Sample records for acrylonitrile butadiene styrene

  1. Constitutive modeling of fused deposition modeling acrylonitrile butadiene styrene (ABS) 

    E-print Network

    Mamadapur, Monish Shivappa

    2009-05-15

    Fused deposition modeling is a rapid prototyping process that is widely used to create prototypes. Acrylonitrile butadiene styrene is the most widely used material for fused deposition modeling. The parts are fabricated in a layer by layer fashion...

  2. Constitutive modeling of fused deposition modeling acrylonitrile butadiene styrene (ABS)

    E-print Network

    Mamadapur, Monish Shivappa

    2009-05-15

    Fused deposition modeling is a rapid prototyping process that is widely used to create prototypes. Acrylonitrile butadiene styrene is the most widely used material for fused deposition modeling. The parts are fabricated in a layer by layer fashion...

  3. Preparation and Properties of Fragrant Acrylonitrile-Butadiene-Styrene Composites

    Microsoft Academic Search

    Xiaolin Liu; Qi Yang; Zhiqiang Jiang; Decai Feng; Guangxian Li

    2009-01-01

    The aim of the present work is to upgrade the functionality and applicability of acrylonitrile-butadiene-styrene (ABS) composites by means of a blending technique. Fragrant ABS composites were prepared by adding a fragrance into the ABS matrix. It was found that the volatility of the essence was greatly affected by the nature of the essence, the environmental temperature and the polymer

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

    Microsoft Academic Search

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

    2008-01-01

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

  5. Fracture initiation and crack propagation of acrylonitrile-butadiene-styrene (ABS) in organic solvents

    Microsoft Academic Search

    Y. W. Mai

    1976-01-01

    The effects of organic liquid environments on the fracture behaviour of acrylonitrile-butadiene-styrene (ABS) have been investigated. Fracture initiation experiments showed thatKi2, (Ki being the stress intensity factor at crack\\/craze initiation), could be meaningfully correlated with the solvent solubility parameter (ds) of the different liquid environments and had a minimum value atds=dp, wheredp was the solubility parameter of ABS. For the

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

    PubMed

    Hirayama, Denise; Saron, Clodoaldo

    2015-06-01

    Polymeric materials constitute a considerable fraction of waste computer equipment and polymers acrylonitrile-butadiene-styrene and high-impact polystyrene are the main thermoplastic polymeric components found in waste computer equipment. Identification, separation and characterisation of additives present in acrylonitrile-butadiene-styrene and high-impact polystyrene are fundamental procedures to mechanical recycling of these polymers. The aim of this study was to evaluate the methods for identification of acrylonitrile-butadiene-styrene and high-impact polystyrene from waste computer equipment in Brazil, as well as their potential for mechanical recycling. The imprecise utilisation of symbols for identification of the polymers and the presence of additives containing toxic elements in determinate computer devices are some of the difficulties found for recycling of acrylonitrile-butadiene-styrene and high-impact polystyrene from waste computer equipment. However, the considerable performance of mechanical properties of the recycled acrylonitrile-butadiene-styrene and high-impact polystyrene when compared with the virgin materials confirms the potential for mechanical recycling of these polymers. PMID:26022280

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

    PubMed

    Díez-Pascual, Ana M; Gascón, David

    2013-11-27

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

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

    PubMed

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

    2010-01-01

    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

  9. Effects of single and repeated exposures to thermo-oxidative degradation products of poly(acrylonitrile-butadiene-styrene) (ABS) on rat lung, liver, kidney, and brain

    Microsoft Academic Search

    Antti Zitting; Heikki Savolainen

    1980-01-01

    Male Wistar rats were exposed to thermo-oxidative degradation products of heated poly(acrylonitrile-butadiene-styrene) (ABS). The exposures were conducted once, three times or ten times (5 nights\\/week, 6 h\\/night) in the nighttime. The degradation products included styrene, various nitriles, aldehydes, acids, and a significant aerosol fraction. The oxygen concentration in the exposure chamber was constantly above 20%. The shortest exposures caused a

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

    NASA Astrophysics Data System (ADS)

    Wang, X.; Yoshimura, N.

    1999-05-01

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

  11. 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

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

    2010-01-01

    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

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

    PubMed

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

    2015-01-01

    This study investigated the feasibility of using acrylonitrile-butadiene-styrene (ABS) waste plastic and nonmetal particles from waste printed circuit boards (WPCB) to manufacture reproduction composites (RC), with the aim of co-recycling these two waste resources. The composites were prepared in a twin-crew extruder and investigated by means of mechanical testing, in situ flexural observation, thermogravimatric analysis, and dimensional stability evaluation. The results showed that the presence of nonmetal particles significantly improved the mechanical properties and the physical performance of the RC. A loading of 30 wt% nonmetal particles could achieve a flexural strength of 72.6 MPa, a flexural modulus of 3.57 GPa, and an impact strength of 15.5 kJ/m(2). Moreover, it was found that the application of maleic anhydride-grafted ABS as compatilizer could effectively promote the interfacial adhesion between the ABS plastic and the nonmetal particles. This research provides a novel method to reuse waste ABS and WPCB nonmetals for manufacturing high value-added product, which represents a promising way for waste recycling and resolving the environmental problem. PMID:25413110

  13. Complex phase separation in poly(acrylonitrile-butadiene-styrene)-modified epoxy/4,4'-diaminodiphenyl sulfone blends: generation of new micro- and nanosubstructures.

