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1

Homogeneous Styrene Butadiene\\/Acrylonitrile Butadiene Rubber Blends  

Microsoft Academic Search

The graft copolymerization of acrylonitrile (AN) onto butadiene rubber (BR) was carried out in toluene at 80°C, using dibenzoyl-peroxide (BPO) as initiator. The synthesized poly acrylonitrile-grafted-butadiene rubber (AN-g-BR) was characterized by N% elemental analysis and Fourier-transform infrared (FT-IR) spectroscopy. Styrene butadiene rubber\\/acrylonitrile butadiene rubber (SBR\\/NBR) blends were prepared with different blend ratios in presence and absence of AN-g-BR, where the

S. H. Botros; A. F. Moustafa; S. A. Ibrahim

2006-01-01

2

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

Code of Federal Regulations, 2013 CFR

...2013-04-01 false Acrylonitrile/butadiene/styrene/methyl methacrylate copolymer...Surfaces § 177.1030 Acrylonitrile/butadiene/styrene/methyl methacrylate copolymer. Acrylonitrile/butadiene/styrene/methyl...

2013-04-01

3

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

Code of Federal Regulations, 2010 CFR

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

2010-01-01

4

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

Code of Federal Regulations, 2010 CFR

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

2009-04-01

5

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

Microsoft Academic Search

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

Chun Chin Wang; Chi Mei Lee

2001-01-01

6

Cure characteristics and mechanical properties of styrene–butadiene rubber\\/acrylonitrile butadiene rubber  

Microsoft Academic Search

Blends of styrene butadiene rubber (SBR) and acrylonitrile–butadiene rubber (NBR) were prepared. Sulfur, dicumyl peroxide (DCP) and a combination of sulfur and DCP were used as vulcanizing agents. The effects of blend ratio and vulcanizing systems on the cure characteristics and mechanical properties, such as stress–strain behaviour, Young's modulus, tensile strength, elongation at break and hardness of SBR\\/NBR blends, were

K. Habeeb Rahiman; G. Unnikrishnan; A. Sujith; C. K. Radhakrishnan

2005-01-01

7

The thermal degradation of acrylonitrile-butadiene-styrene terpolymei as studied by TGA\\/FTIR  

Microsoft Academic Search

The thermal degradation of acrylonitrile-butadiene-styrene (ABS) terpolymer has been studied by TGA\\/FTIR. The degradation of ABS is compared with that of polystyrene, polybutadiene, polyacrylonitrile (PAN), and styreneacrylonitrile (SAN) copolymer. A small amount of acrylonitrile monomer is eliminated from PAN, SAN, and ABS. The grafting of butadiene on to SAN stabilizes the butadiene structure, since the evolution of butadiene begins 50

Masanori Suzuki; Charles A. Wilkie

1995-01-01

8

Reactive processing of recycled polycarbonate/acrylonitrile butadiene styrene.  

PubMed

Cellular phone housings were ground to make original particulates using a knife mill. Foams and adhesives with a lighter density than water were removed from ground mixtures using a sink-float process in water; ground metals, button rubbers, and wires were separated from desired materials by using a sink float process in salt All housing materials, consisting of seven thermoplastics included in cellular phone housings, showed better tensile properties than pure housing materials made of polycarbonate/acrylonitrile butadiene styrene, but they only had about half of the impact strength. In contrast, the low impact strength for all housing materials was improved by adding 25 wt % polyethylene elastomer and/or 2.4 wt % ground epoxy circuit boards for batch mixing. Impact strengths, tensile strengths, and the energy absorption ability of all housing materials were improved by adding 5.4wt% glycidyl methacrylate for twin screw extrusion. PMID:19452917

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

2009-04-01

9

Study of heterotrophic nitrifying bacteria from wastewater treatment systems treating acrylonitrile, butadiene and styrene resin wastewater  

Microsoft Academic Search

In this study we investigated the population of heterotrophic nitrifying bacteria in three biological wastewater treatment systems treating acrylonitrile, butadiene and styrene (ABS) resin wastewater. In addition to isolating and identifying these bacteria, we examined the physiological properties of the isolates, particularly utilization of acrylonitrile and its derivatives. An enrichment process was employed to isolate heterotrophic nitrifying bacteria from sludge

T.-L. Hu; K. T. Kung

2000-01-01

10

The migration of acrylonitrile from acrylonitrile/butadiene/styrene polymers into food-simulating liquids.  

PubMed

The correlation of residual acrylonitrile (AN) monomer concentration in AN-containing polymers with AN migration into food simulants is of interest because the US FDA regulates the use of these polymers on the basis of the amount of AN that may migrate into food simulants. Studies of the migration of AN into water from seven acrylonitrile/butadiene/styrene polymers with varying composition and residual AN levels showed that a linear relationship exists between the concentration of AN in the polymer and the amount of AN migrating, for a given set of exposure conditions. A linear relationship was also observed between the diffusion coefficients generated from the experimental data using a simple Fickian diffusion model and the inverse of the absolute temperature of exposure. PMID:1999304

Lickly, T D; Markham, D A; Rainey, M L

1991-01-01

11

Analysis of trace residual 1,3-butadiene in poly(acrylonitrile- co-butadiene- co-styrene)  

Microsoft Academic Search

Residual 1,3-butadiene in poly(acrylonitrile-co-butadiene-co-styrene) (ABS) was extracted by solvent and using direct thermal desorption. Toluene and N,N-dimethylacetamide were used as the extraction solvents. The extracted 1,3-butadiene was injected by headspace sampling to analyze using GC. The solvent extraction was found to be more efficient than the direct thermal desorption method. Solvent extraction with toluene was more efficient than that with

Sung-Seen Choi; Yun-Ki Kim

2011-01-01

12

Pretreatment of wastewater from acrylonitrile–butadiene–styrene (ABS) resin manufacturing by microelectrolysis  

Microsoft Academic Search

Pretreatment of acrylonitrile–butadiene–styrene (ABS) resin wastewater by microelectrolysis system was investigated to improve the biodegradability of the toxic aromatic compounds and organic nitriles. Two experiment systems, (a) control experiment of Fe and carbon and (b) microelectrolysis reactor, were set up to confirm the importance of macroscopic galvanic cells. In addition, the effect of the influent pH and Fe\\/C ratio on

Bo Lai; Yuexi Zhou; Hongke Qin; Changyong Wu; Cuicui Pang; Yu Lian; Jixian Xu

13

Thermal degradation of acrylonitrile–butadiene–styrene terpolymer in bean oil  

Microsoft Academic Search

Thermal degradation of acrylonitrile–butadiene–styrene terpolymer (ABS) in bean oil has been carried out in the temperature 350 and 370°C. The degradation products have been investigated by means of gel permeation chromatography (GPC) and fourier transform infra-red spectrometry (FTIR). With the presence of bean oil, ABS thermally degrades into asphalt-like degradation residue, which is soluble in common organic solvent such as

Dewen Dong; Shigeru Tasaka; Satoru Aikawa; Shingo Kamiya; Norihiro Inagaki; Youji Inoue

2001-01-01

14

Characterization of styrene butadiene rubber\\/recycled acrylonitrile-butadiene rubber (SBR\\/NBRr) blends: The effects of epoxidized natural rubber (ENR50) as a compatibilizer  

Microsoft Academic Search

The effects of epoxidized natural rubber (ENR-50) as a compatibilizer on the properties of styrene butadiene rubber\\/recycled acrylonitrile-butadiene rubber (SBR\\/NBRr) blends were studied. Styrene butadiene rubber\\/recycled acrylonitrile-butadiene rubber (SBR\\/NBRr) blends were prepared by two-roll mill with five different compositions (i.e., 85\\/5\\/10, 75\\/15\\/10, 65\\/25\\/10, 55\\/35\\/10 and 40\\/50\\/10), with the ENR-50 content fixed at 10 phr. Cure characteristics, mechanical properties, FTIR analysis, differential

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

2010-01-01

15

Toxicity of the components of styrene polymers: Polystyrene, acrylonitrile-butadiene-styrene (ABS) and styrene-butadiene-rubber (SBR). Reactants and additives  

SciTech Connect

The toxicity of the components of styrene polymers, e.g., polystyrene, ABS and SBR, were reviewed with primary focus on the reactive monomers (except styrene) (e.g., acrylonitrile, butadiene) as well as on impurities and solvents such as benzene, hexane and methylethyl ketone, and additives such as phenyl-2-naphthylamine, di-n-butyl phthalate, and a number of peroxide initiators and flame retardants (e.g., 2,3-dibromopropanol, decadibromodiphenyl oxide and antimony trioxide). It is stressed that toxicity data are generally lacking for the majority of additives employed in the production of styrene polymers. Information is also lacking as to the numbers of individuals at potential risk and the extent of their exposure to the large number of additives employed.

Fishbein, L.

1984-01-01

16

Toxicity of the components of styrene polymers: polystyrene, acrylonitrile-butadiene-styrene (ABS) and styrene-butadiene-rubber (SBR). Reactants and additives.  

PubMed

The toxicity of the components of styrene polymers, e.g., polystyrene, ABS and SBR, were reviewed with primary focus on the reactive monomers (except styrene) (e.g., acrylonitrile, butadiene) as well as on impurities and solvents such as benzene, hexane and methylethyl ketone, and additives such as phenyl-2-naphthylamine, di-n-butyl phthalate, and a number of peroxide initiators and flame retardants (e.g., 2,3-dibromopropanol, decadibromodiphenyl oxide and antimony trioxide). It is stressed that toxicity data are generally lacking for the majority of additives employed in the production of styrene polymers. Information is also lacking as to the numbers of individuals at potential risk and the extent of their exposure to the large number of additives employed. PMID:6371825

Fishbein, L

1984-01-01

17

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

18

Natural Weathering Test of Styrene Butadiene Rubber and Recycled Acrylonitrile Butadiene Rubber (SBR\\/NBRr) Blends  

Microsoft Academic Search

The effect of recycled acrylonitrile butadiene rubber (NBRr) content of SBR\\/NBRr blends on natural weathering was studied. Three different size of NBRr (S1; 117–334 µm, S2; 0.85–15.0 mm and S3; direct sheeted form) were used and the blends were exposed to natural weathering for 3 and 6 months. The results indicated that the SBR\\/NBRr blends with smallest size of NBRr (S1) show

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

2010-01-01

19

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

20

Preparation of acrylonitrile-butadiene-styrene terpolymer nanotubes with array structure in anodic aluminium oxide membrane using wetting techniques  

Microsoft Academic Search

Acrylonitrile-butadiene-styrene terpolymer (ABS) nanotubes and their arrays with different structures were prepared successfully using nanoporous Anodic Aluminium Oxide\\u000a (AAO) template through polymer solution and melt wetting method, a simple physical technique. According to the results of\\u000a Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM), nanotubes can be obtained using either polymer\\u000a solution or polymer melt. As for solution wetting

Jinshan Tan; Xi Lin She; Fang Yuan; Shujing Yang; Di Zhou

2008-01-01

21

Development of polycarbonate\\/acrylonitrile–butadiene–styrene copolymer based composites with functional fillers for car audio chassis  

Microsoft Academic Search

Environmental regulations require the improvement of automobile fuel efficiency. This can be achieved mainly by reducing the weight of automobile components. In this study, polycarbonate\\/acrylonitrile–butadiene–styrene copolymer (PC\\/ABS) based composite mixed with glass fibers and metal fibers was developed and its suitability of application into car audio chassis was investigated. The test materials were prepared with various contents of metal fibers

Seong Ho Jeon; Heon Mo Kim; Tae-Hong Park; Byoung-Ho Choi; Woo Chun Choi

2011-01-01

22

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

PubMed

A novel IMRT phantom was designed and fabricated using Acrylonitrile Butadiene Styrene (ABS) plastic. Physical properties of ABS plastic related to radiation interaction and dosimetry were compared with commonly available phantom materials for dose measurements in radiotherapy. The ABS IMRT phantom has provisions to hold various types of detectors such as ion chambers, radiographic/radiochromic films, TLDs, MOSFETs, and gel dosimeters. The measurements related to pre-treatment dose verification in IMRT of carcinoma prostate were carried out using ABS and Scanditronics-Wellhoffer RW3 IMRT phantoms for five different cases. Point dose data were acquired using ionization chamber and TLD discs while Gafchromic EBT and radiographic EDR2 films were used for generating 2-D dose distributions. Treatment planning system (TPS) calculated and measured doses in ABS plastic and RW3 IMRT phantom were in agreement within +/-2%. The dose values at a point in a given patient acquired using ABS and RW3 phantoms were found comparable within 1%. Fluence maps and dose distributions of these patients generated by TPS and measured in ABS IMRT phantom were also found comparable both numerically and spatially. This study indicates that ABS plastic IMRT phantom is a tissue equivalent phantom and dosimetrically it is similar to solid/plastic water IMRT phantoms. Though this material is demonstrated for IMRT dose verification but it can be used as a tissue equivalent phantom material for other dosimetry purposes in radiotherapy. PMID:20160681

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

2009-12-17

23

Formation of ?-iPP in Isotactic Polypropylene\\/Acrylonitrile–Butadiene–Styrene Blends: Effect of Resin Type, Phase Composition, and Thermal Condition  

Microsoft Academic Search

The formation of ?-iPP (?-modification of isotactic polypropylene) in the iPP\\/ABS (acrylonitrile–butadiene–styrene), iPP\\/styrene–butadiene (K resin), and iPP\\/styrene–acrylonitrile (SAN) blends were studied using differential scanning calorimery (DSC), wide angle X-ray diffraction (WAXD), and scanning electron microscopy (SEM). It was found that ?-iPP (?-modification of isotactic polypropylene) and ?-iPP can simultaneously form in the iPP\\/ABS blend, whereas only ?-iPP exists in the

Qiang Shu; Xiaoxuan Zou; Wenli Dai; Zhuo Fu

2012-01-01

24

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

NASA Astrophysics Data System (ADS)

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

Wang, X.; Yoshimura, N.

1999-05-01

25

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

NASA Astrophysics Data System (ADS)

An amine functional styrene-acrylonitrile (SAN-amine) polymer is proposed as a reactive compatibilizer for bisphenol-A-polycarbonate/acrylonitrile-butadiene-styrene (PC/ABS) blends. This polymer is miscible with the styrene/acrylonitrile (SAN) copolymer matrix of ABS materials, and the pendant secondary amine groups react with PC at the carbonate linkage to form a SAN-g-PC copolymer. The graft copolymer molecules reside at the PC/ABS interface and provide improved morphological stability at elevated temperatures by suppressing phase coalescence. The synthesis of this reactive compatibilizer and its reaction with carbonate moieties is described. Characterization of this reaction was done by NMR and GPC using model secondary amine and carbonate containing compounds. A technique was developed for the quantitative measurement of the kinetics of dispersed phase particle coalescence in these blends; the morphology was examined using TEM. While uncompatibilized PC/SAN blends showed an increase in particle size from approximately 1 mum to 2 mum (depending on PC viscosity) in less than five minutes at 270sp°C; compatibilized blends containing as little as 1% SAN-amine exhibited no change in morphology after 20 minutes. The effects of dispersed phase concentration, viscosity ratio and interfacial compatibilization using the SAN-amine compatibilizer on the process induced morphology of PC/SAN blends were also examined. Dispersed phase particle size increased significantly with SAN concentration and, although the morphology of uncompatibilized PC/SAN blends mixed in a Brabender mixer, single and twin screw extruders were quite similar, the twin screw extruder produced significantly finer morphologies in blends containing SAN-amine. The average particle size for blends compatibilized with the SAN-amine polymer was approximately half that of uncompatibilized blends and was relatively independent of viscosity ratio and dispersed phase composition. The fracture of thin (3.18 mm) and thick (6.35 mm) specimens of PC, ABS and PC/ABS blends with both standard and sharp notches was examined by standard Izod and single edge notch three point bend (SEN3PB) instrumented drop tower tests. Load-deflection data were analyzed as a function of ligament length and fracture parameters were calculated using the theoretical framework of the essential work of fracture concept. The effects of blend composition, temperature, rubber concentration and reactive compatibilization on the fracture properties of these materials were examined.

Wildes, Gregg Stephen

1998-11-01

26

Flame retardancy mechanisms of bisphenol A bis(diphenyl phosphate) in combination with zinc borate in bisphenol A polycarbonate\\/acrylonitrile–butadiene–styrene blends  

Microsoft Academic Search

Bisphenol A polycarbonate\\/acrylonitrile–butadiene–styrene (PC\\/ABS) with and without bisphenol A bis(diphenyl phosphate) (BDP) and 5wt.% zinc borate (Znb) were investigated. The pyrolysis was studied by thermogravimetry (TG), TG-FTIR and NMR, the fire behaviour with a cone calorimeter applying different heat fluxes, LOI and UL 94. Fire residues were examined with NMR.BDP affects the decomposition of PC\\/ABS and acts as a flame

Kristin H. Pawlowski; Bernhard Schartel; Mario A. Fichera; Christian Jäger

2010-01-01

27

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

28

21 CFR 181.32 - Acrylonitrile copolymers and resins.  

Code of Federal Regulations, 2013 CFR

...follows: (1) Films. (i) Acrylonitrile/butadiene/styrene copolymersâno restrictions. (ii) Acrylonitrile/butadiene copolymersâno restrictions. (iii) Acrylonitrile/butadiene copolymer blended with vinyl...

2013-04-01

29

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

Code of Federal Regulations, 2010 CFR

...maintained at 120 °F for 10 days when analyzed by a polarographic method titled âExtracted Acrylonitrile by Differential Pulse Polarography,â which is incorporated by reference. Copies are available from the Center for Food Safety and Applied...

2010-01-01

30

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

Code of Federal Regulations, 2010 CFR

...maintained at 120 °F for 10 days when analyzed by a polarographic method titled âExtracted Acrylonitrile by Differential Pulse Polarography,â which is incorporated by reference. Copies are available from the Center for Food Safety and Applied...

2009-04-01

31

Effect of porosity and environment on the mechanical behavior of acrylic bone cement modified with acrylonitrile-butadiene-styrene particles: I. Fracture toughness.  

PubMed

The elastomeric copolymer acrylonitrile-butadiene-styrene (ABS) was added to a conventional acrylic bone cement matrix. The results obtained show that although strength and stiffness decreased with an increasing second phase volume fraction, ductility and toughness both increased. The crack propagation became stable for specimens containing over a 5% volume fraction of the second phase. The fracture toughness increased up to 60% when the amount of ABS reached 20% (v/v). For larger amounts linear elastic fracture mechanics techniques could not be used properly. The effects of porosity and environmental conditions on the mechanical behavior were also studied. The mechanisms that control the fracture process were investigated by means of scanning electron microscopy. PMID:10331904

Vila, M M; Ginebra, M P; Gil, F J; Planell, J A

1999-01-01

32

The individual and cumulative effect of brominated flame retardant and polyvinylchloride (PVC) on thermal degradation of acrylonitrile-butadiene-styrene (ABS) copolymer.  

PubMed

Acrylonitrile-butadiene-styrene (ABS) copolymers without and with a polybrominated epoxy type flame retardant were thermally degraded at 450 degrees C alone (10 g) and mixed with polyvinylchloride (PVC) (8 g/2 g). Gaseous and liquid products of degradation were analysed by various gas chromatographic methods (GC with TCD, FID, AED, MSD) in order to determine the individual and cumulative effect of bromine and chlorine on the quality and quantity of degradation compounds. It was found that nitrogen, chlorine, bromine and oxygen are present as organic compounds in liquid products, their quantity depends on the pyrolysed polymer or polymer mixture. Bromophenol and dibromophenols were the main brominated compounds that come from the flame retardant. 1-Chloroethylbenzene was the main chlorine compound observed in liquid products. It was also determined that interactions appear at high temperatures during decomposition between the flame retardant, PVC and the ABS copolymer. PMID:15212908

Brebu, Mihai; Bhaskar, Thallada; Murai, Kazuya; Muto, Akinori; Sakata, Yusaku; Uddin, Md Azhar

2004-08-01

33

Ultrasonic degradation of butadiene, styrene and their copolymers  

Microsoft Academic Search

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

P. S. Sathiskumar; Giridhar Madras

34

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

2011-09-21

35

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

2013-05-09

36

Molecular simulations of gas transport in nitrile rubber and styrene butadiene rubber  

Microsoft Academic Search

Nitrile rubber (NBR, 39:61wt% of acrylonitrile:butadiene) and styrene butadiene rubber (SBR, 50:50wt% of styrene:butadiene) matrices have been equilibrated by molecular dynamics (MD) simulations. Transition-state approach is used to calculate the diffusion and solubility coefficients of small penetrants in these matrices, indicating quite low values in NBR and reasonable agreement with experimental results. MD simulations have been performed to analyze water

Esra Kucukpinar; Pemra Doruker

2006-01-01

37

Radiation effects on styrene butadiene styrene copolymer  

NASA Astrophysics Data System (ADS)

Styrene butadiene styrene copolymer (SBS) of different configuration and block ratio were irradiated by 60Co ?-rays at 20 °C and 120 °C. The gel fraction and thermal properties before and after irradiation were discussed. The gel fraction increased with both absorbed doses and temperature. This means higher crosslinking efficiency was obtained at higher temperature. The radiation chemical yields were calculated according to the Charlesby Pinner equation. The DSC analysis indicated that the crosslinking had taken place in the polybutadiene (PB) block while the chain scission of polystyrene (PS) block was dominant when irradiated at elevated temperature.

Zhang, Yan; Zhao, Sufang; Li, Yintao; Xie, Leidong; Sheng, Kanglong

2008-08-01

38

Modification of PVC compounds with butadiene-acrylonitrile elastomers  

Microsoft Academic Search

Purpose: The purpose of the paper is to present the research programme on influence of acrylonitrile-butadiene copolymers on properties of plasticized polyvinylchloride as window gaskets material. Design\\/methodology\\/approach: Short literature review concerning application of modified PVC as gasket material was presented. In experimental part two types of acrylonitrile-butadiene copolymers were used as elastomeric plasticizers. Compounds with fifteen different levels of modifiers

M. Rojek; J. Stabik

39

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

Code of Federal Regulations, 2013 CFR

...Acrylonitrile/butadiene/sty-rene co-polymer. 177.1020 Section 177.1020 ...CONTINUED) INDIRECT FOOD ADDITIVES: POLYMERS Substances for Use as Basic Components...Acrylonitrile/butadiene/sty-rene co-polymer....

2013-04-01

40

Rheological properties of styrene butadiene styrene polymer modified road bitumens  

Microsoft Academic Search

The use of polymers for the modification of bitumen in road paving applications has been growing rapidly over the last decade as government authorities and paving contractors seek to improve road life in the face of increased traffic. Currently, the most commonly used polymer for bitumen modification is the elastomer styrene butadiene styrene (SBS) followed by other polymers such as

Gordon D. Airey

2003-01-01

41

Elastomeric nanofibers of styrene-butadiene-styrene triblock copolymer  

Microsoft Academic Search

Nanofibers of a commercial styrene- butadiene-styrene triblock copolymer were electrospun from solution, and collected either as a nonwoven elastomeric fabric, or on a layer of graphite that was evaporated onto a glass microscope slide. The resulting nanofibers were elastic, birefringent, and most had diameters around 100 nm. A few thin, beaded fibers were found among the smooth nanofibers. The diameter

Hao Fong; Darrell H. Reneker

1999-01-01

42

Anionic Polymerization of Butadiene and Styrene.  

National Technical Information Service (NTIS)

A kinetic study was made of the polymerization of butadiene and styrene in an aliphatic hydrocarbon solvent with the use of butyllithium as an initiator. It is shown that the anomalous behavior in the initiation reaction exhibited by isoprene under these ...

A. F. Johnson D. J. Worsfold

1964-01-01

43

Polyblends of Poly(Styrene-b-Butadiene-b-Styrene) and Polystyrene. I. Mechanical Properties.  

National Technical Information Service (NTIS)

Kraton 1101, a styrene-butadiene-styrene triblock copolymer (SBS), was blended with homopolymers of styrene (PS) of various molecular weights by dissolving in mutual solvents. All polyblends cast from mixed solvents of tetrahydrofuran and methyl ethyl ket...

G. Akovali J. Diamant M. Shen

1976-01-01

44

Modification of styrene–butadiene rubber surfaces by plasma chlorination  

Microsoft Academic Search

Chlorination with halogenating agents in organic solutions is a common surface treatment for styrene–butadiene rubber materials to improve their adhesion to polyurethane adhesives. An attempt to replace this wet chemical method with a clean plasma technique has been undertaken. Styrene–butadiene rubbers (both model elastomers, such as Finaprene 435 and Finaprene 507 and a typical composite vulcanised rubber) were exposed to

J. Tyczkowski; I. Krawczyk; B. Wo?niak

2003-01-01

45

Role of dichlorocarbene modified styrene butadiene rubber in compatibilisation of styrene butadiene rubber and chloroprene rubber blends  

Microsoft Academic Search

A study was conducted on the use of dichlorocarbene modified styrene butadiene rubber (DCSBR) for the compatibilisation of blends of styrene butadiene rubber (SBR) and chloroprene rubber (CR). Stress–strain behaviour, mechanical properties, and low temperature transitions of the blends were examined in order to elucidate the efficiency of the compatibiliser. It was found that effective compatibilisation was achieved when chlorine

M. T Ramesan; George Mathew; Baby Kuriakose; Rosamma Alex

2001-01-01

46

Investigations on the addition of styrene butadiene rubber in natural rubber and dichlorocarbene modified styrene butadiene rubber blends  

Microsoft Academic Search

This paper focuses on the use of styrene butadiene rubber (SBR) as a viscosity modifier in novel blends of natural rubber (NR) and dichlorocarbene modified styrene butadiene rubber (DCSBR). The processing characteristics, vulcanisation kinetics, stress-strain behaviour, mechanical properties and low temperature transition of the blends have been examined in order to analyse the influence of SBR in the blends. The

M. T. Ramesan; T. K. Manoj Kumar; R. Alex; B. Kuriakose

2002-01-01

47

Styrene butadiene rubber\\/epoxidized natural rubber blends: Compatibilizer effects  

Microsoft Academic Search

The effects of a compatibilizer, styrene-(epoxidized butadiene) - styrene triblock co-polymer (ESBS) on dynamic properties, curing characteristics and swelling behavior of styrene butadiene rubber (SBR) and epoxidized natural rubber (ENR 50) blends were studied. Results indicate that the presence of ESBS improved the processability, increase the scorch time, t 2 and reduce the cure time, t 90 of the SBR\\/ENR

H. Ismail; H. P. S. Khalil; Y. Tsukahara

2002-01-01

48

Preparation and Characterization of Two Types of Cyanate Ester-epoxy Resin Interpenetrating Network Matrix\\/Butadiene-acrylonitrile Rubber Composites  

Microsoft Academic Search

Two types of butadiene-acrylonitrile rubbers (i.e., carboxyl randomized butadiene-acrylonitrile rubber (CRBN) and hydroxyl terminated butadiene-acrylonitrile rubber (HTBN)) have been used for modifying an interpenetrating network of cyanate ester (CE)\\/epoxy resin (EP) (70\\/30). The toughness of the matrix can be improved effectively with addition of rubbers. The values of impact strength (11.6 KJ\\/m) show a maximum for the CE\\/EP\\/HTBN (70\\/30\\/8) blend.

Zeng Minfeng; Lu Cuiyun; Qi Chenze

2010-01-01

49

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...

2009-07-01

50

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

51

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

52

Heterogeneity in styrene-butadiene latex films.  

PubMed

Low-Tg styrene-butadiene (SB) latex films were investigated by noncontact atomic force microscopy and scanning electric potential microscopy, revealing a number of different morphologies and electric potential patterns across films cast from the same SB latex dispersions under the same conditions. Surface leveling and charge dispersion throughout the films are, thus, restrained even at temperatures above Tg and the minimum film-formation temperature. An unprecedented electric pattern is observed, in which the particle cores are more positive than the contacting particle outer layers. Different packing patterns, including cubic and hexagonal arrays, coexist in neighboring areas. Zonal centrifugation of the SB latex in sucrose density gradient shows that particles cover a broad range of densities. Thus, film surface heterogeneity is at least partly due to particle heterogeneity. Fractal dimensions of topographic profiles are lower than those of the electric potential profiles, showing that charge mobility is much more restrained than polymer chain motion at the film surface and that it imposes a limit to the charged chain-ends motion. PMID:15544387

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

2004-11-23

53

21 CFR 177.1040 - Acrylonitrile/styrene copoly-mer.  

Code of Federal Regulations, 2013 CFR

...Determination of Residual Acrylonitrile and Styrene Monomers-Gas Chromatographic Internal Standard Methodâ; âInfrared Spectrophotometric Determination of Polymer Extracted from Barex 210 Resin Pelletsâ; âProcedure for the...

2013-04-01

54

Polyblends of Poly(Styrene-b-Butadiene-b-Styrene) and Polystyrene. II. Electron Microscopy.  

National Technical Information Service (NTIS)

Electron micrographs of a series of polyblends of poly(styrene-b-butadiene-b-styrene), SBS, and polystyrene, PS, are presented. These polyblends were cast from three different solvents, i.e., tetrahydrofuran/methyl ethyl ketone (THF/MEK), benzene/heptane ...

M. Niinomi G. Akovali M. Shen

1976-01-01

55

Lymphohematopoietic cancer in styrene-butadiene polymerization workers.  

PubMed

1,3-Butadiene and styrene are suspected carcinogens and common chemicals used in the synthesis of rubber. To investigate any potential human hazards from exposure to these chemicals, a case-control study of 59 lymphohematopoietic cancers was conducted within a cohort of male workers employed between 1943 and 1982 in eight North American styrene-butadiene rubber polymer-producing plants. A total of 193 controls were matched to the cases by plant, age, year of hire, duration worked, and survival to time of death of the case. Each job was assigned an estimated exposure rank, and each worker's cumulated rank score was calculated on the basis of the time spent in each job throughout his employment. "Exposure" as a dichotomous variable was defined as a log rank score above the mean of the log scores for the total population of cases and controls within a subtype of cancer. Matched-pair analysis identified a strong association between leukemia and butadiene, with an odds ratio of 9.36 (95% confidence interval 2.05-22.9) and an association between styrene and leukemia (odds ratio = 3.13, 95% confidence interval 0.84-11.2) that did not achieve statistical significance. When exposure to both styrene and butadiene was included in a conditional logistic regression model, the odds ratio for butadiene remained high (odds ratio = 7.39), but the estimated association of leukemia with styrene was small. The results of this study support the hypothesis that exposure to butadiene is associated with the risk of leukemia. There also appears to be an additional risk from work in specific subdivisions of the industry. PMID:1442750

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

1992-10-01

56

Thermal stability and flammability of butadiene- acrylonitrile rubber cross-linked with iodoform  

Microsoft Academic Search

Summary The paper discusses the  results of thermal analysis and flammability of butadiene-acrylonitrile rubber, Perbunan NT 1845 of Bayer, cross-linked with iodoform. The properties of the iodoform vulcanizate have been compared with those of peroxide vulcanizate. The thermal analysis has been performed in air with use of a derivatograph under air and nitrogen atmosphere as well as dynamic scanning calorimetry

P. Rybi?ski; G. Janowska; W. Antkowicz; S. Krauze

2005-01-01

57

Characterization of soy protein\\/styrene–butadiene rubber composites  

Microsoft Academic Search

The use of renewable soy protein aggregates as a reinforcement network in Styrene–butadiene rubber composites is investigated by dynamic mechanical method. The rigid nature of dry protein has a high shear elastic modulus of ?2GPa and therefore is suitable as a reinforcement phase in rubber composites. The addition of soy protein to the rubber composites generates a significant reinforcement effect.

Lei Jong

2005-01-01

58

Application of Lignin as Antioxidant in Styrene Butadiene Rubber Composite  

Microsoft Academic Search

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

Shusheng Liu; Xiansu Cheng

2010-01-01

59

Characteristics of the pyrolysis patterns of styrene-butadiene rubbers with differing microstructures  

Microsoft Academic Search

The pyrolysis patterns of styrene-butadiene rubbers (SBR) with different microstructures were characterized with pyrolysis-gas chromatography. SBRs with different content ratios of the styrene, 1,2, cis-1,4-, and trans-1,4-units were used. The major pyrolysis products were butadiene, 4-vinylcyclohexene (4-VCH), and styrene. The relative abundance of the styrene peak increased with an increase in the styrene unit in SBR. Variation of peak intensity

Sung-Seen Choi

2002-01-01

60

In-Depth Industrial Hygiene Composite Report on Exposure to Styrene and Butadiene at Two Styrene-Butadiene Rubber Processing Plants.  

National Technical Information Service (NTIS)

Worker exposures to styrene (100425) and butadiene (106990) were investigated at two unspecified styrene-butadiene rubber (SBR) processing facilities (SIC-2822) in Port Neches, Texas on July 12 to 16, 1976 and April 11 to 14, 1977. The companies were surv...

