of stoichiometric by-products. PMID:22442385

Zbieg, Jason R; Yamaguchi, Eiji; McInturff, Emma L; Krische, Michael J

2012-04-20

381

EFFECT OF STARCH SWELLING ON THE COMPOSITE MODULUS OF LOW- AND HIGH-GLUTEN WHEAT FLOURS AND CARBOXYLATED STYRENE-BUTADIENE LATEX  

Technology Transfer Automated Retrieval System (TEKTRAN)

Wheat flour is a plentiful renewable resource. The dry flour is rigid and can be used as a potential reinforcement material for soft rubber matrices. Wheat flours with two different gluten contents were investigated and the initial cook temperature of the aqueous wheat flour dispersions was varied...

382

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

Microsoft Academic Search

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

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

2011-01-01

383

Mechanical Properties and Vulcanization Characteristics of Styrene-Butadiene Rubber (sbr) Based Compounds Filled with Eggshell Powder as a Bio-Filler  

NASA Astrophysics Data System (ADS)

Egg shell is an ordered bioceramic composite with five different layers [1, 2]. In this study, the effect of using various types of eggshell powder including after and before hatching eggshell and boiled eggshell on the mechanical properties and vulcanization characteristics of SBR compounds has been investigated. The obtained results were compared with calcium carbonate filled compounds. Evaluation of mechanical properties exhibited that incorporation of eggshell increased almost all of the mechanical properties of the compounds. BET test demonstrated higher specific area of eggshell powders compare with calcium carbonate. Some of the observed results attributed to higher specific area of eggshell powder. However, there is no definitive reason for some other results at this time. Vulcanization characteristics of the compounds showed that incorporation of eggshell powder had no considerable effect on curing time. The results of this research showed that all kinds of eggshell powders can be used in SBR based compounds successfully.

Saeb, Mohammad Reza; Dakhel, Hadi Ramezani; Ghaffari, Akbar

2008-08-01

384

[Study of amount of evaporation residue in extracts from plastic kitchen utensils into four food-simulating solvents].  

PubMed

The amount of evaporation residue was investigated as an index of total amount of non-volatile substances that migrated from plastic kitchen utensils into four food-simulating solvents (water, 4% acetic acid, 20% ethanol and heptane). The samples were 71 products made of 12 types of plastics for food contact use. The amount was determined in accordance with the Japanese testing method. The quantitation limit was 5 µg/mL. In the cases of polyethylene, polypropylene, polystyrene, acrylonitrile styrene resin, acrylonitrile butadiene styrene resin, polyvinyl chloride, polyvinylidene chloride, polymethylpentene, polymethylmethacrylate and polyethylene terephthalate samples, the amount was highest for heptane and very low for the other solvents. On the other hand, in the cases of melamine resin and polyamide samples, the amount was highest for 4% acetic acid or 20% ethanol and lowest for heptane. These results enabled the selection of the most suitable solvent, and the rapid and efficient determination of evaporation residue. PMID:21383537

Ohno, Hiroyuki; Suzuki, Masako; Kawamura, Yoko

2011-01-01

385

Grafting of styrene onto carbon fiber having perester groups  

Microsoft Academic Search

The oxidized carbon fiber having t-butyl perester groups was prepared by the esterification of acid chloride groups on the carbon fiber with t-butyl hydroperoxide. Then, graft polymerization of styrene onto the carbon fiber having t-butyl perester group was carried out. The concentration of monomer affected grafting efficiency. The grafting efficiency increases with the polymerization time and reachs a constant value

Ryutoku Yosomiya; Takao Fujisawa

1985-01-01

386

Density functional theory study of the structure and vibrational modes of acrylonitrile adsorbed on Cu(100).  

PubMed

We present a theoretical study of the structure and vibrations of acrylonitrile adsorbed on a Cu(100) metal surface. Simulations have been carried out by means of the density functional theory adopting periodic boundary conditions and including van der Waals dispersion forces. The two most stable structures (which are almost degenerate in energy) correspond to the molecule adsorbed parallel to the metal surface. In both geometries, the vinyl (C=C) and the cyano (C?N) groups are the anchorage sites to the surface atoms. Low energy transition barriers allow fast isomerization between both structures. Molecular adsorption shifts some of their vibrational frequencies with respect to the gas phase, mainly the C=C and the C?N stretching modes, in agreement with recent experimental measurements [Tornero et al., Phys. Chem. Chem. Phys., 2011, 13, 8475]. PMID:23232941

Díaz-Tendero, Sergio; Alcamí, Manuel; Martín, Fernando

2013-01-28

387

Dielectric Relaxation Behavior of Poly(acrylonitrile-co-methacrylonitrile) Microcapsules Dispersed in a Silicone Matrix  

NASA Technical Reports Server (NTRS)

The dielectric relaxation behavior of poly(acrylonitrile-co-methacrylonitrile) dispersed in a cured polydimethyl siloxane (PDMS) matrix as microcapsules was investigated over multiple thermal cycles and at varying concentrations. The copolymer microcapsules contained an isopentane core. In the PDMS matrix this copolymer displayed a pronounced relaxation signal at temperatures above the glass transition of the copolymers due to Maxwell-Wagner-Sillars (MWS) relaxation. The mechanism of MWS relaxation interpreted by the Havriliak-Negami and Kohlrausch-Williams-Watts relaxation functions was found to be very similar to previous studies of neat polyacrylonitrile and its copolymer. The activation energy of the relaxation decreased over successive thermal cycling coincident with a decreasing strength of the relaxation. These observations were attributed to the decreasing concentration of nitrile groups due to intramolecular cyclizations.

Park, Taigyoo; OBrien, Emmett; Lizotte, Jeremy R.; Glass, Thomas E.; Ward, Thomas C.; Long, Timothy E.; Leo, Donald J.

2006-01-01

388

Prevention of acrylonitrile-induced gastrointestinal bleeding by sulfhydryl compounds, atropine and cimetidine  

SciTech Connect

We have recently demonstrated that acrylonitrile (VCN) causes acute gastric hemorrhage and mucosal erosions. The current studies were undertaken to investigate the effects of the sulfhydryl-containing compounds, cysteine and cysteamine, the cholinergic blocking agent atropine and the histamine H2 receptor antagonist, cimetidine on the VCN-induced gastrointestinal (GI) bleeding in rats. Our data shows that pretreatment with L-cysteine, cysteamine, atropine or cimetidine has significantly protected rats against the VCN-induced GI bleeding. A possible mechanism of the VCN-induced GI bleeding may involve the interaction of VCN with critical sulfhydryl groups that, in turn, causes alteration of acetylcholine muscarinic receptors to lead to gastric hemorrhagic lesions and bleeding.

Ghanayem, B.I.; Ahmed, A.E.

1986-07-01

389

Preparation of hydrophilic amidoxime fibers by cografting acrylonitrile and methacrylic acid from an optimized monomer composition  

NASA Astrophysics Data System (ADS)

To improve the adsorption rate of uranium from seawater, hydrophilic amidoxime (AO) fibers were prepared by cografting of methacrylic acid (MAA) with acrylonitrile (AN) onto polypropylene fibers and subsequent conversion of the produced cyano group to an amidoxime group by reaction with hydroxylamine. An optimum amidoximation time of 0.75 h was selected at a weight ratio of AN to MAA ( x/y) of 80/20. By varying x/y in the monomer mixture, cografted polymers were prepared. The value of x/y governed the AO group density and water content of the resultant fibrous adsorbents. As x/y increased, the AO group density of the fiber increased and its water content decreased. The AO/MAA adsorbent, based on the PP fibers prepared by cografting at an x/y of 60/40 and subsequent amidoximation, exhibited the highest uranium adsorption rate in the flow-through mode.

Kawai, Tomomi; Saito, Kyoichi; Sugita, Kazuyuki; Kawakami, Takashi; Kanno, Jun-ichi; Katakai, Akio; Seko, Noriaki; Sugo, Takanobu

2000-10-01

390

Beyond benzyl grignards: facile generation of benzyl carbanions from styrenes.  

PubMed

Benzylic functionalization is a convenient approach towards the conversion of readily available aromatic hydrocarbon feedstocks into more useful molecules. However, the formation of carbanionic benzyl species from benzyl halides or similar precursors is far from trivial. An alternative approach is the direct reaction of a styrene with a suitable coupling partner, but these reactions often involve the use of precious-metal transition-metal catalysts. Herein, we report the facile and convenient generation of reactive benzyl anionic species from styrenes. A Cu(I)-catalyzed Markovnikov hydroboration of the styrenic double bond by using a bulky pinacol borane source is followed by treatment with KOtBu to facilitate a sterically induced cleavage of the C-B bond to produce a benzylic carbanion. Quenching this intermediate with a variety of electrophiles, including CO(2), CS(2), isocyanates, and isothiocyanates, promotes C-C bond formation at the benzylic carbon atom. The utility of this methodology was demonstrated in a three-step, two-pot synthesis of the nonsteroidal anti-inflammatory drug (±)-flurbiprofen. PMID:22718528

Grigg, R David; Rigoli, Jared W; Van Hoveln, Ryan; Neale, Samuel; Schomaker, Jennifer M

2012-07-23

391

Quantitation of DNA Adducts Induced by 1,3-Butadiene  

NASA Astrophysics Data System (ADS)

Human exposure to 1,3-butadiene (BD) present in automobile exhaust, cigarette smoke, and forest fires is of great concern because of its potent carcinogenicity. The adverse health effects of BD are mediated by its epoxide metabolites such as 3,4-epoxy-1-butene (EB), which covalently modify genomic DNA to form promutagenic nucleobase adducts. Because of their direct role in cancer, BD-DNA adducts can be used as mechanism-based biomarkers of BD exposure. In the present work, a mass spectrometry-based methodology was developed for accurate, sensitive, and precise quantification of EB-induced N-7-(1-hydroxy-3-buten-2-yl) guanine (EB-GII) DNA adducts in vivo. In our approach, EB-GII adducts are selectively released from DNA backbone by neutral thermal hydrolysis, followed by ultrafiltration, offline HPLC purification, and isotope dilution nanoLC/ESI+-HRMS3 analysis on an Orbitrap Velos mass spectrometer. Following method validation, EB-GII lesions were quantified in human fibrosarcoma (HT1080) cells treated with micromolar concentrations of EB and in liver tissues of rats exposed to sub-ppm concentrations of BD (0.5-1.5 ppm). EB-GII concentrations increased linearly from 1.15 ± 0.23 to 10.11 ± 0.45 adducts per 106 nucleotides in HT1080 cells treated with 0.5-10 ?M DEB. EB-GII concentrations in DNA of laboratory rats exposed to 0.5, 1.0, and 1.5 ppm BD were 0.17 ± 0.05, 0.33 ± 0.08, and 0.50 ± 0.04 adducts per 106 nucleotides, respectively. We also used the new method to determine the in vivo half-life of EB-GII adducts in rat liver DNA (2.20 ± 0.12 d) and to detect EB-GII in human blood DNA. To our knowledge, this is the first application of nanoLC/ESI+-HRMS3 Orbitrap methodology to quantitative analysis of DNA adducts in vivo.

Sangaraju, Dewakar; Villalta, Peter W.; Wickramaratne, Susith; Swenberg, James; Tretyakova, Natalia

2014-07-01

392

Nitroxide mediated living radical polymerization of styrene in miniemulsion—modelling persulfate-initiated systems  

Microsoft Academic Search

Recently we have constructed a mechanistic model describing the nitroxide mediated miniemulsion polymerization (NMMP) of styrene at 135°C, using alkoxyamine initiators to control polymer growth (Nitroxide-Mediated Polymerization of Styrene in Miniemulsion. Modeling Studies of Alkoxyamine-Initiated Systems, 2001b). The model has since been expanded to describe styrene NMMP at 135°C using TEMPO and the free radical initiator, potassium persulfate (KPS). The

John W. Ma; Michael F. Cunningham; Kim B. McAuley; Barkev Keoshkerian; Michael Georges

2003-01-01

393

Influence of the water content and water activity on styrene degradation by Exophiala jeanselmei in biofilters  

Microsoft Academic Search

The performance at low water availability of styrene-degrading biofilters with the fungus Exophiala jeanselmei growing on perlite, the inert support, was investigated. E. jeanselmei degrades styrene at a water activity of 0.91–1. In biofilters, the styrene elimination capacity at a water activity of 0.91\\u000a is 5% of the maximal elimination capacity of 79?g?m-3?h-1 (water activity 1). Application of dry air

H. H. J. Cox; F. J. Magielsen; H. J. Doddema; W. Harder

1996-01-01

394

Stabilization of polypropylene, polypropylene blends with poly (styrene-b-(ethylene-co-butylene)-b-styrene) under irradiation: A comparative investigation  

NASA Astrophysics Data System (ADS)

The aim of this paper is to investigate the stabilization of polypropylene in the poly (styrene-b-(ethylene-co-butylene)-b-styrene) (SEBS)/polypropylene (PP) blends under irradiation with respect to PP. The PP films, SEBS/PP films were subjected to electron beam irradiation and characterized by wide angle X-ray diffraction (WAXD), differential scanning calorimetry (DSC), gel permeation chromatography (GPC), and dynamic mechanical thermal analysis (DMTA). It demonstrated that upon irradiation, the molecular weight of PP had a pronounced decrease due to the major chain scission, and the minor chain cross-linking or chain branching occurred at the higher irradiation dose. Stabilization of PP was improved in the presence of SEBS, exhibiting an enhanced irradiation resistance.

Luan, Shifang; Yang, Huawei; Shi, Hengchong; Zhao, Jie; Wang, Jianwei; Yin, Jinghua

2011-01-01

395

Guidance of neurite outgrowth on aligned electrospun polypyrrole/poly(styrene-beta-isobutylene-beta-styrene) fiber platforms.  