    PubMed

    Jyotishkumar, P; Koetz, Joachim; Tiersch, Brigitte; Strehmel, Veronika; Ozdilek, Ceren; Moldenaers, Paula; Hässler, Rudiger; Thomas, Sabu

    2009-04-23

    The epoxy system containing diglycidyl ether of bisphenol A and 4,4'-diaminodiphenyl sulfone is modified with poly(acrylonitrile-butadiene-styrene) (ABS) to explore the effects of the ABS content on the phase morphology, mechanism of phase separation, and viscoelastic properties. The amount of ABS in the blends was 5, 10, 15, and 20 parts per hundred of epoxy resin (phr). Transmission electron microscopy (TEM) and scanning electron microscopy (SEM) were employed to investigate the final morphology of ABS-modified epoxy blends. Scanning electron microscopic studies of 15 phr ABS-modified epoxy blends reveal a bicontinuous structure in which both epoxy and ABS are continuous, with substructures of the ABS phase dispersed in the continuous epoxy phase and substructures of the epoxy phase dispersed in the continuous ABS phase. TEM micrographs of 15 phr ABS-modified epoxy blends confirm the results observed by SEM. TEM micrographs reveal the existence of nanosubstructures of ABS in 20 phr ABS-modified epoxy blends. To the best of our knowledge, to date, nanosubstructures have never been reported in any epoxy/thermoplastic blends. The influence of the concentration of the thermoplastic on the generated morphology as analyzed by SEM and TEM was explained in detail. The evolution and mechanism of phase separation was investigated in detail by optical microscopy (OM) and small-angle laser light scattering (SALLS). At concentrations lower than 10 phr the system phase separates through nucleation and growth (NG). However, at higher concentrations, 15 and 20 phr, the blends phase separate through both NG and spinodal decomposition mechanisms. On the basis of OM and SALLS, we conclude that the phenomenon of complex substructure formation in dynamic asymmetric blends is due to the combined effect of hydrodynamics and viscoelasticity. Additionally, dynamic mechanical analysis was carried out to evaluate the viscoelastic behavior of the cross-linked epoxy/ABS blends. Finally, apparent weight fractions of epoxy and ABS components in epoxy- and ABS-rich phases were evaluated from T(g) analysis. PMID:19331324

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

    NASA Astrophysics Data System (ADS)

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

    2012-06-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2014-09-01

    This study compares two ethylene-tetrafluoroethylene (ETFE) surface activation treatments, namely chemical attack with a solution of sodium naphthenate and plasma erosion via air-ionization corona discharge in order to improve the adhesive properties of the ETFE. An experimental design was prepared for both treatments in order to assess the effect of the treatment characteristics on the tensile load needed to break the bond between the ETFE and the acrylonitrile-butadiene-styrene polymer (ABS) formed with a cyanoacrylate adhesive (CAA) applied between them. The reason for the selection of this problem is that both polymers are frequently used in the biomedical industry for their properties, and they need to be joined firmly in biomedical devices, and the cyanoacrylate adhesive is the adhesive traditionally used for fluoropolymers, in this case the ETFE, and the same CAA has also shown good adhesion with ABS. However, the strength of the bond for the triplet ETFE-CAA-ABS has not been reported and the improvement of the strength of the bond with surface treatments is not found in scholarly journals for modern medical devices such as stents and snares. Both treatments were compared based on the aforementioned design of experiments. The case where ETFE receives no surface treatment serves as the reference. The results indicated that the three factors evaluated (initial drying of the material, temperature of the chemical bath, and immersion time), and their interactions have no significant effect over the tensile load at failure (tensile strength) of the adhesive bond being evaluated. For the air-ionization corona discharge treatment, two factors were evaluated: discharge exposition time and air pressure. The results obtained from this experimental design indicate that there is no significant difference between the levels of the factors evaluated. These results were unexpected as the ranges used were representative of the maximum ranges permissible in manufacturing operations. As for the comparison of the treatments, it was determined that the treatments have statistically significant differences. It was also determined that there is a significant statistical difference between the processes where a surface treatment is performed and the process where no surface treatment is applied to the ETFE. The chemical treatment results in a higher tensile load at failure (tensile strength) of 276.6 N on average, the air ionization treatment has an average of 248.4 N, and the process with no treatment has the lower ultimate tensile strength average of 53 N. This comparison has demonstrated that the best treatment is the chemical treatment with sodium naphthenate under the conditions tested.