L. M. Blade M. S. Crandall R. J. Young

1981-01-01

61

Pyrolysis mass spectrometric analysis of styrene-butadiene block and random copolymers  

Microsoft Academic Search

Direct pyrolysis mass spectrometric analysis of a styrene-butadiene-styrene block copolymer indicated that thermal decomposition of each block shows a resemblance to the related homopolymer, giving a possibility of differentiation of blocks. However, the random analog, the styrene butadiene rubber, degraded in a manner that is somewhat in between in nature of the thermal characteristics of both homopolymers. This technique shows

Jale Hacaloglu; Taner Ersen; Nergis Ertugrul; Muhammed M. Fares; Sefik Suzer

1997-01-01

62

Cure Characteristics and Mechanical Properties of HRH Bonded Nylon6 Short Fiber-Nanosilica-Acrylonitrile Butadiene Rubber Hybrid Composite  

Microsoft Academic Search

Nano silica was synthesized by acid hydrolysis of sodium silicate using diluted hydrochloric acid. This synthetic nanosilica was used in place of hydrated silica in a HRH (hexamethylenetetramine, resorcinol and silica) bonding system for acrylonitrile butadiene rubber–nylon-6 short fiber composite. Nanosilica was also used as a reinforcing filler in acrylonitrile butadiene rubber–nylon-6 short fiber hybrid composite. Cure characteristic and mechanical

Leny Mathew; Sunil K. Narayanankutty

2008-01-01

63

Low-temperature properties of styrene–butadiene–styrene polymer modified bitumens  

Microsoft Academic Search

Low-temperature properties of the modified bitumens containing styrene–butadiene–styrene (SBS) polymers were investigated using conventional methods, dynamic mechanical analysis (DMA) and bending beam rheometer (BBR). Effects of the characteristics of base bitumens and polymers and the proportion of the components on these properties were studied. The results indicated that SBS polymers improved low-temperature properties of bitumens. The degree of improvement generally

Xiaohu Lu; Ulf Isacsson; Jonas Ekblad

1998-01-01

64

Polyblends of poly(styrene-b-butadiene-b-styrene) and polystyrene. II. Electron microscopy  

Microsoft Academic Search

Electron micrographs of a series of polyblends of poly(styrene-b-butadiene-b-styrene (SBS) and polystyrene (PS) are presented. These poly blends were cast from three different solvents, i.e., tetrahydrofuran—methyl ethyl ketone (THF\\/ MEK), benzene—heptane, and carbon tetrachloride. PS of four different molecular weights were used. It is shown that when the molecular weight of PS exceeds that in the block copolymer, a third

M. Niinomi; G. Akovali; M. Shen

1977-01-01

65

Molecular Characterization of Styrene-Butadiene-Styrene Block Copolymers (SBS) by GPC, NMR, and FTIR  

Microsoft Academic Search

Summary  This paper deals with the characterization of styrene-butadiene-styrene (SBS) block copolymers at molecular level through\\u000a different techniques. SBS molecular weight distributions (MWD) were measured by Gel Permeation chromatography (GPC) in tetrahydrofuran\\u000a (THF) solvent and using a calibration curve based on mono-dispersed polystyrene standards; afterwards, the relative molecular\\u000a weights obtained by GPC were adjusted using a correction factor based on Mark-Houwink-Sakurada

L. B. Canto; G. L. Mantovani; E. R. deAzevedo; T. J. Bonagamba; E. Hage; L. A. Pessan

2006-01-01

66

Thermal Stabilities and Thermal Degradation Kinetics of a Styrene-Butadiene-Styrene Star Block Copolymer  

Microsoft Academic Search

The thermal and thermo-oxidative degradation behaviors of styrene-butadiene-styrene (SBS) star block copolymer were reported using thermogravimetric analysis (TGA). TGA coupled with Fourier Transform Infrared spectroscopy was used to characterize the degradation volatile of SBS in air atmosphere. The thermal degradation kinetics of SBS in nitrogen and air atmospheres was studied in three steps: (1) the activation energies E? were estimated

Ting-Ting Su; Heng Jiang; Hong Gong

2009-01-01

67

Carbon nanotubes as reinforcement of styrene–butadiene rubber  

Microsoft Academic Search

This study reports an easy technique to produce cured styrene–butadiene rubber (SBR)\\/multi-walled carbon nanotubes (MWCNT) composites with a sulphur\\/accelerator system at 150°C. Significant improvement in Young's modulus and tensile strength were achieved by incorporating 0.66wt% of filler without sacrificing SBR elastomer high elongation at break. A comparison with carbon black filled SBR was also made. Field emission scanning electron microscopy

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

2007-01-01

68

Weak Boundary Layers in Styrene-Butadiene Rubber  

Microsoft Academic Search

In this paper two kinds of weak boundary layers (WBL) in synthetic vulcanized styrene-butadiene rubber are described.i) WBL produced by the presence of antiadhesion compounds of the rubber formulation (zinc stearate, microcrystalline paraffin wax). These WBL cannot be effectively removed by solvent wiping, whether followed by washing with an ethanol\\/water mix or not. Although this treatment allowed a significant removal

M. M. Pastor-Blas; M. S. Sánchez-Adsuar; J. M. Martín-Martínez

1995-01-01

69

Thermodynamics of tapered styrene-butadiene block copolymers  

Microsoft Academic Search

A modified version of the Leary-Henderson-Williams equilibrium thermodynamic theory is used to predict microstructural properties for tapered poly(styrene-butadiene) diblock copolymers containing a random copolymer between the blocks. The interphase thickness, interphase volume fraction, and repeat distance are all predicted to increase as the volume fraction of the added random copolymer increases, whereas the microphase-separation temperature is shown to decrease. Comparison

Richard J. Spontak; Michael C. Williams

1989-01-01

70

Styrene–butadiene rubber pyrolysis: Products, kinetics, modelling  

Microsoft Academic Search

The pyrolysis of SBR (styrene–butadiene rubber) was investigated by a dynamic thermogravimetric apparatus, where it is possible to treat samples in form of cylinders with a weight of about 30g. Various heating rates between 0.1 and 1°C\\/s were investigated. A distributed parameter model able to describe heating inside the sample and its kinetics of decomposition was built. The pyrolysis enthalpy

E. Grieco; M. Bernardi; G. Baldi

2008-01-01

71

Synthesis and evaluation of new antioxidants for styrene butadiene rubber  

Microsoft Academic Search

Purpose – The purpose of this paper is to study the effect of new heterocyclic compounds on styrene butadiene rubber (SBR) mixes. Design\\/methodology\\/approach – It has been found that the starting material 1 could react with cyromazine (2) and\\/or 4-aminoantipyriene (4) as amino compounds in the presence of triethylorthoformate and in the boiling dioxane to yield triazine-3 and\\/or pyrazolo 5

Galal Nawwar; Sayed Yakout; M. S. A El-Sadiek; Salwa El-Sabbagh

2011-01-01

72

Photooxidation of dyed styrene-butadiene and natural rubbers  

Microsoft Academic Search

Dyed natural rubber (NR) and styrene-butadiene rubber (SBR) designed for outdoor applications were exposed to accelerated\\u000a artificial aging in xenon light. The aging results in the deterioration of the properties of the exposed surface material.\\u000a The ability of dyed polymers to withstand prolonged sunlight exposure without fading or undergoing any physical deterioration\\u000a is largely determined not only by the photochemical

D. Ruch; C. Becker; A. Riche; S. Etienne; J. Bour

2008-01-01

73

Kinetics of nonisothermal thermal degradation of styrene-butadiene rubber  

Microsoft Academic Search

The kinetics of thermal degradation of styrene-butadiene rubber (SBR) was studied by conventional thermo-gravimetric technique\\u000a with various heating rates under nitrogen. A kinetic model which accounts for the effects of scission of polymeric chain at\\u000a any time was proposed to describe the thermal degradation of SBR. Results showed that the contribution of the thermal degradation\\u000a of zero-order reaction is greater

Sea Cheon Oh; Hae Pyeong Lee; Hee Taik Kim; Kyong Ok Yoo

1999-01-01

74

Kinetics of the Nonisothermal Degradation of Styrene-Butadiene Rubber  

Microsoft Academic Search

The kinetics of the thermal degradation of styrene-butadiene rubber (SBR) have been studied using a conventional nonisothermal thermo gravimetric technique at several heating rates ranging from 10°C\\/min to 50°C\\/min. The dynamic thermogravimetric analysis curve and its derivative have been analyzed using a variety of analytical methods reported in the litera ture to obtain the kinetic parameters such as activation energies,

Sea Cheon Oh; Hae Pyeong Lee; Sung-Chul Yi; Kyong Ok Yoo

1999-01-01

75

Rheoptical Studies of Blends of Poly(Styrene-b-Butadiene-b-Styrene) and Polystyrene.  

National Technical Information Service (NTIS)

Polyblends of poly(styrene-b-butadiene) and polystyrene were cast from a tetrahydrofuran/methyl ethyl ketone mixture using a spin caster. These samples were found to undergo a 'strain-induced plastic-rubber transition' upon deformation. Infrared dichroism...

S. D. Hong M. Shen T. Russell R. S. Stein

1977-01-01

76

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

77

Nanocomposites based on silica-reinforced ethylene–propylene–diene–monomer\\/acrylonitrile–butadiene rubber blends  

Microsoft Academic Search

Rheometric characteristics, curing kinetics, mechanical properties before and after thermal aging and morphology of nanocomposites based on various network precursors (i.e., acrylonitrile–butadiene rubber (NBR), ethylene–propilene–diene monomer (EPDM) and its blend (NBR\\/EPDM) reinforced of nanosilica) is presented here. The ratios of EPDM and NBR as binary blend system vary significantly. The rheometric characteristics and curing kinetics of nanocomposites were determined using

Suzana Samaržija-Jovanovi?; Vojislav Jovanovi?; Gordana Markovi?; Sandra Konstantinovi?; Milena Marinovi?-Cincovi?

2011-01-01

78

In Situ Dynamic Vulcanization of Poly(Vinyl Chloride)\\/Acrylonitrile-butadiene Rubber Blends  

Microsoft Academic Search

Poly(vinyl chloride) (PVC)\\/acrylonitrile-butadiene rubber (NBR) blends can be obtained through a dynamic vulcanization process as a melt-processible thermoplastic elastomer which produces parts that look, feel and perform like vulcanized rubber with the advantage of being processible as a thermoplastic material. In this study, a vulcanized thermoplastic was obtained by in situ dynamic vulcanization of PVC\\/NBR blends using a sulphur\\/ tetramethylthiuram

Fábio Roberto Passador; Antonio Rodolfo Jr; Luiz Antonio Pessan

2009-01-01

79

Preparation and characterization of thermoplastic polyurethane-urea and carboxylated acrylonitrile butadiene rubber blend nanocomposites  

Microsoft Academic Search

This study deals with the preparation and characterization of novel thermoplastic polyurethane-urea (TPUU) and carboxylated acrylonitrile butadiene rubber (XNBR) blends. Blends of different compositions were prepared in tetrahydrofuran using a solution technique, following an ultra-sonication. The chemical reaction between the two inherently immiscible blend phases was determined with the help of Fourier transform infrared-attenuated total reflectance (FTIR-ATR) spectroscopy and H-1-nuclear

N. Mahmood; A. U. Khan; Z. Ali; M. S. Khan; A. U. Haq; K. W. Stöckelhuber; U. Gohs; G. Heinrich

2012-01-01

80

Styrene\\/Acrylonitrile Graft Natural Rubber as Compatibilizer in Rubber Blends  

Microsoft Academic Search

A graft copolymer of acrylonitrile (ACN) and styrene (ST) on natural rubber (NR) was prepared by solution polymerization initiated by benzoyl peroxide. The effect of graft NR (GNR) applied as a compatibilizer for NR\\/nitrile rubber (NBR) blends on their mechanical and physical properties was investigated. The results revealed that the tensile properties and oil-swelling resistance of the blends increased with

Siriya Angnanon; Pattarapan Prasassarakich; Napida Hinchiranan

2011-01-01

81

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

Code of Federal Regulations, 2013 CFR

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

2013-07-01

82

Styrene production, use, and human exposure.  

PubMed

Styrene is an extremely important commodity chemical used extensively in the manufacture of numerous polymers and copolymers, including polystyrene, acrylonitrile-butadiene-styrene (ABS), styrene-acrylonitrile (SAN), styrene-butadiene latex, and styrene-butadiene rubber. Styrene is a component of cigarette smoke and automobile exhaust, and it may occur naturally at low levels in various types of foods. The highest potential human exposures to styrene occur in occupational settings, particularly those involving the production of large glass-reinforced polyester products such as boats, which require manual lay-up and spray-up operations. Substantially lower occupational exposures occur in styrene monomer and polymer production facilities. The general public is exposed to very low concentrations of styrene in ambient air, indoor air, food, and drinking water. PMID:7818766

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

1994-01-01

83

Study of two types of styrene butadiene rubber in tire tread compounds  

Microsoft Academic Search

The ratio of vinyl butadiene and styrene groups in styrene butadiene rubber (SBR) structures is a crucial factor that affects the inherent rubber characteristics such as glass transition temperature, Tg, hysteresis, strength, etc. In this paper, two types of SBR (Krynol 1721 and Buna VSL 5025-1) which contain higher ratios of these two groups, were blended with natural rubber (SMR

Pham Thi Hao; Hanafi Ismail; Azanam S Hashim

2001-01-01

84

Metabolic interactions of 1,3-butadiene and styrene in male B6C3F1 mice.  

PubMed

Butadiene and styrene are a mixture of hazardous air pollutants found in the workplace of industries producing polymers such as styrene-butadiene rubber. Both butadiene and styrene require metabolic activation to exert their genotoxic effect; therefore metabolic interactions may influence their genotoxicity. Our objective was to quantitate potential metabolic interactions in mice exposed to a mixture of butadiene and styrene. The rate of metabolism of butadiene and styrene was estimated from the steady-state rate of uptake of the chemicals by male B6C3F1 mice exposed for 8 hr in a dynamic, whole-body inhalation system to 100 or 1000 ppm butadiene in combination with 0, 50, 100, or 250 ppm styrene. Styrene, styrene oxide, 1,2-epoxy-3-butene, and 1,2:3,4-diepoxybutane concentrations in blood were measured by gas chromatography-mass spectrometry at 2, 4, 6, and 8 hr of exposure. As the styrene concentration in the mixture increased, the rate of butadiene metabolism was inhibited up to 48%. 1,2-Epoxy-3-butene blood concentrations were increased by approximately 1.5-fold; however, 1,2:3,4-diepoxybutane blood concentrations were unaffected. Styrene uptake in the inhalation system was inhibited slightly by exposure with butadiene, but styrene blood concentrations increased significantly as the butadiene concentration in the mixture increased to 1000 ppm. Blood concentrations of styrene oxide increased approximately 1.6-fold for the 250-ppm styrene exposures when the butadiene concentration was increased from 0 to 1000 ppm. The data suggest that metabolic interactions occurred among the reactive metabolites (e.g., competition for detoxication pathways) as well as between butadiene and styrene in mice exposed to mixtures of butadiene and styrene. However, metabolic interactions were significant only at concentrations of butadiene and styrene higher than those typically observed in the workplace of industries producing polymers of butadiene and styrene. PMID:8975788

Leavens, T L; Moss, O R; Turner, M J; Janszen, D B; Bond, J A

1996-12-01

85

Rheoptical studies of blends of poly(styrene-b-butadiene-b-styrene) and polystyrene. Technical report  

Microsoft Academic Search

Polyblends of poly(styrene-b-butadiene) and polystyrene were cast from a tetrahydrofuran\\/methyl ethyl ketone mixture using a spin caster. These samples were found to undergo a 'strain-induced plastic-rubber transition' upon deformation. Infrared dichroism, birefringence, small angle x-ray scattering, small angle light scattering and scanning electron micrograph studies were carried out to investigate this phenomenon. Infrared dichroism and birefringence studies both indicate the

S. D. Hong; M. Shen; T. Russell; R. S. Stein

1977-01-01

86

Distribution of monomeric units in butadiene-styrene copolymers according to data of C13 NMR spectroscopy  

SciTech Connect

This paper presents the distribution of the monomeric units in the copolymers of butadiene with styrene as a function of the molar ratio KOH/LiR' in the reaction mixture. In the absence of KOR during a change in the styrene content in the reaction mixture, the authors observed the influence of the styrene concentration on the distribution of the monomeric units in the butadiene-styrene copolymers. The results show that during the copolymerization of butadiene with styrene in the presence of lithium alkyls, styrene considerably influences the distribution of the monomeric units in the polymer chain and the structure of its butadiene segment.

Sysoev, V.Y.; Dolinskaya, E.R.; Kormer, V.A.

1986-03-01

87

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

SciTech Connect

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

Smith, R.E.

1990-01-01

88

Styrene-acrylonitrile (SAN) layered silicate nanocomposites prepared by melt compounding  

Microsoft Academic Search

Poly(styrene-co-acrylonitrile) (SAN) nanocomposites were successfully made by melt compounding and exhibited improved thermal stability and reduced flammability. The organoclays used in these nanocomposites were based upon fluorinated synthetic mica (FSM) or montmorillonite (MMT). Four different organic treatments were used on the clay surface to study the effect of organic treatment on clay dispersion: dimethyl, bis(hydrogenated tallow) ammonium (DMHTA), methyl tallow

Lih-Long Chu; Stephanie K. Anderson; Joseph D. Harris; Mark W. Beach; Alexander B. Morgan

2004-01-01

89

Miscibility and Phase Behavior in Melt Blends of Thermoplastic Polyurethane and Styrene Acrylonitrile Copolymers  

Microsoft Academic Search

Phase behavior of the binary polymer system consisting of thermoplastic polyurethane (TPU) and styrene acrylonitrile (SAN) copolymers of various compositions (100\\/0, 90\\/10, 70\\/30, 50\\/50, 30\\/70, 0\\/100) has been investigated by differential scanning calorimeter (DSC). The phase separation on heating, i.e., lower critical solution temperature (LCST) behavior, was found to occur when these blends were heated to elevated temperatures. The cloud?point

S. N. Jaisankar; Y. Lakshminarayana; Ganga Radhakrishnan

2005-01-01

90

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

SciTech Connect

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

Miller, C.E.; Eichinger, B.E. (Univ. of Washington, Seattle (USA)); Gurley, T.W.; Hermiller, J.G. (Goodyear Tire and Rubber Company, Akron, OH (USA))

1990-09-01

91

The Effect of Morphology on the Mechanical and Rheo-Optical Properties of a Styrene-Butadiene-Styrene Block Copolymer.  

National Technical Information Service (NTIS)

The mechanical and rheo-optical properties of a styrene-butadiene-styrene block copolymer of a given chemical composition are dependent upon the morphology of the polymer as affected by the solvent system from which a polymer film is cast. Films cast from...

G. L. Wilkes R. S. Stein

1969-01-01

92

Cancer epidemiology among styrene-butadiene rubber workers.  

PubMed

The standardized mortality ratios for some cancers of the lymphohaematopoietic system were high in an early cohort analysis. Since the presence of large numbers of unexposed workers could conceal risks within a cohort, a case-control study was designed to examine the relationship between estimated exposures and the occurrence of these cancers. The results suggested that the risk for leukaemia was associated with exposure to butadiene and with work in specific areas. Modelling, using rank scores, indicated an increase in the risk for leukaemia with increasing exposure score. Use of cases validated by review of hospital records and selection of a new set of controls did not change the findings. The data indicated that comparison of scores within the same time frame improved the model and increased the estimated odds ratio, suggesting that exposure time or dose rate may prove to be the important variable for risk. Exact measurements from the companies involved showed significant correlations between assigned ranks and level of exposure derived from personal monitoring for butadiene but not for styrene. Thus, use of the measured values might be expected to show an association between leukaemia and exposure to butadiene. The standardized mortality ratio for leukaemia among long-term workers hired before 1960 who had worked in the three plants where the geometric mean butadiene level was three to five times higher than those in the other plants is 1.8 times higher than that of the US population. An appropriate algorithm for comparing cases and controls on the bases of the measured samples is being developed. PMID:8070882

Matanoski, G; Francis, M; Correa-Villaseñor, A; Elliott, E; Santos-Burgoa, C; Schwartz, L

1993-01-01

93

SAX (Small-Angle X-ray Scattering) Study of Micelle Formation in Mixtures of Butadiene Homopolymer and Styrene-Butadiene Block Copolymer. 3. Comparison with Theory.  

National Technical Information Service (NTIS)

The theory of block copolymer micelle formation formulated by Leibler, Orland and Wheeler is compared with the experimental results of Rigby and Roe obtained with mixtures of styrene-butadiene diblock copolymer and butadiene homopolymer. To facilitate the...

R. J. Roe

1986-01-01

94

Durability of styrene-butadiene latex modified concrete  

SciTech Connect

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

Shaker, F.A.; El-Dieb, A.S.; Reda, M.M. [Ain Shams Univ., Cairo (Egypt). Dept. of Structural Engineering

1997-05-01

95

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

PubMed

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

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

2009-07-01

96

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

NASA Astrophysics Data System (ADS)

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

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

2013-03-01

97

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

98

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

Microsoft Academic Search

Linear and star-shaped styrene–butadiene block copolymers synthesized by anionic polymerization of butadiene and styrene were fractionated by applying a newly developed large-scale fractionation technique, named continuous spin fractionation (CSF). Their molecular weight and polydispersity index (d=Mw\\/Mn) were measured with size-exclusion chromatography and static light scattering. For the linear triblock copolymer a fractionation via temperature variation turned out to be better

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

2006-01-01

99

A hematology survey of workers at a styrene-butadiene synthetic rubber manufacturing plant  

Microsoft Academic Search

A previous epidemiologic study of the U.S. rubber industry indicated that there has been an excess of leukemia and lymphoma mortality among hourly workers at one styrene-butadiene rubber manufacturing plant. This investigation was a combined industrial hygiene and hematology cross-sectional survey at the same plant. The objectives of the survey were to quantify exposure levels for styrene, butadiene, benzene and

HARVEY CHECKOWAY; TED M. WILLIAMS

1982-01-01

100

Characterization of bound rubber of filled styrene-butadiene rubber compounds using pyrolysis-gas chromatography  

Microsoft Academic Search

Variation in the composition of the bound rubber of filled styrene-butadiene rubber (SBR) compounds was studied using pyrolysis-gas chromatography (pyrolysis-GC). The compositions of the bound rubber and the compounded carbon black- and silica-filled SBR rubbers were analyzed and compared. Results of the pyrolysis-GC analysis showed that the ratio of the butadiene\\/styrene components was higher in the bound rubber than in

Sung-Seen Choi

2000-01-01

101

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

2010-03-01

102

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

SciTech Connect

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

Drazkowski, Daniel B.; Lee, Andre; Haddad, Timothy S. (ERC, Inc.); (MSU)

2008-10-03

103

Effects of Dynamic Vulcanization and Acrylic Acid on Properties of Recycled Poly(vinyl chloride)\\/Acrylonitrile Butadiene Rubber (PVCr\\/NBR) Blends  

Microsoft Academic Search

Effects of dynamic vulcanization and acrylic acid (AAc) on processability, mechanical properties, swelling behavior, morphology, and thermal stability of recycled poly(vinyl chloride)\\/acrylonitrile butadiene rubber (PVCr\\/NBR) blends were investigated. Blends were prepared in a Haake Rheomix at a temperature of 150°C and a rotor speed of 50 rpm. Recycled poly(vinyl chloride)\\/acrylonitrile butadiene rubber (PVCr\\/NBR) blends were also prepared as comparison. It was

Supri; H. Ismail; A. M. M. Yusof

2006-01-01

104

Poly (?-caprolactam)-poly (butadiene- co-acrylonitrile) block copolymers II. Processability and properties of pultruded glass-fiber-reinforced composites  

Microsoft Academic Search

Uni-directional glass-fiber-reinforced Nylon 6 and poly(?-caprolactam)-poly(butadiene-co-acrylonitrile) block copolymers (NY6\\/ ATBN) have been prepared by a novel thermoplastic pultrusion process. The effects of processing parameters, ATBN (amine-terminated butadiene-acrylonitrile copolymer) content and glass fiber content on the mechanical and thermal properties of pultruded composites were studied. Results show that NY6\\/ATBN (less than 15 wt.% ATBN) composites possess good fiber wet-out and very

Chen-Chi M Ma; Meng-Song Yn

1995-01-01

105

Secondary ion and laser ablation mass spectrometry for the quantitative characterization of styrene-butadiene copolymers.  

PubMed

Styrene-butadiene copolymers were analyzed by static secondary ion mass spectrometry (S-SIMS) and laser ablation Fourier transform ion cyclotron resonance mass spectrometry (LA-FTICRMS) to obtain quantitative information based on specific ions. Silver deposition was performed on polystyrene, butadiene rubber and styrene-butadiene rubber. Under these experimental conditions, new secondary ions were detected, in particular silver-cationized butadiene [M(butadiene) - Ag](+) and styrene [M(styrene) - Ag](+) monomers. In contrast, LA-FTICRMS experiments did not require pretreatment. At high laser power density, UV photons (193, 266 and 355 nm) allowed the detection of styrene and butadiene monomers at m/z 104 and 54, respectively. The use of the observed ions by SIMS or LA-FTICRMS ensures that quantitative information on the relative distribution of each monomer is obtained. However, the silver coating thickness in the SIMS experiment seems to have an important influence on the quantitative information obtained. For LA-FTICRMS experiments, the best results are obtained at a wavelength of 355 nm. PMID:12526006

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

2003-01-01

106

Addition of ozone in the UV radiation treatment of a synthetic styrene-butadiene-styrene (SBS) rubber  

Microsoft Academic Search

The effect of exposure to different ozone concentrations, in conjunction with UV radiation, on the surface modification and adhesion properties of a block synthetic styrene-butadiene-styrene (S6) rubber was studied. The treatment time varied between 10s and 30min. Three different surface treatments were investigated: ozone only (O3), UV radiation in the presence of air, and UV radiation in the presence of

María D. Romero-Sánchez; M. Mercedes Pastor-Blas; José Miguel Martín-Martínez; M. J. Walzak

2005-01-01

107

Reinforcement of styrene–butadiene–styrene tri-block copolymer by multi-walled carbon nanotubes via melt mixing  

Microsoft Academic Search

Styrene–butadiene–styrene tri-block copolymer (SBS) was reinforced with multi-walled carbon nanotubes (MWCNTs) by the interaction through melt mixing. The tensile strength of SBS\\/MWCNT composites increased with increasing MWCNT content. The interactions between SBS and MWCNTs were characterized by solubility of MWCNTs in tetrahydrofuran, dynamic mechanical analysis, X-ray photoelectron microscope, ultraviolet spectra and transmission electron microscopy. The results showed that there were

Lan Lu; Zhen Zhou; Yong Zhang; Shifeng Wang; Yinxi Zhang

2007-01-01

108

Influence of the styrene content of thermoplastic styrene–butadiene rubbers in the effectiveness of the treatment with sulfuric acid  

Microsoft Academic Search

Three thermoplastic block styrene–butadiene–styrene (TR) rubbers were treated with sulfuric acid to improve their adhesion to polyurethane adhesives. T-peel test, scanning electron microscopy (SEM), contact-angle measurements (water, ethane diol), infra red spectroscopy (ATR-IR) and stress–strain experiments were used to analyze the nature of surface modifications produced in the rubber. The length of the treatment and the neutralization procedure (with and

Carmen M Cepeda-Jiménez; M Mercedes Pastor-Blas; T. P Ferrándiz-Gómez; J. M Mart??n-Mart??nez

2001-01-01

109

Mortality of workers in styrene-butadiene polymer production  

SciTech Connect

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

Matanoski, G.M.; Schwartz, L.

1987-08-01

110

Mortality of workers in styrene-butadiene polymer production.  

PubMed

A total of 13,920 males who had worked in eight styrene-butadiene rubber polymer manufacturing plants in the US and Canada for at least 1 year were followed for deaths from 1943 when the industry began to 1979. Mortality ratios standardized for age, race, and calendar time using US male rates as a comparison revealed no excess mortality in this population for any cause of death. The overall standardized mortality ratio (SMR) for all causes was 0.81. Only the SMR for arteriosclerotic heart disease among black males showed a significant excess (SMR = 1.28). Examination of risks by major work areas such as production, utilities, maintenance, and other jobs, as well as by salaried and hourly pay grade, revealed no significant differences in cancer mortality by specific sites. Because the ratios for selected digestive cancers were above the all-cause SMR, this group of neoplasms is under further investigation as is the exposure profile of specific jobs within the industry. PMID:3655951

Matanoski, G M; Schwartz, L

1987-08-01

111

Water absorption in a rubber-modified epoxy resin; carboxy terminated butadiene acrylonitrile-amine cured epoxy resin system  

Microsoft Academic Search

Gravimetric and dielectric measurements of water uptake by a series of carboxy terminated butadiene acrylonitrile (CTBN) -amine cured epoxy resin systems are reported. The amount of water absorbed and rate of diffusion increases up to approximately 15w\\/w% CTBN content. Anomalous behaviour is observed around a composition of approximately 20% CTBN which is coincident with the occurrence of a co-continuous phase

Iain McEwan; Richard A. Pethrick; Stephen J. Shaw

1999-01-01

112

Response of human cord blood cells to styrene exposure: evaluation of its effects on apoptosis and gene expression by genomic technology  

Microsoft Academic Search

Styrene is one of the most important monomers produced worldwide, and it finds major use in the production of polystyrene, acrylonitrile–butadiene–styrene resins and unsaturated polystyrene resins. Epidemiological studies on styrene showed that the malignancies observed most frequently in humans after exposure are related to the lymphatic and haemopoietic system. IARC classified styrene a possible carcinogenic to humans (Group 2B). In

Cristina Diodovich; Marco Giorgio Bianchi; Gerard Bowe; Francesco Acquati; Roberto Taramelli; Dominique Parent-Massin; Laura Gribaldo

2004-01-01

113

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

PubMed

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 models to calculate job- and time-period-specific average exposures. The resulting estimates were linked with the subjects' work histories to obtain cumulative exposure estimates, which were employed in stratified and Poisson regression analyses of mortality rates. Mantel-Haenszel rate ratios adjusted by race, age, and cumulative styrene exposure increase with cumulative butadiene exposure from 1 in the nonexposed category to 4.5 in the category of 80 ppm-years or more (P = 0.01). The risk pattern is less clear and statistically nonsignificant for styrene exposure. A trend of increasing risk with butadiene exposure is still present after exclusion of the nonexposed category (P = 0.03). A parsimonious interpretation of the findings presented here, in light of previous epidemiologic studies, is that exposure to butadiene in the synthetic rubber industry produces a dose-related increase in the occurrence of leukemia. PMID:8901898

Macaluso, M; Larson, R; Delzell, E; Sathiakumar, N; Hovinga, M; Julian, J; Muir, D; Cole, P

1996-10-28

114

The glass transition and interfacial layer in styrene-butadiene rubber containing silica nanofiller  

Microsoft Academic Search

The mechanical behaviour of a styrene-butadiene rubber, containing 23.5% styrene and filled with up to 55% by weight with silica nanoparticles, has been examined. The tan? spectra of these composites show a second relaxation of relatively low intensity located about 40 °C above the main ? relaxation, the glass transition Tg, which occurs at ?34.5 °C in the unfilled polymer.

V Arrighi; I. J McEwen; H Qian; M. B Serrano Prieto

2003-01-01

115

Strain energy effects on the ordering process in diblock styrene-butadiene copolymer  

Microsoft Academic Search

The technique of time-resolved small-angle x-ray scattering is used to monitor the disorder-order transformation occurring in asymmetric, diblock styrene-butadiene. A rapid thermal quench is applied to drive the system from its initial high-temperature disordered state to a low-temperature ordered structure, a body-centered cubic lattice of styrene spheres characterized by a series of concentric Debye rings in the two-dimensional scattering profile.

L. H. Pan; M. A. Singh; G. J. Salomons; J. A. Gupta; M. S. Capel

1997-01-01

116

Dynamic mechanical properties of styrene butadiene rubber and poly (ethylene-co-vinyl acetate) blends  

Microsoft Academic Search

The dynamic mechanical behaviour of uncrosslinked and crosslinked styrene butadiene rubber\\/poly (ethylene-co-vinyl acetate)\\u000a (SBR\\/EVA) blends was studied with reference to the effects of blend ratio, crosslinking systems, a compatibilizer viz. maleic-anhydride\\u000a grafted poly [styrene-b-(ethylene-co-butylene)-b-styrene] (SEBS-g-MA), frequency and temperature. The two separate tan ? peaks, obtained during DMA, indicated the immiscibility of SBR\\/EVA system. The damping properties increased with SBR content

C. K. Radhakrishnan; Prajitha Kumari; A. Sujith; G. Unnikrishnan

2008-01-01

117

Free surface morphology of block copolymers: 1. Styrene-butadiene diblock copolymers  

Microsoft Academic Search

The topology and morphology of the free surface of styrene-butadiene diblock copolymers were investigated by transmission electron microscopy as functions of molecular weight, composition, diene configuration, casting solvent and solvent evaporation rate. It was found that in solvent-cast thick films the formation of equilibrium free surface depends on a delicate balance of kinetic and thermodynamic parameters. Fast evaporation rates induce

Gian Tommaso Viola

1995-01-01

118

An Evaluation of Certain Methods for the Chemical Analysis of Styrene-Butadiene Rubber.  

National Technical Information Service (NTIS)

The applicability of available methods for the analysis of unvulcanized styrene-butadiene rubber (SBR, formerly GR-S) for organic acid and soap is influenced by the type of coagulation (alum or salt-acid), the type of acid present (fatty acid, rosin acid,...

E. J. Parks F. J. Linnig

1969-01-01

119

Curing Characteristics, Mechanical Properties and Oil Resistance of Styrene Butadiene Rubber\\/Epoxidized Natural Rubber Blends  

Microsoft Academic Search

Styrene butadiene rubber (SBR)\\/epoxidized natural rubber (ENR) blends were prepared with an internal mixer, Haake Rheomix. The blends were prepared at 60 C at a rotor speed of 60 rpm. Curing characteristics, mechanical properties and oil resistance of the blends were studied. The scorch time, t2 and curing time, t90 were found to decrease with increasing ENR composition in the

H. Ismail; S. Suzaimah; H. M. Hairunezam

2002-01-01

120

Peel strength of uncrosslinked styrene-butadiene rubber adhered to polyester film  

Microsoft Academic Search

Testpieces consisting of a fabric-backed styrene-butadiene rubber (SBR 1502) layer bonded directly to polyethylene terephthalate (PET) film were T-peel tested at various rates, R , and temperatures. Peel energies were superposed toformmastercurves using shift factors, a T , in accord with the universal WLF equation. When peeled at intermediate reduced rates, Ra T , failure was cohesive within the SBR

G. R. Hamed; W. Preechatiwong

2003-01-01

121

Diimide reduction of carboxylated styrene–butadiene rubber in latex stage  

Microsoft Academic Search

Carboxylated styrene–butadiene rubber (XSBR) is selectively hydrogenated by diimide reduction technique in latex stage using hydrazine hydrate, hydrogen peroxide and Cu+2 as catalyst. The products are characterised by IR and NMR spectroscopy. Dynamic Mechanical Properties and Transmission Electron Micrographs of the hydrogenated products confirm the existence of ionic aggregates involving carboxyl (–COOH) groups of the substrate and externally added Cu+2

M. De Sarkar; P. P. De; A. K. Bhowmick

2000-01-01

122

Effect of gamma irradiation on the properties of natural rubber\\/styrene butadiene rubber blends  

Microsoft Academic Search

Blends of natural rubber (NR) with styrene butadiene rubber (SBR) with varying ratios have been prepared. Vulcanization of the prepared blends has been induced by irradiation of gamma rays with varying doses up to 250kGy. Mechanical properties, namely tensile strength, tensile modulus at 100% elongation, elongation at break have been followed up as a function of irradiation dose as well

A. B. Moustafa; Rania Mounir; A. A. El Miligy; Maysa A. Mohamed

123

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

Microsoft Academic Search

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

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

2005-01-01

124

Rheology of Short Nylon6 Fiber Reinforced Styrene-Butadiene Rubber  

Microsoft Academic Search

The rheological characteristics of short Nylon-6 fiber reinforced styrene butadiene rubber (SBR) were studied using a capillary rheometer. The study was done with respect to the effect of shear rate, fiber concentration, and temperature on shear viscosity and die swell. All the melts showed pseudoplastic nature, which decreased with increasing temperature. Shear viscosity increased in the presence of fibers. Introduction

A. Seema; S. K. N. Kutty

2005-01-01

125

Styrene butadiene rubber\\/epoxidized natural rubber blends: dynamic properties, curing characteristics and swelling studies  

Microsoft Academic Search

The dynamic properties, curing characteristics and swelling behaviour of styrene butadiene rubber (SBR) and epoxidized natural rubber (ENR) blends were studied. The incorporation of ENR 50 in the blends improved processability, stiffness, resilience and reduced the damping property. In terms of curing characteristics, the scorch time, t2 and curing time, t90 of the SBR\\/ENR blends decrease with increasing ENR content.