PubMed

The purpose of this work was to investigate the potential biomedical application of novel aligned electrospun polypyrrole (PPy)/poly(styrene-beta-isobutylene-beta-styrene) (SIBS) fibers. After successfully aligning the electroactive PPy/SIBS fibers based on our modified electrospinning method, we demonstrated that neurite outgrowth from PC12 cells could be highly orientated parallel to the aligned PPy/SIBS fibers. Physical interactions between the nerve cells and PPy/SIBS fibers through filopodia "sensing" were observed using atomic force microscopy. These observations indicate a role of contact guidance as a mechanism for the observed alignment. This work highlights the capacity for electroactive PPy/SIBS fibers to support and guide nerve cell differentiation through topographic cues, which is a highly desirable characteristic in medical implants for neurological applications. PMID:20694967

Liu, Xiao; Chen, Jun; Gilmore, Kerry J; Higgins, Michael J; Liu, Yong; Wallace, Gordon G

2010-09-15

396

Nuclease-functionalized poly(styrene-b-isobutylene-b-styrene) surface with anti-infection and tissue integration bifunctions.  

PubMed

Hydrophobic thermoplastic elastomers, e.g., poly(styrene-b-isobutylene-b-styrene) (SIBS), have found various in vivo biomedical applications. It has long been recognized that biomaterials can be adversely affected by bacterial contamination and clinical infection. However, inhibiting bacterial colonization while simultaneously preserving or enhancing tissue-cell/material interactions is a great challenge. Herein, SIBS substrates were functionalized with nucleases under mild conditions, through polycarboxylate grafts as intermediate. It was demonstrated that the nuclease-modified SIBS could effectively prevent bacterial adhesion and biofilm formation. Cell adhesion assays confirmed that nuclease coatings generally had no negative effects on L929 cell adhesion, compared with the virgin SIBS reference. Therefore, the as-reported nuclease coating may present a promising approach to inhibit bacterial infection, while preserving tissue-cell integration on polymeric biomaterials. PMID:25253647

Yuan, Shuaishuai; Zhao, Jie; Luan, Shifang; Yan, Shunjie; Zheng, Wanling; Yin, Jinghua

2014-10-22

397

Ternary Ag/MgO-SiO2 Catalysts for the Conversion of Ethanol into Butadiene.  

PubMed

Ternary Ag/Magnesia-silica catalysts were tested in the direct synthesis of 1,3-butadiene from ethanol. The influence of the silver content and the type of silica source on catalytic performance has been studied. Prepared catalysts were characterized by (29) Si NMR, N2 sorption, small-angle X-ray scattering measurements, XRD, environmental scanning electron microscopy with energy dispersive X-ray analysis (ESEM/EDX), FTIR spectroscopy of adsorbed pyridine and CO2 , temperature-programmed desorption of CO2 and UV/Vis diffuse reflectance spectroscopy. Based on these characterization results, the catalytic performance of the catalysts in the 1,3-butadiene formation process was interpreted and a tentative model explaining the role of the different catalytically active sites was elaborated. The balance of the active sites is crucial to obtain an active and selective catalyst to form 1,3-butadiene from ethanol. The optimal silver loading is 1-2?wt?% on a MgO-silica support with a molar Mg/Si ratio of 2. The silver species and basic sites (Mg?O pairs and basic OH groups) are of prime importance in the 1,3-butadiene production, catalyzing mainly the ethanol dehydrogenation and the aldol condensation, respectively. PMID:25410420

Janssens, Wout; Makshina, Ekaterina V; Vanelderen, Pieter; De Clippel, Filip; Houthoofd, Kristof; Kerkhofs, Stef; Martens, Johan A; Jacobs, Pierre A; Sels, Bert F

2015-03-01

398

EFFECTS OF 1,3-BUTADIENE, ISOPRENE, AND THEIR PHOTOCHEMICAL DEGRADATION PRODUCTS ON HUMAN LUNG CELLS  

EPA Science Inventory

Because of potential exposure both in the workplace and from ambient air, the known carcinogen 1,3-butadiene (BD) is considered a priority hazardous air pollutant. BD and its 2-methyl analog, isoprene (ISO), are chemically similar but have very different toxicities, with ISO show...

399

HEALTH AND ENVIRONMENTAL EFFECTS PROFILE FOR 2-CHLORO-1,3-BUTADIENE  

EPA Science Inventory

The Health and Environmental Effects Profile for 2-Chloro-1,3-Butadiene was prepared by the Office of Health and Environmental Assessment, Environmental criteria assessment Office, Cincinnati, OH for the Office of Solid Waste to support listings of hazardous constituents of a wid...

400

Straightforward one-pot stereoselective synthesis of substituted tetrahydrofurans from 1,3-butadienes and aldehydes  

E-print Network

,3-butadienes and aldehydes Maryline Roux, Chahinez Aouf, Jean-Luc Parrain* and Maurice Santelli* Laboratoire de from disilane 1 and added onto a range of aliphatic aldehydes to afford a direct access a sequence involving trans-metallation of 1 and two SE20 reactions of aldehydes. A way to activate the two

Paris-Sud XI, Université de

401

HYDROXYL RADICAL AND OZONE INITIATED PHOTOCHEMICAL REACTIONS OF 1,3-BUTADIENE. (R826247)  

EPA Science Inventory

1,3-Butadiene, classified as hazardous in the 1990 Clean Air Act Amendments, is an important ambient air pollutant. Understanding its atmospheric transformation is useful for its own sake, and is also helpful for eliciting isoprene's fate in the atmosphere (isoprene dominates ...

402

THE OZONE REACTION WITH BUTADIENE: FORMATION OF TOXIC PRODUCTS. (R826236)  

EPA Science Inventory

Abstract The formation yields of acrolein, 1,2-epoxy-3-butene and OH radicals have been measured from reaction of ozone with 1,3-butadiene at room temperature and atmosphere pressure. 1,3,5-Trimethyl benzene was added to scavenge OH radicals in measurements of product ...

403

Cooperative effects for CYP2E1 differ between styrene and its metabolites  

PubMed Central

Cooperative interactions are frequently observed in the metabolism of drugs and pollutants by cytochrome P450s; nevertheless, the molecular determinants for cooperativity remain elusive. Previously, we demonstrated that steady-state styrene metabolism by CYP2E1 exhibits positive cooperativity.We hypothesized that styrene metabolites have lower affinity than styrene toward CYP2E1 and limited ability to induce cooperative effects during metabolism. To test the hypothesis, we determined the potency and mechanism of inhibition for styrene and its metabolites toward oxidation of 4-nitrophenol using CYP2E1 Supersomes® and human liver microsomes.Styrene inhibited the reaction through a mixed cooperative mechanism with high affinity for the catalytic site (67 ?M) and lower affinity for the cooperative site (1100 ?M), while increasing substrate turnover at high concentrations. Styrene oxide and 4-vinylphenol possessed similar affinity for CYP2E1. Styrene oxide behaved cooperatively like styrene, but 4-vinylphenol decreased turnover at high concentrations. Styrene glycol was a very poor competitive inhibitor. Among all compounds, there was a positive correlation with binding and hydrophobicity.Taken together, these findings for CYP2E1 further validate contributions of cooperative mechanisms to metabolic processes, demonstrate the role of molecular structure on those mechanisms and underscore the potential for heterotropic cooperative effects between different compounds. PMID:23327532

Hartman, Jessica H.; Boysen, Gunnar; Miller, Grover P.

2014-01-01

404

Isolation and application of a styrene-degrading strain of Pseudomonas putida to biofiltration.  

PubMed

A bacterial strain ST201 capable of degrading styrene was isolated from soil and identified as Pseudomonas putida. This strain had high tolerance to styrene and could degrade it completely in 48 h at concentrations up to 600 mg/l. P. putida ST201 was also demonstrated to degrade a mixture of benzene, toluene, ethylbenzene and p-xylene. A packed tower biofilter inoculated with P. putida ST201 was constructed which removed styrene vapor with a styrene elimination capacity of 90 g/m3.h. PMID:16233471

Okamoto, Kenji; Izawa, Maki; Yanase, Hideshi

2003-01-01

405

Chitosan-poly (vinyl alcohol)\\/poly (acrylonitrile) (CS–PVA\\/PAN) composite pervaporation membranes for the separation of ethanol–water solutions  

Microsoft Academic Search

Pervaporation (PV) membranes made of a chitosan (CS) homogeneous membrane, poly (vinyl alcohol)-poly (acrylonitrile) (PVA–PAN) and chitosan-poly (vinyl alcohol)\\/poly (acrylonitrile) (CS–PVA\\/PAN) composite membranes for the separation of ethanol–water solutions were manufactured. The swelling behaviors of CS homogeneous membranes and CS–PVA\\/PAN composite membranes were measured. Effects of membrane thickness, CS–PVA concentrations in the coating solution, PVA concentrations in the CS–PVA blend

Bing-Bing Li; Zhen-Liang Xu; F. Alsalhy Qusay; Ran Li

2006-01-01

406

In vivo and in vitro characterization of poly(styrene-b-isobutylene-b-styrene) copolymer stent coatings for biostability, vascular compatibility and mechanical integrity.  

PubMed

The TAXUS Express 2 Paclitaxel Eluting Coronary Stent System employs a coating consisting of the thermoplastic elastomer, poly(styrene-b-isobutylene-b-styrene; SIBS), selected for its drug-eluting characteristics, vascular compatibility, mechanical properties, and biostability. This study was conducted to evaluate the impact of different SIBS (17-51 mole % styrene) compositions on mechanical properties, chemical stability, and vascular compatibility. Mechanical property (stress-strain measurements) and stability studies were conducted on polymer films with five different styrene contents (17, 24, 32, 39, and 51 mole %). The ultimate tensile strength did not change significantly with composition, but the elongation at break decreased with increased styrene content. A pulsatile fatigue test further confirmed the mechanical stability of SIBS up to 39 mole % styrene. The vascular compatibility of five different SIBS compositions was assessed using SIBS-only coated stents, in the coronary and carotid arteries in a porcine model study. The stability of the vessel wall, rate/degree of endothelialization, inflammation, and thrombus at timepoints from 30 to 180 days were evaluated. The results confirm vascular compatibility over the range of 17-51 mole % styrene. PMID:19274717

Strickler, Fred; Richard, Robert; McFadden, Sharon; Lindquist, Jeff; Schwarz, Marlene C; Faust, Rudolf; Wilson, Gregory J; Boden, Mark

2010-02-01

407

40 CFR 721.7020 - Distillates (petroleum), C(3-6), polymers with styrene and mixed terpenes (generic name).  

Code of Federal Regulations, 2014 CFR

...2014-07-01 false Distillates (petroleum), C(3-6), polymers with styrene...Substances § 721.7020 Distillates (petroleum), C(3-6), polymers with styrene...The chemical substance distillates (petroleum), C(3-6), polymers with...

2014-07-01

408

40 CFR 721.7020 - Distillates (petroleum), C(3-6), polymers with styrene and mixed terpenes (generic name).  

Code of Federal Regulations, 2010 CFR

...2010-07-01 false Distillates (petroleum), C(3-6), polymers with styrene...Substances § 721.7020 Distillates (petroleum), C(3-6), polymers with styrene...The chemical substance distillates (petroleum), C(3-6), polymers with...

2010-07-01

409

40 CFR 721.7020 - Distillates (petroleum), C(3-6), polymers with styrene and mixed terpenes (generic name).  

Code of Federal Regulations, 2013 CFR

...2013-07-01 false Distillates (petroleum), C(3-6), polymers with styrene...Substances § 721.7020 Distillates (petroleum), C(3-6), polymers with styrene...The chemical substance distillates (petroleum), C(3-6), polymers with...

2013-07-01

410

40 CFR 721.7020 - Distillates (petroleum), C(3-6), polymers with styrene and mixed terpenes (generic name).  

Code of Federal Regulations, 2012 CFR

...2012-07-01 false Distillates (petroleum), C(3-6), polymers with styrene...Substances § 721.7020 Distillates (petroleum), C(3-6), polymers with styrene...The chemical substance distillates (petroleum), C(3-6), polymers with...

2012-07-01

411

40 CFR 721.7020 - Distillates (petroleum), C(3-6), polymers with styrene and mixed terpenes (generic name).  

Code of Federal Regulations, 2011 CFR

...2011-07-01 false Distillates (petroleum), C(3-6), polymers with styrene...Substances § 721.7020 Distillates (petroleum), C(3-6), polymers with styrene...The chemical substance distillates (petroleum), C(3-6), polymers with...

2011-07-01

412

Comparative chronic toxicity and carcinogenicity of acrylonitrile by drinking water and oral intubation to Spartan® Sprague–Dawley rats  

Microsoft Academic Search

Groups of 100 male and 100 female Spartan® Sprague–Dawley rats were administered lifetime oral doses of Acrylonitrile (AN) by one of two routes of dosing, either at 0.1 or 10 mg\\/kg per day, 7 day per week by intubation or continually at 1 or 100 ppm AN in their drinking water. The doses selected were designed to approximate the same

Frederick R. Johannsen; George J. Levinskas

2002-01-01

413

Preparation and characterization of a special structural poly(acrylonitrile)-based microporous membrane for lithium-ion batteries  

Microsoft Academic Search

In this work, a special structural poly(acrylonitrile) (PAN)-based microporous membrane for lithium-ion batteries is prepared\\u000a from PAN emulsion by simple casting and extracting techniques. It is found that the microporous membrane is fabricated by\\u000a PAN particles with uniform size (about 580 nm), and a lot of micropores exist among the particles. The Gurley number of the\\u000a microporous membrane obviously depends on

Yongjian Huai; Jiandong Gao; Zhenghua Deng; Jishuan Suo

2010-01-01

414

MICROBIAL REDUCTIVE DECHLORINATION OF HEXACHLORO-1,3-BUTADIENE IN A METHANOGENIC ENRICHMENT CULTURE. (R825513C007)  

EPA Science Inventory

Sequential reductive dechlorination of hexachloro-1,3-butadiene (HCBD) was achieved by a mixed, methanogenic culture enriched from a contaminated estuarine sediment. Both methanol and lactate served as carbon and electron sources. Methanol was stoichiometrically converted to m...

415

Use of rice straw and radiation-modified maize starch/acrylonitrile in the treatment of wastewater.  