  16. Fundamental Scratch Behavior of Styrene-Acrylonitrile Random Copolymers 

    E-print Network

    Browning, Robert Lee

    2011-10-21

    The present study employs a standardized progressive load scratch test (ASTM D7027/ISO 19252) to investigate the fundamental physical and mechanistic origins of scratch deformation in styrene-acrylonitrile (SAN) random copolymers. Previous findings...

  17. Modification of Epoxy Resin by Cyanate Ester Resin and Liquid Butadiene-Acrylonitrile Rubbers

    Microsoft Academic Search

    Xudong Sun; Minfeng Zeng; Cuiyun Lu; Fengyuan Yan; Chenze Qi

    2010-01-01

    In this paper, the results showed that the addition of an appropriate amount of reactive rubbers ((ie: carboxyl randomized butadiene-acrylonitrile rubber (CRBN) and hydroxyl terminated butadiene-acrylonitrile rubber (HTBN)) to epoxy resin\\/cyanate ester resin (EP\\/CE) (70\\/30) improved both the mechanical properties and thermal stability of the resulting blends. CRBN and HTBN have different reactive activity and dispersion state in EP\\/CE\\/rubbers. No

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

    Microsoft Academic Search

    Zeng Minfeng; Lu Cuiyun; Qi Chenze

    2010-01-01

    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.

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

    Microsoft Academic Search

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

    1997-01-01

    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

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

    NASA Astrophysics Data System (ADS)

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

    2010-06-01

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

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

    SciTech Connect

    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

    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.

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

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

    PubMed

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

    2009-07-01

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

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

    PubMed Central

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

    2008-01-01

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

  5. Miscibility, morphology and fracture toughness of epoxy resin\\/poly(styrene- co-acrylonitrile) blends

    Microsoft Academic Search

    Jian Li

    1996-01-01

    Poly(styrene-co-acrylonitrile) (SAN) with 25 wt% acrylonitrile (AN) content was found to be miscible with uncured bisphenol-A-type resin, i.e. diglycidylether of bisphenol A (DGEBA), as shown by the existence of a single glass transition temperature within the whole composition range. Miscibility between SAN and DGEBA is considered to be due mainly to entropy contribution. However, SAN was judged to be immiscible

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

    Microsoft Academic Search

    Siriya Angnanon; Pattarapan Prasassarakich; Napida Hinchiranan

    2011-01-01

    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

  7. Effect of Different Inorganic Fillers on the Physical Properties of Styrene-Butadiene Rubber Vulcanizates

    Microsoft Academic Search

    F. M. Helaly; A. S. Badran; A. M. Ramadan

    1991-01-01

    The effect of different inorganic fillers such as lead silicate (amor phous or crystalline), burnt mazote boiler deposits (BMBD), aluminium oxide and ilmenite (FeTiO3) on the physical properties of different filled styrene- butadiene rubbers (SBR) has been investigated. The rate of vulcanization was increased according to the following order: lead silicate (amorphous or crystal line) > BMBD > aluminium oxide

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  9. Kinetics of coarsening in immiscible poly (?-caprolactone)\\/poly(styrene-co-acrylonitrile) blends

    Microsoft Academic Search

    Lenka Jelínková; Petr Svoboda; Petr Sáha; Takashi Inoue

    2012-01-01

    The morphological development of immiscible blends of poly(?-caprolactone) (PCL) and poly(styrene-co-acrylonitrile) (SAN) during static annealing was studied using time-resolved light scattering and optical microscopy. In the melt-blended samples, coarsening was not observable at low temperatures, even above the glass transition temperature of SAN (Tg=113 °C). It occurred when a critical temperature T* (for example, 170 °C for a PCL\\/SAN (50\\/50)

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

    Microsoft Academic Search

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

    2004-01-01

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

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

    Microsoft Academic Search

    A. Seema; S. K. N. Kutty

    2006-01-01

    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

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

    Microsoft Academic Search

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

    1999-01-01

    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

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

    NASA Technical Reports Server (NTRS)

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

    1984-01-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2011-12-01

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

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

    PubMed

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

    2015-09-01

    Starch-graft-acrylonitrile (ANS) is compounded with carboxylated nitrile butadiene rubber (XNBR) latex. The control XNBR and the ANS/XNBR latex films were prepared through a coagulant dipping process. The films were subjected to ageing and soil burial procedures. For the biodegradation experiment, the surface of the film was assessed after the 2nd, 4th and 8th week of soil burial. The ANS, XNBR, and ANS/XNBR colloidal stability were determined with a Malvern(®) Zetasizer. For the dipped latex films, the mechanical, morphological and thermal properties were analyzed. The addition of ANS into the XNBR latex increased the stability of the colloidal dispersions, decreased the latex film tensile strength, but increased the elongation at break due to the bipolar interaction of the ANS and XNBR particles. The ANS/XNBR latex films aged faster than the control films while the morphological analysis showed the existence of a starch crystal region and the formation of microbial colonies on the surfaces of the films. Based on the TGA-DTA curves, a higher ?T was observed for the ANS/XNBR latex films signifying high thermal energy needed for the film to thermally degrade. PMID:26005134