H Ismail; S Suzaimah

2000-01-01

126

THERMAL DEGRADATION OF NATURAL RUBBER\\/STYRENE BUTADIENE RUBBER LATEX BLENDS BY THERMOGRAVIMETRIC METHOD  

Microsoft Academic Search

Thermal properties of natural rubber (NR)\\/styrene butadiene rubber (SBR) latex blends made from latex blending have been investigated using thermogravimetric analysis. It was found that the initial degradation temperature of NR is lower than SBR, and on addition of SBR, the degradation temperature is increased, indicating increased thermal stability of the blend. The main degradation products of NR contain isoprene

JYOTHI T. VARKEY; SUNNY AUGUSTINE; SABU THOMAS

2000-01-01

127

Tapping-mode atomic force microscopy study of the near-surface composition of a styrene-butadiene-styrene triblock copolymer film  

Microsoft Academic Search

Thin films of a styrene-butadiene-styrene triblock copolymer were examined by tapping-mode atomic force microscopy at different levels of tip-sample forces. The height images recorded at minimal forces show the surface topography of the topmost butadiene-rich layer. As the level of the tip-sample force is increased, the height and phase images gradually undergo local changes and eventually reveal patterns of a

S. N. Magonov; J. Cleveland; V. Elings; D. Denley; M.-H. Whangbo

1997-01-01

128

Modification of poly(styrene- stat -acrylonitrile) to promote polymer blend miscibility through hydrogen-bonded (2,4-diamino-1,3,5-triazine)maleimide interactions  

Microsoft Academic Search

The acrylonitrile units in poly(styrene-stat-acrylonitrile) (SAN) have been partially converted to the 2,4-diamino-1,3,5-triazine (DAT) moiety by the reaction with dicyandiamide in dry dimethyl sulfoxide, containing catalytic amounts of potassium hydroxide. This produced a range of terpolymers of poly(styrene-stat-acrylonitrile-stat-vinyl 2,4-diamino-1,3,5-triazine) with mol% composition in the range (54.3:43.0:2.7) to (54.3:25.0:20.7). Copolymers of methyl acrylate (MA) and maleimide (MI) were also synthesised and

J. M. G. Cowie; D. Cocton

1999-01-01

129

Tearing, Cut Growth, and Fracture of Styrene-Butadiene Rubber and Natural Rubber Containing Various Amounts of Carbon Black.  

National Technical Information Service (NTIS)

Morphological features developed in tearing, cut propagation, and fracturing of natural rubber (NR) and styrene-butadiene rubber (SBR) samples containing a wide range of carbon black (CB) were characterized relative to strain rate, temperature, and CB con...

A. Goldberg D. R. Lesuer J. C. Stone J. Patt

1984-01-01

130

Review of the toxicology of styrene.  

PubMed

Styrene is used in the production of plastics and resins, which include polystyrene resins, acrylonitrile-butadiene-styrene resins, styrene-acrylonitrile resins, styrene-butadiene copolymer resins, styrene-butadiene rubber, and unsaturated polyester resins. In 1985, styrene ranked in the top ten of synthetic organic chemicals produced in the U.S. This review focuses on various aspects of styrene toxicology including acute and chronic toxicity, carcinogenicity, genotoxicity, pharmacokinetics, effects on hepatic and extrahepatic xenobiotic-metabolizing enzymes, pharmacokinetic modeling, and covalent interactions with macromolecules. There appear to be many similarities between the toxicity and metabolism of styrene in rodents and humans. Needed areas of future research on styrene include studies on the molecular dosimetry of styrene in terms of both hemoglobin and DNA adducts. The results of such research should improve our ability to assess the relationship between exposure to styrene and surrogate measures of "effective dose", thereby improving our ability to estimate the effects of low-level human exposures. PMID:2653733

Bond, J A

1989-01-01

131

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

132

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

2013-10-01

133

Thermal properties in cured natural rubber\\/styrene butadiene rubber blends  

Microsoft Academic Search

Blends of natural rubber (NR) and styrene butadiene rubber (SBR) were prepared with sulfur and n-t-butyl-2-benzothiazole sulfonamide (TBBS) as accelerator, varying the amount of each polymer in the blend. Samples were analysed by rheometer curing at 433K until their maximum torque was reached. The miscibility among the constituent polymers of the cured compounds was studied in a broad range of

S. Goyanes; C. C. Lopez; G. H. Rubiolo; F. Quasso; A. J. Marzocca

2008-01-01

134

Determination of the composition of styrene, isoprene, butadiene terpolymer by IR attenuated total reflection (ATR) spectroscopy  

NASA Astrophysics Data System (ADS)

A rapid method for quantitative determination of the composition of statistical terpolymers of styrene, butadiene, and isoprene by IR attenuated total reflection (ATR) spectroscopy is described. A quantitative model is designed with the aid of 1 H NMR spectroscopy. This method does not require that the test samples be dissolved or their thickness be monitored precisely, and records the IR spectrum of the rubber rapidly (<5 min). It is easily reproduced and has good convergence. The relative error is less than 5 %.

Orlov, A. S.; Mashukov, V. I.; Rakitin, A. R.; Novikova, E. S.

2012-07-01

135

Influence of molecular architecture on morphology and micromechanical behavior of styrene\\/butadiene block copolymer systems  

Microsoft Academic Search

Using different microscopic and spectroscopic methods, as well as various techniques of mechanical characterization such as tensile testing, microhardness indentation and fracture mechanics, phase behavior and the micromechanical deformation mechanisms active in amorphous styrene\\/butadiene block copolymers were examined with respect to the molecular architecture. Through modification of the chain architecture at a constant molecular weight (ca. 100,000g\\/mol) and constant composition

Rameshwar Adhikari; Goerg H. Michler

2004-01-01

136

Selective hydrogenation of butadiene–styrene copolymers using a Ziegler–Natta type catalyst  

Microsoft Academic Search

The hydrogenation of styrene–butadiene copolymers of known global composition, monomeric distribution, molecular weight and microstructure is here reported. The saturation was carried out through a sequential polymerization–hydrogenation process which efficiency relies on the use of the polymerization solvent and initiator (cyclohexane and n-butyllithium) as the hydrogenation solvent and catalyst promoter, respectively. The SBRs, dissolved in cyclohexane, were homogeneously hydrogenated using

Vladimir A. Escobar Barrios; Rafael Herrera Nájera; Alain Petit; Fernand Pla

2000-01-01

137

Stability of thermo-sensitive properties of carbon-black\\/styrene-butadiene-rubber composite membranes  

Microsoft Academic Search

Conducting composite membranes were prepared by using styrene butadiene rubber as matrices and incorporating carbon blacks and some organic crystals (2,6-di-tert-butyl-4-methyl phenol, BMP). A number of composite membranes exhibited a thermo-sensitive property which corresponded to a positive temperature coefficient (PTC) effect. Their DSC thermograms and x-ray patterns indicated that there were no significant changes in the structure of membranes although

Ying Wan; Dijiang Wen

2005-01-01

138

Comparison Between Mechanical Relaxations Associated with Volume and shear Deformations in Styrene-Butadiene Rubber  

Microsoft Academic Search

Velocity and attenuation of longitudinal ultrasonic waves in styrene butadiene rubber are measured in the temperature from 0° to 50°C at frequencies 1, 3 and 5Mc\\/s and real and imaginary parts of longitudinal wave modulus (K+4G\\/3) are calculated. Comparing the results with the data of bulk moduls (K) previously obtained for the same sample by the suspension method (J. Phys.

Yasaku Wada; Ryoichi Ito; Hazime Ochiai

1962-01-01

139

Organic interfacial tailoring of styrene butadiene rubber–clay nanocomposites prepared by latex compounding method  

Microsoft Academic Search

The styrene butadiene rubber (SBR)-clay nano- compounds were prepared by the latex compounding method, and then hexadecyl trimethyl ammonium bromide (C16) and 3-aminopropyl triethoxy silane (KH550) were added into these nanocompounds on a two-roll mill to prepare nanocomposites with strong interfacial interaction. The structure and properties of SBR-clay nanocomposites were carefully studied by X-ray diffraction (XRD) studies, trans- mission electron

Qing-Xiu Jia; You-Ping Wu; Yi-Qing Wang; Ming Lu; Jian Yang; Li-Qun Zhang

2007-01-01

140

Thermosensitive properties of carbon-black-loaded styrene butadiene rubber composite membranes  

Microsoft Academic Search

Some conducting polymer composite membranes were prepared by using styrene butadiene rubber as matrices and incorporating carbon blacks and a kind of organic crystal (2,6-di-tert-butyl-4-methyl phenol, BMP). Several composite membranes whose resistivities showed a critical percolation threshold at room temperature exhibited a thermo-sensitive property and their resistivities increased with increasing temperature, that is, a positive temperature coefficient (PTC) effect for

Ying Wan; Dijiang Wen

2004-01-01

141

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

142

Treatment of vulcanized styrene-butadiene rubber (SBR) with mixtures of Trichloroisocyanuric Acid and Fumaric Acid  

Microsoft Academic Search

In this study, mixtures of trichloroisocyanuric acid (TCI) and fumaric acid (FA) solutions were applied to a difficult-to-bond, vulcanized styrene-butadiene rubber (R2) to analyze the combined effect of both surface treatments. The treated R2 rubber surfaces were characterized using advancing contact angle measurements, ATR-IR and XPS spectroscopy, and SEM. T-peel tests of treated R2 rubber\\/ polyurethane adhesive\\/leather joints have been

María D. Romero-Sánchez; José Miguel Martín-Martínez

2003-01-01

143

Effect of Nano CaCO 3 on thermal properties of Styrene Butadiene Rubber (SBR)  

Microsoft Academic Search

Styrene butadiene rubber (SBR) as matrix was reinforced separately with 9, 15 and 21 nm sizes of CaCO3, which were synthesized by matrix mediated growth technique. The mixing and compounding was done on two-roll mill and sheets\\u000a were prepared in compression molding machine. The effect of nature and loading of nano CaCO3 on these rubber nanocomposites was investigated thoroughly by different

S. Mishra; N. G. Shimpi; U. D. Patil

2007-01-01

144

Effect of Silane Coupling Agent on the Mechanical Properties of Clay Filled Styrene Butadiene Rubber  

Microsoft Academic Search

The effect of treatment of coupling agent [Bis (3-triethoxy-silyl-propyl) tetrasulphide] on mechanical properties of composites made from styrene butadiene rubber and clay is reported in this paper. The coupling agent in the form of solution (1.0%) was used for treatment of the filler. The treatment resulted in enhancement of mechanical properties of composites when compared with composites containing untreated clay.

Nabil A. N. Alkadasi; D. G. Hundiwale; U. R. Kapadi; S. Mishra

2005-01-01

145

Physical and mechanical properties of styrene–butadiene rubber emulsion modified cement mortars  

Microsoft Academic Search

Polymer-modified cement mortars were prepared by varying polymer\\/cement mass ratio (P\\/C) with a constant water\\/cement mass ratio of 0.4. The effect of styrene–butadiene rubber (SBR) emulsion on the physical and mechanical properties of cement mortars is studied. With P\\/C below 10%, the toughness of the modified mortars enhances with the increase of P\\/C. A relationship between the physical and mechanical

Ru Wang; Pei-Ming Wang; Xin-Gui Li

2005-01-01

146

Die-Swell of Mica-Filled Styrene-Butadiene Rubber Compounds  

Microsoft Academic Search

Die-swell of mica-filled styrene-butadiene rubber has been correlated with the recoverable deformation, elastic energy and shear modulus of the melt at different shear-rate and at various length to diameter ratio of the capillary. The Reynolds number and power consumption of melt flow have been correlated with the die-swell and shear-rate of the melt flow. The inverse relationship between shear-viscosity and

Shankar Debnath

1989-01-01

147

Weak boundary layers on vulcanized styrene–butadiene rubber treated with sulfuric acid  

Microsoft Academic Search

A synthetic vulcanized styrene-butadiene rubber (R2) was used in this study. The presence of paraffin wax and zinc stearate in the rubber composition prevented the adhesion of R2 rubber to solvent-based polyester-urethane adhesive. To increase the adhesion properties of R2 rubber, a surface treatment with sulfuric acid (cyclization) was applied, and the length of the immersion in sulfuric acid and

Carmen M. Cepeda-Jiménez; M. Mercedes Pastor-Blas; José Miguel Martín-Martínez

2001-01-01

148

Performances of a Polymeric Intumescent Flame Retardant in Styrene Butadiene Rubber  

Microsoft Academic Search

A polymeric intumescent flame retardant, PPVAM, was synthesized by the reaction of polyvinyl alcohol with phosphoric acid, and further with melamine. Flame-retardant properties of PPVAM in styrene butadiene rubber (SBR) were evaluated by using LOI and UL-94 test, and thermal decomposition and char of SBR\\/PPVAM composites were investigated by thermogravimetry, Muffle and SEM. The results indicate that SBR\\/PPVAM composites on

Qingfeng Kong; Zhengzhou Wang; Shixian Hu

2012-01-01

149

Physicochemical Characteristics of Styrene-Butadiene Latex modified Mortar Composite vis-à-vis Preferential Interactions  

Microsoft Academic Search

The interaction between styrene-butadiene rubber (SBR) film and the ions from C2S and C3S hydration of Portland cement mortar composites has been evaluated by Fourier Transform Infrared Spectroscopy (FTIR), and the morphology of the composites characterized with scanning electron microscopy (SEM). The specimen used was cured for 28 days. FTIR spectrum supports the interaction of SBR with cement in the

B. B. Konar; Arpita Das; Prabir K. Gupta; Mausumi Saha

2011-01-01

150

An experimental and mesoscopic lattice simulation study of styrene-butadiene latex-cement composites properties  

Microsoft Academic Search

The consequences of styrene-butadiene rubber (SBR) latex addition on the hardness and structural properties of a cement matrix\\u000a have been investigated. The results show that the primary effect of latex addition is the decrease in the so-called capillary\\u000a porosity and a shift of the pore-size distribution towards the nanometer range. In spite of this, addition of latex significantly\\u000a alters the

O. Rozenbaum; R. J.-M. Pellenq; H. Van Damme

2005-01-01

151

Synthesis and characterisation of elastomeric composites prepared from epoxidised styrene butadiene rubber, 3-aminopropyltriethoxysilane and tetraethoxysilane  

Microsoft Academic Search

Hybrid composite materials were obtained by the reaction of epoxidised styrene butadiene rubber with 3-aminopropyltriethoxysilane,\\u000a followed by in situ hydrolysis and polycondensation of tetraethoxysilane (TEOS). The hybrid films were characterised by thermogravimetric\\u000a analysis, differential scanning calorimetry, swelling and stress–strain measurements, scanning electron microscopy and infrared\\u000a spectrometry. Non-solubility of the films in tetrahydrofuran indicated the formation of a network, the microstructure of

Maria Augusta de Luca; Marly Maldaner Jacobi; Lisia Floriani Orlandini

2009-01-01

152

Effect of Bagasse on the Physico-mechanical Properties of Natural and Styrene-Butadiene Rubbers  

Microsoft Academic Search

Different concentrations of bagasse waste with particle sizes 300 nm, 125 nm, 75 nm, and <75nm are incorporated in natural and styrene-butadiene rubber formulations. The rheological characteristics and physico-mechanical properties of the compounded rubber are investigated and determined. The effect of bagasse upon ageing characteristics of corresponding vulcanizates is evaluated. The rubber vulcanizates containing the smallest particle size of bagasse

N. A. Abdelwahab; F. M. Helaly; A. S. Badran

2008-01-01

153

Thermal Degradation of Short Nylon6 Fiber–Reinforced Styrene Butadiene Rubber Composite  

Microsoft Academic Search

The thermal properties of short Nylon-6 fiber–reinforced Styrene butadiene rubber (SBR) composites were studied by Thermogravimetric Analysis (TGA). The effect of epoxy-based bonding agent on thermal degradation of the gum and the composites was also studied. The thermal stability of the SBR was enhanced in the presence of Nylon-6 fibers and the stability of the composites increased in the presence

A. Seema; S. K. N. Kutty

2006-01-01

154

Study on Dynamic Fatigue Properties of Solution-Polymerized Styrene Butadiene Rubber T2000R  

Microsoft Academic Search

Dynamic fatigue properties of solution-polymerized styrene butadiene rubber with the trade name T2000R were studied. The influence of different cure systems, reinforcing agents, anti-degradants, and plasticizers on the flex-cracking property of T2000R vulcanizates was investigated. The results showed that T2000R cured with an effective vulcanization system had relatively high fatigue life. Vulcanizate filled with carbon black N330 with a load

Xuehong Sun; Fei Zhao; Shugao Zhao

2011-01-01

155

Positron annihilation spectroscopy in carbon black–silica–styrene butadiene rubber (SBR) composites under deformation  

Microsoft Academic Search

Positron annihilation lifetime (PAL) spectroscopy has been used to investigate microstructural properties of carbon black–silica–styrene butadiene rubber (SBR) composites. The positron annihilation lifetime shows a direct dependence on the carbon black type as well as the silica content added to the rubber compound. The effect of the tensile strain (?=0–150%) on the positron annihilation parameters has been investigated by constructing

M. Mohsen; M. H. Abd-El Salam; A. Ashry; A. Ismail; H. Ismail

2005-01-01

156

Surface Analysis of Debonded Chlorinated Vulcanized Styrene-Butadiene Rubber Joints  

Microsoft Academic Search

A synthetic vulcanized styrene-butadiene rubber (R) was treated with a halogenation agent (TCI = trichloroisocyanuric acid) to produce improved adhesion (i.e. high T-peel strength) in joints prepared with a one-component, solvent-based polyester urethane adhesive. Several amounts (0.5 to 7 wt%) of TCI solutions in ethyl acetate were applied to the rubber surface and, after T-peel tests were carried out, the

M. Mercedes Pastor-blas; José Miguel Martín-Martínez; John G. Dillard

1997-01-01

157

Dynamic Mechanical Properties of Cross-Linked Rubbers. Iv. Dicumyl Peroxide Vulcanizates of Styrene-Butadiene Rubber.  

National Technical Information Service (NTIS)

The viscoelastic properties of three samples of a random styrene-butadiene copolymer with 23.5 wt-% styrene, cross-linked by dicumyl peroxide to different extents, have been studied by dynamic shear and shear creep measurements, and the unvulcanized precu...

R. G. Mancke J. D. Ferry

1967-01-01

158

Reactions of carboxylated butadiene-styrene rubbers and their mixtures with ?-caprolactam induced by gamma-radiation  

Microsoft Academic Search

Carboxylated butadiene-styrene rubber containing various amounts of ; styrene and methacrylic acid were exposed to 0.1 to 50 Mr doses of gamma ; radiation form a Co⁶° source. This irradiation resulted in a decrease in ; the carboxyl group content, particularly at low doses. The radiochemical yield ; of crosslinked polymers at low doses is a linear function of the

I. Mladenov; B. A. Dogadkin

1962-01-01

159

STUDY OF REDOX PROCESSES IN BUTADIENE-STYRENE COPOLYMER  

Microsoft Academic Search

The work presents the results of the study of thermoinitiated and photoinitiated oxidizing processes occurring in butodiene-styrene copolymer. The identification of the processes was made with the use of IR-spectroscopy and differential thermal analysis. It has been revealed, that the processes of thermo- and photooxidation of BS copolymer are similar. Irrespective of the way of initiation, oxidation proceeds on polybutadiene

Juriy G. Ivaschenko; Natalya N. Karpov; Olga V. Fedotova

160

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

2009-03-04

161

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

SciTech Connect

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

Baetzold, J.P.; Gancarz, I.; Quan, X.; Koberstein, J.T. (Univ. of Connecticut, Storrs, CT (United States))

1994-09-12

162

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

163

Small-Angle X-Ray Scattering Study of Micelle Formation in Mixtures of Butadiene Homopolymer and Styrene-Butadiene Block Copolymer.  

National Technical Information Service (NTIS)

The small-angle X-ray scattering technique is utilized to study the formation of micelles in mixtures containing polybutadiene homopolymer (Mn = 2350) with much smaller amounts (0.5 to 8 wt%) of styrene-butadiene diblock copolymer (Mn = 25000, 52.2 wt% st...

D. Rigby R. J. Roe

1983-01-01

164

Nitroxide-controlled free radical copolymerization of styrene and acrylonitrile monitored by electron spin resonance and fourier transform infrared technique in situ  

Microsoft Academic Search

Nitroxide-mediated homopolymerization of styrene (St) and copolymerization of styrene and acrylonitrile (An) were monitored\\u000a respectively by electron spin resonance and Fourier transform infrared technique in situ, and the polymerization kinetics\\u000a was investigated in detail. Homopolymerization of St was well controlled in the presence of 4-hydroxyl-2,2,6,6-tetramethyl-l-piperidinyloxy\\u000a (HTEMPO, N*) at high temperature. The initiation reactions and polymerization rates were changed by varying

F. J. Hua; S. M. Chen; D. S. Lee; Y. L. Yang

2001-01-01

165

Application of FTIR in characterization of acrylonitrile-butadiene rubber (nitrile rubber)  

Microsoft Academic Search

Infrared spectroscopy can be used efficiently by polymer and rubber technologists for identification of polymer, polymer–blend ratio calculation, raw material evaluation, study of reaction mechanism, microstructure determination, etc. The present article represents a method to characterize nitrile rubber by Fourier-transformed infrared spectrophotometry (FTIR). The absorbance ratio of specific peaks of different grades of nitrile rubber was correlated with the acrylonitrile

S. Chakraborty; S. Bandyopadhyay; R. Ameta; R. Mukhopadhyay; A. S. Deuri

2007-01-01

166

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

Code of Federal Regulations, 2010 CFR

...acid at 150 °F for 15 days when analyzed by a polarographic method titled âExtracted Acrylonitrile by Differential Pulse Polarography,â which is incorporated by reference. Copies are available from the Center for Food Safety and Applied...

2009-04-01

167

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

Code of Federal Regulations, 2010 CFR

...acid at 150 °F for 15 days when analyzed by a polarographic method titled âExtracted Acrylonitrile by Differential Pulse Polarography,â which is incorporated by reference. Copies are available from the Center for Food Safety and Applied...

2010-01-01

168

21 CFR 177.1040 - Acrylonitrile/styrene copoly-mer.  

Code of Federal Regulations, 2010 CFR

...production, with the exception that they shall not contain mercaptans or other substances which form reversible complexes with acryl-onitrile monomer. Permissible adjuvants may include substances generally recognized as safe in food, substances used...

2010-01-01

169

21 CFR 177.1040 - Acrylonitrile/styrene copoly-mer.  

Code of Federal Regulations, 2010 CFR

...production, with the exception that they shall not contain mercaptans or other substances which form reversible complexes with acryl-onitrile monomer. Permissible adjuvants may include substances generally recognized as safe in food, substances used...

2009-04-01

170

Synthesis of polystyrene–styrene\\/butadiene diblock copolymers via reversible addition-fragmentation chain transfer miniemulsion polymerization  

Microsoft Academic Search

Polystyrene–styrene\\/butadiene diblock copolymers were synthesized via reversible addition-fragmentation chain transfer (RAFT) miniemulsion polymerization. During the polymerization process, the molecular weight distribution was narrow and the numerical molecular weight of the copolymers increased with increasing conversion of monomers, which was close to the theoretical. FT-IR and 1H NMR results indicated that the microstructure of the polymer was mainly 1,4-trans-butadiene with small

Zhen Xi Wang; Qing Hua Zhang; Yi Tao Yu; Xiao Li Zhan; Feng Qiu Chen; Ji Hai Xiong

2010-01-01

171

Topological peculiarities in liquid phase of styrene butadiene rubber thin films induced by electrostatic nanolithography  

NASA Astrophysics Data System (ADS)

Nanostructures of 50-200 nm in width were formed in styrene butadiene rubber using atomic force microscopy electrostatic nanolithography combined with vertical manipulation of the tip. The formation of circular nanostructures is attributed to factors such as the strength of the electric field (109-1010 V m-1), a contribution to the radial component of the pressure gradient, and a film thickness of less than 10 nm. Stability of the features (48 h) suggests cross-linking between macromolecules at the nanoscale.

Rackaitis, Mindaugas; Kashyn, Dmytro; Hirano, Tadashi; Lyuksyutov, Sergei F.

2008-11-01

172

Stabilization effect of potential antioxidants on the thermooxidative stability of styrene–butadiene rubber  

Microsoft Academic Search

Effects of several heterocyclic compounds containing nitrogen, trisubstituted amines and diamines and molecules based on N,N,N?,N?,N??,N??-substituted-[1,3,5]triazine-2,4,6-triamine in preventing thermooxidative degradation of styrene–butadiene rubber (SBR)\\u000a have been studied using non-isothermal DSC measurements. The aim of this study was to determine and compare the stabilizing\\u000a effect of individual compounds and to select the structures with the best antioxidative properties. In order to

Zuzana Cibulková; Andrea ?erná; Peter Šimon; Ján Uhlár; Karol Kosár; Peter Lehocký

173

Rheological behaviour of thermoplastic elastomers from polypropylene\\/acrylonitrile–butadiene rubber blends: effect of blend ratio, reactive compatibilization and dynamic vulcanization  

Microsoft Academic Search

The rheological behaviour of polypropylene (PP)\\/acrylonitrile–butadiene rubber (NBR) blends has been investigated with special reference to the effect of blend ratio, compatibilization and dynamic vulcanization. The morphology of the extrudates and the size and distribution of domains were examined. PP\\/NBR blends show pseudoplastic behaviour, which is evidenced by the decrease in viscosity with increasing shear rate. The melt viscosity of

Snooppy George; K Ramamurthy; J. S Anand; G Groeninckx; K. T Varughese; Sabu Thomas

1999-01-01

174

The effect of a compatibilizer on curing characteristics, mechanical properties and oil resistance of styrene butadiene rubber\\/epoxidized natural rubber blends  

Microsoft Academic Search

The effect of a compatibilizer, styrene–(epoxidized butadiene)–styrene triblock copolymer (ESBS) on curing characteristics, mechanical properties and oil resistance of styrene butadiene rubber (SBR) and epoxidized natural rubber (ENR) blends was examined. The results indicate that the increasing compositions of ENR and the presence of ESBS improve processability, tensile strength, tear strength and tensile modulus of SBR\\/ENR blends. The scorch time,

Hanafi Ismail; H. M Hairunezam

2001-01-01

175

Effect of temperature on the fracture surfaces of filled systems based on SKS-85 butadiene-styrene copolymer  

Microsoft Academic Search

The tear fracture surfaces of mixtures of SKS-85 butadiene — styrene copolymer (85% styrene) with ordinary (carbon black, chalk) and polymeric (Kapron and cellophane powder) fillers have been investigated on the interval from -60 to +40°C. As the temperature varies within the limits of the glassy state (Tg SKS-85=~+24°C) of the filled polymer, the nature of the fracture surface of

M. N. Tolmacheva; V. G. Raevskii; T. A. Pirko

1969-01-01

176

Computation of Mechanical Properties of a Poly-(Styrene-Butadiene-Styrene) Copolymer using a Mixed Finite Element Approach  

NASA Astrophysics Data System (ADS)

Despite of several decades of research, the nature of linear elasticity in microphase-separated copolymers with chemically connected glass-rubber phases is still not fully understood. In this presentation we discuss the results of an investigation of the linear elastic properties of a poly-(styrene-butadiene-styrene) triblock copolymer using a mixed finite element approach. The technique permits to deal with phases of full incompressibility as well as phases of near incompressibility as they occur in this two-component system. Strikingly and contrary to the common belief, we find that the continuum description is accurate and that no additional detailed molecular information is needed to reproduce the available linear elastic experimental data. The anomalous Poisson's ratio of the polybutadiene phase of 0.37, determined by previous authors and attributed to molecular characteristics of the polybutadiene phase, is found to be related to end-effect errors made in their tensile and torsional experiments. We also test the suitability of several semi-phenomenological models in reproducing the experimental measurements. We find that some of the methods provide reliable results of accuracy comparable to our mixed finite element approach.

Baeurle, Stephan A.; Fredrickson, Glenn H.; Gusev, Andrei A.

2004-03-01

177

Electrical Conductivity in the Nonconjugated Polymer Styrene-Butadiene-Rubber (SBR)  

NASA Astrophysics Data System (ADS)

Electrical conductivity as a function of doping with iodine has been measured in a nonconjugated polymer, styrene-butadiene-rubber (SBR) which is a copolymer of styrene and butadiene, used extensively in automobile tires. The conductivity reaches a value of about 0.01 S/cm upon doping with iodine. The color of the rubber film changes from colorless to black upon doping. FTIR studies of the polymer show that the intensity of the =CH bending mode decreases with doping - indicating that the dopant interacts with the double bond and leads to a charge-transfer from the double bond to the dopant. The absorption spectrum after doping at a low level has two peaks - one at 4.13 eV and the other at 3.18 eV. The first peak is due to the cation radical formed upon doping and the second one is due to the charge-transfer complex formed with the dopant. The polystyrene segments of the copolymer seem to have less interaction with the dopant since polystyrene is glassy. The radical cation peak of another nonconjugated conductive polymer, polyalloocimene having a higher number-fraction of double bonds in the repeat, is slightly red-shifted compared to that of SBR.

Titus, Jitto; Khatavkar, Sanchit; Thakur, Mrinal

2003-03-01

178

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

PubMed

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

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

2006-02-08

179

Effects of Carbon Black on Chain Mobility and Dynamic Mechanical Properties of Solution Polymerized Styrene-Butadiene Rubber  

Microsoft Academic Search

The structure of the bound rubber, the H NMR relaxation time and the cross-link density of the physical network and the glass transition, were studied for solution polymerized styrene-butadiene rubber (SSBR) filled by carbon black, to investigate the effects of carbon black on the chain mobility and dynamic mechanical properties. It was found by H NMR analysis that the rubber

Zhai Jun-Xue; Wang He; Shi Xin-Yan; Zhao Shu-Gao

2011-01-01

180

Evaluating corn starch and corn stover biochar as renewable filler in carboxylated styrene–butadiene rubber composites  

Microsoft Academic Search

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 the expense of brittleness in the final rubber composite. In an attempt to alleviate this, starch was blended

Steven C. Peterson

2012-01-01

181

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

Microsoft Academic Search

This report is a continuation and extension of the work of the earlier Army contract, where the superiority of the electron beam cured styrene butadiene rubber (SBR) tank pads to the sulfur cured pads was demonstrated. The focus of the present study is the investigation of the extraordinary ozone resistance of our radiation cured SBR, and also on possible alternatives

A. A. Basfar; J. Silverman

1991-01-01

182

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

Technology Transfer Automated Retrieval System (TEKTRAN)

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

183

The study of various styrene-butadiene copolymers as compatibilisers in bulk blends of polystyrene\\/polybutadiene  

Microsoft Academic Search

Bulk blends, produced by compositional quenching, were used to examine the effectiveness of different styrene-butadiene copolymers as interfacial agents in blends of polystyrene (PS) with polybutadiene (PB). Each polymer blend was compression molded for various times to allow particle ripening and was then tested for impact strength. The most effective compatibiliser proved to be a long, asymmetric diblock, which could

Timothy J. Cavanaugh; K. Buttle; J. N. Turner; E. Bruce Nauman

1998-01-01

184

Selective hydrogenation of butadiene–styrene copolymers using a Ziegler–Natta type catalyst 2. Thermal properties  

Microsoft Academic Search

Three types of butadiene–styrene copolymers, diblock, triblock and random, were partially hydrogenated in their elastomeric units in order to determine the influence of hydrogenation extent on their thermal properties. The hydrogenation reactions were carried out using a Ziegler–Natta type catalyst and the extent of hydrogenation was evaluated by FTIR spectroscopic technique. The percentage of crystallinity was determined by differential scanning

Vladimir A Escobar Barrios; Alain Petit; Fernand Pla; Rafael Herrera Nájera

2003-01-01

185

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...

186

Chromatographic Investigations of Macromolecules in the Critical Range of Liquid Chromatography. XII. Analysis of Block Copolymers of Styrene and Butadiene  

Microsoft Academic Search

The separation of di- and triblock copolymers of styrene and butadiene was accomplished by liquid chromatography at the critical point of adsorption. The size of the polybutadiene blocks was determined under chromatographic conditions corresponding to the critical point of adsorption of polystyrene using silica gel as the adsorbent and tetrahydrofuran-hexane as the eluent. The polystyrene blocks were analyzed on a

D. Braun; E. Esser; H. Rasch

1998-01-01

187

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

Microsoft Academic Search

Fourier Transform Infrared (FTIR) studies performed in this work indicate that high ozone resistance of Styrene-Butadiene Rubber (SBR) formulations cured by a combination of sulfur and ionizing radiation is associated with unusually high vinyl concentration. On the other hand, sulfur cured SBR formulations with low vinyl concentration have poor ozone resistance. Curing with peroxides which involves chemistry similar to that

A. A. Basfar; Joseph Silverman

1995-01-01

188

The effects of filler content on cure and mechanical properties of dichlorocarbene modified styrene butadiene rubber\\/carbon black composites  

Microsoft Academic Search

A study has been carried out on the curing characteristics and mechanical properties of carbon black filled dichlorocarbene modified styrene butadiene rubber (DCSBR). Processing characteristics such as optimum cure time and maximum torque increases with increasing of the concentration of carbon black in DCSBR whereas scorch time decreases. The mechanical properties and resistance of the vulcanizate towards thermal, flame and

M. T. Ramesan

2005-01-01

189

Molecular transport of aromatic solvents through microcomposites of natural rubber (NR), carboxylated styrene butadiene rubber (XSBR) and their blends  

Microsoft Academic Search

Transport properties of aromatic solvents such as benzene, toluene and p-xylene through micron sized fillers reinforced natural rubber, carboxylated styrene butadiene rubber and their 70\\/30 blend latex membranes were investigated. The effect of penetrant size, filler loading and temperature on the diffusion properties were studied. The dispersion of filler in the matrix were analysed from scanning electron micrographs. Due to

Ranimol Stephen; Kuruvilla Joseph; Zachariah Oommen; Sabu Thomas

2007-01-01

190

Effect of wheat flour pre-cooking on the composite modulus of wheat flour and carboxylated styrene–butadiene latex  

Microsoft Academic Search

Commercial wheat flours with two different concentrations of insoluble protein were used as fillers to reinforce styrene–butadiene latex composites and their viscoelastic properties were examined. Both wheat flours were also cooked at 55, 70, or 95°C for 1h in an aqueous dispersion prior to mixing with latex in order to swell the starch present in the flour and increase its

Steven C. Peterson; Lei Jong

2008-01-01

191

Water uptake and tensile properties of carboxylated styrene butadiene rubber based water born paints: Models for water uptake prediction  

Microsoft Academic Search

Despite significant advances in water based surface coating technology, the presence of surfactants in emulsion polymer binders leads to loss of performance after prolonged immersion in water, relative to solvent based coatings that are free of surfactant impurities. This study begins with water uptake evaluation of a range of emulsion polymer binders. A carboxylated styrene butadiene rubber latex (c-SBR) performed

Elena Jubete; Christopher M. Liauw; Norman S. Allen

2007-01-01

192

Effect of nature and extent of crosslinking on swelling and mechanical behavior of styrene–butadiene rubber membranes  

Microsoft Academic Search

The influence of crosslink type and crosslink density on the swelling and mechanical behavior of styrene–butadiene rubber (SBR) membranes were studied in four aliphatic hydrocarbons. To vary the crosslink type and crosslink density, SBR was vulcanized by four different vulcanizing systems viz conventional, efficient, peroxide and a mixture of sulfur and peroxide. SBR vulcanizates having mono or disulfidic crosslinks (efficient

Soney C. George; Manfred knörgen; Sabu Thomas

1999-01-01

193

Electrical Conductance of Fast Extrusion Furnace Carbon Black-Loaded Styrene-Butadiene Rubber during Swelling in Kerosene  

Microsoft Academic Search

The effect of swelling in kerosene on the electrical conductance of 60, 80, and 100 part per hundred parts of rubber by weight of Fast Extrusion Furnace (FEF) carbon black-loaded styrene-butadiene rubber (SBR, 1502) was studied. It was found that there is a characteristic time of swelling after which a sudden decrease in conductivity appears. An ideal and simple model

H. H. Hassan; G. M. Nasr

1982-01-01

194

Degree of Mechanochemical Devulcanization of Model Styrene-Butadiene Rubber Compounds Containing Different Amount of Poly, Di and Monosulphidic Bonds  

Microsoft Academic Search

There have been significant attempts to devulcanize waste elastomers to facilitate reusing these valuable resources in applications requiring the unique properties of rubber. The difficulty in recycling of elastomers has traditionally been with devulcanizing the elastomer without comprising its properties due to degradation of main chains. This research aimed to devulcanize model styrene-butadiene rubber (SBR) compounds, which had various amounts

Samra Sangari; Hill Anita; Pavel Dumitru

2004-01-01

195

Evaluation of the polymer–solvent interaction parameter ? for the system cured styrene butadiene rubber and toluene  

Microsoft Academic Search

One of the most popular cured rubbers used in industrial applications is styrene butadiene rubber (SBR) and frequently its network structure is studied by means of swelling techniques in solvent. Normally, toluene is used as solvent in this test. In order to estimate the crosslink density from the equilibrium volume fraction of rubber in the swollen state, the correct evaluation

A. J. Marzocca

2007-01-01

196

Effect of concentration and humidity on the formation of porous polymer films using Styrene Butadiene CoPolymer  

Microsoft Academic Search

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

Renu Jose; A. Sujith; P. Predeep

2011-01-01

197

Evaluation of some arylphosphites as antioxidants and antifatigue agents in natural rubber and styrene–butadiene rubber vulcanizates  

Microsoft Academic Search

Seven arylphosphites were synthesized and incorporated into natural rubber (NR) and styrene–butadiene rubber (SBR) mixes. The rheometric characteristics of the rubber mixes were determined using an oscillating disc rheometer. The prepared compounds were evaluated as antioxidants and antifatigue agents in NR and SBR vulcanizates. It was found that the prepared compounds are good antioxidants and antifatigue agents and their efficiency

M. N Ismail; A. A Yehia; A. A Korium

2001-01-01

198

Thermogravimetric analysis, flammability and oil resistance properties in natural rubber and dichlorocarbene modified styrene butadiene rubber blends  

Microsoft Academic Search

Thermogravimetric analysis (TGA), flammability and oil resistance in natural rubber (NR) and dichlorocarbene modified styrene butadiene rubber (DCSBR) blends were investigated as a function of different composition. TGA plot confirms the better thermal stability and flame resistance of DCSBR as well as its blends with NR. The simultaneous difference temperature plot showed the energy requirement for the degradation pattern of

M. T. Ramesan

2004-01-01

199

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

2013-05-07

200

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

201

Variation of long periodicity in blends of styrene butadiene, styrene copolymer/polyaniline using small angle X-ray scattering data  

NASA Astrophysics Data System (ADS)

Small angle X-ray scattering data have been recorded for the blends of styrene butadiene, styrene copolymer/polyaniline using the beamline of the LNLS (Laboratorio Nacional de Luz sincroton-Campinas, Brazil. Employing one-dimensional Hosemann's paracrystalline model, we have simulated the meridional reflections of these blends in order to compute the long periodicity and hence to find the variation with concentrations of the blends. Within the region of available experimental data we observe that there is a linear relationship between long periodicity and concentration of blends. These parameters are compared with physical measurements like tensile strength to find the structure--property relation in these blends.