PubMed

Graft copolymerization of acrylonitrile onto maize starch by a simultaneous irradiation technique using gamma-rays as the initiator was studied with regard to the various parameters of importance: the monomer-to-maize starch ratio and total dose (kGy). The water absorption of the modified maize starch was measured. The starch modified by acrylonitrile gives low water absorbance. Conversion of the copolymer to the amidoxime form gives high swelling. The gel (%) and the grafting efficiency were measured. An investigation was carried out to study the adsorption of basic violet 7, basic blue 3, direct yellow 50 and acid red 37 from aqueous solutions by the water-insoluble modified starch containing amidoxime groups and rice straw. The effects of initial pH of the solution, pollutant concentration and treatment time on the adsorption were studied and it was found that the maximum adsorption was at 1:2 (starch/acrylonitrile) at irradiation dose 30 kGy. PMID:16300882

Abdel-Aal, S E; Gad, Y H; Dessouki, A M

2006-02-28

416

Physiological analysis of the expression of the styrene degradation gene cluster in Pseudomonas fluorescens ST  

SciTech Connect

The effects of different carbon sources on expression of the styrene catabolism genes in Pseudomonas fluorescens ST were analyzed by using a promoter probe vector, pPR9TT, which contains transcription terminators upstream and downstream of the {beta}-galactosidase reporter system. Expression of the promoter of the stySR operon, which codes for the styrene two-component regulatory system, was found to be constitutive and not subject to catabolite repression. This was confirmed by the results of an analysis of the stySR transcript in P. fluorescens ST cells grown on different carbon sources. The promoter of the operon of the upper pathway, designated PstyA, was induced by styrene and repressed to different extents by organic acids or carbohydrates. In particular, cells grown on succinate or lactate in the presence of styrene started to exhibit {beta}-galactosidase activity during the mid-exponential growth phase, before the preferred carbon sources were depleted, indicating that there is a threshold succinate and lactate concentration which allows induction of styrene catabolic genes. In contrast, cells grown on glucose, acetate, or glutamate and styrene exhibited a diauxic growth curve, and {beta}-galactosidase activity was detected only after the end of the exponential growth phase. In each experiment the reliability of the reporter system constructed was verified by comparing the {beta}-galactosidase activity and the activity of the styrene monooxygenase encoded by the first gene of the styrene catabolic operon.

Santos, P.M.; Blatny, J.M.; Di Bartolo, I.; Valla, S.; Zennaro, E.

2000-03-01

417

76 FR 77709 - Butyl acrylate-methacrylic acid-styrene polymer; Tolerance Exemption  

Federal Register 2010, 2011, 2012, 2013, 2014

...FRL-9327-6] Butyl acrylate-methacrylic acid-styrene polymer; Tolerance Exemption...tolerance for residues of 2-Propenoic acid, 2-methyl-, polymer with butyl 2-propenoate...also known as butyl acrylate-methacrylic acid-styrene polymer when used as an...

2011-12-14

418

Impaired colour discrimination among workers exposed to styrene: relevance of a urinary metabolite  

Microsoft Academic Search

OBJECTIVES--To survey the loss of colour vision among Japanese workers who have been exposed to styrene concentrations currently considered low (about 20 ppm). Also to assess the effects of styrene by examination of the nature of the relation between disorder of colour vision and age, alcohol consumption, and other variables. METHODS--Colour discrimination was examined in 64 male workers exposed to

T Eguchi; R Kishi; I Harabuchi; J Yuasa; Y Arata; Y Katakura; H Miyake

1995-01-01

419

Fatty acid-based monomers as styrene replacements for liquid molding resins  

Microsoft Academic Search

One method of reducing styrene emissions from vinyl ester (VE) and unsaturated polyester resins (UPE) is to replace some or all of the styrene with fatty acid-based monomers. Methacrylated fatty acid (MFA) monomers are ideal candidates because they are inexpensive, have low volatilities, and free-radically polymerize with vinyl ester. The viscosity of VE resins using these fatty acid monomers ranged

John J. La Scala; James M. Sands; Joshua A. Orlicki; E. Jason Robinette; Giuseppe R. Palmese

2004-01-01

420

Physiological Analysis of the Expression of the Styrene Degradation Gene Cluster in Pseudomonas fluorescens ST  

PubMed Central

The effects of different carbon sources on expression of the styrene catabolism genes in Pseudomonas fluorescens ST were analyzed by using a promoter probe vector, pPR9TT, which contains transcription terminators upstream and downstream of the ?-galactosidase reporter system. Expression of the promoter of the stySR operon, which codes for the styrene two-component regulatory system, was found to be constitutive and not subject to catabolite repression. This was confirmed by the results of an analysis of the stySR transcript in P. fluorescens ST cells grown on different carbon sources. The promoter of the operon of the upper pathway, designated PstyA, was induced by styrene and repressed to different extents by organic acids or carbohydrates. In particular, cells grown on succinate or lactate in the presence of styrene started to exhibit ?-galactosidase activity during the mid-exponential growth phase, before the preferred carbon sources were depleted, indicating that there is a threshold succinate and lactate concentration which allows induction of styrene catabolic genes. In contrast, cells grown on glucose, acetate, or glutamate and styrene exhibited a diauxic growth curve, and ?-galactosidase activity was detected only after the end of the exponential growth phase. In each experiment the reliability of the reporter system constructed was verified by comparing the ?-galactosidase activity and the activity of the styrene monooxygenase encoded by the first gene of the styrene catabolic operon. PMID:10742204

Santos, Pedro Miguel; Blatny, Janet Martha; Di Bartolo, Ilaria; Valla, Svein; Zennaro, Elisabetta

2000-01-01

421

The Effect of Uncertainty in Exposure Estimation on the Exposure-Response Relation between 1,3-Butadiene and Leukemia  

PubMed Central

In a follow-up study of mortality among North American synthetic rubber industry workers, cumulative exposure to 1,3-butadiene was positively associated with leukemia. Problems with historical exposure estimation, however, may have distorted the association. To evaluate the impact of potential inaccuracies in exposure estimation, we conducted uncertainty analyses of the relation between cumulative exposure to butadiene and leukemia. We created the 1,000 sets of butadiene estimates using job-exposure matrices consisting of exposure values that corresponded to randomly selected percentiles of the approximate probability distribution of plant-, work area/job group-, and year specific butadiene ppm. We then analyzed the relation between cumulative exposure to butadiene and leukemia for each of the 1,000 sets of butadiene estimates. In the uncertainty analysis, the point estimate of the RR for the first non zero exposure category (>0–<37.5 ppm-years) was most likely to be about 1.5. The rate ratio for the second exposure category (37.5–<184.7 ppm-years) was most likely to range from 1.5 to 1.8. The RR for category 3 of exposure (184.7–<425.0 ppm-years) was most likely between 2.1 and 3.0. The RR for the highest exposure category (425.0+ ppm-years) was likely to be between 2.9 and 3.7. This range off RR point estimates can best be interpreted as a probability distribution that describes our uncertainty in RR point estimates due to uncertainty in exposure estimation. After considering the complete probability distributions of butadiene exposure estimates, the exposure-response association of butadiene and leukemia was maintained. This exercise was a unique example of how uncertainty analyses can be used to investigate and support an observed measure of effect when occupational exposure estimates are employed in the absence of direct exposure measurements. PMID:19826555

Graff, John J.; Sathiakumar, Nalini; Macaluso, Maurizio; Maldonado, George; Matthews, Robert; Delzell, Elizabeth

2009-01-01

422

Optimization of photorefractive polymers doped with styrene-based chromophores  

NASA Astrophysics Data System (ADS)

We present a study on the effects of the dark conductivity on the photorefractive performance of polymers doped with styrene-based chromophores. We find that reducing dark conductivity in such composites increases diffraction efficiency and at the same time decreases the response time. We use a polymer composite based on a polyvinylcarbazole matrix doped with 4-Homopiperidinobenzylidenemalononitrile (7- DCST), sensitized with C60, and plasticized with N- ethylcarbazole (ECZ) and butyl benzyl phthalate (BBP). The reduction of the dark conductivity is achieved by coating one of the electrodes with a SiO blocking layer.

Fuentes-Hernandez, C.; Herlocker, Jon A.; Wang, J. F.; Zhang, Yadong; Marder, Seth R.; Peyghambarian, Nasser; Kippelen, Bernard

2001-06-01

423

Depletion by Styrene of Glutathione in Plasma and Bronchioalveolar Lavage Fluid of Non-Swiss Albino (NSA) Mice  

Microsoft Academic Search

Styrene is a widely used chemical, but it is known to produce lung and liver damage in mice. This may be related to oxidative stress associated with the decrease in the levels of reduced glutathione (GSH) in the target tissues. The purpose of this study was to investigate the effect of styrene and its primary metabolites R-styrene oxide (R-SO) and

Gary P. Carlson

2010-01-01

424

Morphology and mechanical and dynamic mechanical properties of linear and star poly(styrene- b-isobutylene- b-styrene) block copolymers  

Microsoft Academic Search

The morphologies of solution cast linear and star poly(styrene-b-isobutylene-b-styrene) (SIBS) block copolymers, of ?0.3–0.33 polystyrene (PS) volume fraction, were investigated using transmission electron microscopy (TEM) and small angle X-ray scattering (SAXS) methods. The linear (L) and 4-arm star materials have hexagonal packed cylinder morphologies. TEM indicates more continuous domains for the 3-arm SIBS and SAXS indicates lamellar morphology. The diameters

Tety Kwee; Stacy J. Taylor; Kenneth A. Mauritz; Robson F. Storey

2005-01-01

425

A note on individual differences in the urinary excretion of optical enantiomers of styrene metabolities and of styrene-derived mercapturic acids in humans  

Microsoft Academic Search

Urine samples from 20 male workers in the polyester industry exposed by inhalation to styrene concentrations ranging from\\u000a 29 to 41 ppm were investigated. Excretion products of styrene metabolism, mandelic acid and mercapturic acids, were purified\\u000a from the urine over an extraction column packed with Porapak Q, with subsequent ether elution. The optical enantiomers R- and S-mandelic acid were then

E. Hallier; H. W. Goergens; H. Karels; K. Golka

1995-01-01

426

Occupational Styrene Exposure Induces Stress-Responsive Genes Involved in Cytoprotective and Cytotoxic Activities  

PubMed Central

Objective The aim of this study was to evaluate the expression of a panel of genes involved in toxicology in response to styrene exposure at levels below the occupational standard setting. Methods Workers in a fiber glass boat industry were evaluated for a panel of stress- and toxicity-related genes and associated with biochemical parameters related to hepatic injury. Urinary styrene metabolites (MA+PGA) of subjects and environmental sampling data collected for air at workplace were used to estimate styrene exposure. Results Expression array analysis revealed massive upregulation of genes encoding stress-responsive proteins (HSPA1L, EGR1, IL-6, IL-1?, TNSF10 and TNF?) in the styrene-exposed group; the levels of cytokines released were further confirmed in serum. The exposed workers were then stratified by styrene exposure levels. EGR1 gene upregulation paralleled the expression and transcriptional protein levels of IL-6, TNSF10 and TNF? in styrene exposed workers, even at low level. The activation of the EGR1 pathway observed at low-styrene exposure was associated with a slight increase of hepatic markers found in highly exposed subjects, even though they were within normal range. The ALT and AST levels were not affected by alcohol consumption, and positively correlated with urinary styrene metabolites as evaluated by multiple regression analysis. Conclusion The pro-inflammatory cytokines IL-6 and TNF? are the primary mediators of processes involved in the hepatic injury response and regeneration. Here, we show that styrene induced stress responsive genes involved in cytoprotection and cytotoxicity at low-exposure, that proceed to a mild subclinical hepatic toxicity at high-styrene exposure. PMID:24086524

Strafella, Elisabetta; Bracci, Massimo; Staffolani, Sara; Manzella, Nicola; Giantomasi, Daniele; Valentino, Matteo; Amati, Monica; Tomasetti, Marco; Santarelli, Lory

2013-01-01

427

Sequence analysis of styrenic copolymers by tandem mass spectrometry.  

PubMed

Styrene and smaller molar amounts of either m-dimethylsilylstyrene (m-DMSS) or p-dimethylsilylstyrene (p-DMSS) were copolymerized under living anionic polymerization conditions, and the compositions, architectures, and sequences of the resulting copolymers were characterized by matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF-MS) and tandem mass spectrometry (MS(2)). MS analysis revealed that linear copolymer chains containing phenyl-Si(CH3)2H pendants were the major product for both DMSS comonomers. In addition, two-armed architectures with phenyl-Si(CH3)2-benzyl branches were detected as minor products. The comonomer sequence in the linear chains was established by MS(2) experiments on lithiated oligomers, based on the DMSS content of fragments generated by backbone C-C bond scissions and with the help of reference MS(2) spectra obtained from a polystyrene homopolymer and polystyrene end-capped with a p-DMSS block. The MS(2) data provided conclusive evidence that copolymerization of styrene/DMSS mixtures leads to chains with a rather random distribution of the silylated comonomer when m-DMSS is used, but to chains with tapered block structures, with the silylated units near the initiator, when p-DMSS is used. Hence, MS(2) fragmentation patterns permit not only differentiation of the sequences generated in the synthesis, but also the determination of specific comonomer locations along the polymer chain. PMID:25181590

Yol, Aleer M; Janoski, Jonathan; Quirk, Roderic P; Wesdemiotis, Chrys

2014-10-01

428

Vibrational excitation of adsorbed molecules by photoelectrons of very low energy: acrylonitrile on Cu(100).  