  16. Cure Characteristics and Mechanical Properties of Vinyltriethoxysilane Grafted Styrene-Butadiene Rubber\\/Silica Blends

    Microsoft Academic Search

    Changjie Yin; Qiuyu Zhang; Junwei Gu; Zhichao Zhao; Jucheng Zheng; Guangbi Gong; Tao Liang; Hepeng Zhang

    2012-01-01

    Graft polymerization of vinyltriethoxysilane (VTES) onto styrene-butadiene rubber (SBR) was carried out in latex using potassium peroxydisulfate as an initiator. Then SBR-g-VTES\\/silica, SBR\\/TESPT\\/silica and SBR-g-VTES\\/TESPT\\/silica were prepared by mechanical mixing with different silica loading. The silica particles dispersed uniformly in the SBR-g-VTES networks. Among the three composites, the SBR-g-VTES\\/Silica blends show the highest of all. The t90 of SBR-g-VTES\\/TESPT\\/Silica composites

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

    Microsoft Academic Search

    Samra Sangari; Hill Anita; Pavel Dumitru

    2004-01-01

    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

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  19. 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 ...

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

    Microsoft Academic Search

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

    2007-01-01

    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

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

    Microsoft Academic Search

    S. Osterman-Golkar; J. A. Bond

    1996-01-01

    The 1990 Clean Air Act Amendments list several volatile organic chemicals as hazardous air pollutants, including ethylene oxide, butadiene, styrene, and acrylonitrile. The toxicology of many of these compounds shares several common elements such as carcinogenicity in laboratory animals, genotoxicity of the epoxide intermediates, involvement of cytochrome P450 for metabolic activation (except ethylene oxide), and involvement of at least two

  2. Morphology, dynamic mechanical and thermal studies on poly(styrene-co-acrylonitrile) modified epoxy resin\\/glass fibre composites

    Microsoft Academic Search

    Nishar Hameed; P. A. Sreekumar; Bejoy Francis; Weimin Yang; Sabu Thomas

    2007-01-01

    Poly(styrene-co-acrylonitrile) (SAN) was used to modify diglycidyl ether of bisphenol-A (DGEBA) type epoxy resin cured with diamino diphenyl sulfone (DDS) and the modified epoxy resin was used as the matrix for fibre reinforced composites (FRPs) in order to get improved mechanical and thermal properties. E-glass fibre was used as the fibre reinforcement. The morphology, dynamic mechanical and thermal characteristics of

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

    NASA Astrophysics Data System (ADS)

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

    2009-03-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2013-12-01

    The dielectric response of poly(styrene-co-acrylonitrile) (PSAN) thin films fabricated by a solution casting process was investigated in this work. Linear dielectric behavior was obtained in PSAN films under an electric field at frequencies from 100 Hz to 1 MHz and temperature of -50°C to 100°C. The polymer films exhibited an intermediate dielectric permittivity of 4 and low dielectric loss (tan ?) 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.

  5. Magnetic field effect on the photocrosslinking of a butadiene-styrene copolymer modified by benzoyl or phenylacetyl groups

    Microsoft Academic Search

    Klaus Hummel; Raimund Schaller; Michael G. Martl

    1987-01-01

    A butadiene-styrene copolymer was partially modified by Friedel-Crafts reaction of phenyl groups with benzoyl chloride or phenylacetyl chloride. The resulting benzoylphenyl and phenylacetylphenyl groups served as photosensitizers for a subsequent crosslinking by u.v. irradiation. The extent of crosslinking was measured by sol\\/gel analysis. Crosslinking was carried out without magnetic field and with magnetic field of flux density 1.0 Tesla. The

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

    Microsoft Academic Search

    G. R. Hamed; G. D. Roberts

    1994-01-01

    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

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

    PubMed

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

    2011-05-01

    A systematic study on the evolution of free volume as a function of the temperature in vulcanized at 433 K natural rubber (NR) and styrene butadiene rubber (SBR) in 25-75, 50-50, 75-25 NR-SBR (percent content of pure NR and SBR, respectively) blends was studied by positron annihilation lifetime spectroscopy. All samples were prepared with sulfur and TBBS (n-t-butyl-2-benzothiazole sulfenamide) as accelerator. The glass transition temperatures of the samples studied were determined by differential scanning calorimetry (DSC) and from lifetime data. In general, a sigmoidal-like complex behavior of the long-lived lifetime component, linked to the nanohole free volume, as a function of the temperature was found. For SBR, the slope of the ortho-positronium lifetime against temperature curves could be well-fitted using a linear function. For blends and also for NR, two different linear functions were necessary. This last behavior is explained in terms of the supercooled process involving a reconfiguration of the elastomeric chains. In the case of blends, the state of cure of NR and SBR in each NR-SBR sample was also taken into account in the discussion of the results obtained. Besides, thermal expansion coefficients of the free volumes in the transition and glassy region of all compounds were estimated. The differences observed in the values of this parameter are discussed by taking into account the morphology and formulation of each blend, the crosslink densities, and the role of the interphases formed between both NR and SBR elastomers. PMID:21728565