Soares, B. G.; Souza, Fernando G., Jr.; Manjunath, A.; Somashekarappa, H.; Somashekar, R.; Siddaramaiah

2007-09-01

202

Environmental epidemiologic investigations in the styrene-butadiene rubber production industry  

SciTech Connect

A review of the literature and an update that is in progress of a previous retrospective cohort mortality study of the styrene-1,3-butadiene industry are discussed. The follow-up has now been extended from April 1, 1976, through December 31, 1981, for plant B and December 31, 1982, for plant A. The person-years at risk of death have gone from 34,187 to 43,341 in plant A and from 19,742 to 26,314 in plant B. Among the death certificates received to date, observed deaths have increased in both plants, with increases in cancers of the trachea, bronchus and lung and in lymphosarcomas, reticulosarcomas, and cancers of the overall lymphatic and hematopoietic system.16 references.

Lemen, R.A.; Meinhardt, T.J.; Crandall, M.S.; Fajen, J.M.; Brown, D.P. (National Institute for Occupational Safety and Health, Cincinnati, OH (USA))

1990-06-01

203

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

PubMed

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

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

1990-06-01

204

Thermo-sensitive properties of carbon-black-loaded styrene butadiene rubber composite membranes  

NASA Astrophysics Data System (ADS)

Some conducting polymer composite membranes were prepared by using styrene butadiene rubber as matrices and incorporating carbon blacks and a kind of organic crystal (2,6-di-tert-butyl-4-methyl phenol, BMP). Several composite membranes whose resistivities showed a critical percolation threshold at room temperature exhibited a thermo-sensitive property and their resistivities increased with increasing temperature, that is, a positive temperature coefficient (PTC) effect for these membranes was observed. The switching temperature of these composite membranes, which was associated with a sharp variation in resistivity within a certain temperature range, was quite well matched to the melting point of the BMP crystal. A few membranes, loaded with an appropriate amount of Sterling SO-N550 carbon black and the BMP crystal, showed a relatively high PTC intensity.

Wan, Ying; Wen, Dijiang

2004-10-01

205

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

PubMed Central

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

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

1990-01-01

206

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

NASA Astrophysics Data System (ADS)

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

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

2010-09-01

207

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

PubMed

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

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

2010-09-01

208

Direct Analysis of Heavily Loaded Carbon Black Filled Styrene-Butadiene Rubber Used in Tank Track Pads by FT-IR.  

National Technical Information Service (NTIS)

Infrared spectra have been obtained of a heavily loaded (50 per hundred) carbon black filled styrene-butadiene rubber using a Fourier transform infrared spectrometer (FT-IT). Attenuated total reflectance (ATR) spectroscopy sampling employing a germanium (...

J. M. Sloan J. P. Clements

1984-01-01

209

Strengthening acrylonitrile-butadiene-styrene (ABS) with nano-sized and micron-sized calcium carbonate  

Microsoft Academic Search

ABS was reinforced by both micron-sized (MCC) and nano-sized precipitated calcium carbonate (NPCC) particles through melt compounding. The MCC\\/ABS composites were found to have higher modulus but lower tensile and impact strength than neat ABS. In contrast, NPCC increased modulus of ABS whilst maintained or even increased its impact strength for a certain NPCC loading range. SEM examinations revealed that

L. Jiang; Y. C. Lam; K. C. Tam; T. H. Chua; G. W. Sim; L. S. Ang

2005-01-01

210

Epidemiologic investigations of styrene-butadiene rubber production and reinforced plastics production.  

PubMed

The United States National Institute for Occupational Safety and Health (NIOSH) began an epidemiologic study of workers employed in the styrene-butadiene rubber (SBR) industry during 1976. This study was prompted by reports of relatively high numbers of leukemia deaths occurring within SBR production work populations. Simultaneous with the initiation of this investigation, the University of North Carolina released a report associating an excess risk of death due to hematopoietic and lymphatic malignancies among workers producing several synthetic rubbers, including SBR. This report presents NIOSH's preliminary mortality observations and a discussion of progress made on the analyses of contaminants found in two SBR production facilities. Currently, NIOSH is determining the feasibility of doing an epidemiologic study in the reinforced plastics industry. Interest in this study developed as part of an effort to determine health hazards associated with occupational exposure to styrene. Most of the technology for the reinforced plastics industry developed in the 1950s, and therefore this process represents a relatively new industry. This report also includes information on environmental conditions observed in the reinforced plastics industry and enumerates some of the complicating characteristics of this industry which increase the complexity of this study. PMID:282663

Meinhardt, T J; Young, R J; Hartle, R W

1978-01-01

211

Development of Fibers Containing a Reaction Product of Chloromethylated Styrene Polymer and Diethylenetriamine.  

National Technical Information Service (NTIS)

Fibers with an anion exchange capacity as high as 2.7 meq/g were obtained by preparing ion exchange resins in situ within two phase fiber systems. Initially, blends of polypropylene with acrylonitrile-butadiene (NBR) and a styrene containing polymer (ABS)...

M. J. Smith

1974-01-01

212

Low-pressure plasma chlorination of styrene–butadiene block copolymer for improved adhesion to polyurethane adhesives  

Microsoft Academic Search

Studies concerning plasma-surface chlorination of a styrene–butadiene block copolymer (SBS), improving its adhesion to polyurethane adhesives (PU), are presented in this paper. The plasma was generated by an RF discharge (13.56MHz, plate electrode reactor) in CCl4 under low pressure. The 180°-peel test, contact angle measurements and XPS spectroscopy were utilized to investigate the SBS surface. A drastic increase in the

J. Tyczkowski; I. Krawczyk; B. Wo?niak; J. M. Martin-Martinez

2009-01-01

213

Leukemia and exposure to 1,3-butadiene, styrene and dimethyldithiocarbamate among workers in the synthetic rubber industry  

Microsoft Academic Search

This study evaluated relations between exposure to 1,3-butadiene (BD), styrene (STY) and dimethyldithiocarbamate (DMDTC) and mortality from leukemia among synthetic rubber industry workers. Subjects were 13?130 men employed for at least 1 year during 1943–1991 at any of six plants that manufactured synthetic rubber. Death certificates and medical records identified workers with leukemia. Cumulative exposure estimates were based on plant-

Elizabeth Delzell; Maurizio Macaluso; Nalini Sathiakumar; Robert Matthews

2001-01-01

214

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

Microsoft Academic Search

A detailed study of the kinetics of phase transformations of the diblock copolymer, styrene-butadiene, is reported. The technique of [ital in] [ital situ] time-resolved small-angle x-ray scattering with the use of synchrotron radiation has been used to study the first-order phase transitions of microphase separation and microdomain ordering. These transitions occur following a rapid, thermal quench from the homogeneous, disordered

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

1993-01-01

215

CORRELATION BETWEEN MORPHOLOGY AND MECHANICAL PROPERTIES OF DIFFERENT STYRENE\\/BUTADIENE TRIBLOCK COPOLYMERS: A SCANNING FORCE MICROSCOPY STUDY  

Microsoft Academic Search

The morphology of different styrene\\/butadiene (SB) block copolymers with triblock architectures was investigated using tapping mode scanning force microscopy (SFM). Comparative analysis of the morphology of the samples at the polymer\\/substrate interface of solution-cast films and in bulk was performed. It was found that, besides the total phase volume ratio, the interfacial structure between the incompatible chains determines the phase

R. Adhikari; R. Godehardt; W. Lebek; R. Weidisch; G. H. Michler; K. Knoll

2001-01-01

216

Effect of pressure on the microphase separation of the symmetric diblock copolymer poly(styrene–block–butadiene)  

Microsoft Academic Search

A pressure induced microphase separation transition (MST) of a symmetric poly(styrene–block–butadiene) (P(S-b-B)) copolymer melt has been observed in-situ by analysing the small-angle X-ray scattering (SAXS) peak intensity, width and position. With increasing pressure the system undergoes a microphase separation from a disordered to an ordered (lamellar) phase, indicated by an increase of the scattering maximum intensity connected with a decrease

H. Ladynski; W De Odorico; M Stamm

1998-01-01

217

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

Microsoft Academic Search

A detailed study of the kinetics of phase transformations of the diblock copolymer, styrene-butadiene, is reported. The technique of in situ time-resolved small-angle x-ray scattering with the use of synchrotron radiation has been used to study the first-order phase transitions of microphase separation and microdomain ordering. These transitions occur following a rapid, thermal quench from the homogeneous, disordered state to

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

1993-01-01

218

Developing a coarse-grained force field for the diblock copolymer poly(styrene-b-butadiene) from atomistic simulation  

Microsoft Academic Search

We have developed a coarse-grained force field for the poly(styrene-b-butadiene) diblock copolymer. We describe the computational methods and discuss how they were applied to develop a coarse-grained force field for this diblock copolymer from the atomistic simulation. The new force field contains three different bonds, four angles, five dihedral angles, and three nonbonded terms. We successfully tested this coarse-grained model

Xuejin Li; Dazhi Kou; Shuling Rao; Haojun Liang

2006-01-01

219

Determination of the chemical composition distribution of copolymers of styrene and butadiene by gradient polymer elution chromatography  

Microsoft Academic Search

In order to determine the chemical composition distribution (CCD) of styrene-butadiene copolymers, gradient polymer elution chromatography has been performed. The separation is mainly based on differences in solubility among the copolymer molecules with different chemical composition. The solubility of a copolymer is dependent on the following parameters: temperature, type of solvent\\/non-solvent mixture, molecular mass of the polymer and the chemical

P. J. C. H. Cools; F. Maesen; B. Klumperman; A. M. van Herk; A. L. German

1996-01-01

220

Surface Modifications Produced by N2 and O2 RF Plasma Treatment on a Synthetic Vulcanized Styrene-Butadiene Rubber  

Microsoft Academic Search

A low-pressure gas RF plasma-treatment has been used to improve the adhesion of a synthetic vulcanized rubber to polyurethane adhesive as an environmentally friendly alternative surface treatment to the conventional chemical treatments. A sulfur vulcanized styrene-butadiene rubber (R2) containing a noticeable amount of zinc stearate and paraffin wax (both providing a lack of adhesion) in its formulation was used. Two

Ana B. Ortiz-Magán; M. Mercedes Pastor-Blas; Teresa P. Ferrándiz-Gómez; Carmen Morant-Zacarés; José Miguel Martín-Martínez

2001-01-01

221

Comparison of the Effect of a Hydrocarbon Oil and a Terpene Tackifier on the Autohesion of Styrene-Butadiene Rubber  

Microsoft Academic Search

Blends of uncrosslinked styrene-butadiene rubber (SBR) with a terpene tackifier resin or a naphthenic oil have been characterized, and their autohesion and cohesion determined using a T-peel geometry. SBR\\/oil blends are homogeneous at all proportions, while SBR\\/resin blends, based on DSC and DMA analysis, undergo bulk phase separation at about 50% resin. However, migration of tackifier to the surface region

G. R. Hamed; G. D. Roberts

1994-01-01

222

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

Microsoft Academic Search

The kinetics of thermal decomposition of styrene-butadiene rubber have been investigated thermo-gravimetrically under various heating rates either in nitrogen or mixed with 5–25% oxygen in nitrogen. The results show that in pure nitrogen the reaction involves only one stage, with an initial reaction temperature of 622–661 K and an apparent activation energy at 211 ± 15 kJ\\/mol. The initial reaction

Y. R. Chang; R. Z. Yeh

1997-01-01

223

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

224

Effect of styrene–butadiene rubber latex on the chloride permeability and microstructure of Portland cement mortar  

Microsoft Academic Search

We evaluated the chloride permeability and microstructure of Portland cement mortar modified by styrene–butadiene rubber (SBR) latex, using mortar samples with various polymer\\/cement (P\\/C) mass ratios. The incorporation of SBR improved the chloride penetration resistance along with the general ionic permeability of the mortar, while increasing its ionic transport resistance and decreasing its electric capacitance. These data suggest that admixing

Zhengxian Yang; Xianming Shi; Andrew T. Creighton; Marijean M. Peterson

2009-01-01

225

Quantitative analysis of natural rubber, polybutadiene rubber and styrene\\/butadiene rubber blends by infra-red spectroscopy  

Microsoft Academic Search

Infra-red spectra of natural rubber (NR), polybutadiene rubber (PBR) and styrene butadiene rubber (SBR) have been studied for the estimation of these polymers in ternary rubber blends. A study of different infra-red active bands suggests that the bands at 1316 Cm-1, 1379 Cm-1 and 1493 Cm-1 are most appropriate for quantitative purpose. A detailed analysis of observed data has been

V. K. Kaushik; Y. N. Sharma

1985-01-01

226

Synergistic effect of carbon black and nanoclay fillers in styrene butadiene rubber matrix: Development of dual structure  

Microsoft Academic Search

Styrene butadiene rubber (SBR) based hybrid nanocomposites containing carbon black (CB) and organo-modified nanoclay (NC) was prepared. X-ray diffraction (XRD) and transmission electron microscopy (TEM) revealed the presence of intercalated, aggregated, and partially exfoliated structures. Incorporating 10phr NC to the control SBR containing 20phr CB resulted 153% increase in tensile strength, 157% increase in elongation at break and 144% stress

S. Praveen; P. K. Chattopadhyay; P. Albert; V. G. Dalvi; B. C. Chakraborty; S. Chattopadhyay

2009-01-01

227

Preparation and properties of powder styrene–butadiene rubber composites filled with carbon black and carbon nanotubes  

Microsoft Academic Search

Carbon nanotubes (CNTs) and carbon black (CB) filled powder styrene–butadiene rubber (SBR) composites were prepared by spray drying of the suspension of CNTs and CB in SBR latex. The powders were sphere like and fine with uniform diameters of 10–15?m. Experimental results showed that the introduction of CNTs into the matrix was beneficial to improve the security of the vulcanization

Xiang-Wen Zhou; Yue-Feng Zhu; Ji Liang

2007-01-01

228

Surface Characterization of Chlorinated Synthetic Vulcanized Styrene-Butadiene Rubber Using Contact Angle Measurements, InfraRed Spectroscopy and XPS  

Microsoft Academic Search

The surface of a sulfur-vulcanized synthetic styrene-butadiene rubber (SBR) was treated with ethyl acetate solutions containing different amounts of trichloroisocyanuric acid (TCI). The chlorinated SBR surfaces were characterized using contact angle measurements (water, ethane diol, n-hexadecane), infra-red (IR) spectroscopy and XPS. Chlorination produced an increase of surface free energy which was mainly due to the enhancement of the acid-base component

M. M. Pastor-Blas; J. M. Martín-Martínez; J. G. Dillard

1997-01-01

229

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

Microsoft Academic Search

The rheological properties of styrene-butadiene rubber (SBR) loaded with dual phase filler were measured using Monsanto Processability Tester (MPT) at three different temperatures (100°C, 110°C and 130°C) and four different shear rates (61.3, 306.3, 613, and 1004.5s-1). The effect of electron beam modification of dual phase filler in absence and presence of trimethylol propane triacrylate (TMPTA) or triethoxysilylpropyltetrasulphide (Si-69) on

A. M. Shanmugharaj; Anil K. Bhowmick

2004-01-01

230

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

Microsoft Academic Search

The rheological properties of styrene–butadiene rubber (SBR) loaded with dual phase filler were measured using Monsanto Processability Tester (MPT) at three different temperatures (100°C, 110°C and 130°C) and four different shear rates (61.3, 306.3, 613, and 1004.5s?1). The effect of electron beam modification of dual phase filler in absence and presence of trimethylol propane triacrylate (TMPTA) or triethoxysilylpropyltetrasulphide (Si-69) on

A. M Shanmugharaj; Anil K Bhowmick

2004-01-01

231

Rheological Characteristics of Short Nylon6 Fiber Reinforced Styrene Butadiene Rubber Containing Epoxy Resin as Bonding Agent  

Microsoft Academic Search

The rheological characteristics of short Nylon-6 fiber–reinforced Styrene Butadiene rubber (SBR) in the presence of epoxy resin–based bonding agent were studied with respect to the effect of shear rate, fiber concentration, and temperature on shear viscosity and die swell using a capillary rheometer. All the composites containing bonding agent showed a pseudoplastic nature, which decreased with increasing temperature. Shear viscosity

A. Seema; S. K. N. Kutty

2005-01-01

232

Effect of electron beam irradiation and degree of boric acid loading on the properties of styrene-butadiene rubber  

Microsoft Academic Search

Synthetic and totally amorphous styrene-butadiene rubber (SBR) has been loaded with varying contents of boric acid. Vulcanization of prepared composites as well as of unloaded rubber has been induced by ionizing radiation of accelerated electron beam of varying doses up to 250kGy. Evaluation of prepared composite subjected to this range of irradiation has been followed up through the measurement of

N. A. Shaltout

2009-01-01

233

Diffusion and transport through nanocomposites of natural rubber (NR), carboxylated styrene butadiene rubber (XSBR) and their blends  

Microsoft Academic Search

Solvent resistance properties of nano-structured layered silicates filled natural rubber (NR), carboxylated styrene butadiene rubber (XSBR) and their 70\\/30 latex blend were investigated by equilibrium swelling method using benzene, toluene and p-xylene. The layered nano-structured sodium bentonite and sodium fluorohectorite were used in the present study. The impact of concentration of filler, temperature and penetrant size on the transport properties

Ranimol Stephen; Siby Varghese; Kuruvilla Joseph; Zachariah Oommen; Sabu Thomas

2006-01-01

234

Preparation and properties of styrene butadiene rubber\\/natural rubber\\/organo-bentonite nanocomposites prepared from latex dispersions  

Microsoft Academic Search

Styrene butadiene rubber (SBR)\\/natural rubber (NR)\\/organo-bentonite nanocomposites were prepared from emulsions. The structure of the nanocomposites was characterized by TEM and XRD. The effect of organo-bentonite on the mechanical properties, thermal stability and swelling behavior was investigated. TEM and XRD confirmed that rubber chains were intercalated into the organo-montmorillonite particles. When the organo-bentonite content was lower than 12mass%, the nanocomposites

Zheng Gu; Guojun Song; Weisheng Liu; Peiyao Li; Li Gao; Hanhua Li; Xiong Hu

2009-01-01

235

Study of the crosslinking evolution of styrene-butadiene rubber\\/zinc dimethacrylate based on dissolution\\/swelling experiments  

Microsoft Academic Search

ABSTRACT: The crosslinking evolution of styrene-butadiene rubber (SBR) filled with in-situ zinc dimethacrylate (ZDMA) during dicumyl peroxide (DCP) curing was studied. The crosslink density of the composites with different extent of curing was evaluated by dissolution\\/swelling experiments. The cure curve was determined by rheometry measurements. The results revealed that the crosslinking of the SBR matrix was not affected by the

Chuanhui Xu; Yukun Chen; Liming Cao; Yanpeng Wang; Xingrong Zeng

2012-01-01

236

Physico-mechanical properties and thermal stability of thermoset nanocomposites based on styrene-butadiene rubber\\/phenolic resin blend  

Microsoft Academic Search

Effect of organoclay (OC) on the performance of styrene-butadiene rubber (SBR)\\/phenolic resin (PH) blend prepared by two-roll mill was investigated. The influence of OC content ranging between 2.5 and 30phr on the performance of SBR\\/PH was investigated using X-ray diffraction (XRD), scanning electron microscopy (SEM), interfacial energy analysis, tensile, dynamic mechanical, swelling, cure rheometry and thermogravimetric analysis (TGA). It was

Akbar Shojaei; Morteza Faghihi

2010-01-01

237

Preparation and characterization of polyvinyl chloride\\/styrene butadiene rubber blend heterogeneous cation exchange membrane modified by potassium perchlorate  

Microsoft Academic Search

In the current research, polyvinylchloride (PVC)\\/styrene-Butadiene-Rubber (SBR) blend heterogeneous cation exchange membranes were prepared by solution casting technique using tetrahydrofuran as solvent and cation exchange resin powder as functional groups agent. Potassium perchlorate was also employed as an additive in membrane fabrication. The effect of additive concentration in the casting solution on physico-chemical properties of home-made membranes was studied. Sonication

S. M. Hosseini; S. S. Madaeni; A. R. Heidari; A. R. Moghadassi

2011-01-01

238

Kinetics of thermal degradation and thermo-oxidative degradation of conductive styrene-butadiene rubber-carbon black composites  

Microsoft Academic Search

The kinetics of the thermal degradation and thermo-oxidative degradation of conductive styrene-butadiene rubber (SBR)-carbon black composites were investigated using thermogravimetric analysis both in nitrogen and oxygen atmospheres. Experiments were carried out at heating rates of 5, 10, 15 and 20 C\\/min in both the atmospheres. Friedman method, Kissinger method, Flynn–Wall–Ozawa method and Coats–Redfern method have been used to determine the activation

G. T. Mohanraj; T. Vikram; A. M. Shanmugharaj; D. Khastgir; T. K. Chaki

2006-01-01

239

Thermal and mechanical properties of styrene-butadiene rubber\\/lead oxide composites as gamma-radiation shields  

Microsoft Academic Search

Styrene-butadiene rubber\\/lead oxide composites were prepared as ?-radiation shields. The composites were prepared with three different types of lead oxide, namely lead mono-oxide (PbO), lead dioxide (PbO2) and red lead oxide (Pb3O4). Concentrations of about 87–88 wt% for the three lead oxides were used. The assessment of the linear attenuation coefficient of the SBR\\/lead oxide composites for ?-rays from different

M. M. Abdel-Aziz; S. E. Gwaily

1997-01-01

240

An Investigation into the Mechanisms for Styrene-Butadiene Copolymer (SBR) Conversion in Combustion and Gasification Environments  

Microsoft Academic Search

The thermal degradation (pyrolysis and combustion) of styrene-butadiene rubber has been studied thermo-gravimetrically using various heating rates (10, 20, 30, 40 K\\/min) and various atmospheres (pure N2, 3% H2\\/N2, air, 30% O2\\/N2). Calculation of apparent kinetic parameters pre-exponential factor, activation energy and reaction order for the different conditions was done to enable modeling efforts. Gas phase chemical species measurement provides

Marco J. Castaldi; Eilhann Kwon

2007-01-01

241

DSC study of the influence of p -subtituted diphenyl amines on the thermooxidative stability of styrene-butadiene rubber  

Microsoft Academic Search

Effect of several p- and p,p?-substituted diphenyl amines on the thermooxidative stability of styrene-butadiene rubber (SBR) has been studied using non-isothermal\\u000a DSC measurements with the aim of exploring the relation between the structure of the compound and its antioxidative performance.\\u000a The treatment of the experimental data was carried out by applying a new method based on a non-Arrhenian temperature function.

Zuzana Cibulková; Peter Šimon; Peter Lehocký; Károly Kosár; Ján Uhlár

2010-01-01

242

Analysis of a Styrene-Butadiene Graft Copolymer by Size Exclusion Chromatography II. Determination of the Branching Exponent with the Help of a Polymerization Model  

Microsoft Academic Search

A styrene — butadiene graft copolymer is analyzed by size exclusion chromatography (SEC) with on-line viscometry with the aim of estimating the ? exponent that relates the two branching parameters through g = g?. Three copolymer samples synthesized in a solution polymerization of styrene in the presence of polybutadiene were analyzed. Theoretical predictions on the branching characteristics were obtained with

J. R. Vega; D. A. Estenoz; H. M. Oliva; G. R. Meirra

2001-01-01

243

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

PubMed

In the tire industry, synthetic styrene-butadiene rubber (SBR), butadiene rubber (BR), and isoprene rubber (IR) elastomers are essential for conferring to the product its properties of grip and rolling resistance. Their physical properties depend on their chemical composition, i. e., their microstructure and styrene content, which must be accurately controlled. This paper describes a fast, robust, and highly reproducible near-infrared analytical method for the quantitative determination of the microstructure and styrene content. The quantitative models are calculated with the help of pure spectral profiles estimated from a partial least squares (PLS) regression, using (13)C nuclear magnetic resonance (NMR) as the reference method. This versatile approach allows the models to be applied over a large range of compositions, from a single BR to an SBR-IR blend. The resulting quantitative predictions are independent of the sample path length. As a consequence, the sample preparation is solvent free and simplified with a very fast (five minutes) hot filming step of a bulk polymer piece. No precise thickness control is required. Thus, the operator effect becomes negligible and the method is easily transferable. The root mean square error of prediction, depending on the rubber composition, is between 0.7% and 1.3%. The reproducibility standard error is less than 0.2% in every case. PMID:16808863

Vilmin, Franck; Dussap, Claude; Coste, Nathalie

2006-06-01

244

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

PubMed

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

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

2013-09-16

245

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

Code of Federal Regulations, 2013 CFR

...d) Extractives limitations. The following extractives limitations are determined by an infrared spectro-photo-metric method titled âInfrared Spectro-photo-metric Determination of Polymer Extracted from Borex ® 210 Resin...

2013-04-01

246

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

NASA Astrophysics Data System (ADS)

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

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

2008-12-01

247

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

NASA Astrophysics Data System (ADS)

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

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

2009-05-01

248

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

PubMed

A series of carboxylated styrene-butadiene rubber (XSBR)/cellulose nanocrystals (CNs) latex composites were successfully prepared. The vulcanization process, morphology, dynamic viscoelastic behavior, dynamic mechanical property, thermal and mechanical performance of the XSBR/CNs composites were investigated in detail. The results revealed that CNs were dispersed uniformly in the XSBR matrix and formed a strong filler-filler network. The dynamic mechanical analysis (DMA) showed that the glass transition temperature (T(g)) of XSBR matrix was shifted from 48.45 to 50.64 °C with 3 phr CNs, but decreased from 50.64 to 46.28 °C when further increasing CNs content up to 15 phr. The composites exhibited a significant enhancement in tensile strength (from 16.9 to 24.1 MPa) and tear strength (from 43.5 to 65.2 MPa) with loading CNs from 0 to 15 phr. In addition, the thermo-gravimetric analysis (TGA) showed that the temperature at 5% weight loss of the XSBR/CNs composites decreased slightly with an increase of the CNs content. PMID:23218267

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

2012-10-03

249

Stability of thermo-sensitive properties of carbon-black/styrene-butadiene-rubber composite membranes  

NASA Astrophysics Data System (ADS)

Conducting composite membranes were prepared by using styrene butadiene rubber as matrices and incorporating carbon blacks and some organic crystals (2,6-di-tert-butyl-4-methyl phenol, BMP). A number of composite membranes exhibited a thermo-sensitive property which corresponded to a positive temperature coefficient (PTC) effect. Their DSC thermograms and x-ray patterns indicated that there were no significant changes in the structure of membranes although these membranes were subjected to discontinuous and repeated thermal cycle measurements of more than 100 runs. The switching characteristic and PTC intensity of membranes showed a satisfyingly reproducible stability. It was also found that the thermal ageing treatment could remarkably influence conductive and PTC properties of composite membranes. When these composite membranes were thermally aged at a temperature of 90 or 100 °C for various times up to 480 h, no essential changes in the resistivity were observed and their PTC intensity and switching characteristic were still effectively maintained. However, when these composite membranes were exposed to an elevated thermal ageing temperature higher than 100 °C over various time intervals from 24 to 480 h, significant changes in resistivity were detected and their original PTC properties could almost totally disappear depending on the thermal ageing temperature and time. The obtained results revealed that these composite membranes could maintain their thermo-sensitive stability for a long term in a thermal environment in which the temperature was lower than 100 °C.

Wan, Ying; Wen, Dijiang

2005-10-01

250

Electrochemical performance of lithium-ion polymer cell using gel polymer electrolyte based on acrylonitrile-methyl methacrylate-styrene terpolymer  

Microsoft Academic Search

Gel polymer electrolyte (GPE) was prepared by encapsulating organic electrolyte solution in acrylonitrile-methyl methacrylate-styrene(AMS) terpolymer and applied as a solid electrolyte material for lithium-ion polymer battery. The composite electrodes prepared with mesocarbon microbeads and LiNi0.83Co0.17O2 active materials were used as anode and cathode, respectively, and cycling characteristics of these half-cells (Li\\/GPE\\/carbon and Li\\/GPE\\/LiNi0.83Co0.17O2) has been investigated using the AMS-based gel

Dong-Won Kim; Boo-Keun Oh; Young-Min Choi

1999-01-01

251

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

SciTech Connect

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

Basfar, A.A.; Silverman, J.

1991-08-01

252

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

PubMed

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. PMID:21728565

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

2011-05-27

253

Developing a coarse-grained force field for the diblock copolymer poly(styrene-b-butadiene) from atomistic simulation.  

PubMed

We have developed a coarse-grained force field for the poly(styrene-b-butadiene) diblock copolymer. We describe the computational methods and discuss how they were applied to develop a coarse-grained force field for this diblock copolymer from the atomistic simulation. The new force field contains three different bonds, four angles, five dihedral angles, and three nonbonded terms. We successfully tested this coarse-grained model against the chain properties, including static and dynamic properties, derived from the atomistic simulation; the results suggest that the coarse-grained force field is an effective model. PMID:16774386

Li, Xuejin; Kou, Dazhi; Rao, Shuling; Liang, Haojun

2006-05-28

254

Developing a coarse-grained force field for the diblock copolymer poly(styrene-b-butadiene) from atomistic simulation  

NASA Astrophysics Data System (ADS)

We have developed a coarse-grained force field for the poly(styrene-b-butadiene) diblock copolymer. We describe the computational methods and discuss how they were applied to develop a coarse-grained force field for this diblock copolymer from the atomistic simulation. The new force field contains three different bonds, four angles, five dihedral angles, and three nonbonded terms. We successfully tested this coarse-grained model against the chain properties, including static and dynamic properties, derived from the atomistic simulation; the results suggest that the coarse-grained force field is an effective model.

Li, Xuejin; Kou, Dazhi; Rao, Shuling; Liang, Haojun

2006-05-01

255

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

NASA Astrophysics Data System (ADS)

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

Mathew, Anisha Mary; Neena, P.

2011-10-01

256

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

NASA Astrophysics Data System (ADS)

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

Mathew, Anisha Mary; Neena, P.

2011-10-01

257

The occupational scene of styrene.  

PubMed

Styrene readily undergoes homopolymerization as well as copolymerization with other monomers, such as acrylonitrile and butadiene. In closed polymerization processes, exposure of workers to styrene is generally lower than current reference values (20-50 ppm), but high peaks of exposure may occur during the cleaning, filling and maintenance of reaction vessels and during transport of liquid styrene. Styrene is used not only in styrene polymers but also as a reactive solvent in the manufacture of unsaturated polyester resins. During the lamination process, when resins are applied manually or by spraying in open moulds, workers are exposed to styrene at concentrations that are on average two or three times higher than the 8-h time-weighted average hygienic standard, 20 ppm. Further, exposures during the open mould process tend to fluctuate widely, so that short-term exposures are often twice the short-term reference value (100 ppm; 15-min time-weighted average). These processes also involve exposure to styrene oxide, which is a suspected carcinogen. Use of low-emission resins reduces exposure during curing but not during lamination itself. The exposure of laminators can be reduced by use of combined, carefully planned, general and local ventilation, adequately designed work places and promotion of safe working habits. The best way of controlling exposures to styrene in the reinforced plastic industry in general would be to automate the processes and to use closed moulds. PMID:8070861

Pfäffli, P; Säämänen, A

1993-01-01

258

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

PubMed

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

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

2013-09-21

259

Butadiene cancer exposure-response modeling: based on workers in the styrene-butadiene-rubber industry: total leukemia, acute myelogenous leukemia, chronic lymphocytic leukemia, and chronic myelogenous leukemia.  

PubMed

Cox regression is used to estimate exposure-response models (with cumulative 1,3-butadiene (BD) ppm-years as the exposure metric) based on the most recent data and validated exposure estimates from UAB's study of North American workers in the styrene-butadiene-rubber industry. These data are substantially updated from those in USEPA's 2002 risk assessment. The slope for cumulative BD ppm-years is not statistically significantly different than zero for CML, AML, or, when any one of eight exposure covariates is added to the model, for all leukemias combined (total leukemia). For total leukemia, the EC(1/100,000) is approximately 0.15 BD environmental ppm and the corresponding unit risk factor is approximately 0.00007 per BD environmental ppm. The excess risk for CML is approximately 15-fold less than for total leukemia. The maximum likelihood estimates suggest that there is no excess risk for AML from cumulative BD ppm-years. For CLL, the slope is statistically significantly different than zero. The excess risk for CLL is approximately 2.5-fold less than for total leukemia. For both total leukemia and CLL, the slope is not statistically significantly different than zero when the exposure-response modeling is based on the person-years with cumulative BD ppm-years less than or equal to 300 ppm-years. PMID:21600953

Sielken, Robert L; Valdez-Flores, Ciriaco

2011-05-12

260

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

Microsoft Academic Search

An experimental investigation was performed to study the effect on the free volume of the advance of the cross-linking reaction in a copolymer of styrene butadiene rubber by sulfur vulcanization. The dynamic modulus and loss tangent were evaluated over samples cured for different times at 433 K by dynamic mechanical tests over a range of frequencies between 5 and 80

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

2002-01-01

261

Possibility of an Excess of Leukemia among Workers in a Styrene-Butadiene Rubber Plant with Attached Letter from ARCO Polymer, Inc., to NIOSH.  