PubMed

In this study, we report on a powerful method of primary photoelectron scattering by adsorbed species. Specifically, threshold-energy (E(kin,max) < 0.5 eV) two-photon photoelectrons (2PPE) are used to probe acrylonitrile (ACN) molecules chemisorbed onto a Cu(100) substrate, held at room temperature. This has proven to constitute a perfect tool to reveal the ACN vibrational modes in the chemisorbed state. From the dynamics of the directional (perpendicular to the copper surface) electron energy loss we conclude that only a few fundamental vibrational motions of adsorbed ACN are excited, namely the C=C, C?N and C-H stretch modes. From the excitation probability spectra threshold energies, E(th), of these modes was extracted: E(th)(C=C) = 182(15) meV, E(th)(C?N) = 248(16) meV--which are shifted noticeably from the equivalent gas phase values; and E(th)(C-H) ?360-380 meV--which varies only marginally from the gas phase value. The interpretation of the excitation spectra suggests that the di-? adsorption configuration of the terminal C- and N-atoms dominates, which agrees well with the orientation and bindings predicted in Density Functional Theory (DFT) calculations. Consistent with this is the observation that the contribution to the 2PPE excitation spectra from the C-H stretch motion is by far the largest, which are not directly affected by chemisorption bonding. PMID:21399839

Tornero, J; Telle, H H; García, G; González Ureña, A

2011-05-14

429

Pre-irradiation grafting of acrylonitrile onto chitin for adsorption of arsenic in water  

NASA Astrophysics Data System (ADS)

Radiation-induced grafting is an effective technique for preparation of novel materials. In this study, partially deacetylated chitin with deacetylation degree (DDA) of about 40% was graft-copolymerized with acrylonitrile (AN) by a ?-ray pre-irradiation method. The maximal grafting degree of AN onto pre-irradiated chitin at 25±1.2 kGy was 114% for AN concentration in dimethylformamide of 40% (v/v) at 70 °C for 8 h. The mixture ratio of 0.1 N NH2OH·HCl to 0.1 N NaOH was selected to be 7:3 (v/v) for amidoxime conversion of cyano-groups on grafted chitin (Chi-g-AN). The characteristics of modified chitin were depicted by the FT-IR spectra, BET area and SEM images. Adsorption equilibrium of As(III) onto Chi-g-AN converted amidoxime (Chi-g-AN-C) fits with the Langmuir model and the maximal adsorption capacity was 19.724 mg/g. The break-through times of As(III) on Chi-g-AN-C in column adsorption experiments increased with the increase in bed depths.

Hanh, Truong Thi; Huy, Ha Thuc; Hien, Nguyen Quoc

2015-01-01

430

Nanostructured Synthetic Carbons Obtained by Pyrolysis of Spherical Acrylonitrile/Divinylbenzene Copolymers  

PubMed Central

Novel carbon materials have been prepared by the carbonization of acrylonitrile (AN)/divinylbenzene (DVB) suspension porous copolymers having nominal crosslinking degrees in the range of 30–70% and obtained in the presence of various amounts of porogens. The carbons were obtained by pre-oxidation of AN/DVB copolymers at 250?350°C in air followed by pyrolysis at 850°C in an N2 atmosphere. Both processes were carried out in one furnace and the resulting material needed no further activation. Resulting materials were characterized by XPS and low temperature nitrogen adsorption/desorption. It was found that maximum pyrolysis yield was ca. 50% depending on the oxidation conditions but almost independent of the crosslinking degree of the polymers. Porous structure of the carbons was characterized for the presence of micropores and macropores, when obtained from highly crosslinked polymers or polymers oxidized at 350°C and meso- and macropores in all other cases. The latter pores are prevailing in the structure of carbons obtained from less porous AN/DVB resins. Specific surface area (BET) of polymer derived carbons can vary between 440 m2/g and 250 m2/g depending on the amount of porogen used in the synthesis of the AN/DVB polymeric precursors. PMID:22916245

Malik, Danish J.; Trochimczuk, Andrzej W.; Ronka, Sylwia

2012-01-01

431

Modification of fiber properties through grafting of acrylonitrile to rayon by chemical and radiation methods  

PubMed Central

Fibrous properties of rayon has been modified through synthesis of graft copolymers of rayon with acrylonitrile (AN) by chemical method using ceric ammonium nitrate (CAN/HNO3) as a redox initiator and gamma radiation mutual method. Percentage of grafting (Pg) was determined as a function of initiator concentration, monomer concentration, irradiation dose, temperature, time of reaction and the amount of water. Maximum percentage of grafting (160.01%) using CAN/HNO3 was obtained at [CAN] = 22.80 × 10?3 mol/L, [HNO3] = 112.68 × 10?2 mol/L and [AN] = 114.49 × 10?2 mol/L in 20 mL of water at 45 °C within 120 min while in case of gamma radiation method, maximum Pg (90.24%) was obtained at an optimum concentration of AN of 76.32 × 10?2 mol/L using 10 mL of water at room temperature with total dose exposure of 3.456 kGy/h. The grafted fiber was characterized by FTIR, SEM, TGA and XRD studies. Swelling behavior of grafted rayon in different solvents such as water, methanol, ethanol, DMF and acetone was studied and compared with the unmodified rayon. Dyeing behavior of the grafted fiber was also investigated. PMID:25685464

Kaur, Inderjeet; Sharma, Neelam; Kumari, Vandna

2013-01-01

432

Modification of fiber properties through grafting of acrylonitrile to rayon by chemical and radiation methods.  

PubMed

Fibrous properties of rayon has been modified through synthesis of graft copolymers of rayon with acrylonitrile (AN) by chemical method using ceric ammonium nitrate (CAN/HNO3) as a redox initiator and gamma radiation mutual method. Percentage of grafting (Pg) was determined as a function of initiator concentration, monomer concentration, irradiation dose, temperature, time of reaction and the amount of water. Maximum percentage of grafting (160.01%) using CAN/HNO3 was obtained at [CAN] = 22.80 × 10(-3) mol/L, [HNO3] = 112.68 × 10(-2) mol/L and [AN] = 114.49 × 10(-2) mol/L in 20 mL of water at 45 °C within 120 min while in case of gamma radiation method, maximum Pg (90.24%) was obtained at an optimum concentration of AN of 76.32 × 10(-2) mol/L using 10 mL of water at room temperature with total dose exposure of 3.456 kGy/h. The grafted fiber was characterized by FTIR, SEM, TGA and XRD studies. Swelling behavior of grafted rayon in different solvents such as water, methanol, ethanol, DMF and acetone was studied and compared with the unmodified rayon. Dyeing behavior of the grafted fiber was also investigated. PMID:25685464

Kaur, Inderjeet; Sharma, Neelam; Kumari, Vandna

2013-11-01

433

Thermodynamic calculations for molecules with asymmetric internal rotors - application to 1, 3-butadiene  

Microsoft Academic Search

We present quantum mechanical partition functions, free energies, entropies, and heat capacities of 1,3- butadiene derived from ab initio calculations. Our technique makes use of a reaction path-like Hamiltonian to couple all 23 vibrational modes to the large-amplitude torsion, which involves heavy asymmetric functional groups. Ab ini- tio calculations were performed at the B3LYP, MP2, and CCSD(T) levels of theory

Bryan M. Wong; Sumathy Raman

2007-01-01

434

The tonotopicity of styrene-induced hearing loss depends on the associated noise spectrum.  

PubMed

The neuropharmacological and cochleotoxic effects of styrene can exacerbate the impact of noise on the peripheral auditory receptor. The mechanisms through which co-exposure to noise and styrene impairs hearing are complex as the slowly developing cochleotoxic process can be masked in the short-term by the rapid pharmacological effect on the central nervous system. The current investigation was therefore designed to delineate the auditory frequency range sensitive to noise, to styrene, and to noise and styrene combined. In case of different frequency ranges targeted by noise and styrene, it would be possible to point out the main factor responsible for cases of deafness by looking at the location of the audiometric deficits. Male Brown-Norway rats were exposed to 600-ppm styrene, to an octave band noise centered at 8kHz, or to both noise and styrene. The noise exposure was of two different types: impulse noise with a LEX,8h (equivalent continuous noise level averaged over 8h) of 80dB and continuous noise with a LEX,8h of 85dB SPL. Hearing was tested using a non-invasive technique based on distortion product otoacoustic emissions. Hearing data were completed with histological analysis of cochleae. The results showed that exposure to styrene alone caused outer hair cell losses in the apical cochlear region, which discriminates low frequencies. In contrast, noise-induced hearing loss was located at half an octave above the central frequency of the spectrum, around 10-12kHz. Damage due to impulse noise was significantly exacerbated by styrene, and the noise spectrum defined the location of the cochlear trauma. Combined exposure caused greater cell losses than the sum of losses measured with the impulse noise and styrene alone. The fact that the tonotopicity of the styrene-induced damage depends on the associated noise spectrum complicates the diagnosis of styrene-related hearing loss with a tone-frequency audiometric approach. In conclusion, there is not really a frequency specificity of impairments due to styrene. PMID:25689156

Venet, Thomas; Campo, Pierre; Thomas, Aurélie; Cour, Chantal; Rieger, Benoît; Cosnier, Frédéric

2015-01-01

435

Evidence of delayed light emission of tetraphenyl-butadiene excited by liquid-argon scintillation light  

NASA Astrophysics Data System (ADS)

Tetraphenyl-butadiene is the wavelength shifter most widely used in combination with liquid argon. The latter emits scintillation photons with a wavelength of 127 nm that need to be downshifted to be detected by photomultipliers with glass or quartz windows. Tetraphenyl-butadiene has been demonstrated to have an extremely high conversion efficiency, possibly higher than 100% for 127 nm photons, while there is no precise information about the time dependence of its emission. It is usually assumed to be exponentially decaying with a characteristic time of the order of one ns, as an extrapolation from measurements with exciting radiation in the near UV. This work shows that tetraphenyl-butadiene, when excited by 127 nm photons, re-emits photons not only with a very short decay time, but also with slower ones due to triplet states de-excitations. This fact can strongly contribute to clarifying the anomalies in liquid-argon scintillation light reported in the literature since the 1970s, namely, the inconsistency in the measured values of the long decay time constant and the appearance of an intermediate component. Similar effects should be also expected when the TPB is used in combination with helium and neon, which emit scintillation photons with wavelengths shorter than 127 nm.

Segreto, E.

2015-03-01

436

Evidence of delayed light emission of TetraPhenyl Butadiene excited by liquid Argon scintillation light  

E-print Network

TetraPhenyl Butadiene is the wavelength shifter most widely used in combination with liquid Argon. The latter emits scintillation photons with a wavelength of 127 nm that need to be downshifted to be detected by photomultipliers with glass or quartz windows. TetraPhenyl Butadiene has been demonstrated to have an extremely high conversion efficiency, possibly higher than 100% for 127 nm photons, while there is no precise information about the time dependence of its emission. It is usually assumed to be exponentially decaying with a characteristic time of the order of one ns, as an extrapolation from measurements with exciting radiation in the near UV. This work shows that TetraPhenyl Butadiene, when excited by 127 nm photons, reemits photons not only with a very short decay time, but also with slower ones due to triplet states de-excitations. This fact can strongly contribute to clarify the anomalies of liquid Argon scintillation light reported in literature since seventies, namely the inconsistency in the measured values of the long decay time constant and the appearence of an intermediate component.

Ettore Segreto

2014-11-17

437

Inhalation developmental toxicology studies: Teratology study of 1,3-butadiene in mice: Final report  

SciTech Connect

Maternal toxicity, reproductive performance and developmental toxicology were evaluated in CD-1 mice following whole-body, inhalation exposures to 0, 40, 200 and 1000 ppM of 1,3-butadiene. The female mice, which had mated with unexposed males were exposed to the chemical for 6 hours/day on 6 through 15 dg and sacrificed on 18 dg. Maternal animals were weighed prior to mating and on 0, 6, 11 and 18 dg; the mice were observed for mortality, morbidity and signs of toxicity during exposure and examined for gross tissue abnormalities at necropsy. Live fetuses were weighed and subjected to external, visceral and skeletal examinations to detect growth retardation and morphologic anomalies. Significant concentration-related decreases were detected in a number of maternal body weight measures. There was a significant concentration-related depression of fetal body weights and placental weights. Body weights of male fetuses of all exposed groups were significantly lower than values for control fetuses; weights of female fetuses were significantly depressed in the mice exposed to 200 and 1000 ppM. In the 200- and 1000-ppM exposure groups, weights of placentas of male fetuses were significantly decreased, but placental weights of female fetuses were significantly affected only in litters exposed to the highest 1,3-butadiene concentration. This exposure regimen produced significant signs of maternal toxicity at concentrations of 200 and 1000 ppM 1,3-butadiene.

Hackett, P.L.; Sikov, M.R.; Mast, T.J.; Brown, M.G.; Buschbom, R.L.; Clark, M.L.; Decker, J.R.; Evanoff, J.J.; Rommereim, R.L.; Rowe, S.E.; Westerberg, R.B.

1987-11-01

438

Dodecagonal Quasicrystalline Morphology in a Poly(styrene-b-isoprene-b-styrene-b-ethylene oxide) Tetrablock Terpolymer  

SciTech Connect

A dodecagonal quasicrystalline (QC) morphology is identified in a poly(styrene-b-isoprene-b-styrene-b-ethylene oxide) (SISO) tetrablock terpolymer based on evidence provided by transmission electron microscopy (TEM), small-angle X-ray scattering, and dynamic mechanical spectroscopy measurements. The QC state occurs at temperatures between those associated with simple hexagonal order (HEX) and the {sigma}-phase (P4{sub 2}/mnm), T{sub HEX} < T{sub QC} < T{sub {sigma}} < T{sub ODT}, where T{sub ODT} is the order-disorder transition temperature. All three morphologies are formed from spherical domains containing an O core surrounded by a shell of S that screens unfavorable segment-segment interactions with an I-rich matrix. TEM analysis reveals a QC morphology with 12-fold rotational symmetry but devoid of long-range translational order, along with locally coordinated structures consistent with dodecagonal quasicrystalline approximants. The SISO molecular architecture decouples control over the domain shape and interdomain interactions, leading to a multiplicity of packing symmetries.

Zhang, Jingwen; Bates, Frank S. (UMM)

2012-10-26

439

Hemocompatibility of drug-eluting coronary stents coated with sulfonated poly (styrene-block-isobutylene-block-styrene).  