  8. 21 CFR 177.1050 - Acrylonitrile/styrene copoly-mer modified with butadiene/styrene elastomer.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

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

  9. 21 CFR 177.1050 - Acrylonitrile/styrene copoly-mer modified with butadiene/styrene elastomer.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

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

  10. 21 CFR 177.1050 - Acrylonitrile/styrene copoly-mer modified with butadiene/styrene elastomer.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

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

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

    Code of Federal Regulations, 2012 CFR

    2012-04-01

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

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

    Code of Federal Regulations, 2013 CFR

    2013-04-01

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

  13. 21 CFR 177.1040 - Acrylonitrile/styrene copoly-mer.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

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

  14. 21 CFR 177.1040 - Acrylonitrile/styrene copoly-mer.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

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

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

    Code of Federal Regulations, 2010 CFR

    2010-04-01

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

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

    Code of Federal Regulations, 2012 CFR

    2012-04-01

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

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

    Code of Federal Regulations, 2013 CFR

    2013-04-01

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

  18. Isotope dilution gas chromatography-mass spectrometry in the determination of benzene, toluene, styrene and acrylonitrile in mainstream cigarette smoke.

    PubMed

    Byrd, G D; Fowler, K W; Hicks, R D; Lovette, M E; Borgerding, M F

    1990-03-23

    A cryogenic trapping method with isotope dilution gas chromatography-mass spectrometry analysis has been developed for the determination of benzene, toluene, styrene and acrylonitrile in mainstream vapor phase cigarette smoke. The method is simple, direct, and quantitative. Vapor phase samples are collected cryogenically in a series of four traps following removal of the particulate phase with a Cambridge filter pad. For all four analytes, 75-85% of the total amounts recovered were found in the initial trap and less than 1% in the final trap. Assessment of instrumental precision by multiple injections of a sample gave relative standard deviations of less than 2%. Linear calibration for all analytes over the analysis range gave an r2 value greater than 0.99 with average relative standard deviations at the mean ranging from 1.4 to 8.2%. The cigarettes analyzed include a reference cigarette (Kentucky 1R4F), a commercial ultra-low "tar" mentholated cigarette, and two cigarettes that heat but do not burn tobacco. The values determined for the four analytes in the 1R4F samples are comparable to reported values of similar cigarettes. The cigarettes which heat rather than burn tobacco yield less of all four analytes compared to the other cigarettes in the study. PMID:2185256

  19. Degradation of carboxylated styrene butadiene rubber based water born paints. Part 1: Effect of talc filler and titania pigment on UV stability

    Microsoft Academic Search

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

    2007-01-01

    The photo-oxidation of cast self-supporting films of a carboxylated styrene butadiene random copolymer (c-SBR) containing talc and TR92 (coated rutile) (both separately and together) has been investigated using ATR-FTIR, toluene swelling measurements and DSC (for Tg determination). An imaging chemiluminescence (ICL) method was also used to depth profile the oxidation. Both the wavelength of the UV source and the presence

  20. 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

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

    2007-01-01

    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

  1. Molecular dynamics of an epoxy resin modified with an epoxidized poly(styrene–butadiene) linear block copolymer during cure and microphase separation processes

    Microsoft Academic Search

    E. Serrano; G. Kortaberria; P. Arruti; A. Tercjak; I. Mondragon

    2009-01-01

    Molecular dynamics of diglycidyl ether of bisphenol A (DGEBA) epoxy resin modified with an epoxidized poly(styrene-b-butadiene) (SepB) linear block copolymer has been monitored during cure and microphase separation process by dielectric relaxation spectroscopy (DRS) for wide frequency and temperature ranges. Different primary and secondary relaxation processes have been analyzed for neat components and ternary mixture. Relaxational behaviour has been modelled

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

    NASA Astrophysics Data System (ADS)

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

    2004-01-01

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

  3. Styrene

    MedlinePLUS

    ... such as insulation, pipes, automobile parts, printing cartridges, food containers, and carpet backing. How are people exposed ... may also leach from polystyrene containers used for food products, but levels of styrene in food are ...