National Technical Information Service (NTIS)

As a result of the March 25, 1976 announcement by B. F. Goodrich Company of a possibility of an excess of leukemia among workers in a styrene-butadiene rubber plant, ARCO/Polymers, Inc., a subsidiary of Atlantic Richfield Company, voluntarily initiated an...

1978-01-01

262

Effect of filling mixtures of sepiolite and a surface modified fumed silica on the mechanical and swelling behavior of a styrene–butadiene rubber  

Microsoft Academic Search

A styrene–butadiene copolymer is filled with mixtures of pyrogenic silica combined with a silane coupling agent and fibers of organophilic sepiolite. The mechanical properties of the composites reveal that a mixture of double fillers impart to the elastomeric matrix a higher degree of reinforcement than that which would result from a simple addition of the two types of fillers. The

Liliane Bokobza; Eric Leroy; Valérie Lalanne

2009-01-01

263

Studies on the cure and mechanical properties of blends of natural rubber with dichlorocarbene modified styrene–butadiene rubber and chloroprene rubber  

Microsoft Academic Search

This paper focused on the comparative evaluation of cure characteristics and mechanical properties of blends of natural rubber with dichlorocarbene modified styrene–butadiene rubber and chloroprene rubber with different blend composition. It was found that the Mooney scorch time and cure index shows a negative deviation from the calculated value based on the interpolation between the two component elastomers. However for

M. T. Ramesan; Rosamma Alex; N. V. Khanh

2005-01-01

264

Thermal stability and ageing properties of sulphur and gamma radiation vulcanized natural rubber (NR) and carboxylated styrene butadiene rubber (XSBR) latices and their blends  

Microsoft Academic Search

The thermal stability of natural rubber (NR) and carboxylated styrene butadiene rubber (XSBR) latices and their blends was studied by thermogravimetric methods. Ageing characteristics of these latex blends were studied by applying hot air oven thermal ageing for seven days at 70°C. The mechanical properties of the aged samples were studied. Thermal degradation and ageing properties of these individual latices

Ranimol Stephen; Seno Jose; Kuruvilla Joseph; Sabu Thomas; Zachariah Oommen

2006-01-01

265

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

Microsoft Academic Search

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

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

1984-01-01

266

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

NASA Astrophysics Data System (ADS)

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

Basfar, A. A.; Silverman, Joseph

1995-09-01

267

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

SciTech Connect

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

Singh, M.A. (Department of Physics, Queen's University, Kingston, Ontario, K7L 3N6 (Canada)); Harkless, C.R. (XonTech Inc., Van Nuys, California 91406 (United States)); Nagler, S.E. (Department of Physics, University of Florida, Gainesville, Florida 32611 (United States)); Shannon, R.F. Jr.; Ghosh, S.S. (Department of Physics, Queen's University, Kingston, Ontario, K7L 3N6 (Canada))

1993-04-01

268

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

NASA Astrophysics Data System (ADS)

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

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

1993-04-01

269

Characterization of functionalized styrene-butadiene rubber by flow field-flow fractionation/light scattering in organic solvent.  

PubMed

Flow field-flow fractionation (FlFFF) using an organic solvent as mobile phase has been effectively utilized for the separation and characterization of functionalized styrene-butadiene rubbers (SBR) that are polymerized and followed by coupling reaction in solution. Separation of broad molecular weight SBR was accomplished by an asymmetrical FlFFF channel in THF under field programming and the molecular weight distribution (MWD) of the SBR sample was determined by on-line measurement of light scattering. In this study, FlFFF has been utilized to characterize high-MW functionalized SBR from the low-MW non-functionalized molecules which were used for coupling reaction to produce high-MW functionalized SBRs, and to determine the coupling number of the functionalized SBRs depending on the type of the coupling reagents. The resulting MWD of the SBR samples prepared by the different coupling reagents (SnCl(4) and a polydimethylsiloxane compound) were compared. PMID:17343864

Bang, Dae Young; Shin, Da Young; Lee, Seunghwa; Moon, Myeong Hee

2007-02-24

270

Investigation on the early and late stage phase-separation dynamics of poly(methyl methacrylate)\\/poly(?-methyl styrene- co-acrylonitrile) blends through rheological and scattering functions  

Microsoft Academic Search

The phase-separation behavior of poly(methyl methacrylate)\\/poly(?-methyl styrene-co-acrylonitrile) (PMMA\\/?-MSAN) blends with two different compositions was studied by time-resolved small angle light scattering (SALS) in the spinodal decomposition (SD) regime from 160 to 210°C. The rheological function (WLF-like equation) was introduced into the processing of light scattering data. It was found that the WLF-like equation was applicable to describe the temperature dependence

Min Zuo; Mao Peng; Qiang Zheng

2005-01-01

271

Nanostructured poly(urethane)s and poly(urethane-urea)s from reactive solutions of poly[styrene- b-butadiene- b-(methyl methacrylate)]-triblock copolymers  

Microsoft Academic Search

Poly[Styrene-b-Butadiene-b-(Methyl Methacrylate)], SBM triblock copolymers have been incorporated in different polyurethane, PU formulations in order to prepare nanostructured materials. Macrodiols used for PU synthesis were based on a central bis-phenol A, BPA unit with two hydroxyl-terminated oligo(oxypropylene), BPA-POx or oligo(oxyethylene), BPA-EO chains with varying lengths. The initial solubility of the three blocks and the rheological behavior of the solutions in

Boris Jaffrennou; Julien Portal; Françoise Méchin; Jean-Pierre Pascault

2008-01-01

272

Effect of processing parameters on electrical resistivity and thermo-sensitive properties of carbon-black\\/styrene–butadiene–rubber composite membranes  

Microsoft Academic Search

Carbon-black-filled conducting composite membranes were prepared by using styrene–butadiene–rubber as matrices and incorporating with some organic crystals (2,6-di-tert-butyl-4-methyl phenol). A number of composite membranes exhibited a thermo-sensitive property which corresponded to a positive temperature coefficient (PTC) effect. It was found that processing parameters strongly affected the microstructure of composite membranes and in turn, the resistivity of membranes as well as

Ying Wan; Chuanxi Xiong; Jianying Yu; Dijiang Wen

2005-01-01

273

Composition effect on the core–shell morphology and mechanical properties of ternary polystyrene\\/styrene–butadiene rubber\\/polyethylene blends  

Microsoft Academic Search

The morphology of ternary polystyrene\\/styrene–butadiene rubber\\/polyethylene (PS\\/SBR\\/PE) blends has been investigated in the limits of a constant content of the major component (PS; 75wt%) while changing the weight ratio of the two minor constitutive polymers. A core–shell structure for the dispersed phase has been predicted from the spreading coefficients and observed by transmission electron microscopy. Actually, upon increasing the relative

I Luzinov; K Xi; C Pagnoulle; G Huynh-Ba; R Jérôme

1999-01-01

274

Influence of storage time and temperature and silane coupling agent on bound rubber formation in filled styrene–butadiene rubber compounds  

Microsoft Academic Search

Bound rubber reflects the filler–polymer interactions involving physical adsorption, chemisorption, and mechanical interaction. For silica-filled rubber compounds, silane coupling agent is used to improve the filler dispersion. In the present work, variation of the bound rubber content with the storage time was studied using styrene–butadiene rubber (SBR) compounds filled with silica or carbon black. Influence of the silane content on

Sung-Seen Choi

2002-01-01

275

Effect of silane coupling agent on vulcanization, network structure, polymer-filler interaction, physical properties and failure mode of mica-filled styrene-butadiene rubber  

Microsoft Academic Search

Physical properties of composites from mica and styrene-butadiene rubber (SBR) have been studied with special reference to the effect of silane coupling agent (A-174) in the compound. Tensile and tear properties increase with the addition of mica. The increase of tensile properties in more pronounced in the case of silane-treated mica. Silane treatment also raises the volume fraction of rubber

S. Debnath; S. K. De; D. Khastgir

1987-01-01

276

Preparation and Electrochemical Characterization of Monovalent Ion Selective Poly (Vinyl Chloride)-blend-Poly (Styrene-Co-butadiene) Heterogeneous Cation Exchange Membrane Coated with Poly (Methyl Methacrylate)  

Microsoft Academic Search

In this research, polyvinylchloride\\/ styrene-butadiene-rubber blend heterogeneous cation exchange membranes were prepared by solution casting technique using tetrahydrofuran as solvent and cation exchange resin powder as functional groups agent. Poly methyl methacrylate (PMMA) was also employed as membrane surface modifier by emulsion polymerization technique to improve the membrane selectivity and anti-fouling property. The effect of used emulsion composition on properties

S. M. Hosseini; S. S. Madaeni; H. Asiani; A. R. Heidari

2012-01-01

277

Degradation of carboxylated styrene butadiene rubber based water born paints: Part 2 – Models to predict UV stability and water absorption through central composite design  

Microsoft Academic Search

Central composite experimental design methods have been used to examine the simultaneous effects of talc (Viaton Viatalc® 30), titanium dioxide (modified Rutile, Tioxide® TR92) and additional hindered phenolic stabiliser (Aquanox® L, a 50% w\\/w aqueous dispersion of Winstay® L) on the water uptake and UV stability of composite films based on a carboxylated styrene butadiene rubber (c-SBR) latex. The talc

Elena Jubete; Christopher M. Liauw; Norman S. Allen

2007-01-01

278

Use of rice husks as potential filler in styrene butadiene rubber\\/linear low density polyethylene blends in the presence of maleic anhydride  

Microsoft Academic Search

In the present study, rice husks filled styrene butadiene rubber (SBR)\\/linear low density polyethylene (LLDPE) 50\\/50 blends with a compatibilizer, maleic anhydride (MAH) were prepared using a brabender plasti-corder. Virgin SBR\\/LLDPE blend was also prepared. The physico-mechanical as well as dielectric properties were investigated. Increasing MAH concentrations in SBR\\/LLDPE blends resulted in an increase in the tensile strength, elongation at

A. I. Khalf; A. A. Ward

2010-01-01

279

Effects of sealed pressing and ozonization on properties of styrene-butadiene rubber and polyethylene glycol adhesive bonded board produced by two-stage pressing  

Microsoft Academic Search

Boards were produced by using SP adhesive, which contains styrene-butadiene rubber and polyethylene glycol as major constituents.\\u000a The use of polyethylene in place of clay, which is also a generally used constituent of SP adhesive, was confirmed to improve\\u000a board properties. In general, the properties of boards are poorer when produced by two-stage pressing, in which mats are first\\u000a processed

Hideaki Korai; Nan Ling; Atsushi Sumida; Osamu Yasuda; Takayoshi Osada

2010-01-01

280

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

281

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

282

Kinetic analysis of thermal degradation of recycled polycarbonate\\/acrylonitrile–butadiene–styrene mixtures from waste electric and electronic equipment  

Microsoft Academic Search

The study of properties in waste polymeric materials is important for a further recycling and eventual reuse. The determination of thermal properties of PC–ABS mixtures obtained from waste electric and electronic equipment (WEEE) by using thermogravimetric analysis (TGA) has been carried out in this work. Kinetic parameters, such as apparent activation energies, have been calculated by using the autocatalytic model,

R. Balart; L. Sánchez; J. López; A. Jiménez

2006-01-01

283

Sampling and Analysis of Volatile Organic Compounds Evolved During Thermal Processing of Acrylonitrile Butadiene Styrene Composite Resins  

Microsoft Academic Search

The evaluation of emissions of volatile organic compounds (VOCs) during processing of resins is of interest to resin manufacturers and resin processors. An accurate estimate of the VOCs emitted from resin processing has been difficult due to the wide variation in processing facilities. This study was designed to estimate the emissions in terms of mass of emitted VOC per mass

D. A. Contos; M. W. Holdren; D. L. Smith; R. C. Brooke; V. L. Rhodes; M. L. Rainey

1995-01-01

284

Mechanical properties and electrical conductivity of carbon-nanotube filled polyamide-6 and its blends with acrylonitrile\\/butadiene\\/styrene  

Microsoft Academic Search

Composites of polyamide-6 and carbon nanotubes (NT) have been prepared on a corotating twinscrew extruder. It is shown by transmission electron microscopy (TEM) that the nanotubes are dispersed homogeneously in the polyamide-matrix. The electrical conductivity of these composites was analyzed and compared to carbon black filled polyamide-6. It is found that the NT-filled polyamide-6 shows an onset of the electrical

Olaf Meincke; Dirk Kaempfer; Hans Weickmann; Christian Friedrich; Marc Vathauer; Holger Warth

2004-01-01

285

21 CFR 177.1820 - Styrene-maleic anhydride copolymers.  

Code of Federal Regulations, 2013 CFR

...Styrene-maleic anhydride copolymer modified with butadiene, (CAS Reg. No. 27288-99-9) containing...by weight and not more than 20 percent styrene-butadiene and/or butadiene rubber units by weight; for use (except...

2013-04-01

286

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

SciTech Connect

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

Chen, K.S.; Yeh, R.Z. [National Sun Yat-Sen Univ., Kaohsiung (Taiwan, Province of China). Inst. of Environmental Engineering; Chang, Y.R. [Yung-Ta Coll. of Technology and Commerce, Ping-Tung (Taiwan, Province of China). Dept. of Mechanical Engineering

1997-03-01

287

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

NASA Astrophysics Data System (ADS)

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

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

2004-01-01

288

Degree of Mechanochemical Devulcanization of Model Styrene-Butadiene Rubber Compounds Containing Different Amount of Poly-, Di- and Monosulphidic Bonds  

NASA Astrophysics Data System (ADS)

There have been significant attempts to devulcanize waste elastomers to facilitate reusing these valuable resources in applications requiring the unique properties of rubber. The difficulty in recycling of elastomers has traditionally been with devulcanizing the elastomer without comprising its properties due to degradation of main chains. This research aimed to devulcanize model styrene-butadiene rubber (SBR) compounds, which had various amounts of poly-, di- and monosulfidic crosslinks using a mechanochemical process. Three model compounds were prepared using SBR using a laboratory two-roll mill. They were then vulcanized in a compression molding press at 140r C. The prepared vulcanized compounds were then ground and devulcanized in an internal mixer using a chemical mixture at a constant rotor speed and temperature. The crosslink density of the compounds before and after the devulcanization was calculated using volume-swelling measurements. The obtained data was used to establish the correlation between crosslink density of the compounds and the degree of devulcanization. The results showed that mechanochemical devulcanization caused a significant decrease in the crosslink density of the compounds by breaking the sulfidic linkages. The break up of polysulfidic crosslinks was predominant, meaning that mechanochemical process selectively affected different types of crosslinks.

Sangari, Samra; Anita, Hill; Dumitru, Pavel

2004-03-01

289

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

PubMed

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

1990-06-01

290

Voltage-assisted asperity formation in styrene butadiene at room temperature: Cross-linking at the nanoscale  

NASA Astrophysics Data System (ADS)

Nanoscale surface modification is reported for styrene butadiene rubber using an electrically biased conducting atomic force microscope tip. Under appropriate bias conditions, the local electric field magnitude is of the order of 108-109Vm-1 , which is sufficiently large to initiate cross-linking in the rubber. Peaklike surface features, surrounded by a circular trough and a raised ring, are created by careful and controlled retraction of the biased tip. The features’ aspect ratios can be controlled by modifying the tip retraction protocol, tip geometry, and bias voltage. Typical feature dimensions reported here vary from approximately (0.5-10)-nm high and up to several hundreds of nanometer in diameter. Although the temperature of the rubber is above the glass transition and the rubber is in a viscous state, the features are stable over a period of several days once created—which is believed to be due to cross-linking of the rubber during feature formation. Modeling of the electric field distribution in the vicinity of the tip is presented, which strongly supports the assertion that the resulting nonuniform electric field induces nanostructure formation and initiates cross-linking. A mechanism is proposed whereby source material is redistributed in the proximity of the tip/surface region to form the observed features.

Rackaitis, M.; Kashyn, D.; Rowicka, E.; Paramonov, P. B.; Mallik, R. R.; Lyuksyutov, S. F.

2008-08-01

291

Styrene–butadiene rubber electrolytes modified with MgCl 2, NiCl 2, ZnCl 2, and active carbon  

Microsoft Academic Search

Styrene–butadiene rubber (SBR), as a solvent and repository of electric charges, starts to gain these properties after adding to SBR MgCl2 or NiCl2 or ZnCl2 in the form of methanol solution with addition of active carbon. Electrical conductivity of such an SBR-active carbon system with added MgCl2 or NiCl2 or ZnCl2 equals from 10?5 to 10?4 S cm?1 at a room

Tomasz Borowski

2008-01-01

292

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

SciTech Connect

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

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

1988-02-01

293

Contribution made by multivariate curve resolution applied to gel permeation chromatography-Fourier transform infrared data for an in-depth characterization of styrene-butadiene rubber blends.  

PubMed

We evaluate the contribution made by multivariate curve resolution-alternating least squares (MCR-ALS) for resolving gel permeation chromatography-Fourier transform infrared (GPC-FT-IR) data collected on butadiene rubber (BR) and styrene butadiene rubber (SBR) blends in order to access in-depth knowledge of polymers along the molecular weight distribution (MWD). In the BR-SBR case, individual polymers differ in chemical composition but share almost the same MWD. Principal component analysis (PCA) gives a general overview of the data structure and attests to the feasibility of modeling blends as a binary system. MCR-ALS is then performed. It allows resolving the chromatographic coelution and validates the chosen methodology. For SBR-SBR blends, the problem is more challenging since the individual elastomers present the same chemical composition. Rank deficiency is detected from the PCA data structure analysis. MCR-ALS is thus performed on column-wise augmented matrices. It brings very useful insight into the composition of the analyzed blends. In particular, a weak change in the composition of individual SBR in the MWD's lowest mass region is revealed. PMID:18935830

Ruckebusch, C; Vilmin, F; Coste, N; Huvenne, J P

2008-07-01

294

A lutetium allyl complex that bears a pyridyl-functionalized cyclopentadienyl ligand: dual catalysis on highly syndiospecific and cis-1,4-selective (co)polymerizations of styrene and butadiene.  

PubMed

A novel linked-half-sandwich lutetium-bis(allyl) complex [(C(5)Me(4)-C(5)H(4)N)Lu(?(3)-C(3)H(5))(2)] (1) attached by a pyridyl-functionalized cyclopentadienyl ligand was synthesized and fully characterized. Complex 1 in combination with [Ph(3)C][B(C(6)F(5))(4)] exhibited unprecedented dual catalysis with outstanding activities in highly syndiotactic (rrrr>99%) styrene polymerization and distinguished cis-1,4-selective (99%) butadiene polymerization, respectively. Strikingly, this catalyst system exhibited remarkable activity (396 kg copolymer?(mol(Lu) h)(-1)) for the copolymerization of butadiene and styrene. Irrespective of whether the monomers were fed in concurrent mode or sequential addition of butadiene followed by styrene, diblock copolymers were obtained exclusively, which was confirmed by a kinetics investigation of monomer conversion of copolymerization with time. In the copolymers, the styrene incorporation rate varied from 4.7 to 85.4 mol%, whereas the polybutadiene (PBD) block was highly cis-1,4-regulated (95%) and the polystyrene segment remained purely syndiotactic (rrrr>99%). Correspondingly, the copolymers exhibited glass transition temperatures (T(g)) around -107 °C and melting points (T(m)) around 268 °C; typical values for diblock microstructures. Such copolymers cannot be accessed by any other methods known to date. X-ray powder diffraction analysis of these diblock copolymers showed that the crystallizable syndiotactic polystyrene (syn-PS) block was in the toluene ? clathrate form. The AFM micrographs of diblock copolymer showed a remarkable phase-separation morphology of the cis-1,4-PBD block and syn-PS block. This represents the first example of a lutetium-based catalyst showing both high activity and selectivity for the (co)polymerization of styrene and butadiene. PMID:20967902

Jian, Zhongbao; Tang, Shijia; Cui, Dongmei

2010-12-17

295

A Comparative Study on Processing, Mechanical Properties, Thermo-oxidative Aging, Water Absorption, and Morphology of Rice Husk Powder and Silica Fillers in Polystyrene\\/Styrene Butadiene Rubber Blends  

Microsoft Academic Search

Rice husk powder (RHP) and silica-filled polystyrene (PS)\\/styrene butadiene rubber (SBR) composites were prepared by using the laboratory size internal mixer (Brabender Plasti-corder). The torque development, morphology, and mechanical properties such as tensile strength, elongation at break, Young modulus, and impact strength were studied. Water absorption and the effect of thermo-oxidative aging on tensile properties of composites were also examined.

H. Ismail; Z. Mohamad; A. A. Bakar

2003-01-01

296

Resolution of two-way data from on-line Fouriertransform Raman spectroscopic monitoring of the anionic dispersion polymerization of styrene and 1,3-butadiene by parallel vector analysis (PVA) and window factor analysis (WFA)  

Microsoft Academic Search

On-line Fourier-transform Raman spectroscopic monitoring of the anionic dispersion polymerization of styrene and 1,3-butadiene has been implemented with a noninvasive optic fiber Raman probe. After suitable pretreatment of the Raman spectra obtained, the resulting two-way data are analyzed using two self-modeling curve resolution (SMCR) techniques, parallel vector analysis (PVA) proposed in the preceding paper, as well as window factor analysis

Jian-Hui Jiang; Yukihiro Ozaki; Michael Kleimann; Heinz W Siesler

2004-01-01

297

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

298

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

2012-09-18

299

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

PubMed

An experimental investigation was performed to study the effect on the free volume of the advance of the cross-linking reaction in a copolymer of styrene butadiene rubber by sulfur vulcanization. The dynamic modulus and loss tangent were evaluated over samples cured for different times at 433 K by dynamic mechanical tests over a range of frequencies between 5 and 80 Hz at temperatures between 200 and 300 K. Using the William-Landel-Ferry relationship, master curves were obtained at a reference temperature of 298 K and the coefficients c(0)(1) and c(0)(2) were evaluated. From these parameters the dependence of the free volume on the cure time is obtained. Positron annihilation lifetime spectroscopy was also used to estimate the size and number density of free volume sites in the material. The spectra were analyzed in terms of continuous distributions of free volume size. The results suggest an increase of the lower free volume size when cross linking takes place. Both techniques give similar results for the dependence of free volume on the time of cure of the polymer. PMID:11863549

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

2002-01-15

300

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

NASA Astrophysics Data System (ADS)

An experimental investigation was performed to study the effect on the free volume of the advance of the cross-linking reaction in a copolymer of styrene butadiene rubber by sulfur vulcanization. The dynamic modulus and loss tangent were evaluated over samples cured for different times at 433 K by dynamic mechanical tests over a range of frequencies between 5 and 80 Hz at temperatures between 200 and 300 K. Using the William-Landel-Ferry relationship, master curves were obtained at a reference temperature of 298 K and the coefficients c01 and c02 were evaluated. From these parameters the dependence of the free volume on the cure time is obtained. Positron annihilation lifetime spectroscopy was also used to estimate the size and number density of free volume sites in the material. The spectra were analyzed in terms of continuous distributions of free volume size. The results suggest an increase of the lower free volume size when cross linking takes place. Both techniques give similar results for the dependence of free volume on the time of cure of the polymer.

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

2002-02-01

301

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

PubMed

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

1990-06-01

302

The Effect of Electron Beam (EB) Irradiation in Presence of TMPTA on Cure Characteristics and Mechanical Properties of Styrene Butadiene Rubber\\/Recycled Acrylonitrile-Butadiene Rubber (SBR\\/NBRr) Blends  

Microsoft Academic Search

The effect of electron beam (EB) irradiation on the cure characteristics and mechanical properties of unirradiated and irradiated SBR\\/NBRr blends were investigated. The SBR\\/NBRr blends were prepared at 95\\/5, 85\\/15, 75\\/25, 65\\/35, and 50\\/50 blend ratio with and without the presence of a polyfunctional monomer, trimethylolpropane triacrylate (TMPTA). Results indicated that the scorch time t2, cure time t90 and minimum

N. Z. Noriman; H. Ismail; C. T. Ratnam; A. A. Rashid

2010-01-01

303

Health Assessment of 1, 3-Butadiene (October 2002).  

National Technical Information Service (NTIS)

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 ...

2002-01-01

304

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

Code of Federal Regulations, 2013 CFR

...with ethyl acrylate and/or styrene and/or methacrylic acid, and the copolymer subsequently reacted with formaldehyde and butanol Butadiene-acrylonitrile copolymer Butadiene-acrylonitrile-styrene terpolymer Butyl rubber N,N...

2013-04-01

305

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...

306

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

2007-06-03

307

Degradation of Acrylonitrile Polymers.  

National Technical Information Service (NTIS)

This article considers in detail the chemical reactions which occur in acrylonitrile polymers during: (1) the 'low-temperature' thermal (below 150C), oxidative, and nucleophilic induced degradation that is so important to avoid in forming textile fibers; ...

L. H. Pebbles

1975-01-01

308

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...

309

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

310

Polymerisation process for acrylonitrile  

Microsoft Academic Search

An improved method is described for the production of a ; polyacrylonitrile solution from which fibers may be spun. Earlier methods for ; polymerizing acrylonitrile have required the use of catalysts in order to obtain ; satisfactory spinning solutions, and the polymer thus produced incorporates ; traces of the catalyst, which is not only expensive, but also promotes ; degradation

I. G. Murgulescu; T. O. Oncescu; I. I. Vlagiu

1973-01-01

311

Bromination of some styrene-diene block copolymers  

Microsoft Academic Search

The bromine addition at the polydiene block double bonds of a radial styrene-butadiene (SBS) and a linear styrene-isoprene (SIS) block copolymer (thermoplastic elastomers), in tetrahydrofurane solution at 0 °C, has been investigated by IR spectroscopy. In both cases the bromine reacts exclusively with the polydiene middle block double bonds; the polystyrene blocks are unaffected. The bromine reacts preferentially with the

N. Stribeck

1997-01-01

312

Health Assessment Document for Acrylonitrile.  

National Technical Information Service (NTIS)

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 organic...

D. K. Basu J. Santodonato M. W. Neal R. H. Sugatt R. S. Hsu

1983-01-01

313

Exposure to butadiene and lymphatic and hematopoietic cancer.  

PubMed

Several follow-up studies have assessed lymphatic and hematopoietic cancer (LHC) among workers with potential exposure to 1,3-butadiene. These investigations of the styrene-butadiene rubber and butadiene manufacturing industries include 17,448 subjects with an average of 22 years of follow-up. When the results of the studies are combined, the total number of observed leukemia deaths is 36, compared with 34.2 expected. The standardized mortality ratio is 1.05, with a 95% confidence interval of 0.74-1.46. These null data are compatible with, at most, a weak positive association of butadiene with leukemia. There is little evidence of an association with other forms of LHC among styrene-butadiene rubber workers (55 observed/50.1 expected deaths). Only one study has evaluated directly the relation between estimates of butadiene exposure and leukemia, and this investigation reports a positive association. The result, however, cannot be interpreted as causal, because there is no satisfactory explanation for the marked discrepancy between this case-control study and a null follow-up study based on the same subjects. Overall, the epidemiologic evidence does not provide persuasive evidence that butadiene exposure causes LHC. PMID:8452913

Cole, P; Delzell, E; Acquavella, J

1993-03-01

314

Linear viscoelasticity of styrenic block copolymers–clay nanocomposites  

Microsoft Academic Search

In this work, the rheological behavior of block copolymers with different morphologies (lamellar, cylindrical, spherical,\\u000a and disordered) and their clay-containing nanocomposites was studied using small amplitude oscillatory shear. The copolymers\\u000a studied were one asymmetric starblock styrene–butadiene–styrene copolymer and four styrene–ethylene\\/butylenes–styrene copolymers\\u000a with different molecular architectures, one of them being modified with maleic anhydride. The nanocomposites of those copolymers\\u000a were prepared

Danilo Justino Carastan; Nicole Raymonde Demarquette; Alexandre Vermogen; Karine Masenelli-Varlot

2008-01-01

315

Thermal cracking of butadiene  

SciTech Connect

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

Duisters, H.A.M. (DSM Research, Geleen (Netherlands))

1994-01-01

316

Butadiene and isoprene: future studies and implications.  

PubMed

Based on the symposium on 1,-3-butadiene and isoprene at Blaine, WA, the following areas need special attention for future research: (1) discrepancies in PBPK modelling by different groups should be solved; (2) potential human target tissues (bone marrow, lymphatic tissues) should be better integrated into PBPK models; (3) the present rapid development in research on human genetic interindividual differences in 1,3-butadiene metabolism and toxicity should be supported, with the intention to determine human subgroups of differential susceptibility and to integrate this into epidemiological research; (4) further validation of past exposures in the epidemiologically studied corhorts is very desirable; (5) the question of possibly differential effects in 1,3-butadiene monomer workers and styrene-butadiene-rubber workers (lymphosarcoma?, reticulosarcoma?, leukemia?) should be resolved in future epidemiological studies; (6) potential human target tissues (bone marrow, lymphatic tissues) should be better integrated into PBPK modelling; (7) risk assessment of isoprene and, by quantitative comparison, of 1,3-butadiene in humans should consider the physiological background of endogenous isoprene production; and (8) future research on biomarkers should establish practical tools for medical surveillance of presently exposed persons. PMID:8901925

Bolt, H M

1996-10-28

317

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.

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

1993-01-01

318

Carcinogenicity of 1,3-butadiene.  

PubMed

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

1993-04-01

319

AMBIENT ACRYLONITRILE LEVELS NEAR MAJOR ACRYLONITRILE PRODUCTION AND USE FACILITIES  

EPA Science Inventory

In this study, ambient acrylonitrile (AN) levels were measured in the vicinity of two major AN user facilities and two major AN production facilities. Approximately 100 duplicate air samples were collected on charcoal sorption tubes at different locations at or beyond the fenceli...

320

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

SciTech Connect

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

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

1986-04-01

321

21 CFR 177.1635 - Poly(p-methylstyrene) and rubber-modified poly(p-methyl-styrene).  

Code of Federal Regulations, 2013 CFR

...Rubber-modified poly(p -methylstyrene) (CAS Reg. No. 33520-88-6) polymer produced by combining styrene-butadiene copolymer and/or polybutadiene with poly(p -methylstyrene), either during or after polymerization of the...

2013-04-01

322

Sampling and analysis of butadiene at a synthetic rubber plant  

SciTech Connect

Butadiene emission samples were collected from the process vent stream of a plant manufacturing synthetic rubber from styrene and butadiene. On-site analysis of samples was performed using a gas chromatograph equipped with a flame ionization detector. The precision of butadiene concentrations was determined from simultaneous samples collected at a nominal sampling rate of 0.050 L/min, rather than at the recommended sampling rate of 0.5 L/min. In addition, simultaneous samples were collected at both 0.20 L/min and 0.050 L/min and analyzed to determine if the mean values or precisions of the measured concentrations were influenced by the sampling rate. Acceptable precision was observed at both sampling rates, and the mean values and precisions of butadiene levels determined were statistically equal for simultaneous samples.

Goodrich, J.D.; DeWees, W.G.; Segall, R.R.

1989-01-01

323

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,...

324

Occupational-hazard control options for chemical process unit operations, preliminary survey report for the site visit of October 19, 1981 to Borg-Warner Chemicals Woodmar Plant, Washington, West Virginia  

Microsoft Academic Search

A survey was conducted to investigate techniques used to control worker exposures to acrylonitrile at the Woodmar Facility of the Borg-Warner Chemicals Company in Washington, West Virginia. At this facility, many products were made including acrylonitrile butadiene styrene (ABS) resins, methyl-methacrylate butadiene styrene resins, and other modifier and reinforcing resins used to process other polymers. Personal protective equipment was used

Telesca

1982-01-01

325

Performance Characteristics of Abs Resins Prepared By Melt Blending  

Microsoft Academic Search

ABS plastics, as the name indicates, are a family of thermoplastics which are composed of acrylonitrile (A), butadiene (B), and styrene (S). The properties of ABS are determined by these constituent monomers: acrylonitrile imparts chemical and heat resistance; styrene imparts rigidity, hardness, and process-ability; and butadiene imparts impact strength. By varying the proportions of these constituents and the manner by

J. W. F. Bley; S. A. H. Mohammed

1983-01-01

326

Effect of grafting cellulose acetate and methylmethacrylate as compatibilizer onto NBR\\/SBR blends  

Microsoft Academic Search

Compatibilizer is used for improving of processability, interfacial interaction and mechanical properties of polymer blends. In this study acrylonitrile butadiene rubber (NBR) and styrene-butadiene rubber (SBR) blends were compatibilized by a graft copolymer of acrylonitrile butadiene rubber (NBR) grafted with cellulose acetate (CA) i.e. (NBR-g-CA) and acrylonitrile butadiene rubber (NBR) grafted with methylmethacrylate i.e. (NBR-g-MMA). Compatibilizers were prepared by gamma

A. I. Khalf; D. E. El. Nashar; N. A. Maziad

2010-01-01

327

Mortality among workers at a butadiene facility.  

PubMed

Several studies of styrene-butadiene rubber (SBR) workers have reported excess cancers at various sites; however, little could be concluded concerning specific etiologic agents because of the multiple exposures encountered by these groups. The current study examined cause-specific mortality in a cohort of 2,586 male workers employed for at least 6 months between 1943 and 1979 in a butadiene manufacturing plant that supplied butadiene to two SBR plants. Standardized mortality ratios were calculated using national (NSMR) and local (LSMR) comparison populations. The all-cause NSMR was 80 (p less than 0.05) and the all-cancer NSMR was 84; the corresponding LSMRs were 96 and 76 (p less than 0.05). No significant excesses were observed for any cause of death except lymphosarcoma and reticulum cell sarcoma (NSMR = 235). When the cohort was subdivided into routine, nonroutine, and low-exposure groups, the SMRs were consistently elevated for this cause of death in all three groups. However, direct comparisons between each of the two exposure groups and the low-exposure group were inconsistent. This suggests butadiene may not be responsible for the excess, but the association deserves close attention in future studies. PMID:3674024

Downs, T D; Crane, M M; Kim, K W

1987-01-01

328

A Study of FTIR, Thermal Properties and Natural Weathering Test on NBRVirgin\\/Recycled with SBR Blends  

Microsoft Academic Search

The effects of styrene butadiene rubber\\/virgin acrylonitrile butadiene rubber (SBR\\/NBRv) blends and styrene butadiene rubber\\/recycled acrylonitrile butadiene rubber (SBR\\/NBRr) blends on properties such Fourier transform infrared (FTIR), thermal gravimetric analysis (TGA) and differential scanning calorimetry (DSC) were carried out. Results indicated that, based on intensity of amine peak from FTIR at 85\\/15 blend ratio (R15) revealed optimum formation of crosslink

Nik Noriman Zulkepli; Hanafi Ismail

2012-01-01

329

Occupational contact dermatitis due to acrylonitrile.  