PubMed

The presence of polymer coating on a coronary stent is a major mediator of coronary inflammation reaction thereby affects re-endothelialization. Poly(styrene-block-isobutylene-block-styrene) (SIBS) is one of the most attractive alternatives to serve as stent coating, but has shown less than optimal biocompatibility. Increasing the sulfonic acid content in the polymer can result in increased strength and hydrophilicity. The present study was undertaken to determine the mechanism of action and in vivo efficacy of sulfonated SIBS (S-SIBS) designed specifically as a stent polymer with reduced inflammatory potential and greater endothelialization preservation potential. The blood compatibility of S-SIBS in vitro and its ability to support the attachment of human umbilical vein endothelial cells (HUVECs) were first assessed to get some insight into its potential use in vivo. Baer metal stent (BMS), S-SIBS-coated stent without drug (BMS Plus S-SIBS), standard drug-eluting stent (DES) and S-SIBS-coated drug-eluting stent (DES Plus S-SIBS) were then implanted in the coronary arteries of a porcine model. Neointimal hyperplasia was evaluated at 28 and 180 days, and re-endothelialization was evaluated at 7 and 28 days post stents implantation. The results showed that DES Plus S-SIBS exhibited similar ability to reduce neointimal hyperplasia but preserved endothelialization compared with standard DES. These results suggest potentially promising performance of S-SIBS-coated stent in human clinical applications of coronary stenting. PMID:22898183

Zhu, Jin-Zhou; Xiong, Xiao-Wei; Du, Run; Jing, Ya-Jun; Ying, Yuan; Fan, Xiao-Ming; Zhu, Tian-Qi; Zhang, Rui-Yan

2012-11-01

440

Dodecagonal quasicrystalline morphology in a poly(styrene-b-isoprene-b-styrene-b-ethylene oxide) tetrablock terpolymer.  

PubMed

A dodecagonal quasicrystalline (QC) morphology is identified in a poly(styrene-b-isoprene-b-styrene-b-ethylene oxide) (SISO) tetrablock terpolymer based on evidence provided by transmission electron microscopy (TEM), small-angle X-ray scattering, and dynamic mechanical spectroscopy measurements. The QC state occurs at temperatures between those associated with simple hexagonal order (HEX) and the ?-phase (P4(2)/mnm), T(HEX) < T(QC) < T(?) < T(ODT), where T(ODT) is the order-disorder transition temperature. All three morphologies are formed from spherical domains containing an O core surrounded by a shell of S that screens unfavorable segment-segment interactions with an I-rich matrix. TEM analysis reveals a QC morphology with 12-fold rotational symmetry but devoid of long-range translational order, along with locally coordinated structures consistent with dodecagonal quasicrystalline approximants. The SISO molecular architecture decouples control over the domain shape and interdomain interactions, leading to a multiplicity of packing symmetries. PMID:22506899

Zhang, Jingwen; Bates, Frank S

2012-05-01

441

Studies of the mutagenic effects of styrene to man: conclusions for the surveillance of styrene-exposed workers  

NASA Astrophysics Data System (ADS)

One hundred fifty-six styrene-exposed workers had a fourfold higher rate of chromosome aberrations in peripheral lymphocytes than the control persons. The parameters of clinical chemistry (liver, kidney, and blood) remained in the normal range. Further analyses of the data of this study revealed no connections of the degree of effects in clinical chemistry and the exposure level. But a connection exists to the duration of exposure (3 - 26 years): in the comparison of the mean values (all mean values within the normal range) significant differences were found between long-term exposed workers (more than ten years) and control persons. In the higher age groups (above 45 years) also the GAP-rate differences are more pronounced. Seventy percent of the TWA-values were found to be below 85 mg/m3; the arithmetic mean of the TWA-values 72,3 mg/m3. A health surveillance program to styrene-exposed workers is to be reviewed (clinical chemistry and genetic effects). Proposals concerning both problems are presented.

Rothe, Roland; Schmidt, P.; Grummt, T.; Grummt, H. J.; Kersten, N.; Weigmann, Hans-Juergen

1993-03-01

442

Leaching of styrene and other aromatic compounds in drinking water from PS bottles.  

PubMed

Bottled water may not be safer, or healthier, than tap water. The present studies have proved that styrene and some other aromatic compounds leach continuously from polystyrene (PS) bottles used locally for packaging. Water sapmles in contact with PS were extracted by a preconcentration technique called as "purge and trap" and analysed by gas chromatograph-mass spectrometer (GC/MS). Eleven aromatic compounds were identified in these studies. Maximum concentration of styrene in PS bottles was 29.5 microg/L. Apart from styrene, ethyl benzene, toluene and benzene were also quantified but their concentrations were much less than WHO guide line values. All other compounds were in traces. Quality of plastic and storage time were the major factor in leaching of styrene. Concentration of styrene was increased to 69.53 microg/L after one-year storage. In Styrofoam and PS cups studies, hot water was found to be contaminated with styrene and other aromatic compounds. It was observed that temperature played a major role in the leaching of styrene monomer from Styrofoam cups. Paper cups were found to be safe for hot drinks. PMID:17915704

Ahmad, Maqbool; Bajahlan, Ahmad S

2007-01-01

443

Combined effects of noise and styrene exposure on hearing function in the rat.  

PubMed

Combined exposure to both noise and aromatic solvents such as styrene is common in many industries. In order to study the combined effects of simultaneous exposure to both noise and styrene on hearing, male adult Long-Evans rats were exposed either to 750 ppm styrene alone, to a 97 dB SPL octave band of noise centered at 8 kHz, or to a combination of noise and styrene. The exposure duration was 6 h/day, 5 days/week, for 4 consecutive weeks. Auditory function was tested over a frequency range from 2 to 32 kHz by recording near field potentials from the inferior colliculus, whereas histopathological analyses of the cochleae were performed with conventional morphometric approaches. Whereas both noise and styrene each caused permanent threshold shifts, the mechanisms of cochlear damage were different. Noise-induced hearing loss was mainly related to injuries of the stereocilia, whereas styrene-induced hearing loss was related to outer hair cell losses. Following the combined exposure, the threshold elevations as well as the cell losses exceeded the summed loss caused by noise and by styrene alone in the range of 8-16 kHz. Therefore, these results suggest that the two ototoxicants can cause a permanent synergistic loss of auditory sensitivity. PMID:10601715

Lataye, R; Campo, P; Loquet, G

2000-01-01

444

The Nature of the Reaction Intermediates in the FAD-Dependent Epoxidation Mechanism of Styrene Monooxygenase*  

PubMed Central

Styrene monooxygenase (SMO) is a two-component flavoenzyme composed of an NADH-specific flavin reductase (SMOB) and FAD-specific styrene epoxidase (NSMOA). NSMOA binds tightly to reduced FAD and catalyzes the stereospecific addition of one atom of molecular oxygen to the vinyl side chain of styrene in the enantioselective synthesis of S-styrene oxide. In this mechanism, molecular oxygen first reacts with NSMOA(FADred) to yield an FAD C(4a)- peroxide intermediate. This species is non-fluorescent and has an absorbance maximum of 382 nm. Styrene then reacts with the peroxide intermediate with a second order rate constant of 2.6 × 106 ± 0.1 × 106 M?1 s?1 to yield a fluorescent intermediate with an absorbance maximum of 368 nm. We compute an activation free energy of 8.7 kcal.mol??1 for the oxygenation step in good agreement with that expected for a peroxide-catalyzed epoxidation, and acid-quenched samples recovered at defined time points in the single-turnover reaction indicate that styrene oxide synthesis is coincident with the formation phase of the fluorescent intermediate. These findings support FAD C(4a)-peroxide as the oxygen atom donor and identity of the fluorescent intermediate as an FAD C(4a)-hydroxide product of the styrene epoxidation. Overall, four pH-dependent rate constants corresponding to peroxyflavin formation (pKa = 7.2), styrene epoxidation (pKa = 7.7), styrene oxide dissociation (pKa = 8.3), and hydroxyflavin dehydration (pKa 7.6) are needed to fit the single-turnover kinetics. PMID:21166448

Kantz, Auric; Gassner, George T.

2010-01-01

445

Production of super-smooth articles  

SciTech Connect

Super-smooth rounded or formed articles made of thermoplastic materials including various poly(methyl methacrylate) or acrylonitrile-butadiene-styrene copolymers are produced by immersing the articles into a bath, the composition of which is slowly changed with time. The starting composition of the bath is made up of at least one solvent for the polymer and a diluent made up of at least one nonsolvent for the polymer and optional materials which are soluble in the bath. The resulting extremely smooth articles are useful as mandrels for laser fusion and should be useful for a wide variety of other purposes, for example lenses.

Duchane, D.V.

1981-05-29

446

Production of super-smooth articles  

DOEpatents

Super-smooth rounded or formed articles made of thermoplastic materials including various poly(methyl methacrylate) or acrylonitrile-butadiene-styrene copolymers are produced by immersing the articles into a bath, the composition of which is slowly changed with time. The starting composition of the bath is made up of at least one solvent for the polymer and a diluent made up of at least one nonsolvent for the polymer and optional materials which are soluble in the bath. The resulting extremely smooth articles are useful as mandrels for laser fusion and should be useful for a wide variety of other purposes, for example lenses.

Duchane, David V. (Los Alamos, NM)

1983-01-01

447

Artificial biometric finger driven by shape-memory alloy wires.  

PubMed

This paper presents the design and testing of an artificial finger based partly on biomechanics. The prototype was manufactured in acrylonitrile butadiene styrene plastic using a rapid prototyping three-dimensional printer. The flexing of the finger was realized by Ni-Ti shape-memory alloy (SMA) wires with diameters of 0.3 mm, activated by resistive heating. The results obtained show the new prototype to be superior in performance, mainly in terms of angles of rotation of the phalanges, compared with some SMA fingers discussed in the literature. PMID:24237311

Silva, André Fellipe Cavalcante; dos Santos, Alexsandro José Virgínio; Souto, Cícero da Rocha; de Araújo, Carlos José; da Silva, Simplício Arnaud

2013-11-01

448

Preparation and Characterization of ABS Resin/Clay Nanocomposite by Melt Compounding  

NASA Astrophysics Data System (ADS)

Nanocomposite of ABS (acrylonitrile-butadiene-styrene copolymer) resin and clay was prepared by melt compounding using a twin screw extruder. The state of dispersion and microstructure in ABS resin/clay nanocomposite were observed by XRD. The mechanical and thermal properties of nanocomposite were also investigated. When ABS resin was intercalated to the silicate layer in clay, the separation distance between the layers increased by 1.7nm. In the nanocomposite studied here, both tensile and flexural strength were hardly improved and Izod impact was severely deteriorated. However, modulus and heat distortion temperature were improved. The reduction of modulus above Tg was observed by the dynamic viscoelasticity measurement.

Yamada, Nobuya; Ogihara, Takashi; Ogata, Nobuo; Saito, Shuichi; Ueyama, Akihiko; Maekawa, Tomokazu; Unryu, Tsunemune

449

Process for the recovery and separation of plastics  

DOEpatents

A method of separating a portion of acrylonitrile-butadiene-styrene (ABS) from a mixture containing ABS and for separating a portion of ABS and polycarbonate (PC) from a mixture of plastics containing ABS and PC is disclosed. The method includes shredding and/or granulating the mixture of plastics containing ABS and PC to provide a selected particle size; sequentially dispersing the shredded mixture of plastics in a series aqueous solutions having different specific gravities and separating the floating fraction until the desired separation is obtained. Surface tension and pH are also variable to be controlled.

Jody, Bassam J.; Daniels, Edward J.; Pomykala Jr., Joseph A.

2003-07-29

450

Mechanical Spectroscopy of Nanostructured Composite Materials  

NASA Astrophysics Data System (ADS)

The thermo-mechanical behavior of different nano-structured composite materials, which were processed within the SAPHIR European Integrated Project, has been characterized by mechanical spectroscopy. The obtained results show clearly that creep resistance of fine grain ceramics such as zirconia can be improved by carbon nano-tube (CNT) reinforcements. On the other hand the elastic modulus and the damping capacity of aluminum matrix composites were increased by SiC nano-particle additions. It has also been observed that CNT additions are responsible for a better thermal stability of polymer such as ABS (Acrylonitrile-Butadiene-Styrene) used in automotive industry.

Mari, Daniele; Schaller, Robert; Mazaheri, Mehdi

2011-07-01

451

Diaphragm-based fiber optic Fabry-Perot hydrophone with hydrostatic pressure compensation  

NASA Astrophysics Data System (ADS)

A fiber optic Fabry-Perot (FP) hydrophone with hydrostatic pressure compensation was demonstrated. A polyimide (PI) diaphragm attached on the end of an Acrylonitrile Butadiene Styrene (ABS) tube was used as the sensing element. A pair of grooves was designed in an inner ABS tube to connect the Fabry-Perot cavity with the outside environment, which made the hydrophone hydrostatic pressure compensated. The operation principle, design and testing of polyimide diaphragm-based sensor were described. Experiment results show that it has not only high stability in different hydrostatic pressures, but also flat frequency response of about 158 ±3 dB within 300-3000 Hz.

Wang, Zhaogang; Zhang, Wentao; Li, Fang

2013-09-01

452

Uncertainty and variability in the exposure reconstruction of chemical incidents--the case of acrylonitrile.  

PubMed

The application of human physiologically based pharmacokinetic (PBPK) modeling combined with measured biomonitoring data, has a great potential to backtrack external exposure to chemicals during chemical incidents. So far, an important shortcoming of 'reversed dosimetry' is that uncertainty and variability in the model predictions are often neglected. The aim of this paper is to characterize the variation in predicted environmental air concentrations by means of reversed dosimetry as a result of uncertainty in chemical-specific input data and variability in physiological parameters. Human biomonitoring data (N-2-cyanoethylvaline in blood) from a chemical incident with acrylonitrile (ACN) combined with the BioNormtox PBPK model are used as a case to reconstruct the air concentration and uncertainty thereof at the time of the incident. The influence of uncertainty in chemical-specific properties and exposure duration, and interindividual variability in physiological parameters on the reconstructed air exposure concentrations were quantified via nested Monte Carlo simulation. The range in the reconstructed air concentrations of ACN during the incident was within a factor of 3. Uncertainty in the exact exposure duration directly after the chemical accident was found to have a dominant influence on the model outcomes. It was also shown that uncertainty can be further reduced by collecting human biomonitoring data as soon as possible after the incident. Finally, the collection of specific information about individual physiological parameters from the victims, such as body weight, may further reduce the variation by 5 to 20% in our case study. Future research should include the comparison of reversed dosimetry model outcomes with measured air and biological concentrations to further increase the confidence in the model approach and its implementation in practice. PMID:25050995

Huizer, Daan; Ragas, Ad M J; Oldenkamp, Rik; van Rooij, Joost G M; Huijbregts, Mark A J

2014-12-15

453

Modeling contaminant transport and remediation at an acrylonitrile spill site in Turkey.  