  4. The morphology and property of ultra-fine full-vulcanized acrylonitrile butadiene rubber particles\\/EPDM blends

    Microsoft Academic Search

    Liqun Zhang; Tie Li; Yonglai Lu; Yuanwang Tang; Jinliang Qiao; Ming Tian

    2006-01-01

    A novel UFNBRP\\/EPDM blend was pre- pared by compounding ultra-fine full-vulcanized acryloni- trile butadiene rubber particles (UFNBRP) with ethylene- propylene- diene monomer (EPDM) matrix. The morphol- ogy, dynamic property, and curing property of the blend were discussed in detail. TEM and SEM observations showed that, no matter how high the blend ratio of UFNBRP to EPDM matrix was, UFNBRP particles

  5. 21 CFR 181.32 - Acrylonitrile copolymers and resins.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...copolymer—no restrictions. (2) Coatings. (i) Acrylonitrile/butadiene copolymer...chloride resin—for use only as extruded pipe. (b) Limitations for acrylonitrile...using the method of analysis titled “Gas-Solid Chromatographic...

  6. 21 CFR 181.32 - Acrylonitrile copolymers and resins.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...copolymer—no restrictions. (2) Coatings. (i) Acrylonitrile/butadiene copolymer...chloride resin—for use only as extruded pipe. (b) Limitations for acrylonitrile...using the method of analysis titled “Gas-Solid Chromatographic...

  7. 21 CFR 181.32 - Acrylonitrile copolymers and resins.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...copolymer—no restrictions. (2) Coatings. (i) Acrylonitrile/butadiene copolymer...chloride resin—for use only as extruded pipe. (b) Limitations for acrylonitrile...using the method of analysis titled “Gas-Solid Chromatographic...

  8. 21 CFR 181.32 - Acrylonitrile copolymers and resins.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...copolymer—no restrictions. (2) Coatings. (i) Acrylonitrile/butadiene copolymer...chloride resin—for use only as extruded pipe. (b) Limitations for acrylonitrile...using the method of analysis titled “Gas-Solid Chromatographic...

  9. 21 CFR 181.32 - Acrylonitrile copolymers and resins.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...copolymer—no restrictions. (2) Coatings. (i) Acrylonitrile/butadiene copolymer...chloride resin—for use only as extruded pipe. (b) Limitations for acrylonitrile...using the method of analysis titled “Gas-Solid Chromatographic...

  10. Chemiluminescence in evaluating thermal oxidative stability of acrylonitrile-butadiene-styrene (ABS) copolymers. III. Emulsion-grade products

    Microsoft Academic Search

    Sunil S. Parikh; Lev Zlatkevich

    1995-01-01

    The thermal oxidative stability of various formulations based on emulsion-grade ABS was studied by the chemiluminescence technique. Emulsion products were found to be essentially less stable than ionic mass polymerization resins. Among the antioxidants studied, Santonox R is clearly more efficient than Irganox 1076 and Irganox 3114, and its superiority is reflected primarily in improved induction period values. The introduction

  11. Chemiluminescence in evaluating the thermal oxidative stability of acrylonitrile-butadiene-styrene (ABS) copolymers. II. ABS\\/polycarbonate (PC) blends

    Microsoft Academic Search

    Sunil S. Parikh; Lev Zlatkevich

    1993-01-01

    The thermal oxidative stability of various ABS\\/PC compounds was studied by means of the chemiluminescence technique. Similarly to pure ABS, Irganox 1076 and Irganox MD 1024 perform as moderate antioxidants in ABS\\/PC and (ABS\\/PC + lubricant) blends. Neither Tinuvin 144, Irgaphos 168, nor their mixture affects the durability of the ABS\\/PC blend. At the same time, (Irgaphos 168 + Tinuvin

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

    PubMed

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

    2012-10-01

    The CO(2) cofeed impact on the pyrolysis of styrene butadiene rubber (SBR) was investigated using thermogravimetric analysis (TGA) coupled to online gas chromatography/mass spectroscopy (GC/MS). The direct comparison of the chemical species evolved from the thermal degradation of SBR in N(2) and CO(2) led to a preliminary mechanistic understanding of the formation and relationship of light hydrocarbons (C(1-4)), aromatic derivatives, and polycyclic aromatic hydrocarbons (PAHs), clarifying the role of CO(2) in the thermal degradation of SBR. The identification and quantification of over 50 major and minor chemical species from hydrogen and benzo[ghi]perylene were carried out experimentally in the temperature regime between 300 and 500 °C in N(2) and CO(2). The significant amounts of benzene derivatives from the direct bond dissociation of the backbone of SBR, induced by thermal degradation, provided favorable conditions for PAHs by the gas-phase addition reaction at a relatively low temperature compared to that with conventional fuels such as coal and petroleum-derived fuels. However, the formation of PAHs in a CO(2) atmosphere was decreased considerably (i.e., ?50%) by the enhanced thermal cracking behavior, and the ultimate fates of these species were determined by different pathways in CO(2) and N(2) atmospheres. Consequently, this work has provided a new approach to mitigate PAHs by utilizing CO(2) as a reaction medium in thermochemical processes. PMID:22950720

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

    NASA Astrophysics Data System (ADS)

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

    2015-07-01

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

  14. HEALTH ASSESSMENT OF 1,3-BUTADIENE

    EPA Science Inventory

    This assessment was conducted to review the new information that has become available since EPA's 1985 health assessment of 1,3-butadiene. 1,3-Butadiene is a gas used commercially in the production of styrene-butadiene rubber, plastics, and thermoplastic resins. The major...