PubMed

Within DSM Chemicals BV, a producer of acrylonitrile, skin complaints are frequent. The majority of these are of an irritant nature, while a smaller portion is based on acquired allergies. Allergological examination revealed 5 employees with an allergy to acrylonitrile. 1 of these subjects also developed paraesthesiae in the skin sites affected, a finding not previously described for acrylonitrile. In the guinea pig maximization test (GPMT), acrylonitrile showed strong allergenic potential. For prevention and treatment of contact allergologic disorders, close cooperation between occupational health officer, dermatologist and toxicologist in chemical companies is recommended. PMID:1828409

Bakker, J G; Jongen, S M; Van Neer, F C; Neis, J M

1991-01-01

330

Dynamics of deuterated polystyrene-protonated butadiene diblock copolymer micelles by neutron spin echo  

Microsoft Academic Search

We report on neutron spin-echo (NSE) measurements on deuterated styrene-protonated butadiene diblock copolymer micelles in deuterated n-decane to investigate the dynamics of butadiene blocks in the corona. Before the NSE measurements, we performed small-angle neutron-scattering (SANS) measurements on the micelles to evaluate the structure to give a basis for the discussion of the dynamics. In the SANS study, we have

T. Kanaya; M. Monkenbusch; H. Watanabe; M. Nagao; D. Richter

2005-01-01

331

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...

332

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...

333

Status Assessment of Toxic Chemicals: Acrylonitrile.  

National Technical Information Service (NTIS)

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 d...

D. R. Tierney T. R. Blackwood G. E. Wilkins

1979-01-01

334

Source Assessment: Acrylonitrile Manufacture (Air Emissions).  

National Technical Information Service (NTIS)

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 p...

T. W. Hughes D. A. Horn

1977-01-01

335

Assessment of 1,3-butadiene epidemiology studies  

SciTech Connect

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. 22 refs.

Ott, M.G. (BASF Corporation, Parisppany, NJ (USA))

1990-06-01

336

Assessment of 1,3-butadiene epidemiology studies.  

PubMed

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

1990-06-01

337

Biological monitoring for mutagenic effects of occupational exposure to butadiene.  

PubMed

The use of biological markers in the evaluation of human exposure to hazardous agents has increased rapidly in recent years. Because 1,3-butadiene is a mutagenic carcinogen, existing occupational levels of exposure may be appropriately evaluated using somatic cell mutation as a biomarker. Previously, we have described a biomarker study of workers in a butadiene monomer plant (Ward et al., 1994). We now report results from a second study of the same group of workers, conducted after plant modernization, and present preliminary results from a study of exposures in a styrene butadiene rubber (SBR) plant. Air levels of butadiene were determined using either charcoal tubes with air pumps or passive badge dosimeters. The quantity of a butadiene metabolite in the urine was used as a biomarker of exposure and the mutagenic effects of exposure were measured using the autoradiographic hprt mutant lymphocyte assay. In all three studies, the frequencies of hprt mutants were significantly elevated in workers from the areas of highest exposure when compared to workers from lower exposure areas or non-exposed subjects. The concentration of the urinary metabolite was significantly increased in high-exposed workers in the first study of monomer plant workers but not in the second. In the first monomer plant study, historical air concentrations of butadiene were higher in the production units than in the central control unit. While concurrent determined air concentrations were not elevated in the second monomer plant study, they were elevated in high exposure areas in the SBR plant study. Mutant frequencies in the lower-exposure and the non-exposed groups were consistent with historical values for non-smoking individuals who were not exposed to known mutagens. The use of biomarkers, including the hprt mutant lymphocyte assay, may be of great value in determining an appropriate occupational exposure limit for butadiene. PMID:8901886

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

1996-10-28

338

Measurement of styrene-7,8-oxide and other oxidation products of styrene in air.  

PubMed

Styrene-7,8-oxide (SO) is generated at low concentrations from the oxidation of styrene during the processing of reinforced plastics. Since exposure to SO has important health implications, we developed air sampling and analytical methods to measure low levels of airborne SO in the presence of styrene and its other oxidation products, namely phenylacetaldehyde (PAA) and acetophenone (AP). Both active and passive air monitors were used. The active sampling method, which employed adsorption on Tenax, was suitable for measuring SO, PAA and AP but had limited capacity for styrene due to breakthrough. The passive monitor employed a carbon adsorbent and was suitable for measurement of styrene and SO but not PAA and AP due to poor recovery. After sampling, the analytes were extracted from the adsorbents with ethyl acetate and measured by gas chromatography with flame ionization detection or mass spectrometry. By maintaining the injection port at 70 degrees C, the thermal rearrangement of SO to PAA was minimized. Recovery of styrene and SO from the passive monitor depended upon loading and was corrected by linearization of the Freundlich isotherm. The limits of detection for SO, PAA, and AP were 0.2 ppb using the active monitor, and for SO was 1 ppb using the passive monitor. The sampling precision for SO (RSD from personal measurements) was 5.0% for the passive monitor and was 13.4% for the active monitor over a range of exposures from 5-150 ppb. The corresponding precision for styrene was 5.3% for the passive monitor for levels ranging from 1.2 to 104 ppm. Measurements of 235 personal exposures with the active monitor in 12 facilities manufacturing fiberglass-reinforced plastics (FRP) showed that levels of AP and PAA were below 7.8 ppb and 5 ppb, respectively. In contrast, SO averaged 30.4 ppb (SE=2.4) in these FRP facilities, ranging from below 0.2 ppb to 190 ppb. The active monitor was also used to detect airborne SO at levels of approximately equals 1 ppb in one facility manufacturing styrene butadiene rubber, suggesting that SO is generally present during the polymerization of styrene. Personal passive monitoring in the 12 FRP facilities (n = 657) revealed mean concentrations of styrene ranging between 1.8 and 55.4 ppm, and for SO between 1.7 and 62.6 ppb. The ratio of the mean styrene level to the mean SO level varied between 449:1 and 1,635:1 among the 12 FRP facilities. PMID:11253028

Tornero-Velez, R; Waidyanatha, S; Echeverria, D; Rappaport, S M

2000-04-01

339

Human exposure to styrene  

Microsoft Academic Search

An industrial hygiene study of 10 glassfiber reinforced polyester plants (including 90 workers) was undertaken to investigate the styrene exposure in this industry and to estimate biological limit values (BLV's) for the urinary metabolites of styrene: mandelic (MA) and phenylglyoxylic acids (PGA). Time weighted average (TWA) styrene exposures were found ranging from 2 to 200 ppm. The urinary elimination of

Michel P. Guillemin; Daniel Bauer; Brigitte Martin; Alfio Marazzi

1982-01-01

340

Occupational exposure to butadiene, isoprene and chloroprene.  

PubMed

Workers are exposed to butadiene, isoprene and chloroprene in the manufacture of these monomers and in their use in the production of various elastomers. These include styrene butadiene rubber, polybutadiene, polyisoprene, butyl rubber and neoprene. Monomer production and extraction are done in typical closed chemical process units where low background levels of the monomers are the result of minor leaks in valves and pumps. Occasionally, higher levels occur as a result of planned or unplanned events that cause releases. Polymer production is also a closed process, but the occasional clogging of pipes and equipment with polymer requiring maintenance operations where some release is likely occurs much more often than for monomer production. For this reason, exposure levels are generally higher on polymer production units. Polymer finishing is essentially an open process, but almost all monomer should have been stripped from the polymer before finishing. Where small amounts of solvents or monomers remain in the polymer and are volatilized in finishing, they are captured by vapor control systems. As a result, exposures in finishing are typically low. Measured levels of exposure in recent years are presented. In general, modern levels of exposure are well below OSHA, ACGIH and other applicable limits. Few measurements were made prior to the 1970s, but epidemiological estimates made by modeling suggest that levels could have been quite high in the 1940s and 1950s. In these years, manual reactor cleaning was common, and pumps often leaked. PMID:11397391

Lynch, J

2001-06-01

341

Dithiocarbamates as potential confounders in butadiene epidemiology.  

PubMed

Hematopoietic neoplasms associated with occupational exposure to 1,3-butadiene (BD) have been the subject of controversy. This has largely been due to the inconsistent results of epidemiology studies that have reported alternatively no or weak associations between exposure to BD and hematopoietic neoplasms. Moreover, the specificity of association of BD exposure with individual leukemia types remains unclear. In addition, a distinct difference in the pattern of leukemia risk has been observed between workers employed in BD monomer production and those involved in styrene-butadiene rubber (SBR) production: with no increase in leukemia risk observed for exposure to BD monomer alone. These observations are consistent with an increase in leukemia risk associated with the SBR process but not BD monomer and suggest the possibility that the increase may be the result of exposure to confounding factors previously not considered. In this regard, evidence is accumulating to suggest that SBR studies may be confounded by the presence of an important class of biologically active chemicals employed in the rubber industry, dithiocarbamates. The hematotoxicity and immunotoxicity of dithiocarbamates have been implicated in a wide range of clinical, animal and molecular studies, and an extremely high concordance exists between the risk of developing leukemia in SBR production and opportunity for exposure to this class of agents. Based on these findings additional studies on the epidemiology, carcinogenesis and molecular biology of dithiocarbamates are clearly warranted. PMID:9600335

Irons, R D; Pyatt, D W

1998-04-01

342

The effects of clay on the thermal degradation behavior of poly(styrene- co-acrylonitirile)  

Microsoft Academic Search

The thermal degradation of poly(acrylonitrile-co-styrene) (SAN) and its clay nanocomposites were studied using TGA\\/FTIR and GC\\/MS. Virgin SAN degrades by chain scission followed by ?-scission, producing monomers, dimers and trimers. The degradation pathway of SAN in clay nanocomposites contains additional steps; extensive random chain scission, evolving additional compounds having an odd number of carbons in the chain backbones, and radical

Bok Nam Jang; Charles A. Wilkie

2005-01-01

343

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

344

Durability of Styrene-Butadiene latex modified concrete  

Microsoft Academic Search

The durability of reinforced concrete structures represents a major concern to many investigators. The use of latex modified concrete (LMC) in construction has urged researchers to review and investigate its different properties.This study is part of a comprehensive investigation carried on the use of polymers in concrete. The main objective of this study to investigate and evaluate the main durability

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

1997-01-01

345

Nucleation and growth kinetics in diblock styrene-butadiene  

Microsoft Academic Search

Time-resolved small-angle x-ray scattering has been used to study the phase transformation kinetics of a thermally quenched, asymmetric, diblock copolymer. The roles played by homogeneous and heterogeneous nucleation in the microdomain ordering process are considered through comparison of results from pure samples and samples doped with impurities. This crystallization process is unique in that it involves constituent particles (microdomains) that

R. F. Shannon Jr; M. G. Glavicic; M. A. Singh

1994-01-01

346

Evaluation of tearing energies in styrene-butadiene rubbers  

Microsoft Academic Search

Tearing energies were obtained on samples removed from commercial tank-track pads and on a series of SBR laboratory formulations in which the carbon-black content varied from 0 to 40 wt %. The commercial materials were tested at a strain rate of 10⁻¹\\/s with temperatures ranging from 22 to 140°C. The laboratory materials were tested also at both lower and higher

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

1985-01-01

347

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...

348

Anionic polymerization of isoprene, butadiene and styrene with 3-dimethylaminopropyllithium  

Microsoft Academic Search

The synthesis of dimethylaminopropyllithium (DMAPLi), from the corresponding chloride and lithium metal, by using high-vacuum techniques, is described. DMAPLi was purified by crystallization under vacuum. Gas chromatography-mass spectrometry analysis of the purified product, after neutralization with degassed methanol, showed the existence of ? 2% impurities. The most important of these impurities (? 1.5%) were tetramethylhexamethylenediamine and dimethylaminohex-1-ene. By using DMAPLi

Patrizia Dardani; Francesco Morandi

1995-01-01

349

Evaluation of tearing energies in styrene-butadiene rubbers  

SciTech Connect

Tearing energies were obtained on samples removed from commercial tank-track pads and on a series of SBR laboratory formulations in which the carbon-black content varied from 0 to 40 wt %. The commercial materials were tested at a strain rate of 10/sup -1//s with temperatures ranging from 22 to 140/sup 0/C. The laboratory materials were tested also at both lower and higher strain rates and at -20/sup 0/C. We evaluated the effect of temperature, strain rate, and carbon-black content on tearing energy, failure stress, and failure strain. The results, including the shape of the stress-strain curves, are discussed in terms of viscoelasticity, uncoiling of the long molecular chains, carbon-black rubber interactions, and knotty tearing. In the absence of knotty tearing and for carbon-black contents of 20 wt % or less the tearing energy, the failure stress, and failure elongation increased with either a decrease in temperature or an increase in carbon-black content. With the first appearance of knotty tearing, which occurred at 20 to 25 wt % carbon black, large increases in tearing energy and failure strength were obtained. Between 25 and 40 wt % carbon black both tearing energy and failure stress varied irregularly with either the carbon-black content or temperature. The trends obtained with the commercial materials are consistent with those exhibited by the laboratory formulations in the 25 to 40% carbon-black range. Results for the 35-wt % formulation fell within the range of results obtained for the commercial materials.

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

1985-06-25

350

Adhesion of flame-treated polyolefins to styrene butadiene rubber  

Microsoft Academic Search

Samples of polyethylene and polypropylene have been submitted to repeated short duration (75 ms) flame treatments, at optimum flaming conditions. Surface energies of untreated and flamed specimens were determined by liquid contact angle measurements. It appears that the surface energy of polyethylene increases much more than that of polypropylene after flame treatment. The flamed polymer surfaces were further examined by

E. Papirer; D. Y. Wu; J. Schultz

1993-01-01

351

29 CFR 1910.1045 - Acrylonitrile.  

Code of Federal Regulations, 2010 CFR

...can be found as a liquid or vapor, and can...Colorless to pale yellow liquid with a pungent odor...eye contact with liquid AN is prohibited...Acrylonitrile can affect your body if you inhale the...your skin. B. Effects of...

2010-07-01

352

29 CFR 1910.1045 - Acrylonitrile.  

Code of Federal Regulations, 2010 CFR

...can be found as a liquid or vapor, and can...Colorless to pale yellow liquid with a pungent odor...eye contact with liquid AN is prohibited...Acrylonitrile can affect your body if you inhale the...your skin. B. Effects of...

2009-07-01

353

Wastewater Treatment of MTC Acrylonitrile Plant.  

National Technical Information Service (NTIS)

We selected a wet oxidation process as a method of treating COD and HCN in acrylonitrile plant waste water efficiently and simultaneously and in 1972 constructed a 670 m sup 3 /d wet oxidation treatment plant which has been working well since that time. (...

Y. Iwai

1976-01-01

354

Metabolism of acrylonitrile by Klebsiella pneumoniae  

Microsoft Academic Search

A gram-negative rod-shaped bacterium capable of utilizing acrylonitrile as the sole source of nitrogen was isolated from industrial sewage and identified as Klebsiella pneumoniae. The isolate was capable of utilizing aliphatic nitriles containing 1 to 5 carbon atoms or benzonitrile as the sole source of nitrogen and either acetamide or propionamide as the sole source of both carbon and nitrogen.

Mohamed S. Nawaz; Wirt Franklin; Warren L. Campbell; Thomas M. Heinze; Carl E. Cerniglia

1991-01-01

355

Mutagenicity, carcinogenicity, and teratogenicity of acrylonitrile  

Microsoft Academic Search

Acrylonitrile (AN) is an important intermediary for the synthesis of a variety of organic products, such as artificial fibres, household articles and resins. Although acute effects are the primary concern for an exposure to AN, potential genotoxic, carcinogenic and teratogenic risks of AN have to be taken seriously in view of the large number of workers employed in such industries

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

1999-01-01

356

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

357

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

358

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

Code of Federal Regulations, 2013 CFR

...3)(ii), (g)(4)(i), (g)(4)(iii) (except the dewatering step during polymerization of acrylonitrile/butadiene/styrene), and (g)(5). (iii) Industrial, commercial, and consumer activities. Requirements as...

2013-07-01

359

Toxicity of Pyrolysis Gases from Elastomers.  

National Technical Information Service (NTIS)

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 ru...

A. N. Solis C. J. Hilado D. A. Kourtides J. A. Parker K. L. Kosola

1977-01-01

360

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

Federal Register 2010, 2011, 2012, 2013

...polyethylene (PE), polyurethane (PU), and polyvinyl chloride (PVC). ISRI also mentions acrylonitrile styrene butadiene (ABS...000 tons; nylon (12.4%): 124,000-248,000 tons; PVC (7.9%): 79,000-158,000 tons; ABS...

2012-12-12

361

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

PubMed

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

Acquavella, J F

1990-06-01

362

Mortality update of workers exposed to acrylonitrile in The Netherlands.  

PubMed

To study the possible carcinogenic effects of acrylonitrile, we updated the follow up of a cohort of 2842 acrylonitrile workers. The comparison group consisted of 3961 workers from a nitrogen fixation plant. Industrial hygiene assessments quantified past exposure to acrylonitrile, 8-hour averages as well as peak exposure, the use of personal protective equipment, and exposure to other potential carcinogenic agents. Standardized mortality ratios were calculated to adjust for the effect of age distribution, length of follow up, and temporal changes in background mortality rates. Cumulative dose-effect relations were determined for 3 exposure categories and 3 latency periods. The results show that no cancer excess seems related to exposure to acrylonitrile. This additional follow up of a cohort of 2842 workers exposed to acrylonitrile further supports the notion that occupational exposures to acrylonitrile that have occurred in the past have not noticeably increased workers' cancer mortality rates. PMID:15247808

Swaen, Gerard M H; Bloemen, Louis J N; Twisk, Jan; Scheffers, Theo; Slangen, Jos J M; Collins, James J; ten Berge, Wil F J P

2004-07-01

363

21 CFR 177.1635 - Poly(p-methylstyrene) and rubber-modified poly(p-methyl-styrene).  

Code of Federal Regulations, 2010 CFR

...p -methylstyrene) and rubber-modified poly(p -methylstyrene...p -methylstyrene) and rubber-modified poly(p -methylstyrene... -methylstyrene. (2) Rubber-modified poly(p -methylstyrene...polymer produced by combining styrene-butadiene copolymer and/or...

2009-04-01

364

21 CFR 177.1635 - Poly(p-methylstyrene) and rubber-modified poly(p-methyl-styrene).  

Code of Federal Regulations, 2010 CFR

...p -methylstyrene) and rubber-modified poly(p -methylstyrene...p -methylstyrene) and rubber-modified poly(p -methylstyrene... -methylstyrene. (2) Rubber-modified poly(p -methylstyrene...polymer produced by combining styrene-butadiene copolymer and/or...

2010-01-01

365

PROVISIONAL ADVISORY LEVELS (PALs) FOR ACRYLONITRILE  

SciTech Connect

Application of PAL protocols was performed for acrylonitrile, as experimental data permitted. Human data were limited to inhalation exposures. The animal experimental data set for this chemical was robust for inhalation and oral studies, with the exception of appropriate data for inhalation 30-d, 90-d, and 2-yr PAL 3 values. PAL estimates were approved by the Expert Consultation Panel for Provisional Advisory Levels in October 2007. Oral 24-hr PALs for acrylonitrile are: PAL 1 = 7 mg/L; PAL 2 = 23 mg/L; and PAL 3 = 88 mg/L. Oral 30-d and 90-d PALs are: PAL 1 = 0.35 mg/L; PAL 2 = 7 mg/L; and PAL 3 = 17 mg/L. Oral 2-yr PALs are: PAL 1 = 0.35 mg/L; PAL 2 = 3.5 mg/L; and PAL 3 = 12 mg/L. Acrylonitrile inhalation PAL values for 24 hr exposure are: PAL 1 = 0.17 ppm; PAL 2 = 3.5 ppm; and PAL 3 = 5.1 ppm; the 30-d and 90-d inhalation exposure values are: PAL 1 = 0.15 ppm and PAL 2 = 0.60 ppm. The 2-yr inhalation values are: PAL 1 = 0.014 ppm and PAL 2 = 0.12 ppm. PAL 3 values for 30-d, 90-d, and 2-yr are not recommended due to insufficient data.

Goldhaber, Susan [Oak Ridge National Laboratory (ORNL); Dorman, David [College of Veterinary Medicine, North Carolina University; Gardner, Donald [Inhalation Toxicology Associates; Adeshina, Femi [U.S. Environmental Protection Agency; Ross, Robert Hord [ORNL

2009-01-01

366

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

367

Yield stress determination of styrene-butadiene-styrene triblock copolymer solutions  

Microsoft Academic Search

Conventional methods of yield stress determination involve extrapolation of shear stress data to zero shear rate, and are thus susceptible to errors. This paper reports the application of a quasi-static technique for direct yield stress measurement, which obviates data extrapolation. Yield stresses of 38%, 42%, and 46% (by weight) SBS block copolymer solutions in a mixed solvent of tetrahydrofuran and

D. De Kee; P. Mohan; D. S. Soong

1986-01-01

368

MODIFICATION OF COTTON WITH ACRYLONITRILE BY RADIATION POLYMERIZATION  

Microsoft Academic Search

The modification of cellulose (cotton fabric or yarn) was carried out ; with acrylonitrile under ionizing radiation. Irradiation of the cotton in ; aqueous acrylonitrile solutions with gamma or electron radiation produces a ; modified cotton with improved rot and mildew resistance similar to that of ; cyanoethylated cotton. Strength properties are not significantly affected, ; provided the radiation dose

F. L. Saunders; R. C. Sovish

1963-01-01

369

Metabolism and toxicity of styrene.  

PubMed Central

The absorption, blood levels, distribution, excretion, and biotransformation of styrene in man and experimental animals are briefly reviewed. The acute toxicity of styrene appears to be unrelated to its biotransformation. Reports of organ toxicity upon chronic exposure to styrene are rare; however, since the chief intermediate in styrene metabolism is an epoxide, hepatotoxicity due to covalent binding at the site of formation appears to be a possibility.

Leibman, K C

1975-01-01

370

1,3-Butadiene: toxicity and carcinogenicity in laboratory animals and in humans.  

PubMed

1,3-Butadiene is a high production volume chemical used largely in the manufacture of synthetic rubber. The production and use of 1,3-butadiene increased dramatically during World War II with the development of the synthetic rubber industry. Before the 1980s, 1,3-butadiene was not considered to be particularly hazardous to human health; therefore, OSHA established a permissible limit of 1,000 ppm for occupational exposure to this chemical. Results of recent inhalation carcinogenicity studies have demonstrated clearly that 1,3-butadiene is a multiple-organ carcinogen in Sprague-Dawley rats and in B6C3F1 mice. Particularly noteworthy in mice were the early occurrences and extensive development of lymphomas, the induction of uncommon hemangiosarcomas of the heart, and the development of malignant lung tumors at exposure concentrations as low as 6.25 ppm. Because 6.25 ppm was the lowest concentration ever used in a long-term carcinogenicity of this gas, it is likely that lower exposure levels would also cause cancers in laboratory animals. In addition, multiple organ site neoplasia was induced in mice after only 13 weeks of exposure. Two reactive epoxides, 1,2-epoxy-3-butene and diepoxybutane, have been identified as intermediates in the biotransformation of 1,3-butadiene in rats and mice. Metabolism is probably an important factor in the carcinogenicity of 1,3-butadiene, because in vitro mutagenicity of 1,3-butadiene requires metabolic activation, whereas these epoxide intermediates are direct acting mutagens in bacteria and are carcinogens in rats and mice. The metabolism of 1,3-butadiene in rats and mice is linear up to concentrations of at least 1000 ppm. Pharmacokinetic studies on 1,3-butadiene and on 1,2-epoxy-3-butene have revealed certain quantitative differences in metabolic rates between Sprague-Dawley rats and B6C3F1 mice; however, these differences were not of sufficient magnitude to account for the reported different target site carcinogenic responses in these two strains of animals. Thus, additional factors must be involved in distinguishing site specificity in the carcinogenicity of 1,3-butadiene between species. In addition to its carcinogenic effects, 1,3-butadiene is a potent in vivo genotoxic agent to mouse bone marrow cells. Hematologic changes indicative of a partially regenerative anemia were induced in mice at 62.5 and higher concentrations. 1,3-Butadiene is also a reproductive and developmental toxicant. Epidemiology studies of workers employed in the production of 1,3-butadiene or of styrene-butadiene rubber have consistently revealed associations between occupational exposure to 1,3-butadiene and excess mortality due to lymphatic and hematopoietic cancers.(ABSTRACT TRUNCATED AT 400 WORDS) PMID:1732994

Melnick, R L; Huff, J

1992-01-01

371

IRIS DOCUMENTATION FOR STYRENE  

EPA Science Inventory

Portions of the dose-response assessment for styrene are now being drafted through contract mechanisims and will be reviewed, when available, by Agency scientists. Those sections that need to be updated and recast include those involving inherently governmental functions such a...

372

Thermal stability of acrylonitrile\\/chlorosulphonated polyethylene rubber blend  

Microsoft Academic Search

The properties of chlorosulphonated polyethylene (CSM) rubber, acrylonitrile rubber (NBR) and their blend (50\\/50 w\\/w) were\\u000a studied. Fourier transform infrared (FTIR) studies supported that CSM\\/NBR rubber blend is self curable, when cross-linking\\u000a takes place between acrylonitrile groups of NBR and –SO2Cl groups or in situ generated allyl chloride moieties of CSM. The thermal stability of vulcanizates was analyzed in nitrogen\\u000a by

Gordana Markovi?; Milena Marinovi?-Cincovi?; Vesna Vodnik; Blaga Radovanovi?; Jaroslava Budinski-Simendi?; Olivera Veljkovi?

2009-01-01

373

Viscometric Study of Dilute Poly(Acrylonitrile–Ammonium Itaconate) Solutions  

Microsoft Academic Search

The intrinsic viscosity of dilute poly(acrylonitrile–ammonium itaconate) copolymer solution in dimethyl sulfoxide was studied by viscometry. Abnormal phenomena of the ?sp\\/c versus c curves of poly(acrylonitrile–ammonium itaconate) were found. Owing to the effect of NH4\\u000a +, there were three anomalistic turning points in the curve of the Huggins dependence compared with other polyacrylonitrile copolymers.

Chuansheng Cui; Chengguo Wang; Wenjie Jia; Yaqi Zhao

2006-01-01

374

Styrene exposure and ischemic heart disease: a case-cohort study.  

PubMed

Epidemiologic studies have consistently reported increased daily mortality and hospital admissions for ischemic heart disease related to daily changes in ambient particulate levels. One theory is that substances adhering to particulates might have a cardiovascular effect. Styrene has been found in very low doses in air and has chemical characteristics that would cause adherence to particles. Industrial studies have found an increase in cardiovascular disease among styrene-exposed workers. To explore a possible dose-response relation between styrene exposure and ischemic heart disease, the authors of this case-cohort study included 498 cases that died from ischemic heart disease and a 15% random sample (n = 997) of all male workers who were employed during 1943-1984 in two styrene-butadiene rubber-manufacturing plants in the United States. Proportional hazards models showed that recent styrene exposure was significantly associated with acute ischemic heart disease death among active workers. The relative hazard of death from acute ischemic heart disease for exposure during the most recent 2 years among active workers with 2 or more years of employment was 2.95 (95% confidence interval: 1.02, 8.57) at a time-weighted styrene concentration of 0.2-<0.3 ppm and 4.30 (95% confidence interval: 1.56, 11.84) at >or=0.3 ppm for the same exposure period, respectively. PMID:14607807

Matanoski, Genevieve M; Tao, Xuguang Grant

2003-11-15

375

Critical assessment of epidemiologic studies on the human carcinogenicity of 1,3-butadiene  

SciTech Connect

1,3-Butadiene, a major ingredient of synthetic rubber, has been shown to be carcinogenic in two animal species. To assess the possible human carcinogenicity of 1,3-butadiene, a critical review was undertaken of the epidemiologic literature. An early retrospective study of 8017 males employed in tire manufacturing found excess mortality for lymphatic and hematopoietic neoplasms in production workers (standardized mortality ratio, SMR = 560); these workers were exposed to 1,3-butadiene as well as to styrene and possibly to benzene. A recently updated epidemiologic study of 2568 workers at a butadiene manufacturing plant in Texas reported low mortality overall (SMR = 84) but found excess deaths for lymphosarcoma and reticulum cell sarcoma (SMR = 229). A retrospective study of workers employed at two synthetic rubber plants in Texas found excess mortality for lymphatic and hematopoietic malignancies in the older of these facilities; the excesses for lymphosarcoma (SMR = 224) and leukemia (SMR = 278) were most significant in wartime workers. A large, recently updated retrospective study of 12,113 workers employed in eight synthetic rubber manufacturing plants in the United States and Canada found excess mortality for lymphatic and hematopoietic cancer in production workers; the SMR for other lymphatic cancers in white production workers was 230, and the SMR for all lymphatic malignancies in black production workers was 507. These updated epidemiologic results strongly suggest an etiologic association between occupational exposure to 1,3-butadiene and human cancer. It is reasonable, therefore, to conclude that there now exists at least limited evidence for the human carcinogenicity of 1,3-butadiene. 27 refs.

Landrigan, P.J. (Mt. Sinai School of Medicine, New York, NY (USA))

1990-06-01

376

International Symposium on the Evaluation of Butadiene and Chloroprene Health Risks.  

PubMed

These proceedings represent nearly all the platform and poster presentations given during the International Symposium on Evaluation of Butadiene and Chloroprene Health Risks, held in Charleston, South Carolina, USA, on September 20-22, 2005. The Symposium was attended by 78 participants representing private industry (37), academia (21), government (11), not-for-profit organizations (5), and consulting (4). The program followed the format of previous symposia on butadiene, chloroprene, and isoprene in London UK (2000) and butadiene and isoprene in Blaine, Washington USA (1995). This format enabled the exchange of significant new scientific results and discussion of future research needs. Isoprene was not evaluated during the 2005 Symposium because of lack of new data. For background information, the reader is referred to the proceedings of the London 2000 meeting for a thorough historical perspective and overview of scientific and regulatory issues concerning butadiene, chloroprene, and isoprene [Chem.-Biol. Interact. (2001) 135-136:1-7]. The Symposium consisted of seven sessions: (1) Introduction and Opening Remarks, (2) Butadiene/styrene-butadiene rubber (SBR)--Process Overview, Exposure and Health Effects/Human Studies; (3) Chloroprene--Process Overview, Exposure and Health Effects/Human Studies; (4) Mode of Action/Key Events; (5) Risk Assessment; (6) Poster Presentations; and (7) Panel Discussion and Future Directions. The Symposium concluded with a discussion by all participants of issues that arose throughout the course of the Symposium. The Proceedings of the Symposium published in this Special Issue are organized according to the Sessions outlined above. The purpose of this foreword is to summarize the presentations and their key findings and recommend future research directions for each chemical. PMID:17336954

Himmelstein, Matthew W; Baan, Robert A; Albertini, Richard J; Bird, Michael G; Lewis, R Jeffrey

2007-02-15

377

Disposition of butadiene monoepoxide and butadiene diepoxide in various tissues of rats and mice following a low-level inhalation exposure to 1,3-butadiene.  

PubMed

1,3-Butadiene (BD), a chemical used extensively in the production of styrene-butadiene rubber, is carcinogenic in Sprague-Dawley rats and B6C3F1 mice. Chronic inhalation studies revealed profound species differences in the potency and organ-site specificity of BD carcinogenesis between rats and mice. BD is a potent carcinogen in mice and a weak carcinogen in rats. Previous studies from our laboratory and others have shown marked differences between rats and mice in the metabolism of BD, which may account for species differences in carcinogenicity. The purpose of the present study was to examine the production and disposition of two mutagenic BD metabolites, butadiene monoepoxide (BDO) and butadiene diepoxide (BDO2), in blood and other tissues of rats and mice during and following inhalation exposures to a target concentration of 62.5 p.p.m. BD. BDO was increased above background in blood, bone marrow, heart, lung, fat, spleen and thymus tissues of mice after 2 h and 4 h exposures to BD. In rats, levels of BDO were increased in blood, fat, spleen and thymus tissues. No increases in BDO were observed in rat lungs. BDO2, the more mutagenic of the two epoxides, was increased in the blood of rats and mice at 2 and 4 h after initiation of exposure to BD. In mice, BDO2 was detected in all tissues examined immediately following the 4 h exposure. This metabolite was detected in heart, lung, fat, spleen and thymus of rats, but at levels 40- to 160-fold lower than those seen in mice. Immediately after the 4 h exposure, blood levels of BDO2 were 204 +/- 15 pmol/g for mice but were 41-fold lower for rats. In the sensitive mouse target organs, heart and lungs, levels of BDO2 exceeded BDO levels immediately after the exposure. This study shows that the levels of BD epoxides are markedly greater in the mouse BD target organs. The high concentrations of BDO2 in these organs suggest that this compound may be particularly important in BD-induced carcinogenesis. Thus, although BD is oxidatively metabolized by similar metabolic pathways in rats and mice, the substantial quantitative differences in tissue levels of mutagenic epoxides between species may be responsible for the increased sensitivity of mice to BD-induced carcinogenicity. PMID:7634396

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

1995-08-01

378

A review of the epidemiology of 1,3-butadiene and chloroprene.  

PubMed

Butadiene epidemiologic research has focused primarily on one cohort of workers in the North American styrene-butadiene rubber (SBR) industry and on the largest cohort of workers in the United States butadiene monomer industry. The most recent studies of these populations are characterized by carefully enumerated study populations, extremely long and high quality mortality follow-up, accurate job categorizations, detailed exposure assessments, and comprehensive statistical analyses. Leukemia was clearly associated with increasing estimated butadiene exposure in the SBR study, but not in the monomer industry study. This has lead to hypotheses about exposure differences between these two industries and the presence of co-factors or confounders in the SBR industry. Research presented at this symposium should shed some light on these hypotheses. The chloroprene epidemiologic literature, on the other hand, is in an early stage of development. The existing studies are limited by poor exposure characterization, lack of control of potential confounding factors, incompleteness in cohort enumeration, short follow-up periods, and small numbers of cancer cases. The state of the science for chloroprene would be advanced by arranging more comprehensive studies than those that have been conducted to date. PMID:11397380

Acquavella, J F; Leonard, R C

2001-06-01

379

The structure and dynamics of thin poly(styrene)-b-(polybutadiene) copolymer films studied by x-ray scattering  

Microsoft Academic Search

We have investigated the structure and dynamics of thin diblock copolymer films of poly(styrene)-b-poly(butadiene) using x-ray reflectivity, diffuse scattering, grazing incidence small angle scattering (GISAXS), and x-ray photon correlation spectroscopy (XPCS), respectively. The measurements were performed at temperatures below and above the order-disorder transition temperature (ODT) of bulk with different film thicknesses. The x-ray reflectivity and GISAXS results show that

Sanghoon Song; Youngsuk Byun; Jeeun Kim; Daeyong Eom; Wonsuk Cha; Hyunjung Kim

2007-01-01

380

Mortality of workers exposed to acrylonitrile.  