PubMed

The August 1999 earthquake in Turkey damaged three acrylonitrile (AN) storage tanks at a plant producing synthetic fiber by polymerization. A numerical modeling study was carried out to analyze the groundwater flow and contaminant (AN) transport at the spill site. This study presents the application of a numerical groundwater model to determine the hydrogeological parameters of the site, where such data were not available during the field surveys prior to the simulation studies. The two- and three-dimensional transient flow and transport models were first calibrated using the first 266days of observed head and concentration data and then verified using the remaining 540-day observed data set. Off-site migration of the contaminant plume was kept under control within the site boundaries owing to the favorable geology of the site, the characteristics of the local groundwater flow regime and the pumping operations. As expected, the applied pump-and-treat system was effective at high-permeability zones, but not fully effective at low-permeability zones. The results of long-term simulations for unconfined aquifer showed that the size of the plume in the high permeability zone shrank significantly due to the dilution by natural recharge. However, in the low permeability zone, it was not significantly affected. The study showed that accurate and sufficient data regarding the source characteristics, concentration and groundwater level measurements, groundwater pumping rates and their durations at each of the extraction points involved in the pump-and-treat system along with the hydrogeological site characterization are the key parameters for successful flow and transport model calibrations. PMID:23680827

Sengör, S Sevinç; Unlü, Kahraman

2013-07-01

454

Design of poly(acrylonitrile)-based gel electrolytes for high-performance lithium ion batteries.  

PubMed

The use of polyacrylonitrile (PAN) as a host for gel polymer electrolytes (GPEs) commonly produces a strong dipole-dipole interaction with the polymer. This study presents a strategy for the application of PAN in GPEs for the production of high performance lithium ion batteries. The resulting gel electrolyte GPE-AVM comprises a poly(acrylonitrile-co-vinyl acetate) copolymer blending poly(methyl methacrylate) as a host, which is swelled using a liquid electrolyte (LE) of 1 M LiPF6 in carbonate solvent. Vinyl acetate and methacrylate groups segregate the PAN chains in the GPE, which produces high ionic conductivity (3.5 × 10 (-3) S cm(-1) at 30 °C) and a wide electrochemical voltage range (>6.5 V) as well as an excellent Li(+) transference number of 0.6. This study includes GPE-AVM in a full-cell battery comprising a LiFePO4 cathode and graphite anode to promote ion motion, which reduced resistance in the battery by 39% and increased the specific power by 110%, relative to the performance of batteries based on LE. The proposed GPE-based battery has a capacity of 140 mAh g(-1) at a discharge rate of 0.1 C and is able to deliver 67 mAh g(-1) of electricity at 17 C. The proposed GPE-AVM provides a robust interface with the electrodes in full-cell batteries, resulting in 93% capacity retention after 100 charge-discharge cycles at 17 C and 63% retention after 1000 cycles. PMID:25361495

Wang, Shih-Hong; Kuo, Ping-Lin; Hsieh, Chien-Te; Teng, Hsisheng

2014-11-12

455

A correlation study applied to biomarkers of internal and effective dose for acrylonitrile and 4-aminobiphenyl in smokers  

PubMed Central

The urinary metabolites 2-cyanoethylmercapturic acid and 4-aminobiphenyl have been correlated with tobacco smoke exposure. Similarly, 2-cyanoethylvaline and 4-aminobiphenyl haemoglobin adducts have been used as biomarkers of effective dose for the exposure to acrylonitrile and 4-aminobiphenyl, respectively. Each pair of biomarkers is derived from the same parent chemical; however, the correlation between the urinary and the haemoglobin biomarkers has not been investigated. Using clinical study samples, we report a weak correlation between urinary and haemoglobin biomarkers due to different accumulation and elimination rates. Time course analysis showed that a reduction in exposure was paralleled by a delayed reduction in haemoglobin adducts. PMID:24754403

Scherer, Gerhard; Newland, Kirk; Papadopoulou, Ermioni

2014-01-01

456

Pre-irradiation induced emulsion co-graft polymerization of acrylonitrile and acrylic acid onto a polyethylene nonwoven fabric  

NASA Astrophysics Data System (ADS)

A pre-irradiation induced emulsion co-graft polymerization method was used to introduce acrylonitrile and acrylic acid onto a PE nonwoven fabric. The use of acrylic acid is meant to improve the hydrophilicity of the modified fabric. The kinetics of co-graft polymerization were studied. The existence of polyacrylonitrile (PAN) and poly(acrylic acid) (PAAc) graft chains was proven by Fourier transform infrared spectroscopy (FTIR) analysis. The existence of the nitrile groups in the graft chains indicates that they are ready for further amidoximation and adsorption of heavy metal ions.

Liu, Hanzhou; Yu, Ming; Ma, Hongjuan; Wang, Ziqiang; Li, Linfan; Li, Jingye

2014-01-01

457

Real-Time Small-Angle X-ray Scattering from Rubber-Modified Thermoplastics  

NASA Astrophysics Data System (ADS)

Real-time small-angle X-ray scattering (RTSAXS) studies have been performed on a series of rubber-modified thermoplastics. These include: High Impact Polystyrene (HIPS), (2) Acrylonitrile Butadiene Styrene copolymers (ABS), (3) weatherable ABS-type resins containing grafted rubber particles derived from acrylonitrile ethylene styrene (AES) or acrylonitrile styrene acrylate (ASA), and (4) rubber-toughened syndiotactic polystyrene (sPS). Scattering patterns were measured at successive time intervals of from 2 to 3 ms. and were analyzed to determine the plastic strain due to crazing. Simultaneous measurements of the absorption of the primary beam by the sample allowed the total plastic strain to be computed. The plastic strain due to other deformation mechanisms (e.g. particle cavitation and macroscopic shear deformation) was determined by the difference. The contribution from microscopic shear deformation was determined from video-based optical data obtained along with the RTSAXS data. One example is an experimental AES system in an SAN matrix with insufficient gel particle graft which was found to lack substantial contributions from crazing and microshear yielding mechanisms. Manipulating the graft and cross linking levels in the AES system results in a ten-fold increase in microshear yield, but not much additional cavitation and crazing.

Bubeck, R. A.

1997-03-01

458

Preparation and characterization of emulsifier-free polyphenylsilsesquioxane-poly (styrene-butyl acrylate) hybrid particles  

NASA Astrophysics Data System (ADS)

The core-shell polyphenylsilsesquioxane-poly (styrene-butyl acrylate) hybrid latex paticles with polyphenylsilsesquioxane as core and poly (styrene-butyl acrylate) as shell were successfully synthesized by seeded emulsion polymerization using polyphenylsisesquioxane (PPSQ) latex particles as seeds. X-ray diffraction (XRD) indicated that the polyphenylsilsesquioxane (PPSQ) had ladder structure, and PPSQ had incorporated into the hybrid latex particles. Transmission electron microscopy (TEM) confirmed that the resultant hybrid latex particles had the core-shell structure. TEM and dynamic light scattering (DLS) analysis indicated that the polyphenylsisesquioxane latex particles and obtained core-shell hybrid latex particles were uniform and possessed narrow size distributions. X-ray photoelectron spectroscopy (XPS) analysis also indicated that the PPSQ core particles were enwrapped by the polymer shell. In addition, compared with pure poly (styrene-butyl acrylate) latex film, the polyphenylsilsesquioxane-poly (styrene-butyl acrylate) hybrid latex film exhibited lower water uptake, higher pencil hardness and better thermal stability.

Bai, Ruiqin; Qiu, Teng; Han, Feng; He, Lifan; Li, Xiaoyu

2013-10-01

459

Offshore experiments on styrene spillage in marine waters for risk assessment.  

PubMed

Within the context of risk evaluation of chemical spillages into the marine environment, this paper reports on an offshore experiment to study the behaviour of styrene spilled into sea under natural conditions and discusses theoretical approaches. Floating structures were used to enclose the spillage and the gaseous cloud formation, and dissolution processes were in situ monitored. The identification of spill risks for man and marine environment through GESAMP's hazard profile is described for styrene: Styrene is rated as a chemical with a significant health hazard that will float but also evaporate. However, monitoring of the water column in the experiments showed that the concentration of styrene in water during the first hour represents 50% of the product spilled. For the potentially exposed public, the GESAMP hazard rating recommends the closure of beaches and evacuation. The risk assessment developed from experimental data confirms this safety advice. PMID:22607845

Fuhrer, Mélanie; Péron, Olivier; Höfer, Thomas; Morrissette, Mike; Le Floch, Stéphane

2012-07-01

460

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

Code of Federal Regulations, 2010 CFR

...protect the following nutrients: (1) Methionine. The resulting product must contain a...2-vinylpyridine-co-styrene) by weight and a minimum of 55 percent methionine by weight. The coated methionine must be established through in vitro...

2010-04-01

461

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

Code of Federal Regulations, 2011 CFR

...protect the following nutrients: (1) Methionine. The resulting product must contain a...2-vinylpyridine-co-styrene) by weight and a minimum of 55 percent methionine by weight. The coated methionine must be established through in vitro...

2011-04-01

462

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

Code of Federal Regulations, 2013 CFR

...specifications: Component/property Limitation Inherent viscosity 1.0-1.6 deciliter per gram.1 Styrene moiety ...Arsenic 3 parts per million maximum. 1 Inherent viscosity of a 0.25 percent (weight/volume) solution in...

2013-04-01

463

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

Code of Federal Regulations, 2012 CFR

...specifications: Component/property Limitation Inherent viscosity 1.0-1.6 deciliter per gram.1 Styrene moiety ...Arsenic 3 parts per million maximum. 1 Inherent viscosity of a 0.25 percent (weight/volume) solution in...

2012-04-01

464

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

Code of Federal Regulations, 2014 CFR

...specifications: Component/property Limitation Inherent viscosity 1.0-1.6 deciliter per gram.1 Styrene moiety ...Arsenic 3 parts per million maximum. 1 Inherent viscosity of a 0.25 percent (weight/volume) solution in...

2014-04-01

465

Updated evaluation of the migration of styrene monomer and oligomers from polystyrene food contact materials to foods and food simulants.  

PubMed

Due to the 2011 labelling of styrene monomer as "reasonably anticipated to be a human carcinogen" by the National Institutes of Health's National Toxicology Program (NTP) and the controversy over whether styrene oligomers mimic the physiological effects of estrogen, an updated review of styrene monomer and oligomers in food and food contact materials (FCMs) was performed. The concentrations of styrene monomer and oligomers were determined in 24 polystyrene (PS) products and ranged from 9.3 to 3100 mg kg(-1) for the styrene monomer, 130-2900 mg kg(-1) for the sum of three styrene dimers, and 220-16,000 mg kg(-1) for the sum of six styrene trimers. Foods in contact with PS packaging had styrene monomer concentrations ranging from 2.6 to 163 ng g(-1); dimer concentrations from the limit of quantitation (LOQ) to 4.8 ng g(-1) and trimer concentrations were all below the LOQ (2 ng g(-1)). Diffusion coefficients (Dp) and partition coefficients (K) were also calculated for styrene dimers and trimers. The results presented here indicate that styrene monomer concentrations in foods have not significantly changed since the 1980s and monomer concentrations in food packaging quantified in this study were all below USFDA limits. Although styrene dimers and trimers are present in higher concentrations in PS FCMs than the monomer, their migration to food is limited because of their high K values (4 × 10(2) to 2 × 10(6)) and their low diffusion coefficients in PS products. Additionally, diffusion coefficients calculated using USFDA-recommended food simulants and Arrhenius plots describing the temperature dependence of styrene dimers and trimers can be used in future calculations of dietary intake of the styrene oligomers. PMID:24383702

Genualdi, Susan; Nyman, Patricia; Begley, Timothy

2014-04-01

466

Deconvolution of high resolution GPC chromatograms and fractionation of poly(styrene-isobutylene-styrene) block copolymers made by living cationic polymerization  

SciTech Connect

A poly(styrene-isobutylene-styrene) block copolymer made by living cationic polymerization using a difunctional initiator and the sequential monomer addition technique was analyzed using curve-resolution software in conjunction with high-resolution GPC. Additionally, fractional precipitation was applied to the sample in order to both determine the identity of contaminating species and to produce a narrow MWD sample for morphological characterization using transmission electron microscopy (TEM). Contaminating species were found to be low molecular weight homopolymers as well as higher molecular weight segmented block copolymers formed by interchain electrophilic aromatic substitution linking reactions occurring late in the polymerization of the styrene outer blocks. TEM revealed hexagonally packed PS cylinders ({approximately}11 nm dia.) dispersed in a PIB matrix.