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

    PubMed Central

    Morrow, N L

    1990-01-01

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

  16. 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...

  17. Polybenzoxazole-filled nitrile butadiene rubber compositions

    NASA Technical Reports Server (NTRS)

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

    2008-01-01

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

  18. Scratch Behavior of Multiphase Styrenic Copolymers and Effects of Environmental Conditioning 

    E-print Network

    Moghbelli, Ehsan

    2014-09-05

    ........................................................................................... 46 vii CHAPTER III EFFECT OF HIGH TEMPERATURE ANNEALING ON SCRATCH BEHAVIOR OF ACRYLONITRILE STYRENE ACRYLATE COPOLYMERS ............................................................................................................... 48 3.... However, no detailed knowledge was gained in addressing correlation between the material properties and scratch damage mechanisms. Browning et al. [8] investigated the effect of acrylonitrile (AN) content and molecular weight (MW) on scratch behavior...

  19. Carcinogenicity of 1,3-butadiene.

    PubMed Central

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

    1993-01-01

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

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

    Microsoft Academic Search

    Carper

    1990-01-01

    This paper reports on the development of two hydrocarbon-based resin formulations that could be used with different thermoplastic block copolymers to formulate pressure-sensitive adhesives. Results are examined with one of these resins in formulations with styrene-isoprene-styrene (SIS) and styrene-butadiene (SB) compounds. The new modified hydrocarbon resin, with a softening point of 98° C, matches the adhesive performance of a terpene

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

    SciTech Connect

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

    1986-04-01

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

  2. Molecular Structure of Acrylonitrile

    NSDL National Science Digital Library

    2002-09-27

    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.

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

    PubMed

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

    2015-05-01

    In the present research, blending of polymers used in electrical and electronic equipment, i.e. acrylonitrile-butadiene-styrene terpolymer, polycarbonate and polypropylene, was performed in a twin-screw extruder, in order to explore the effect process parameters on the mixture properties, in an attempt to determine some characteristics of a fast and economical procedure for waste management. The addition of polycarbonate in acrylonitrile-butadiene-styrene terpolymer seemed to increase its thermal stability. Also, the addition of polypropylene in acrylonitrile-butadiene-styrene terpolymer facilitates its melt processing, whereas the addition of acrylonitrile-butadiene-styrene terpolymer in polypropylene improves its mechanical performance. Moreover, the upgrading of the above blends by incorporating 2?phr organically modified montmorillonite was investigated. The prepared nanocomposites exhibit greater tensile strength, elastic modulus and storage modulus, as well as higher melt viscosity, compared with the unreinforced blends. The incorporation of montmorillonite nanoplatelets in polycarbonate-rich acrylonitrile-butadiene-styrene terpolymer/polycarbonate blends turns the thermal degradation mechanism into a two-stage process. Alternatively to mechanical recycling, the energy recovery from the combustion of acrylonitrile-butadiene-styrene terpolymer/polycarbonate and acrylonitrile-butadiene-styrene terpolymer/polypropylene blends was recorded by measuring the gross calorific value. Comparing the investigated polymers, polypropylene presents the higher gross calorific value, followed by acrylonitrile-butadiene-styrene terpolymer and then polycarbonate. The above study allows a rough comparative evaluation of various methodologies for treating plastics from waste from electrical and electronic equipment. PMID:25750055

  4. Metabolism of acrylonitrile and interactions

    SciTech Connect

    Hogy, L.L.

    1986-01-01

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

  5. Fundamental Scratch Behavior of Styrene-Acrylonitrile Random Copolymers

    E-print Network

    Browning, Robert Lee

    2011-10-21

    scratches can lead to damage that compromises the lifetime of the component. This is especially important in transport applications where metal pipes are often coated with polymeric materials to prevent corrosion while exposed to the atmosphere or buried... and the Polymer Technology Center at Texas A&M University. The evaluation of scratch resistance must be founded on the fundamental principles of material science. Intuitively, the scratch-induced deformation is strongly related to the stress and strain...