PubMed

A retrospective cohort study was carried out in The Netherlands to investigate the potential carcinogenic effects in humans of occupational exposure to acrylonitrile (AN). The total study group consisted of 6803 workers "from eight chemical plants and one control plant" of whom 2842 had been exposed to AN between January 1, 1956 and July 1, 1979 for at least 6 months. All workers were employed by one of eight chemical companies. An extensive review of the available industrial hygiene data was conducted to assess the magnitude of past exposure to AN, occurrence of peak exposures, exposure to recognized potential human carcinogens, and respirator use. The total cohort was observed for mortality until January 1, 1988. In collaboration with the Central Bureau of Statistics, the causes of death were traced for the workers who died before 01-01-1988. In the exposed as well as in the nonexposed cohorts the total mortality was lower than expected, based on national mortality statistics. The observed cancer mortality in the exposed cohort was similar to the expected mortality. Specific analyses were carried out to investigate dose-response relationships and latency for total mortality and lung cancer mortality. Overall, no indications were found for a carcinogenic effect in this cohort of workers exposed to AN. PMID:1506938

Swaen, G M; Bloemen, L J; Twisk, J; Scheffers, T; Slangen, J J; Sturmans, F

1992-08-01

381

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

Microsoft Academic Search

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

Ram B. Gupta; John M. Prausnitz

1995-01-01

382

Mortality update of workers exposed to acrylonitrile in The Netherlands.  

PubMed

A retrospective cohort study investigating the cause-specific mortality patterns of 2842 workers occupationally exposed to acrylonitrile for at least 6 months before 1 July 1979 was updated. The comparison group consisted of 3961 workers from a nitrogen fixation plant during the same time interval. Industrial hygiene assessments quantified past exposure to acrylonitrile, the use of personal protective equipment, and exposure to other potential carcinogenic agents. All 6803 workers were followed for mortality until 1 January 1996. The follow-up was almost complete (99.6%), and for 99.3% the cause of death was ascertained. Age distribution, follow-up period, and temporal changes in background mortality rates were adjusted for in calculations of standardized mortality ratios for separate causes of death. Cumulative dose-effect relations were determined for 3 exposure categories and 3 latency periods. The results showed that, although cancer mortality fluctuated slightly, no cancer excess seems related to exposure to acrylonitrile. PMID:9714509

Swaen, G M; Bloemen, L J; Twisk, J; Scheffers, T; Slangen, J J; Collins, J J; ten Berge, W F; Sturmans, F

1998-01-01

383

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

PubMed

A Na(2)CO(3)-promoted addition of phenols to propiolonitriles generated (Z)-3-aryloxy-acrylonitriles in nearly quantitative yields with exclusively Z-isomers, and a DABCO-promoted addition reaction of phenols with propiolonitriles afforded mainly (E)-3-aryloxy-acrylonitriles with high yields. The obtained (E)-3-aryloxy-acrylonitriles underwent intramolecular cyclization to give 3-cyanobenzofurans in good yields through palladium-catalyzed direct C-H bond functionalization. PMID:22847603

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

2012-07-31

384

Synthesis and impact properties of in situ bulk made ABS resins toughened by high cis-1,4 polybutadiene  

Microsoft Academic Search

In situ bulk polymerization process was employed for the synthesis of poly(acrylonitrile–butadiene–styrene) (ABS) resin. Butadiene (Bd) prepolymer solution was obtained through selective polymerization of Bd in styrene (St) catalyzed by Nd(P507)3\\/Al(i-Bu)2H\\/Et3Al2Cl3 catalyst. The catalyst exhibited high activity and selectivity towards the Bd polymerization. The Bd prepolymer yield was higher than 95%. Determined by IR and 1H NMR spectra, the prepolymer

Yanming Hu; Zhongming Jia; Yang Li; Li Chang; Yurong Wang

2011-01-01

385

Physiologically based toxicokinetic modeling of 1,3-butadiene lung metabolism in mice becomes more important at low doses  

SciTech Connect

Butadiene is used for the production of styrene-butadiene rubber. It has been detected in cigarette smoke and automobile exhaust and is currently listed as one of the 189 hazardous air pollutants in the 1990 Clean Air Act Amendments. This paper describes a physiologically based toxicokinetic model for 1,3-butadiene uptake, distribution, and metabolic clearance in mice. Model parameters for metabolic activity were estimated from the correspondence between computer simulation studies and experimental results as published in the literature. The parameterized model was validated with independent literature data. With the resulting model, the relative importance of lung metabolism as compared to metabolism in the liver increased with decreasing ambient air concentrations. This was due to saturation of metabolism in the alveolar area of the lung, which occurred in the simulations at ambient air concentrations well below current threshold limit values. At higher air concentration, liver metabolism became relatively more important. The tendency toward increased importance of lung metabolism at low doses indicates the necessity of careful extrapolation of in vivo results to low doses. Moreover, this trend may also contribute to species difference in susceptibility to the carcinogenic activity of butadiene.

Evelo, C.T.A.; Oostendorp, J.G.M.; Borm, P.J.A. (Univ. of Limburg, Maastricht (Netherlands)); Berge, W.F. ten (DSM, Heerlen (Netherlands))

1993-11-01

386

Haemoglobin adducts of epoxybutanediol from exposure to 1,3-butadiene or butadiene epoxides  

Microsoft Academic Search

Epoxybutanediol is one of the reactive metabolites of butadiene. It is formed via hydrolysis followed by oxidation of the primary metabolite of butadiene, epoxybutene, or via hydrolysis of diepoxybutane, a secondary metabolite of butadiene. Groups of male Sprague Dawley rats were treated by intraperitoneal injection of epoxybutene, epoxybutanediol or diepoxybutane. N-(2,3,4-Trihydroxybutyl)valine adducts in haemoglobin, formed from epoxybutanediol in its reaction

Hermes Licea Pérez; Jaana Lähdetie; Helena Hindsø Landin; Ilkka Kilpeläinen; Pertti Koivisto; Kimmo Peltonen; Siv Osterman-Golkar

1997-01-01

387

Study on Effective Microorganisms Bacteria for Acrylonitrile Wastewater Treatment  

Microsoft Academic Search

In this study, according to the specific characteristics of acrylonitrile wastewater, Effective Microorganisms (EM) was used as Contact oxidation strain. The optimum conditions of EM bacteria domestication and contact oxidation treatment, such as pH, concentration and temperature, was confirmed. In addition, the results of aerobic treatment of wastewater suggested that COD effluent reduced to below 100mg\\/L, the removal efficiency to

Zhou Guizhong; Sun Jing

2010-01-01

388

Solution polymerization behavior of acrylonitrile by moderate temperature azoinitiator  

Microsoft Academic Search

Acrylonitrile (AN) was solution-polymerized in dimethyl sulfoxide (DMSO) and tertiary butyl alcohol (TBA) at 30, 40 and 50°C using a moderate temperature initiator, 2,2?-azobis(2,4,-dimethylvaleronitrile) (ADMVN); the effects of type and amount of solvent, polymerization temperature, and initiator concentration were investigated. On the whole, the experimental results corresponded to predictions. Moderate polymerization temperature using ADMVN proved to be successful in obtaining

Won Seok Lyoo; Han Do Ghim; Won Sik Yoon; Jinwon Lee; Hyun Seok Lee; Byung Chul Ji

1999-01-01

389

Styrene exposure and risk of cancer  

PubMed Central

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

Huff, James; Infante, Peter F.

2011-01-01

390

Review of the metabolic fate of styrene.  

PubMed

Styrene and styrene oxide have been implicated as reproductive toxicants, neurotoxicants, or carcinogens in vivo or in vitro. The use of these chemicals in the manufacture of plastics and polymers and in the boat-building industry has raised concerns related to the risk associated with human exposure. This review describes the literature to date on the metabolic fate of styrene and styrene oxide in laboratory animals and in humans. Many studies have been conducted to assess the metabolic fate of styrene in rats, and investigations on the metabolism of styrene in humans have been of considerable interest. Limited research has been done to assess metabolism in the mouse. The metabolism of styrene to styrene oxide and further conversion to styrene glycol (via epoxide hydrolase), mandelic acid, and phenylglyoxylic acid has been given considerable attention, and is considered to be the major pathway of activation and detoxication for humans. While the hydrolysis of styrene oxide to styrene glycol historically has been the favored pathway for the rat, studies in more recent years have indicated that glutathione conjugation also is a viable and significant pathway for both the rat and the mouse. This pathway has not been established in humans. Mandelic acid and phenylglyoxylic acid have been used as urinary markers of exposure in humans exposed to styrene. Extensive investigations have been conducted on the kinetics of styrene and styrene oxide in rodents. In people, the kinetics of styrene and styrene oxide in the blood of occupationally exposed workers and volunteers have been determined. Pharmacokinetic models developed in the last decade have become increasingly complex, with the most recent physiologically based model describing the kinetics of styrene and styrene oxide. This model shows pronounced species differences in sensitivity coefficients for styrene or styrene oxide between mice, rats, and humans, where mice are the more sensitive species to the Vmax for both epoxide hydrolase and monooxygenase. This result is particularly interesting in light of the recent findings of extensive mortality and hepatotoxicity for mice exposed to relatively low levels of styrene (250 to 500 ppm), while rats and humans exhibit only nasal and eye irritations at exposure concentrations well above 500 ppm. PMID:7818768

Sumner, S J; Fennell, T R

1994-01-01

391

Investigation of Selected Potential Environmental Contaminants: Butadiene and Its Oligomers.  

National Technical Information Service (NTIS)

The report is a survey and summary of the literature on butadiene and its oligomers. Major aspects of their biological effects, environmental exposure, chemistry, production and use, and regulations are reviewed and assessed. Butadiene is a reactive gas u...

L. M. Miller

1978-01-01

392

Application of control technology developed in the polyvinyl chloride industry to polymerization processes using acrylonitrile  

Microsoft Academic Search

Polymerization processes for PVC are sufficiently similar to acrylonitrile polymerization processes to allow a significant transfer of control technology. This transfer should be of value to manufacturers of polyacrylonitrile, ABS\\/SAN resins, nitrile elastomer and latex who will need to install extensive additional controls to comply with the new permanent standard for acrylonitrile scheduled to be issued by OSHA in late

KENNETH S. SCHOULTZ; JAMES A. GIDEON; JULIUS H. BOCHINSKI

1979-01-01

393

Congenital abnormalities and indicators of germinal mutations in the vicinity of an acrylonitrile producing factory  

Microsoft Academic Search

The results of an environmental mutation and teratologic epidemiological study are presented which was performed in inhabitants living in the surrounding region of an acrylonitrile factory in Nyergesújfalu. The endpoint of the study was congenital abnormalities in 46,326 infants born to mothers living in the 30 settlements of the study region within a 25 km radius of the acrylonitrile factory

Andrew E. Czeizel; Susan Hegedüs; László T??már

1999-01-01

394

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

PubMed Central

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

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

1990-01-01

395

The structure and dynamics of thin poly(styrene)-b-(polybutadiene) copolymer films studied by x-ray scattering  

NASA Astrophysics Data System (ADS)

We have investigated the structure and dynamics of thin diblock copolymer films of poly(styrene)-b-poly(butadiene) using x-ray reflectivity, diffuse scattering, grazing incidence small angle scattering (GISAXS), and x-ray photon correlation spectroscopy (XPCS), respectively. The measurements were performed at temperatures below and above the order-disorder transition temperature (ODT) of bulk with different film thicknesses. The x-ray reflectivity and GISAXS results show that the structural changes appear at lower temperature than ODT of bulk. These results will be discussed with the findings from the XPCS.

Song, Sanghoon; Byun, Youngsuk; Kim, Jeeun; Eom, Daeyong; Cha, Wonsuk; Kim, Hyunjung

2007-03-01

396

Dynamics of deuterated polystyrene-protonated butadiene diblock copolymer micelles by neutron spin echo.  

PubMed

We report on neutron spin-echo (NSE) measurements on deuterated styrene-protonated butadiene diblock copolymer micelles in deuterated n-decane to investigate the dynamics of butadiene blocks in the corona. Before the NSE measurements, we performed small-angle neutron-scattering (SANS) measurements on the micelles to evaluate the structure to give a basis for the discussion of the dynamics. In the SANS study, we have estimated the form factor P(Q) in terms of a hard-core-shell model from the direct evaluation without curve-fitting procedure while a more flexible core-shell model with the structure factor S(Q) gives a better fit to the observed data. The observed normalized intermediate scattering function I(Q,t)/I(Q,0) by NSE does not show the collective motions corresponding to the so-called breathing mode but rather single chain motion (Zimm modes) for both the 2 and 20 wt % micelle solutions. The Zimm decay rate Gamma(z) in the micelle solution is slow compared with that in the homopolymer solution. This slowing down is assigned to the effective high concentration in the corona. The differences in Gamma(z) between concentrated solutions and the 20% micellar solution are attributed to end-tethering effect of the corona chains on the core surface. The possible reasons why the breathing mode was not observed in the present micelle system are discussed on the basis of chain density in the corona. PMID:15847563

Kanaya, T; Monkenbusch, M; Watanabe, H; Nagao, M; Richter, D

2005-04-01

397

Dynamics of deuterated polystyrene-protonated butadiene diblock copolymer micelles by neutron spin echo  

NASA Astrophysics Data System (ADS)

We report on neutron spin-echo (NSE) measurements on deuterated styrene-protonated butadiene diblock copolymer micelles in deuterated n-decane to investigate the dynamics of butadiene blocks in the corona. Before the NSE measurements, we performed small-angle neutron-scattering (SANS) measurements on the micelles to evaluate the structure to give a basis for the discussion of the dynamics. In the SANS study, we have estimated the form factor P(Q) in terms of a hard-core-shell model from the direct evaluation without curve-fitting procedure while a more flexible core-shell model with the structure factor S(Q) gives a better fit to the observed data. The observed normalized intermediate scattering function I(Q,t)/I(Q,0) by NSE does not show the collective motions corresponding to the so-called breathing mode but rather single chain motion (Zimm modes) for both the 2 and 20 wt % micelle solutions. The Zimm decay rate ?z in the micelle solution is slow compared with that in the homopolymer solution. This slowing down is assigned to the effective high concentration in the corona. The differences in ?z between concentrated solutions and the 20% micellar solution are attributed to end-tethering effect of the corona chains on the core surface. The possible reasons why the breathing mode was not observed in the present micelle system are discussed on the basis of chain density in the corona.

Kanaya, T.; Monkenbusch, M.; Watanabe, H.; Nagao, M.; Richter, D.

2005-04-01

398

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

PubMed

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

2001-12-01

399

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.

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

2001-01-01

400

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

Technology Transfer Automated Retrieval System (TEKTRAN)

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

401

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

Technology Transfer Automated Retrieval System (TEKTRAN)

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

402

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

Technology Transfer Automated Retrieval System (TEKTRAN)

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

403

Block-graft copolymers on the basis of a styrene-butadiene diblock copolymer  

Microsoft Academic Search

Grafting from the diblock copolymers ?b? leads to block-graft copolymers of the form ?b?g?, the chemistry and architecture of which can be varied over wide limits. A family of compatibilizers for polymer blends can be prepared from one anionically produced and thus expensive copolymer, by a radically initiated grafting process, which is a comparatively cheap method. When ?b? is asymmetric,

M. Fischer; G. P. Hellmann

1996-01-01

404

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

Microsoft Academic Search

The Lawrence Livermore National Laboratory (LLNL) has been involved with investigations dealing with the response of the rubber in tank track pads to various loading scenarios, both in the field and in the laboratory. In the laboratory, numerous studies were also performed on a number of other rubber formulations primarily involving a range of carbon-black loadings in SBR and NR.

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

1988-01-01

405

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

SciTech Connect

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

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

1988-09-15

406

Medium strain hysteresis loss of natural rubber and styrene-butadiene rubber vulcanizates: a predictive model  

Microsoft Academic Search

A model for hysteresis loss of rubber vulcanizates at medium strain (less than 100%) under dynamic condition has been proposed by using Boltzmann superposition principle, statistical theory of rubber elasticity and phenomenological theory. The theory incorporates both experimental and analytical parameters to quantify hysteresis loss. The model with no adjustment parameter has been successfully tested using the experimental results for

Kamal K. Kar; Anil K. Bhowmick

1999-01-01

407

Molecular transport of aromatic hydrocarbons through crosslinked styrene-butadiene rubber membranes  

Microsoft Academic Search

Molecular transport of aromatic hydrocarbons through crosslinked SBR has been carried out in the temperature range (25–65°C). SBR has been vulcanized by four different vulcanizing techniques viz., conventional, efficient, dicumyl peroxide and a mixture consisting of sulfur and peroxide. SBR vulcanized with EV system showed highest solvent uptake tendency and that vulcanized with peroxide showed the lowest. The influence of

K. N. Ninan

1996-01-01

408

Comprehensive Testing to Measure the Response of Styrene Butadiene Rubber to Hanford Tank Waste Simulant.  

National Technical Information Service (NTIS)

This report presents the findings of the Chemical Compatibility Program developed to evaluate plastic packaging components that may be incorporated in packaging mixed-waste forms for transportation. Consistent with the methodology outlined in this report,...

P. J. Nigrey

2000-01-01

409

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

PubMed

The compatibility of solid blends: PS/SBR, PS/SBR filled with glass fiber and PS/SBR filled with talc were studied using ultrasonic pulse echo technique. Measurements were carried out at room temperature (298 K) and a frequency of 3 MHz. The ultrasonic velocity for the compressional wave and that for shear wave have been measured to obtain the elastic moduli data by knowing of density. The variation of ultrasonic wave velocities and elastic moduli with weight percent of the blend was found to be linear in PS/SBR blend, indicating some degree of compatibility but the drawback of elastic moduli indicate incompatibility of the system blend, while it deviates from linearity in blends of PS/SBR filled with glass fiber and talc but the increase in elastic moduli indicates that there is an increase in degree of compatibility between PS and SBR due to adding of glass fiber or talc. The ultrasonic absorptions for longitudinal wave in the temperature range from 298 to 423 K in the studied system were measured using ultrasonic pulse echo technique. Typical results showing the temperature dependence of the ultrasonic absorption at frequencies of 1, 2, 3 and 5 MHz are illustrated for all samples of the different compositions. The study of compositional and temperature dependence of the ultrasonic absorption in the present studied blends reveals the same behavior of the compatibility degree of the blends. Density data of the blends confirmed the ultrasonic results. Also the correlation between hardness and elastic moduli for the present blend systems has been studied. PMID:16842835

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

2006-06-30

410

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

411

Parameters Affecting the Migration of Molluscicidal Saponin from Styrene Butadiene Rubber Formulations Containing Phytolacca Dioica L  

Microsoft Academic Search

Discs of SBR containing Phytolacca dioica L. plant can be used to release saponin of the plant which has an efficient toxic effect on Bimpholaria alexandrine snails, the intermediate hosts of Schistosomiasis. Such a snail control system is used to protect the human beings from schistosomiasis. Schistosomiasis is a major health problem of increasing severity, especially in the developing countries.

F. M. Helaly; A. A. Ahmed

2000-01-01

412

Thermodynamic Study of Polar Modifiers in the Equilibrium Staged Processes for the Styrene Butadiene Rubber Processing  

Microsoft Academic Search

To analyze the behaviour of polar modifier in the separation steps of the synthetic rubber processing is necessary a thermodynamic study of these compounds with water, solvent and rubber. In this work, polymer-additive, solvent-additive and water-additive pairs were studied and measurements of vapor-liquid (VLE) and liquid-liquid equilibria (LLE) were carried out. The results of the thermodynamic modeling and steam stripping

G. Ovejero; M. D. Romero; I. Díaz; E. Díez; J. Galán

413

Species differences in the formation of butadiene monoxide from 1,3-butadiene  

Microsoft Academic Search

When 1,3-butadiene is incubated with liver postmitochondrial fractions from mouse, rat, monkey or man and a NADPH-regenerating system, the formation rate of butadiene monoxide is different in the four species. With the exception of the rhesus monkey, the amount of epoxide is proportional to the monooxygenase activity. The sequence of epoxide formation is B6C3F1 mouse, Sprague Dawley rat, man, rhesus

U. Schmidt; E. Loeser

1985-01-01

414

21 CFR 177.1810 - Styrene block polymers.  

Code of Federal Regulations, 2010 CFR

...2009-04-01 true Styrene block polymers. 177.1810 Section 177.1810...CONTINUED) INDIRECT FOOD ADDITIVES: POLYMERS Substances for Use as Basic Components...Surfaces § 177.1810 Styrene block polymers. The styrene block polymers...

2010-01-01

415

21 CFR 177.1810 - Styrene block polymers.  

Code of Federal Regulations, 2010 CFR

...2009-04-01 false Styrene block polymers. 177.1810 Section 177.1810...CONTINUED) INDIRECT FOOD ADDITIVES: POLYMERS Substances for Use as Basic Components...Surfaces § 177.1810 Styrene block polymers. The styrene block polymers...

2009-04-01

416

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

417

21 CFR 177.1830 - Styrene-methyl methacrylate copolymers.  

Code of Federal Regulations, 2010 CFR

...2009-04-01 false Styrene-methyl methacrylate copolymers. 177.1830 Section 177...Surfaces § 177.1830 Styrene-methyl methacrylate copolymers. Styrene-methyl methacrylate copolymers identified in this...

2009-04-01

418

21 CFR 177.1820 - Styrene-maleic anhydride copolymers.  

Code of Federal Regulations, 2010 CFR

...2010-01-01 2009-04-01 true Styrene-maleic anhydride copolymers. 177.1820 Section 177...Contact Surfaces § 177.1820 Styrene-maleic anhydride copolymers. Styrene-maleic anhydride copolymers identified in...

2010-01-01

419

21 CFR 177.1820 - Styrene-maleic anhydride copolymers.  

Code of Federal Regulations, 2010 CFR

...2009-04-01 2009-04-01 false Styrene-maleic anhydride copolymers. 177.1820 Section 177...Contact Surfaces § 177.1820 Styrene-maleic anhydride copolymers. Styrene-maleic anhydride copolymers identified in...

2009-04-01

420

Mortality update of butadiene production workers  

Microsoft Academic Search

This is a further update of a cohort mortality study of 2795 male workers employed at least 6 months between 1942 and 1994 at a 1,3-butadiene facility. Earlier reports on this cohort found a statistically significant deficit for all causes of death and lower than expected mortality for most leading causes of death. Prior reports noted an excess of deaths

Barbara J. Divine; Christine M. Hartman

1996-01-01

421

Pi-Electron Structure of Butadiene  

Microsoft Academic Search

The spectrum and structure of butadiene have been considered by application of several nonempirical methods to the problem of the energy levels of the ?-electron system. Six spatial configurations of the nuclei have been treated, of which three correspond to the trans- form of the molecule and three, cis. The methods used include the use of antisymmetrized molecular orbitals with

R. Stephen Berry

1957-01-01

422

1,3-Butadiene, isoprene and chloroprene: reviews by the IARC monographs programme, outstanding issues, and research priorities in epidemiology.  

PubMed

1,3-Butadiene, isoprene and chloroprene have all been evaluated more than once by the IARC Monographs Programme on the Evaluation of Carcinogenic Risks to Humans, most recently in February 1998 (Volume 71). Summaries are available on-line at http://monographs.iarc.fr. 1,3-Butadiene is currently classified in Group 2A (probably carcinogenic to humans), on the basis of limited evidence for increased occupational cancer risk in humans plus sufficient evidence of carcinogenicity at multiple organ sites in rats and especially in mice exposed by inhalation. Four epidemiologic studies are available on cancer risk among workers exposed to 1,3-butadiene, one large study among styrene-butadiene rubber (SBR) workers, and one large and two small studies among 1,3-butadiene production workers. The results of the study of SBR workers suggest an association between butadiene exposure and leukaemia risk, which is consistent with the results of the large study of production workers. This latter study also suggested an increased risk of lymphoreticulosarcoma (ICD-8, 200). The major factors hampering the assessment of the available results are (i) possible misclassification of lymphoid and haematopoietic neoplasms, (ii) limitations in the assessment of past exposure (with the exception of the study of SBR workers) and (iii) a potential confounding effect of agents other than butadiene. Future research priorities include (i) the incorporation of newly developed biomarkers of exposure, (ii) the possible application of intermediate biomarkers, (iii) the replication of the study among SBR workers, possibly in Europe, and (iv) reanalysis of existing data in light of revisions of the classifications of leukaemias and lymphomas in the International Classification of Diseases for Oncology, Third Edition (2000). Isoprene is classified in Group 2B (possibly carcinogenic to humans), on the basis of sufficient evidence for carcinogenicity at multiple organ sites in both mice and rats, especially male mice, exposed by inhalation. No epidemiologic studies are available on cancer risk from occupational exposure to isoprene. Such studies could be conducted within the framework of existing or future studies of SBR workers, assuming that isoprene exposure can be disentangled from butadiene and styrene exposure. Chloroprene is classified in Group 2B on the basis of sufficient evidence for carcinogenicity at multiple organ sites in both mice and rats exposed by inhalation. Studies of chloroprene exposed workers now include chemical workers from the United States, China and Armenia as well as shoe workers from Russia. The results of the studies from China, Armenia and Russia suggest an excess risk of liver cancer. The risk of other neoplasms was not consistently increased. Limitations of available studies include possible bias from cohort enumeration, follow-up, and choice of reference population. In most studies the exposure assessment was poor, the possible confounding effect of co-exposures was not addressed and the statistical power was low. The pathology of the cases of liver cancer should be reviewed. Future research priorities include a replication of available studies in well-defined populations and the development of biomarkers of exposure. PMID:11397378

Rice, J M; Boffetta, P

2001-06-01

423

Development of a unit risk factor for 1,3-butadiene based on an updated carcinogenic toxicity assessment.  

PubMed

The Texas Commission on Environmental Quality (TCEQ) has developed an inhalation unit risk factor (URF) for 1,3-butadiene based on leukemia mortality in an updated epidemiological study on styrene-butadiene rubber production workers conducted by researchers at the University of Alabama at Birmingham. Exposure estimates were updated and an exposure estimate validation study as well as dose-response modeling were conducted by these researchers. This information was not available to the U.S. Environmental Protection Agency when it prepared its health assessment of 1,3-butadiene in 2002. An extensive analysis conducted by TCEQ discusses dose-response modeling, estimating risk for the general population from occupational workers, estimating risk for potentially sensitive subpopulations, effect of occupational exposure estimation error, and use of mortality rates to predict incidence. The URF is 5.0 x 10(-7) per microg/m(3) or 1.1 x 10(-6) per ppb and is based on a Cox regression dose-response model using restricted continuous data with age as a covariate, and a linear low-dose extrapolation default approach using the 95% lower confidence limit as the point of departure. Age-dependent adjustment factors were applied to account for possible increased susceptibility for early life exposure. The air concentration at 1 in 100,000 excess leukemia mortality, the no-significant-risk level, is 20 microg/m(3) (9.1 ppb), which is slightly lower than the TCEQ chronic reference value of 33 microg/m(3) (15 ppb) protective of ovarian atrophy. These values will be used to evaluate ambient air monitoring data so the general public is protected against adverse health effects from chronic exposure to 1,3-butadiene. PMID:19878488

Grant, Roberta L; Haney, Joseph; Curry, Angela L; Honeycutt, Michael

2009-10-29

424

Pyrolysis of plastic packaging waste: A comparison of plastic residuals from material recovery facilities with simulated plastic waste  

Microsoft Academic Search

Pyrolysis may be an alternative for the reclamation of rejected streams of waste from sorting plants where packing and packaging plastic waste is separated and classified. These rejected streams consist of many different materials (e.g., polyethylene (PE), polypropylene (PP), polystyrene (PS), polyvinyl chloride (PVC), polyethylene terephthalate (PET), acrylonitrile butadiene styrene (ABS), aluminum, tetra-brik, and film) for which an attempt at

A. Adrados; I. de Marco; B. M. Caballero; A. López; M. F. Laresgoiti; A. Torres

425

Thermal decomposition behavior and the mechanical properties of an epoxy\\/cycloaliphatic amine resin with ABS  

Microsoft Academic Search

A bifunctional epoxy resin was modified with several amounts of a thermoplastic based on a mixture of acrylonitrile–butadiene–styrene (ABS) in order to improve the toughness of the resin. Previous to study of the mechanical properties, thermal degradation behavior and the kinetic data of the modified systems were calculated using isothermal and dynamic thermogravimetric methods. The results have shown good agreement

M. J Abad; L Barral; J Cano; J López; P Nogueira; C Ram??rez; A Torres

2001-01-01

426

Fast fracture of rubber-toughened thermoplastics used for the shells of motorcycle helmets  

Microsoft Academic Search

The effects of outdoor ageing and of accelerated UV exposure on the grade of acrylonitrile butadiene styrene copolymer (ABS) used by UK manufacturers of motorcycle helmets were compared. Although the surface layer becomes embrittled the helmets still survive an impact test after conditioning at -20° C because the cracks are arrested before they penetrate the full thickness of the shell.

A. Gilchrist; N. J. Mills

1987-01-01

427

Investigation on the thermoformability of polyolefin blends by hot tensile and rheological tests  

Microsoft Academic Search

Due to desirable performance\\/cost properties, polypropylene (PP) is a suitable alternative for acrylonitrile butadiene styrene, polyvinyl chloride and polystyrene in packaging and automotive thermoformed articles. Because of low elasticity and poor melt strength, thermoforming of PP is difficult. In this study, the effect of blending of PP with high-density polyethylene (HDPE) and ethylene propylene diene monomer (EPDM) is presented. Ternary

Somayyeh Mohammadian-Gezaz; Ismaeil Ghasemi; Mohammad Karrabi; Hamed Azizi

2006-01-01

428

24 CFR 3280.611 - Vents and venting.  

Code of Federal Regulations, 2013 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 stainless steel...

2013-04-01

429

An investigation into welding of engineering thermoplastics using focused microwave energy  

Microsoft Academic Search

Microwaves have been used for many years in industrial heating applications because of their ability to heat materials volumetrically. The dielectric properties of a material determine its ability to absorb microwave radiation. In this paper, the dielectric properties of engineering thermoplastic materials, which include ultra high molecular weight polyethylene (UHMW PE), polycarbonate (PC) and acrylonitrile-butadiene-styrene (ABS) polymers under room temperature

Prasad K. D. V Yarlagadda; Tan Chuan Chai

1998-01-01

430

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

PubMed Central

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

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

1989-01-01

431

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...

432

New Catalyst for the Efficient and Selective Beta-Hydrosilylation of Acrylonitrile. Effect of Ultrasound,  

National Technical Information Service (NTIS)

While there is an abundance of catalysts that are useful in promoting the addition of the Si-H bond across alkenes and alkynes, relatively few agents efficiently catalyze the hydrosilylation of acrylonitrile. In particular, catalysts that lead to exclusiv...

A. B. Rajkumar P. Boudjouk

1989-01-01

433

The development of a novel strategy for the microbial treatment of acrylonitrile effluents.  

PubMed

Effluent from the manufacture of acrylonitrile is difficult to biodegrade. It contains nine major organic components: acetic acid, acrylonitrile, acrylamide, acrylic acid, acrolein, cyanopyridine, fumaronitrile, succinonitrile, and maleimide. A range of bacteria have been isolated that can grow on, or convert all of the organic components of effluent from the manufacture of acrylonitrile. These bacteria can be used as the basis of a mixed culture system to treat the effluent. The bacteria were utilised in batch and continuous cultures to degrade a synthetic wastewater containing acrylonitrile, acrylamide, acrylic acid, cyanopyridine and succinonitrile. The mixed microbial population was adapted by varying the growth rate and switching from continuous to batch and back to continuous growth, to degrade these five compounds as well as acrolein, fumaronitrile and maleimide. PMID:7772945

Wyatt, J M; Knowles, C J

1995-06-01

434

Polyhedral Oligomeric Silsesquioxane (POSS) Styrene Macromers.  

National Technical Information Service (NTIS)

Four polyhedral oligomeric silsesquioxane (POSS) macromers, R7Si8O12Styrene (R = isobutyl, cyclopentyl, cyclohexyl or phenyl) containing a single polymerizable styrene unit were synthesized from the POSS-trisilanols R7Si7O9(OH)3 in high yield and purity. ...

T. S. Haddad B. D. Viers S. H. Phillips

2001-01-01

435

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...154.1750 Butadiene or vinyl chloride: Refrigeration system. A refrigeration system for butadiene or vinyl chloride must not use vapor compression...

2011-10-01

436

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

Code of Federal Regulations, 2013 CFR

...Benzene ethenyl-, polymer with 1,3-butadiene, brominated. 721.10280 Section...Benzene ethenyl-, polymer with 1,3-butadiene, brominated. (a) Chemical substance...benzene ethenyl-, polymer with 1,3-butadiene, brominated (PMN...

2013-07-01

437

Removal of methylene blue dye from aqueous medium by nano poly acrylonitrile particles  

Microsoft Academic Search

This article concerns the removal of Methylene Blue (MB) dye using nano-poly Acrylonitrile (PAN) and hydroximated nano-poly Acrylonitrile (HPAN) particles prepared by precipitation polymerization technique. The effect of the process variables including contact time, pH, initial dye concentration and temperature on the adsorption characters for PAN and HPAN was studied. The removal percentage varied from 100% to 60% with MB

Mohamed Samir Mohy Eldin; S. A. El-Sakka; M. M. El-Masry; I. I. Abdel-Gawad; S. S. Garybe

2012-01-01

438

Rheological Properties of ABS at Low Shear Rates: Effects of Phase Heterogeneity  

Microsoft Academic Search

Acrylonitrile-butadiene-styrene (ABS), owing to its multiphase heterogeneity, has good service properties, especially, impact resistance. Butadiene rubber phase, both its content and morphology, play vital role in the rheology of ABS resin. The dependence of melt viscosity, both shear and elongational, and its pseudo-plastic character on temperature were investigated on a commercial ABS resin using a simple capillary rheometer. Shear stress

Asif Ali Qaiser; Yasir Qayyum; Rehman Rafiq

439

A comparison of polymeric materials as pre-concentrating media for use with ATR\\/FTIR sensing  

Microsoft Academic Search

Polymer-modified ATR-FTIR spectroscopy was investigated to determine its potential suitability for use as an analytical methodology for process stream analysis. The process stream under investigation contains toluene, tetrahydrofuran, ethanol, and acetonitrile in an aqueous matrix. Four polymers, Teflon® AF2400, poly(acrylonitrile-co-butadiene) (PAB), polydimethylsiloxane (PDMS), and poly(styrene-co-butadiene) (PSB), were chosen for study based on partition coefficients measured using a novel automated GC

Kevin Flavin; Helen Hughes; Valarie Dobbyn; Padraig Kirwan; Kieran Murphy; Hans Steiner; Boris Mizaikoff; Peter Mcloughlin

2006-01-01

440

The use of montmorillonite as a reinforcing and compatibilizing filler for NBR\\/SBR rubber blend  

Microsoft Academic Search

Montmorillonite clay was added at different ratios to some polymer blends of acrylonitrile–butadiene rubber (NBR) and styrene–butadiene rubber (SBR). Both the reinforcing and compatibilizing performance of the filler were investigated using rheometric measurements, physico-mechanical properties, scanning electron microscopy (SEM) and differential scanning calorimetry (DSC). There was a remarkable decrease in the optimum cure time (tc90) and the scorch time (ts2),

Hisham Essawy; Doaa El-Nashar

2004-01-01

441

Ionic conductivity of dual-phase polymer electrolytes comprised of NBR\\/SBR latex films swollen with lithium salt solutions  

Microsoft Academic Search

Dual-phase polymer electrolytes (DPE) with high ionic conductivity and good mechanical strength were prepared by swelling poly(acrylonitrile-co-butadiene) rubber (NBR) and poly(styrene-co-butadiene) rubber (SBR) mixed latex films with lithium salt solutions (e.g., 1M LiClO[sub 4]\\/[gamma]-butyrolactone). The latex films retain particle morphology in the solid state. The NBR phase (formed from fused NBR latex particles) is polar and is impregnated selectively with

Morihiko Matsumoto; Toshihiro Ichino; J. S. Rutt; Shiro Nishi

1994-01-01

442

Evidence for cellular protein covalent binding derived from styrene metabolite  

PubMed Central

Styrene is one of the most important industrial intermediates consumed in the world. Human exposure to styrene occurs mainly in the reinforced plastics industry, particularly in developing countries. Styrene has been found to be hepatotoxic and pneumotoxic in humans and animals. The biochemical mechanisms of styrene-induced toxicities remain unknown. Albumin and hemoglobin adduction derived from styrene oxide, a major reactive metabolite of styrene, has been reported in blood samples obtained from styrene exposed workers. The objectives of the current study focused on cellular protein covalent binding of styrene metabolite and its correlation with cytotoxicity induced by styrene. We found that radioactivity was bound to cellular proteins obtained from mouse airway trees after incubation with 14C-styrene. Microsomal incubation studies showed that the observed protein covalent binding required the metabolic activation of styrene. The observed radioactivity binding in protein samples obtained from the cultured airways and microsomal incubations were significantly suppressed by co-incubation with disulfiram, a CYP2E1 inhibitor, although disulfiram apparently did not show a protective effect against the cytotoxicity of styrene. A 2-fold increase in radioactivity bound to cellular proteins was detected in cells stably transfected with CYP2E1 compared to the wild-type cells after 14C-styrene exposure. With the polyclonal antibody developed in our lab, we detected cellular protein adduction derived from styrene oxide at cysteinyl residues in cells treated with styrene. Competitive immunoblot studies confirmed the modification of cysteine residues by styrene oxide. Cell culture studies showed that the styrene-induced protein modification and cell death increased with the increasing concentration of styrene exposure. In conclusion, we detected cellular protein covalent modification by styrene oxide in microsomal incubations, cultured cells, and mouse airways after exposure to styrene and found a good correlation between styrene-induced cytotoxicity and styrene oxide-derived cellular protein adduction.