Storey, R.F.; Baugh, D.W. [Univ. of Southern Mississippi, Hattiesburg, MS (United States)

1996-10-01

467

Ionic polymer-metal composite actuators employing sulfonated poly (styrene-ethylene-butylene-styrene) as ionic-exchange membranes  

NASA Astrophysics Data System (ADS)

There is growing interest in biomimetic motions by employing ionic polymer-metal composites (IPMCs) as the candidates for the fabrication of artificial muscle. However, the membrane materials currently used in IPMC actuators have been limited to a few commercially available perfluorinated ionic polymers, such as Nafion, and they suffer from several shortcomings among which their high cost presents a major obstacle for wide application. With excellent proton conductivity and high water uptake capacity, commercially available Sulfonated poly (styrene-ethylene-butylene-styrene) (SEBS) of low cost has been investigated for many years as a fuel cell membrane. Herein, we report the preparation of a novel IPMC actuator based on the sulfonated SEBS (SSEBS) membrane. The platinum electrodes of the SEBS actuators were obtained with electroless plating procedure, and the cation exchange with lithium was performed by soaking the composite membranes into a 1.5N LiCl solution. The surface and cross-sectional morphologies of the SSEBS actuators were observed by using scanning electron microscopy (SEM), which revealed that the platinum layer up to 8µm was deposited on the top and bottom surfaces of the SSEBS membrane. The electromechanical bending responses were investigated under alternating current excitations with various driving frequencies and voltage amplitudes, which showed high electrical strains under sinusoidal signal. The effect of the membrane thickness on the performance of the actuators was also addressed in this presentation. This kind of IPMC has great potentials for the applications in biomimetic sensors and actuators, which can be utilized to mimic the locomotion of fish and insects and can be applied to micro-robots and bio-medical devices as well.

Wang, Xuan-Lun; Oh, Il-Kwon; Lu, Jun; Ju, Jin-Hun; Lee, Sun-Woo

2007-07-01

468

An evaluation of styrene levels emitted during cast polymer production of cultured marble building materials  

E-print Network

the preparation of this document with their insight about the cultured marble industry. Finally, the aid received from my family deserves special attention. Their patience, comfort, helpfulness, love and motivation were plentiful throughout my instruction. I... these recommendations. BACKGROUND In 1831, the French chemist Bonastre first isolated and described natural styrene distilled from a balsamic resin called liquid amber. i2) Berthelot et al. published a procedure to synthesize styrene in 1866. This process paved...

Bell, Lewis Ray

1994-01-01

469

Styrene-terminated polysulfone oligomers as matrix material for graphite reinforced composites: An initial study  

NASA Technical Reports Server (NTRS)

Styrene terminated polysulfone oligomers are part of an oligomeric class of compounds with end groups capable of thermal polymerization. These materials can be used as matrices for graphite reinforced composites. The initial evaluation of styrene terminated polysulfone oligomer based composites are summarized in terms of fabrication methods, and mechanical and environmental properties. In addition, a description and evaluation is provided of the NASA/Industry Fellowship Program for Technology Transfer.

Garcia, Dana; Bowles, Kenneth J.; Vannucci, Raymond D.

1987-01-01

470

Radiation-induced grafting of styrene into radiation-modified fluoropolymer films  

Microsoft Academic Search

Poly(tetrafluoroethylene) (PTFE), poly(tetrafluoroethylene-co-hexafluoropropylene) (FEP) and poly(tetrafluoroethylene-co-perfluoropropylvinyl ether) (PFA) films were modified by electron beam irradiation in the molten state. These radiation-modified films and original films were irradiated in vacuum at room temperature to initiate the grafting of styrene in the subsequent step. The grafting of styrene into the fluoropolymer films was proved by FT-IR spectroscopy. The influence of cross-linking dose,

Uwe Lappan; Uwe Geißler; Steffi Uhlmann

2005-01-01

471

Retention of styrene following controlled exposure to constant and fluctuating air concentrations  

Microsoft Academic Search

An experiment was designed to determine whether the respiratory retention of sytrene vapor, as estimated from measurements of end-exhaled air, was the same during periods of both constant and fluctuating exposure. Six human subjects were exposed to styrene inside an experimental chamber. A computer-controlled system was used to generate time-varying air concentrations of styrene over 4–5 h in both multistep

Myrto X. Petreas; Jeff Woodlee; Charles E. Becker; Stephen M. Rappaport

1995-01-01

472

Inhalation developmental toxicology studies of 1,3-butadiene in the rat: Final report  

SciTech Connect

Maternal toxicity, reproductive performance and developmental toxicology were evaluated in Sprague-Dawley-derived rats during and following 6 hours/day, whole-body, inhalation exposures to 0, 40, 200, and 1000 ppM of 1,3-butadiene. The female rats (Ns = 24 to 28), which had mated with unexposed males, were exposed to the chemical from 6 through 15 dg and sacrificed on 20 dg. Maternal animals were weighed prior to mating and on 0, 6, 11, 16 and 20 dg; the rats were observed for mortality, morbidity and signs of toxicity during exposure and examined for gross tissue abnormalities at necropsy. Live fetuses were weighed and subjected to external, visceral and skeletal examinations to detect growth retardation and morphologic anomalies. There were no significant differences among treatment groups in maternal body weights or extragestational weights of rats exposed to 1,3-butadiene concentrations of 40 or 200 ppM, but, in animals exposed to 1000 ppM, significantly depressed body weight gains were observed during the first 5 days of exposure and extragestational weight gains tended to be lower than control values. These results, and the absence of clinical signs of toxicity, were considered to indicate that there was no maternal toxicity at exposure levels of 200 ppM or lower. The percentage of pregnant animals and the number of litters with live fetuses were unaffected by treatment. Under the conditions of this exposure regimen, there was no evidence for a teratogenic response to 1,3-butadiene exposure.

Hackett, P.L.; Sikov, M.R.; Mast, T.J.; Brown, M.G.; Buschbom, R.L.; Clark, M.L.; Decker, J.R.; Evanoff, J.J.; Rommereim, R.L.; Rowe, S.E.; Westerberg, R.B.

1987-11-01

473

Poly(styrene- b-isobutylene- b-styrene) block copolymer ionomers (BCPI) and BCPI\\/silicate nanocomposites. 2. Na +BCPI sol–gel polymerization templates  

Microsoft Academic Search

Polystyrene (PS) blocks in poly(styrene-b-isobutylene-b-styrene) (PS–PIB–PS) block copolymers were partially sulfonated and the acid groups converted to Na+SO3? groups to create ionomers. Then, dimethylacetamide was used to selectively swell the ionic PS domains and the swollen films were exposed to sol–gel reactive tetraethylorthosilicate solutions. (EtO)4?xSi(OH)x monomers then permeated films so that sol–gel reactions occurred within\\/around the ionic PS domains. Environmental

Kenneth A. Mauritz; Robson F. Storey; David A. Reuschle; Nora Beck Tan

2002-01-01

474

Measurements of environmental 1,3-butadiene with pumped and diffusive samplers using the sorbent Carbopack X  

NASA Astrophysics Data System (ADS)

Studies with the sorbent Carbopack X in pumped and diffusive samplers, of the Perkin-Elmer-type, have been carried out using a controlled atmosphere test facility (CATFAC) to generate 1,3-butadiene, together with benzene, at environmental levels. The 7-day and 14-day 1,3-butadiene diffusive uptake rates for this sorbent have been determined to be respectively (1.24±0.16) ng ppm -1 min -1 ((0.55±0.07) cm 3 min -1)) and (1.02±0.12) ng ppm -1 min -1 ((0.45±0.05) cm 3 min -1)) under a wide range of concentrations at 20 °C, 50% relative humidity and a wind speed of 1 m s -1. Preliminary studies indicate that this sorbent may also be useful in radial diffusive samplers for short-term monitoring over a few hours. A pumped sampling method has been developed to measure both 1,3-butadiene and benzene simultaneously over a period of 14-days using two Perkin-Elmer-type devices coupled to an in-house developed controlled flow air sampler. The 1,3-butadiene safe sampling volume for Carbopack X has been measured yielding a value of ?82 litre g -1. Tests carried out with calibrated amounts of 1,3-butadiene (50 ng and 150 ng) on Carbopack X indicate that samplers should be stored in a refrigerator prior to thermal desorption in order to achieve a recovery of effectively 100%. Ambient ozone does not appear to react with 1,3-butadiene adsorbed in the samplers.

Martin, Nicholas A.; Duckworth, Philippa; Henderson, Malcolm H.; Swann, Nigel R. W.; Granshaw, Simon T.; Lipscombe, Robert P.; Goody, Brian A.

475

Thermoplastic nanoclay-modified vulcanizates based on polypropylene and nitrile-butadiene rubber  

NASA Astrophysics Data System (ADS)

Thermoplastic vulcanizates based on polypropylene and nitrile-butadiene rubber, containing modified organoclay were developed. It was shown that composites containing 1 to 5 pbw of Cloisite 15A montmorillonite added to rubber show improved physical-mechanical characteristics. Their swelling degree in AI-92 and motor oil was determined. The swelling degree of composites in petrol and motor oil decreases substantially, by 20-63%, due to the introduction of Cloisite 15A montmorillonite. Modification of thermoplastic vulcanizates using layered silicates raised the degradation onset temperature and decreases weight loss upon high temperature heating.

Volfson, Svetoslav I.; Okhotina, Natalya A.; Nigmatullina, Alina I.; Panfilova, Olga A.

2014-05-01

476

Destruction of Gaseous Styrene with a Low-Temperature Plasma Induced by a Tubular Multilayer Dielectric Barrier Discharge  

NASA Astrophysics Data System (ADS)

The destruction of gaseous styrene was studied using a low-temperature plasma induced by tubular multilayer dielectric barrier discharge (DBD). The results indicate that the applied voltage, gas flow rate, inlet styrene concentration and reactor configuration play important roles in styrene removal efficiency (?styrene) and energy yield (EY). Values of ?styrene and EY reached 96% and 15567 mg/kWh when the applied voltage, gas flow rate, inlet styrene concentration and layers of quartz tubes were set at 10.8 kV, 5.0 m/s, 229 mg/m3 and 5 layers, respectively. A qualitative analysis of the byproducts and a detailed discussion of the reaction mechanism are also presented. The results could facilitate industrial applications of the new DBD reactor for waste gas treatment.

Zhang, Jiahui; Liu, Juanjuan; Zhang, Renxi; Hou, Huiqi; Chen, Shanping; Zhang, Yi

2015-01-01

477

Acrylonitrile potentiates hearing loss and cochlear damage induced by moderate noise exposure in rats  

SciTech Connect

The diversity of chemical and drugs that can potentiate noise-induced hearing loss (NIHL) has impeded efforts to predict such interactions. We have hypothesized that chemical contaminants that disrupt intrinsic antioxidant defenses hold significant risk for potentiating NIHL. If this is true, then acrylonitrile (ACN) would be expected to potentiate NIHL. ACN, one of the 50 most commonly used chemicals in the United States, is metabolized via two pathways that are likely to disrupt intrinsic reactive oxygen species (ROS) buffering systems: (1) it conjugates glutathione, depleting this important antioxidant rapidly; (2) a second pathway involves the formation of cyanide, which can inhibit superoxide dismutase. We hypothesized that moderate noise exposure, that does not produce permanent hearing loss by itself, could initiate oxidative stress and that ACN could render the inner ear more sensitive to noise by disrupting intrinsic antioxidant defenses. Temporary and persistent effects of ACN alone (50 mg/kg, sc 5 days), noise alone (95 or 97 dB octave band noise, 4 h/day for 5 days), or ACN in combination with noise were determined using distortion product otoacoustic emissions (DPOAEs) and compound action potential (CAP) amplitudes. Histopathological damage to hair cells resulting from these treatments was also investigated using surface preparations of the organ of Corti. Individually, neither ACN nor noise exposures caused any permanent hearing or hair cell loss; only a reversible temporary threshold shift was measured in noise-exposed animals. However, when given in combination, ACN and noise induced permanent threshold shifts (13-16 dB between 7 and 40 kHz) and a decrease in DPOAE amplitudes (up to 25 dB at 19 kHz), as well as significant outer hair cell (OHC) loss (up to 20% in the first row between 13 and 47 kHz). This investigation demonstrates that ACN can potentiate NIHL at noise levels that are realistic in terms of human exposure, and that the OHCs are the main target of toxicity. While the exact mechanism is unknown, the results are consistent with the hypothesis of ROS involvement in NIHL at moderate levels.

Pouyatos, BenoIt [Jerry Pettis Memorial Veterans Medical Center, Research Service (151), Loma Linda, CA 92357 (United States)]. E-mail: benoit.pouyatos@med.va.gov; Gearhart, Caroline A. [Jerry Pettis Memorial Veterans Medical Center, Research Service (151), Loma Linda, CA 92357 (United States); Fechter, Laurence D. [Jerry Pettis Memorial Veterans Medical Center, Research Service (151), Loma Linda, CA 92357 (United States)

2005-04-01

478

Synthesis of Triblock Copolymers via Photopolymerization of Styrene and Methyl Methacrylate Using Macrophotoinitiators Possessing Poly(ethylene glycol) Units  

Microsoft Academic Search

Macrophotoinitiators based on poly(ethylene glycol)s bearing benzyl tereftalmono amid moieties were synthesized by the reaction of poly(ethylene glycol) (PEG) terminated with terephtaloyl chloride and benzyl amine. The initiators possessing PEG with different molecular weights were used in the photoinduced radical polymerization of styrene (S) and methyl methacrylate (MMA) to yield poly(styrene-b-ethylene glycol-b-styrene) and poly(methyl methacrylate-ethylene glycol-b-methyl methacrylate) triblock copolymers. Characterization

Ismail Cakmak; Temel Ozturk

2005-01-01

479

Biosynthesis of ( R )-phenyl-1,2-ethanediol from racemic styrene oxide by using bacterial and marine fish epoxide hydrolases  

Microsoft Academic Search

Enantio-convergent hydrolysis of racemic styrene oxides was achieved to prepare enantiopure (R)-phenyl-1,2-ethanediol by using two recombinant epoxide hydrolases (EHs) of a bacterium, Caulobacter crescentus, and a marine fish, Mugil cephalus. The recombinant C. crescentus EH primarily attacked the benzylic carbon of (S)-styrene oxide, while the M. cephalus EH preferentially attacked the terminal carbon of (R)-styrene oxide, thus leading to the

Hee Sook Kim; Ok Kyung Lee; Seungha Hwang; Beum Jun Kim; Eun Yeol Lee

2008-01-01

480

Effects of Low-Level Occupational Exposure to Styrene on Color Vision: Dose Relation with a Urinary Metabolite  

Microsoft Academic Search

To investigate the threshold effects of chronic low-level occupational exposure to styrene on color vision, we examined color discrimination in 105 male workers exposed to styrene (mean age 37.7 years; mean length of exposure 6.2 years; mean urinary concentration of mandelic acid 0.21 g\\/L) and in 117 referents (mean age 37.7 years). We also assessed the effects of styrene by

Reiko Kishi; Teruko Eguchi; Junko Yuasa; Yoko Katakura; Yoshihiko Arata; Izumi Harabuchi; Toshio Kawai; Ayumi Masuchi

2001-01-01

481

The desorption purge time and thermal stability of 1,3-butadiene in a charcoal sampling tube  

E-print Network

are summarized in detail. From these observations, it is possible to select combinations of temperatures and carrier gas flow rates that allow quantification of 1,3-butadiene thermally desorbed from coconut charcoal packed in the glass tubes. This study suggests...