Yuan, Wei; Jin, Hua; Chung, Jou-Ku; Zheng, Jiang

2012-01-01

443

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

PubMed

Recent epidemiologic studies have consistently reported increased daily mortalities and hospital admissions associated with exposure to particulate air pollution. Ischemic heart disease (IHD*, International Classification of Diseases, Eighth Revision [ICD-8], codes 410-414) is among those diseases that contribute in large measure to this excess mortality. Some occupational studies have suggested elevated risk of IHD among workers exposed for short periods to styrene, which can be emitted from fossil fuel combustion, aircraft exhausts, and motor vehicle exhausts. Styrene is found in ambient air at average concentrations of a few micrograms per cubic meter or less but may reach very high concentrations at particular locations and times. Unmeasured aerosols of styrene may also increase population exposures. This case-cohort study explored a possible association and dose-response relation between styrene exposure and risk of acute IHD in an occupational setting. The population under study was 6587 male workers employed between 1943 and 1982 in two US plants manufacturing styrene-butadiene polymers used in synthetic rubber. The study assessed all 498 subjects who died from IHD along with a subcohort of twice that size, 997 subjects, selected as a 15% random sample of the full target cohort. IHD deaths during the study led to some overlap between cases and the subcohort, leaving 1424 unique subjects. Job histories were collected for all subjects. Industrial hygienists and engineers from the industry estimated relative exposures for all jobs. Exposure data were collected for many of the jobs from different sources. For any job with no available exposure measurements, z scores were used to estimate job exposure in each plant from the relative exposure level for that job in similar plants and the measurement distribution parameters of the study plant. Standardized mortality ratio (SMR) analyses were used to examine the overall risk of dying from IHD among study subjects compared with the US general population. A significantly elevated SMR of 1.47 with a 95% confidence interval (95% CI) of 1.17 to 1.77 for chronic IHD was found among black workers who had left the plants. A modification of the Cox proportional hazard regression model was used to control for confounders and examine dose-response relations between styrene exposure and the risk of IHD. Employment time-weighted average (TWA) styrene concentration intensity for the most recent 2 years was found significantly associated with death from acute IHD among active workers with a relative hazard of 3.26 to 6.60, depending on duration of employment. In this analysis, the highest relative hazard of 6.60 (95% CI, 1.78-24.54) was among active workers who had been employed for at least 5 years. The results suggest that the exposure intensity was more important than duration of exposure. On the basis of the dose-response relation established in this study, we estimate that for each 10 microg/m3 increase in ambient styrene, acute IHD mortality might increase 0.4%. At normal ambient styrene levels, the relative risk would be increased, at most, 0.1% compared with no exposure. At certain locations and times, however, ambient styrene could reach levels that would result in a relative hazard for acute IHD mortality as high as 3.386-fold the risk at no exposure. PMID:12214600

Matanoski, Genevieve M; Tao, Xuguang

2002-05-01

444

Occupational exposure of workers to 1,3-butadiene  

Microsoft Academic Search

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

John M. Fajen; Dennis R. Roberts; Leslie J. Ungers; E. Radha Krishnan

1990-01-01

445

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

446

Halogen-free Intumescent Flame Retardant for ABS\\/PA6\\/SMA Alloys  

Microsoft Academic Search

The intumescent flame-retardant system of acrylonitrile-butadiene-styrene (ABS) copolymer\\/polyamide 6 (PA6)\\/styrene-maleic anhydride (SMA) alloys (ratio 80\\/20\\/6) with ammonium polyphosphate (APP) was evaluated by the limiting oxygen index (LOI) and UL-94 tests. Furthermore, the different effects of various synergistic charring agents on the flame retardancy of the ABS\\/PA6\\/SMA alloys were also investigated, including caged bicyclicphosphates (PEPA), thermoplastic phenolic resin (TPPFR), epoxy resin

Chengxiang Lu; Tan Chen; Xufu Cai

2009-01-01

447

Epidemiologic Study of Mortality and Cancer Incidence among Workers Exposed to Acrylonitrile at the Waynesboro Plant with Cover Letter Dated 02/21/85.  

National Technical Information Service (NTIS)

The objective of this study was to determine whether employees exposed to acrylonitrile at the Waynesboro Plant experienced excess cancer incidence or mortality. In total, 1083 male employees who had worked with acrylonitrile from 1946 through 1970 at the...

1985-01-01

448

Ring-Oxidized Metabolites of Styrene Contribute to Styrene-Induced Clara-Cell Toxicity in Mice  

Microsoft Academic Search

Styrene produced cytotoxicity in the terminal bronchioles of mice, but not rats, due to metabolites produced in situ by CYP2F2 metabolism. It has generally been presumed that styrene toxicity is mediated by styrene 7,8-oxide, but styrene oxide is not much more toxic than styrene. In contrast, ring-oxidized metabolites (4-vinylphenol or its metabolites) induce much greater toxicity. Administration of 4-vinylphenol results

George Cruzan; Gary P. Carlson; Meredith Turner; Werner Mellert

2005-01-01

449

ENGINEERING THE BIOSYNTHESIS OF STYRENE IN YEAST  

EPA Science Inventory

The strategy pursued was to insert genes for phenylalanine ammonia lysase (pal) and phenolic acid decarboxylase (pad) into the yeast that would convert phenylalanine to styrene through a cinnamic acid intermediate. ...

450

HEALTH AND ENVIRONMENTAL EFFECTS PROFILE FOR STYRENE  

EPA Science Inventory

The Health and Environmental Effects Profile for styrene 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 constitue...

451

Mutagenicity and Carcinogenicity Assessment of 1,3-Butadiene.  

National Technical Information Service (NTIS)

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...

S. Bayard R. P. Beliles A. Chiu H. J. Gibb B. Sadler

1985-01-01

452

Biological monitoring for mutagenic effects of occupational exposure to butadiene  

Microsoft Academic Search

The use of biological markers in the evaluation of human exposure to hazardous agents has increased rapidly in recent years. Because 1,3-butadiene is a mutagenic carcinogen, existing occupational levels of exposure may be appropriately evaluated using somatic cell mutation as a biomarker. Previously, we have described a biomarker study of workers in a butadiene monomer plant (Ward et al., 1994).

Jonathan B. Ward; Marinel M. Ammenheuser; Elbert B. Whorton; William E. Bechtold; Karl T. Kelsey; Marvin S. Legator

1996-01-01

453

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

454

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...

455

Oxidative carbonylation of styrene to methyl cinnamate  

SciTech Connect

Oxidative carbonylation technology is used for making methyl cinnamate from styrene as an alternative to Claisen condensation of benzaldehyde with methyl acetate. Using this approach, the optimum yield of cinnamate is greater than 90%, with CO{sub 2}, acetophenone, and phenylsuccinate as the major by-products. The conversion of styrene and the selectivity to cinnamate depend upon the types of catalysts and reaction conditions used. A plausible reaction mechanism is proposed to account for the selective formation of cinnamate.

Hsu, C.Y.

1987-04-01

456

New two-stage process converts butadiene to ethylbenzene  

SciTech Connect

In recent years, there has been a growing surplus of butadiene. DSM Research B.V. has developed to a semitechnical scale, a two-stage process to produce ethylbenzene from butadiene. The first step is the liquid-phase dimerization of butadiene to vinylcyclohexene. This step is carried out using an iron dinitrosyl-on-zinc catalyst. Butadiene conversion is more than 95% and selectivity is 100 %. In the second step, vinylcyclohexene is dehydrogenated to the end-product ethylbenzene in the gas phase, using a magnesium-oxide-based palladium catalyst. With 100% conversion, selectivity of greater than 95% is achieved for this reaction. The process design of this new ethylbenzene route is fairly simple, which translates to relatively low investment costs. Based on the 1992 Western European situation, a 100,00 metric tons/year (mty) ethylbenzene plant is economically feasible. And if butadiene prices drop to cracking value, the new process becomes even more attractive.

Not Available

1993-03-29

457

Study of Oxide-Based Catalysts for the Oxidative Transformation of Acetonitrile to Acrylonitrile with CH 4  

Microsoft Academic Search

Various oxides and metal-supported oxides were studied for the oxidative transformation of acetonitrile to acrylonitrile with methane in the range 550 to 730°C. This reaction requires the activation of both methane and the ?-carbon of the acetonitrile. Surprisingly, it was found that the effective coupling of the reactants to acrylonitrile does not occur over all the catalysts that are effective

Wenmin Zhang; Panagiotis G. Smirniotis

1999-01-01

458

Comparative toxicity of dithiocarbamates and butadiene metabolites in human lymphoid and bone marrow cells.  

PubMed

Apparent differences in the pattern of leukemia risk have been observed between workers employed in 1,3-butadiene (BD) monomer production and those working in styrene-butadiene rubber production (SBR). There are a number of possible explanations for these discrepancies, including differences in disease classification and diagnosis as well as possible quantitative and qualitative differences in occupational exposure between these two industries. This led us to evaluate the possibility that the pattern of disease observed in SBR might be influenced by the presence of an important class of biologically reactive chemicals, dithiocarbamates (DTC), that were present in SBR but not BD monomer production. Therefore, we compared the immunotoxic and hematotoxic activities of DTC and BD metabolites in human immune and hematopoietic cells. Relative to the mouse, human CD34+ bone marrow cells are relatively resistant to the direct effects of BD metabolites, with only the bis-oxide producing any evidence of suppression of clonogenic response at concentrations between 1 and 10 microM. Similarly, treatment of human CD4+ lymphocytes with known (2,3-epoxybutene) and putative BD metabolites (D,L-butane-bis-oxide, (2S,3R)-3-epoxybutane-1,2-diol) does not result in appreciable T-cell toxicity at concentrations likely to be encountered in vivo. In contrast, treatment of human cells with DTC at concentrations as low as 100 nM results in significant suppression of hematopoietic clonogenic response and T-lymphocyte function. Additional studies in our laboratory and others suggest a role for copper in DTC toxicity in both human lymphocytes and bone marrow cells, although the pattern of altered transcriptional regulation observed is markedly different in these two cell populations. These results are consistent with the pattern of DTC toxicity previously observed in clinical and molecular studies. PMID:11397416

Irons, R D; Stillman, W S; Pyatt, D W; Yang, Y; Le, A; Gustafson, D L; Hua Zheng, J

2001-06-01

459

Industrial emissions of 1,3-butadiene.  

PubMed

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

Mullins, J A

1990-06-01

460

Microbial transformations of styrene and [14C] styrene in soil and enrichment cultures.  

PubMed Central

Two different mechanisms were responsible for the disappearance of styrene in enrichment cultures: (i) a mixed population of microorganisms, capable of utilizing styrene as a sole carbon source, oxidized this substrate to phenylethanol and phenylacetic acid; (ii) the culture also mediated polymerization of the monomer to low-molecular-weight styrene oligomers. This chemical reaction probably occurred as the result of microbial degradation of butylcatechol, an antioxidant polymerization inhibitor present in commercial styrene. The resultant polymer material was subsequently metabolized. In soil incubation studies, 14CO2 evolution from applied [8-14C] styrene was used to estimate microbial degradation. Approximately 90 percent of the labeled carbon was evolved from a 0.2 percent addition, and about 75 percent was lost from the 0.5 percent application over a 16-week period.

Sielicki, M; Focht, D D; Martin, J P

1978-01-01

461

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

NASA Astrophysics Data System (ADS)

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

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

2012-01-01

462

40 CFR Table 5 to Subpart U of... - Known Organic HAP Emitted From the Production of Elastomer Products  

Code of Federal Regulations, 2010 CFR

...Butadiene Rubber. PBR/SBRS = Polybutadiene and Styrene Butadiene Rubber by Solution. PSR = Polysulfide Rubber. SBL = Styrene Butadiene Latex. SBRE = Styrene Butadiene Rubber by Emulsion. [66 FR 36928, July 16,...

2010-07-01

463

40 CFR Table 5 to Subpart U of... - Known Organic HAP Emitted From the Production of Elastomer Products  

Code of Federal Regulations, 2010 CFR

...Butadiene Rubber. PBR/SBRS = Polybutadiene and Styrene Butadiene Rubber by Solution. PSR = Polysulfide Rubber. SBL = Styrene Butadiene Latex. SBRE = Styrene Butadiene Rubber by Emulsion. [66 FR 36928, July 16,...

2009-07-01

464

Butadiene measurement technology. Final report, June 1987-February 1988  

SciTech Connect

The program involved the development and validation of a gas-chromatography procedure to measure 1,3-butadiene levels in vehicle exhaust. After development and validation, the procedure was used to measure 1,3-butadiene emissions from each of two gasoline-fueled light-duty test vehicles over duplicate cold-start Federal Test Procedure (FTP) tests. In addition to the 1,3-butadiene measurements, regulated exhaust emissions, other C4 hydrocarbons, and fuel economy measurements were conducted for each FTP test.

Smith, L.R.

1988-08-01

465

Viscoelastic Properties of Poly(ethylene-g-styrene).  

National Technical Information Service (NTIS)

The Time Temperature Superposition Principle was applied to the stress relaxation isotherms of two samples of poly-(ethylene-g-styrene). The graft copolymers were prepared by mutual irradiation of polyethylene powder and styrene monomer in a nuclear react...

J. Diamant D. R. Hansen M. Shen

1976-01-01

466

Multiobjective optimization of an industrial styrene monomer manufacturing process  

Microsoft Academic Search

Multi-objective optimization of the operation and design of a styrene manufacturing process has been studied with the elitist non-dominated sorting genetic algorithm (NSGA-II). In the first part, the study focused on bi-objective optimization and comparative analysis of three different styrene reactor designs—the single-bed, the steam-injected and the double-bed reactors. The objectives were to simultaneously maximize styrene flow rate and styrene

A. Tarafder; G. P. Rangaiah; Ajay K. Ray

2005-01-01

467

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

468

Recent advance in living anionic polymerization of functionalized styrene derivatives  

Microsoft Academic Search

This review covers recent advance of living anionic polymerization of styrene derivatives with functional groups. Although there have so far been reported several successful systems of living anionic polymerization of functionalized styrene derivatives, most useful functional groups are not amenable to the conditions of living anionic polymerization of styrene. Therefore, we herein present two generalized strategies to be able to

Akira Hirao; Surapich Loykulnant; Takashi Ishizone

2002-01-01

469

Polymerization of Styrene in Water-Alcohol-lonic Surfactant Solutions  

Microsoft Academic Search

The stability regions of styrene and polystyrene W\\/O micro-emulsions stabilized by sodium dodecyl sulfate with pentanol or butyl cellosolve as cosurfactant were determined. The polystyrene microemulsions showed considerably smaller stability regions than the ones with the monomer. Hence, early phase separation (turbidity) was encountered in polymerizing styrene within the microemulsion region. The maximally permitted conversion percentage of styrene in the

L. M. Gan; C. H. Chew; S. E. Friberg

1983-01-01

470

Non-staining, non-sticking styrenic polymers  

SciTech Connect

A method is described for preparing a non-staining, non-sticking, high impact polystyrene, which comprises: (a) a solution formed by dissolving a rubber in a mixture consisting essentially of a styrene, a polysiloxane and a solvent; (b) heating the resultant solution to graft polymerize the styrene onto the rubber; and (c) separating the solvent and any unreacted styrene present.

Gunesin, B.Z.

1987-09-08

471

Electrical properties of the plasticized polymer electrolytes based on acrylonitrile-methyl methacrylate copolymers  

Microsoft Academic Search

The plasticized polymer electrolytes composed of acrylonitrile (AN)-methyl methacrylate (MMA) copolymer and liquid electrolyte solution have been prepared. The electrochemical characteristics of these polymer electrolytes were investigated in terms of copolymer composition and content of liquid electrolyte. The relative molar ratio of AN-MMA in the copolymer proved to play a critical role in determining the ionic conductivity and capacity to

Dong-Won Kim; Young-Roak Kim; Jung-Ki Park; Seong-In Moon

1998-01-01

472

Radiation Grafting of Acrylonitrile onto Polyester Fiber as the Reinforcing Filler for Poly (Vinyl Chloride).  

National Technical Information Service (NTIS)

Studies have been carried out on radiation-induced grafting of acrylonitrile onto polyester fiber and on the properties of the grafted fiber in an attempt to increase the strength of polyester fiber reinforced soft poly (vinyl chloride) (PVC) sheet by imp...

K. Kaji I. Ando

1985-01-01

473

Species differences in the distribution of inhaled butadiene in tissues  

SciTech Connect

1,3-butadiene is produced commercially for use in the manufacture of elastomers, polymers and other chemicals. Recent inhalation carcinogenicity studies of butadiene indicate that B6C3F/sub 1/ mice are more sensitive to the tumorigenic effects of inhaled butadiene than are Sprague Dawley rats. The purpose of this investigation was to determine if there were differences in distribution in tissues of inhaled butadiene between rats and mice. Male Sprague Dawley rats and B6C3F/sub 1/ mice were exposed nose-only for 3.4 hr to (mean +/- SE) 1220 +/- 71 ..mu..g /sup 14/C-butadiene/L air and 121 +/- 2 ..mu..g /sup 14/C-butadiene/L air, respectively. Radioactivity was distributed widely in tissues immediately following exposure of both rats and mice to /sup 14/C-butadiene. In both species, respiratory tract tissue (lung, trachea, nasal turbinates), gastrointestinal tract (small and large intestine), liver, kidneys, urinary bladder and pancreas contained high concentrations of radioactivity within 1 hr after the end of a exposure. In all cases, tissues of mice contained 15 to 100 times the concentration of /sup 14/C-butadience equivalents per ..mu..m mole of butadiene inhaled than did rats. For both rats and mice, elimination of /sup 14/C from tissues and blood was rapid, with 77% to 99% of the initial tissue burden being eliminated with half-times of 2 to 10 hr. Within 1 hr after the end of exposure, all rat tissues retained a substantial amount of /sup 14/C that was associated with volatile material that was probably butadiene and/or metabolites. A similar observation was noted in mouse liver, the only tissue of mice examined. The data indicate that there were no apparent differences between rats and mice in tissue depots for /sup 14/C derived from butadiene, but that, per ..mu..mole of butadiene inhaled, tissues of mice attained significantly greater concentrations of /sup 14/C than did rats.

Bond, J.A.; Dahl, A.R.; Henderson, R.F.; Birnbaum, L.S.

1987-10-01

474

Some selected chapters from the (butadiene)zirconocene story  

Microsoft Academic Search

(Butadiene)zirconocene was the first mono-nuclear metal complex for which the s-trans-?4-conjugated diene coordination mode was established. Meanwhile a variety of additional examples from metals throughout the Periodic Table was found. The (butadiene)zirconocenes have found use as valuable reagents in organic and organometallic synthesis, for which various representative examples are described. They have also found extensive use as precursors for the

Gerhard Erker; Gerald Kehr; Roland Fröhlich

2004-01-01

475

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

476

Pilot-scale production of (S)-styrene oxide from styrene by recombinant Escherichia coli synthesizing styrene monooxygenase.  

PubMed

Recombinant Escherichia coli JM101(pSPZ10) cells produce the styrene monooxygenase of Pseudomonas sp. strain VLB120, which catalyzes the oxidation of styrene to (S)-styrene oxide at an enantiomeric excess larger than 99%. This biocatalyst was used to produce 388 g of styrene oxide in a two-liquid phase 30-L fed-batch bioconversion. The average overall volumetric activity was 170 U per liter over a period of more than 10 h, equivalent to mass transfer rates of 10.2 mmoles per liter per hour at a phase ratio of 0.5. At this transfer rate, the biotransformation system appeared to be substrate mass-transfer limited. The reactor had an estimated power input in the order of 5 W. L(-1), which is close to values typically obtained with commercially operating units. The product could be easily purified by fractional distillation to a purity in excess of 97%. The process illustrates the feasibility of recombinant whole cell biotransformations in two-liquid phase systems with toxic substrates and products. PMID:12209784

Panke, Sven; Held, Martin; Wubbolts, Marcel G; Witholt, Bernard; Schmid, Andreas

2002-10-01

477

Biodegradation of styrene in waterlogged soils and aquifer solids  

SciTech Connect

The biodegradation of styrene in waterlogged soils and aquifer solids was initially rapid, but the rate then declined. Significant amounts of styrene persisted under waterlogged conditions. Trace amounts of phenylethanol, phenylacetic acid, phenylacetaldehyde, and benzoic acid appeared in soils but not in aquifer solids. Styrene oxide was not detected. Addition of nitrate did not stimulate styrene degradation in aquifer solids and Lima Loam. Because many waste sites are anoxic, the persistence of styrene under waterlogged conditions may be of environmental importance. 18 refs., 4 tabs.

Fu, Min Hong; Alexander, M. [Cornell Univ., Ithaca, NY (United States)

1996-12-01

478

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

479

Cell sealant  

SciTech Connect

An electrochemical cell is described comprising an anode, a cathode and an electrolyte disposed within an open ended cylindrical metallic cell container, with an insulative cell top member being positioned within the open end of a sealant at the interface between the cell top member and the metallic cell container. The sealant is a mixture of a Type 2 BUR asphalt and an elastomeric material selected from the group consisting of (cis-1,4-polyisoprene), styrene-butadiene copolymer (SBR), cis-1,4-polybutadiene and styrene butadiene styrene (SBS), styrene isoprene styrene (SIS), neoprene (poly-chloprene), acrylonitrile-butadiene copolymer (NBR), ethylene-propylene elastomers (EPR), butyl rubber (copolymers of isobutylene), urethane, nitrile (polymers of butadiene and acrylonitrile), polysulfide, polyacrylate, silicone, chlorosulfonated polyethylene, and EPDM (terpolymers of ethylene, propylene and diene monomers), and mixtures thereof, and wherein the elastomeric material is substantially inert to the electrolyte and is present in an amount between 0.5% to 10% by weight of the asphalt.

Markin, C.; Book, R.J.; James, D.A.

1988-04-26

480

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

481

Occupational exposure of workers to 1,3-butadiene  

SciTech Connect

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.

Fajen, J.M.; Roberts, D.R.; Ungers, L.J.; Krishnan, E.R. (National Institute for Occupational Safety and Health, Cincinnati, OH (USA))

1990-06-01

482

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.

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

1990-01-01

483

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...

484

Predictors of occupational exposure to styrene and styrene-7,8-oxide in the reinforced plastics industry  

PubMed Central

Objective To identify demographic and work related factors that predict blood levels of styrene and styrene?7,8?oxide (SO) in the fibreglass reinforced plastics (FRP) industry. Methods Personal breathing?zone air samples and whole blood samples were collected repeatedly from 328 reinforced plastics workers in the Unuted States between 1996 and 1999. Styrene and its major metabolite SO were measured in these samples. Multivariable linear regression analyses were applied to the subject?specific levels to explain the variation in exposure and biomarker levels. Results Exposure levels of styrene were approximately 500?fold higher than those of SO. Exposure levels of styrene and SO varied greatly among the types of products manufactured, with an 11?fold range of median air levels among categories for styrene and a 23?fold range for SO. Even after stratification by job title, median exposures of styrene and SO among laminators varied 14? and 31?fold across product categories. Furthermore, the relative proportions of exposures to styrene and SO varied among product categories. Multivariable regression analyses explained 70% and 63% of the variation in air levels of styrene and SO, respectively, and 72% and 34% of the variation in blood levels of styrene and SO, respectively. Overall, air levels of styrene and SO appear to have decreased substantially in this industry over the last 10–20 years in the US and were greatest among workers with the least seniority. Conclusions As levels of styrene and SO in air and blood varied among product categories in the FRP industry, use of job title as a surrogate for exposure can introduce unpredictable measurement errors and can confound the relation between exposure and health outcomes in epidemiology studies. Also, inverse relations between the intensity of exposure to styrene and SO and years on the job suggest that younger workers with little seniority are typically exposed to higher levels of styrene and SO than their coworkers.

Serdar, B; Tornero-Velez, R; Echeverria, D; Nylander-French, L A; Kupper, L L; Rappaport, S M

2006-01-01

485

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

Federal Register 2010, 2011, 2012, 2013

...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...level for residues of 2-propenoic acid polymer, with 1,3-butadiene and...

2010-06-04

486

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

Code of Federal Regulations, 2010 CFR

...Measurement methods for benzene and 1,3-butadiene. 80.55 Section 80.55 Protection...Measurement methods for benzene and 1,3-butadiene. (a) Sampling for benzene and 1,3-butadiene must be accomplished by bag...

2010-07-01

487

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

Code of Federal Regulations, 2010 CFR

...Measurement methods for benzene and 1,3-butadiene. 80.55 Section 80.55 Protection...Measurement methods for benzene and 1,3-butadiene. (a) Sampling for benzene and 1,3-butadiene must be accomplished by bag...

2009-07-01

488

Species differences in butadiene metabolism between mice and rats evaluated by inhalation pharmacokinetics  

Microsoft Academic Search

Metabolism of 1,3-butadiene to 1,2-epoxybutene-3 in rats follows saturation kinetics. Comparative investigation of inhalation pharmacokinetics in mice also revealed a saturation pattern. For both species “linear” pharmacokinetics apply at exposure concentrations below 1000 ppm 1,3-butadiene; saturation of butadiene metabolism is observed at atmospheric concentrations of about 2000 ppm.

R. Kreiling; R. J. Laib; J. G. Filser; H. M. Bolt

1986-01-01

489

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

Code of Federal Regulations, 2013 CFR

...Measurement methods for benzene and 1,3-butadiene. 80.55 Section 80.55 Protection...Measurement methods for benzene and 1,3-butadiene. (a) Sampling for benzene and 1,3-butadiene must be accomplished by bag...

2013-07-01

490

Detection of acrolein and acrylonitrile with a pulsed room temperature quantum cascade laser  

NASA Astrophysics Data System (ADS)

We investigated the use of a pulsed, distributed feedback quantum cascade laser centered at 957 cm-1 in combination with an astigmatic Herriot cell with 250 m path length for the detection of acrolein and acrylonitrile. These molecules have been identified as hazardous air-pollutants because of their adverse health effects. The spectrometer utilizes the intra-pulse method, where a linear frequency down-chirp, that is induced when a top-hat current pulse is applied to the laser, is used for sweeping across the absorption line. Up to 450 ns long pulses were used for these measurements which resulted in a spectral window of ~2.2 cm-1. A room temperature mercury-cadmium-telluride detector was used, resulting in a completely cryogen free spectrometer. We demonstrated detection limits of ~3 ppb for acrylonitrile and ~6 ppb for acrolein with ~10 s averaging time. Laser characterization and optimization of the operational parameters for sensitivity improvement are discussed.

Manne, J.; Jäger, W.; Tulip, J.

2010-06-01

491

Multi-walled carbon nanotubes fabricated by electrospinning of acrylonitrile/nylon solution and subsequent carbonization.  

PubMed

The poly(acrylonitrile) (PAN) nanofiber web interpenetrated nylon-6 nanofiber supporters were prepared by electrospinning of an acrylonitrile (AN)/nylon-6 solution. It was realized that the average diameters of PAN and nylon-6 nanofiber were 20 and 100 nm, respectively, and that the PAN nanofibers constructed spider-mat networks which were supported by the robust nylon-6 nanofiber pillars. After stabilization and carbonization above 600 degrees C, both hollow-shaped and bamboo-shaped multi-walled carbon nanotubes (MWCNTs) were formed with the diameter range from 5 to 20 nm. The morphology and structure of MWCNTs had been further investigated by the combination techniques of transmission electron microscopy (TEM), electron diffraction (ED), X-ray diffraction (XRD) and elemental analyzer (EA). PMID:21125878

Park, Soo-Jin; Parajuli, Daman Chandra; Bajagi, Madhab Prasad; Jeong, Kwang-Un; Barakat, Nasser Aly Mohamed; Kim, Hak Yong

2010-08-01

492

Zinc, Copper, Iron, and Selenium Levels in Brain and Liver of Mice Exposed to Acrylonitrile  

Microsoft Academic Search

The mechanism of toxicity of acrylonitrile (AN) has not been fully defined. The research described herein was undertaken to\\u000a investigate the possible effects of AN on the levels of metallic elements in liver and brain of mice. Thirty-two mice were\\u000a randomly assigned to four separate groups and treated intraperitoneal (i.p.) once daily for 1 week. Mice in the control group\\u000a received

Lu Rongzhu; Wang Suhua; Xing Guangwei; Ren Chunlan; Han Fangan; Jing Junjie; Michael Aschner

2009-01-01

493

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

494

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

495

Copolymerization of acrylonitrile with N-vinyl-2-pyrrolidone to improve the hemocompatibility of polyacrylonitrile  

Microsoft Academic Search

Poly(acrylonitrile-co-N-vinyl-2-pyrrolidone)s (PANCNVP) were synthesized by water-phase precipitation copolymerization (WPPCP) with sodium chlorate–sodium metabisulfite as an oxidant\\/reducer initiator system. The copolymers were also synthesized by a solution copolymerization (SCP) initiated with azobis(isobutyronitrile) for comparison. Fourier transform infrared spectroscopy (FT-IR), nuclear magnetic resonance (1H NMR), and differential scanning calorimetry (DSC) were used to characterize the copolymers. It was found that the copolymerization

Ling-Shu Wan; Zhi-Kang Xu; Xiao-Jun Huang; Zhen-Gang Wang; Jian-Li Wang

2005-01-01

496

Effect of Low-Temperature Solution Polymerization Conditions of Acrylonitrile on the Molecular Characteristics of Polyacrylonitrile  

Microsoft Academic Search

Acrylonitrile (AN) was solution-polymerized in dimethyl sulfoxide (DMSO) and tertiary butyl alcohol (TBA) at 30,40 and 50°C using a low temperature initiator, 2,2?-azobis(2,4-dimethylvaleronitrile) (ADMVN), and effects of polymerization conditions were investigated in terms of molecular structures of polyacrylonitrile (PAN). Low polymerization temperature by adopting ADMVN proved to be successful in obtaining PAN of high molecular weight with smaller temperature rise

Byung Chul Jl; Hyun Seok Lee; Nam Sik Yoon; Sung Soo Han; Won Sik Yoon; Jinwon Lee; Won Seok Lyoo

2000-01-01

497

Adsorption of acrylonitrile and methyl acrylate on activated carbon in a packed bed column  

Microsoft Academic Search

The adsorption equilibrium and dynamics of acrylonitrile (ACN), methyl acrylate (MA) and the ACN-MA mixture on activated carbon\\u000a were investigated in a packed bed column at 40?C. The study indicated that the adsorption isotherms of the pure components belong to the classical Langmuir type; in the\\u000a case of the binary mixture adsorption, the Ideal Adsorption Solution Theory (IAST) could predict

Fengsong Wang; Jun Li; Jiarong Wang; Haoqi Gao

2006-01-01

498

Mechanical Responses of 2-Hydroxyethyl Methacrylate-Methacrylonitrile and 2-Hydroxyethyl Methacrylate-Acrylonitrile Copolymer Networks  

Microsoft Academic Search

The mechanical behaviour of 2-hydroxyethyl methacrylate-methacrylonitrile (HEMA-MAN)and 2-hydroxyethyl methacrylate-acrylonitrile (HEMA-AN) copolymer networks of various composition prepared in presence of 0.6 × 10 mol cm ethylene dimethacrylate and 20 vol.-% dimethylformamide were investigated. The viscoelastic and stress-strain behaviour of samples swollen in water to equilibrium and the dynamic relaxation behaviour of dry polymers from liquid nitrogen temperature onwards was investigated.It was

J. Janá?ek; J. Vacík; J. Kope?ek

1976-01-01

499

Subacute and chronic action of acrylonitrile on adrenals and gastrointestinal tract: biochemical, functional and ultrastructural studies in the rat.  

PubMed

A single dose of acrylonitrile can produce fatal adrenal apoplexy within approximately 2 h. Our previous studies also indicate that multiple injections of the chemical cause acute hemorrhagic and occasional nonperforating duodenal ulcers. Other authors have reported increase in gut and lung neoplasia after chronic exposure. The present study was designed to elucidate the subacute and chronic actions of acrylonitrile on the adrenals, stomach and duodenum by correlating biochemical, functional and morphologic investigations, as well as to gain insight into the mechanisms of action of acrylonitrile. Rats were exposed to 0, 0.0001% (1 ppm), 0.002%, 0.01%, 0.05% or 0.2% acrylonitrile in drinking water, or to the same amount of the chemical given through daily gavage, for 7, 21 or 60 days. Acrylonitrile caused a time- and dose-dependent decrease in plasma corticosterone levels; aldosterone was affected only by the 'high' dose and prolonged time of exposure. Young rats were more susceptible than adults to this action of acrylonitrile. The adrenal cortex, especially the zona fasciculata, was atrophic in rats that had ingested the nitrile through drinking water. At 0.05% and 0.2%, it also caused decreased food intake and body weight gain. The adrenals were enlarged with a hyperplastic zona fasciculata after daily doses of a bolus of acrylonitrile. Ingestion of the chemical did not interfere with compensatory enlargement of the adrenal gland following unilateral adrenalectomy. On the other hand, the ACTH-induced elevation of corticosterone plasma concentration was significantly attenuated by acrylonitrile in drinking water. Electron microscopy of the adrenal glands revealed no consistent changes in the steroid-producing cells. We thus postulate that accelerated turnover of circulating corticoids and/or interference with the secretion or action of ACTH may primarily be responsible for the decreased plasma levels of corticosterone and aldosterone in rats that ingest acrylonitrile. The mucosa in the stomach at the junction of the forestomach and glandular region of animals that had ingested acrylonitrile was hyperplastic. The corpus also showed regional mucosal hyperplasia with the appearance of 'cobble-stoning'. These changes were preceded and associated with an elevated concentration of non-protein sulfhydryls mostly in the mucosa of the glandular stomach. A similar, less prominent elevation also occurred in the proximal duodenum. These alt