Xie, Jianghua

1997-01-01

482

A REVIEW OF THE GENETIC AND RELATED EFFECTS OF 1,3-BUTADIENE IN RODENTS AND HUMANS  

EPA Science Inventory

In this paper, the metabolism and genetic toxicity of 1,3-butadiene (BD) and its oxidative metabolites in humans and rodents is reviewed with attention to newer data that have been published since the latest evaluation of BD by the International Agency for Research on Cancer (IAR...

483

THE GAS PHASE REACTION OF OZONE WITH 1,3-BUTADIENE: FORMATION YIELDS OF SOME TOXIC PRODUCTS. (R826236)  

EPA Science Inventory

The formation yields of acrolein, 1,2-epoxy-3-butene and OH radicals have been measured from reaction of ozone with 1,3-butadiene at room temperature and atmosphere pressure. 1,3,5-Trimethyl benzene was added to scavenge OH radicals in measurements of product yields. In separa...

484

PAH formation under single collision conditions: reaction of phenyl radical and 1,3-butadiene to form 1,4-dihydronaphthalene.  

PubMed

The crossed beam reactions of the phenyl radical (C(6)H(5), X(2)A(1)) with 1,3-butadiene (C(4)H(6), X(1)A(g)) and D6-1,3-butadiene (C(4)D(6), X(1)A(g)) as well as of the D5-phenyl radical (C(6)D(5), X(2)A(1)) with 2,3-D2-1,3-butadiene and 1,1,4,4-D4-1,3-butadiene were carried out under single collision conditions at collision energies of about 55 kJ mol(-1). Experimentally, the bicyclic 1,4-dihydronaphthalene molecule was identified as a major product of this reaction (58 ± 15%) with the 1-phenyl-1,3-butadiene contributing 34 ± 10%. The reaction is initiated by a barrierless addition of the phenyl radical to the terminal carbon atom of the 1,3-butadiene (C1/C4) to form a bound intermediate; the latter underwent hydrogen elimination from the terminal CH(2) group of the 1,3-butadiene molecule leading to 1-phenyl-trans-1,3-butadiene through a submerged barrier. The dominant product, 1,4-dihydronaphthalene, is formed via an isomerization of the adduct by ring closure and emission of the hydrogen atom from the phenyl moiety at the bridging carbon atom through a tight exit transition state located about 31 kJ mol(-1) above the separated products. The hydrogen atom was found to leave the decomposing complex almost parallel to the total angular momentum vector and perpendicularly to the rotation plane of the decomposing intermediate. The defacto barrierless formation of the 1,4-dihydronaphthalene molecule involving a single collision between a phenyl radical and 1,3-butadiene represents an important step in the formation of polycyclic aromatic hydrocarbons (PAHs) and their partially hydrogenated counterparts in combustion and interstellar chemistry. PMID:22497458

Kaiser, R I; Parker, D S N; Zhang, F; Landera, A; Kislov, V V; Mebel, A M

2012-05-01

485

Ambient air 1,3-butadiene concentrations in Canada (1995-2003): seasonal, day of week variations, trends, and source influences  

NASA Astrophysics Data System (ADS)

Since 1987, the Environmental Protection Service of Environment Canada has operated a field program for measuring 1,3-butadiene and other volatile organic compounds (VOCs) in ambient air. With the co-operation of provincial and municipal environmental agencies, samples have been collected at urban and rural monitoring sites across the country. Samples were collected in evacuated canisters and analyzed by gas chromatography with a mass-selective detector. Using data from all sites, the composite average 1,3-butadiene concentration at urban sites in Canada for the years 1995-2003 was found to be 0.22 ?g m -3 and the composite median was 0.17 ?g m -3. In general, 1,3-butadiene concentrations were higher at commercial and industrial sites than at residential sites, particularly at sites close to street level in the urban core. The highest 24-h 1,3-butadiene concentration of 2.58 ?g m -3 was measured at the Sarnia, Ontario, site in 2001; this site was significantly influenced by industrial point sources. Mean 24-h 1,3-butadiene concentrations at rural sites were typically an order of magnitude lower than at urban sites. 1,3-Butadiene concentrations varied by season, particularly in western Canada, and by day of week. Concentrations of 1,3-butadiene decreased from 1995 to 2003 in response to reduced rates of emissions from mobile and point sources. At most urban monitoring sites, the concentrations of 1,3-butadiene and acetylene were highly correlated; this supports the hypothesis that 1,3-butadiene is emitted primarily by mobile sources.

Curren, Kristina C.; Dann, Tom F.; Wang, Daniel K.

486

[Mechanism and performance of styrene oxidation by O3/H2O2].  

PubMed

It can produce a large number of free radicals in O3/H2O2, system, ozone and free radical coupling oxidation can improve the styrene removal efficiency. Styrene oxidation by O3/H2O2 was investigated. Ozone dosage, residence time, H2o2 volume fraction, spray density and molar ratio of O3/C8H8 on styrene removal were evaluated. The experimental results showed that styrene removal efficiency achieved 85.7%. The optimal residence time, H2O2, volume fraction, spray density and O3/C8H8 molar ratio were 20. 6 s, 10% , 1.72 m3.(m2.h)-1 and 0.46, respectively. The gas-phase degradation intermediate products were benzaldehyde(C6H5CHO) and benzoic acid (C6H5 COOH) , which were identified by means of gas chromatography-mass spectrometry(GC-MS). The degradation mechanism of styrene is presented. PMID:24364291

He, Jue-Cong; Huang, Qian-Ru; Ye, Qi-Hong; Luo, Yu-Wei; Zhang, Zai-Li; Fan, Qing-Juan; Wei, Zai-Shan

2013-10-01

487

Styrene Oxide Isomerase of Rhodococcus opacus 1CP, a Highly Stable and Considerably Active Enzyme  

PubMed Central

Styrene oxide isomerase (SOI) is involved in peripheral styrene catabolism of bacteria and converts styrene oxide to phenylacetaldehyde. Here, we report on the identification, enrichment, and biochemical characterization of a novel representative from the actinobacterium Rhodococcus opacus 1CP. The enzyme, which is strongly induced during growth on styrene, was shown to be membrane integrated, and a convenient procedure was developed to highly enrich the protein in active form from the wild-type host. A specific activity of about 370 U mg?1 represents the highest activity reported for this enzyme class so far. This, in combination with a wide pH and temperature tolerance, the independence from cofactors, and the ability to convert a spectrum of substituted styrene oxides, makes a biocatalytic application imaginable. First, semipreparative conversions were performed from which up to 760 ?mol of the pure phenylacetaldehyde could be obtained from 130 U of enriched SOI. Product concentrations of up to 76 mM were achieved. However, due to the high chemical reactivity of the aldehyde function, SOI was shown to be the subject of an irreversible product inhibition. A half-life of 15 min was determined at a phenylacetaldehyde concentration of about 55 mM, indicating substantial limitations of applicability and the need to modify the process. PMID:22504818

Gröning, Janosch A. D.; Tischler, Dirk; Kaschabek, Stefan R.; Schlömann, Michael

2012-01-01

488

Highly thermostable anatase titania-pillared clay for the photocatalytic degradation of airborne styrene.  

PubMed

Airborne styrene is a suspected human carcinogen, and traditional ways of mitigation include the use of adsorption technologies (activated carbon or zeolites) or thermal destruction. These methods presenttheir own shortcomings, i.e., adsorbents need to be regenerated or replaced regularly, and relatively large energy inputs are required in thermal treatment. Photocatalysis offers a potentially sustainable and clean means of controlling such fugitive emissions of styrene in air. The present study demonstrates a new type of well-characterized, highly thermostable titania-pillared clay photocatalysts for airborne styrene decomposition in a custom-designed fluidized-bed photoreactor. This photocatalytic system is found to be capable of destroying up to 87% of 300 ppmV airborne styrene in the presence of ultraviolet (UV) irradiation. The effects of relative humidity (RH: 0 or 20%) are also studied, together with the arising physical structures (in terms of porosity and surface characteristics) of the catalysts when subjected to relatively high calcination temperatures of 1000-1200 degrees C. Such a temperature range may be encountered, e.g., in flue gas emissions (1). It is found that relative humidity levels of 20% retard the degradation efficiencies of airborne styrene when using highly porous catalysts. PMID:19238991

Lim, Melvin; Zhou, Yan; Wood, Barry; Wang, Lian Zhou; Rudolph, Victor; Lu, Gao Qing

2009-01-15

489

Biofiltration of mixtures of gas-phase styrene and acetone with the fungus Sporothrix variecibatus.  

PubMed

The biodegradation performance of a biofilter, inoculated with the fungus Sporothrix variecibatus, to treat gas-phase styrene and acetone mixtures under steady-state and transient conditions was evaluated. Experiments were carried out by varying the gas-flow rates (0.05-0.4m(3)h(-1)), leading to empty bed residence times as low as 17.1s, and by changing the concentrations of gas-phase styrene (0.01-6.3 g m(-3)) and acetone (0.01-8.9 g m(-3)). The total elimination capacities were as high as 360 g m(-3)h(-1), with nearly 97.5% removal of styrene and 75.6% for acetone. The biodegradation of acetone was inhibited by the presence of styrene, while styrene removal was affected only slightly by the presence of acetone. During transient-state experiments, increasing the overall pollutant load by almost 3-fold, i.e., from 220 to 600 g m(-3)h(-1), resulted in a sudden drop of removal efficiency (>90-70%), but still high elimination capacities were maintained. Periodic microscopic observations revealed that the originally inoculated Sporothrix sp. remained present in the reactor and actively dominant in the biofilm. PMID:20869172

Rene, Eldon R; Spa?ková, Radka; Veiga, María C; Kennes, Christian

2010-12-15

490

21 CFR 176.180 - Components of paper and paperboard in contact with dry food.  

Code of Federal Regulations, 2010 CFR

...Basic polymer. Acrylamide. Acrylic acid and its methyl, ethyl, butyl, propyl, or octyl esters. Acrylonitrile. Butadiene. Crotonic acid. Cyclol acrylate. Decyl acrylate. Diallyl fumarate. Diallyl maleate....

2010-04-01

491

75 FR 14153 - National Advisory Committee for Acute Exposure Guideline Levels for Hazardous Substances; Notice...  

Federal Register 2010, 2011, 2012, 2013, 2014

...and the development of Acute Exposure Guideline Levels (AEGLs) for the following chemicals: 1,3- butadiene; acetaldehyde; acrylonitrile; arsenic trioxide; benzene; bromine pentafluoride; butane; carbon dioxide; chlorine...

2010-03-24

492

40 CFR Appendix - Tables to Part 132  

Code of Federal Regulations, 2010 CFR

...Hexachlorobenzene Hexachlorobutadiene; hexachloro-1, 3-butadiene Hexachlorocyclohexanes; BHCs alpha-Hexachlorocyclohexane...Acenaphthene Acenaphthylene Acrolein; 2-propenal Acrylonitrile Aldrin Aluminum Anthracene Antimony Arsenic...

2010-07-01

493

40 CFR Table 8 to Subpart Ffff of... - Partially Soluble Hazardous Air Pollutants  

Code of Federal Regulations, 2010 CFR

...13. Acetaldehyde 75070 14. Acrolein 107028 15. Acrylonitrile 107131 16. Allyl chloride 107051 17. Benzene ...tribromomethane) 75252 21. Bromomethane 74839 22. Butadiene 106990 23. Carbon disulfide 75150 24....

2010-07-01

494

24 CFR Appendix I to Subpart C of... - Specific Hazardous Substances  

Code of Federal Regulations, 2010 CFR

...Hazardous Liquids Acetic Acid Acetic Anhydride Acetone Acrylonitrile Amyl Acetate Amyl Alcohol Benzene Butyl Acetate...Vinyl Acetate Xylene Hazardous Gases Acetaldehyde Butadiene Butane Ethene Ethylene Ethylene Oxide...

2010-04-01

495

40 CFR 132.6 - Application of part 132 requirements in Great Lakes States and Tribes.  

Code of Federal Regulations, 2010 CFR

...Hexachlorobenzene Hexachlorobutadiene; hexachloro-1, 3-butadiene Hexachlorocyclohexanes; BHCs alpha-Hexachlorocyclohexane...Acenaphthene Acenaphthylene Acrolein; 2-propenal Acrylonitrile Aldrin Aluminum Anthracene Antimony Arsenic...

2010-07-01

496

40 CFR Table 36 to Subpart G of... - Compound Lists Used for Compliance Demonstrations for Enhanced Biological Treatment Processes...  

Code of Federal Regulations, 2010 CFR

...Acetonitrile Acetaldehyde. Acetophenone Acrolein. Acrylonitrile Allyl Chloride. Biphenyl Benzene. Chlorobenzene... Diethyl Sulfate Bromomethane. Dimethyl Sulfate Butadiene 1,3. Dimethyl Hydrazine 1,1 Carbon Disulfide....

2010-07-01

497

40 CFR Table 7 to Subpart Vvvvvv... - Partially Soluble HAP  

Code of Federal Regulations, 2010 CFR

...13. Acetaldehyde 75070 14. Acrolein 107028 15. Acrylonitrile 107131 16. Allyl chloride 107051 17. Benzene ...tribromomethane) 75252 21. Bromomethane 74839 22. Butadiene 106990 23. Carbon disulfide 75150 24....

2010-07-01

498