  6. Under microscopes the poly(styrene/butadiene) nanoparticles.

    PubMed

    Wang, Xiaorong; Sadhukhan, Pat

    2007-12-01

    There has been considerable interest, both academic and industrial, in developing synthesis processes for making polymeric nanoparticles. Our effort relied on the nanoassembly concepts of block macromolecules in solutions to prepare particles with a hard core made of crosslinked plastics and a soft shell made of low T(g) elastomer. By a suitable variation of the composition, polymer molecular weight and solute concentration, we were able to produce spherical, ellipsoidal, cylindrical, and chain-like nanoparticles. Under microscopes, the chain-like nanoparticles displayed very rich conformational features in diluted and dense states. Our observation on the conformation characters of the nanochains in 3D diluted state agreed well with the proposition of the self-avoid coil model. However, in 2D dense state, our observation on the nanochains appeared to be in contradiction with the segregated globule model proposed by de Gennes. PMID:18048455

  7. 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...

  8. HEALTH ASSESSMENT DOCUMENT FOR ACRYLONITRILE. FINAL REPORT

    EPA Science Inventory

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

  9. Molecular Structure of Styrene

    NSDL National Science Digital Library

    2004-11-11

    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.

  10. Optimize styrene units

    SciTech Connect

    Huang, W.

    1983-04-01

    A simulation system is introduced to improve production on older EB reactors and styrene plants to compete with the latest styrene processes such as the Monsanto process. A simulation model of ethyl benzene styrene process flow was built and tested and is schematicized. Each tower, the EB reactor, the PEB recovery tower, and the benzene-toluene separator are specified. Sloppy design in the lumping of described components is eliminated. An integrated reactor fractionation system with EB reactor and styrene process units is created.

  11. 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...

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

    PubMed

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

    2014-05-01

    This study is focused on the recovery and recycling of plastics waste, primarily polycarbonate, poly(acrylonitrile-butadiene-styrene) and high impact polystyrene, from end-of-life waste electrical and electronic equipments. Recycling of used polycarbonate, acrylonitrile-butadiene-styrene, polycarbonate/acrylonitrile-butadiene-styrene and acrylonitrile-butadiene-styrene/high impact polystrene material was carried out using material recycling through a melt blending process. An optimized blend composition was formulated to achieve desired properties from different plastics present in the waste electrical and electronic equipments. The toughness of blended plastics was improved with the addition of 10 wt% of virgin polycarbonate and impact modifier (ethylene-acrylic ester-glycidyl methacrylate). The mechanical, thermal, dynamic-mechanical and morphological properties of recycled blend were investigated. Improved properties of blended plastics indicate better miscibility in the presence of a compatibilizer suitable for high-end application. PMID:24695435

  13. Reduction of acrylamide and acrylonitrile emissions

    SciTech Connect

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

    1985-10-01

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

  14. Styrene Purification and Recovery Using Freeze Crystallization 

    E-print Network

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

    1992-01-01

    Lab tests have demonstrated the ability to separate styrene from ABS and SAN plastics wastes by cooling the waste until the styrene begins to crystallize. The same process that recovers styrene from these wastes can be used to purify styrene...

  15. Effects of rubber content and matrix structure on static and fatigue fracture in ABS copolymers

    Microsoft Academic Search

    L. Castellani

    2000-01-01

    Rubber toughening mechanisms in acrylonitrile-butadiene-styrene (ABS) may be affected by the dispersed phase size, structure and content and by the characteristics of the styrene-acrylonitrile copolymer (SAN) matrix, namely by its molecular weight distribution and acrylonitrile (AN) content. In this work a series of ABS samples having different matrix average molecular weights and AN contents, and different dispersed rubber-phase content were

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

    SciTech Connect

    Henderson, R.F.

    1995-02-01

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

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

    SciTech Connect

    Carper, J.D. (Hercules Inc., Wilmington, DE (US))

    1990-06-01

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

  18. 21 CFR 180.22 - Acrylonitrile copolymers.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...determine the complex and the acrylonitrile migration, and validation studies of these... (1) Qualitative and quantitative migration values at a time equivalent to initial... (2) Qualitative and quantitative migration values at the time of equilibrium...

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

    Microsoft Academic Search

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

    1997-01-01

    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

  20. Butadiene Complexes of Titanium(II) and Titanium(0): Synthesis, Butadiene Dimerization Catalysis, and Crystal

    E-print Network

    Girolami, Gregory S.

    -3 Although nickel and palladium compounds are most commonly used to catalyze the dimerization of buta- diene "butadiene" complex is formed, which has been identified as the titanium(IV) 3 ,1 - octa-1,6-diene-1,8-diyl ligands are bound like true dienes. We propose that the preferred bonding mode for butadiene complexes

  1. Improved Dipole Moments for Acrylonitrile and Propionitrile

    NASA Astrophysics Data System (ADS)

    Kisiel, Zbigniew; Kra?nicki, Adam

    2011-06-01

    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)

  2. Species Differences in the Distribution of Inhaled Butadiene in Tissues

    Microsoft Academic Search

    JAMES A. BOND; ALAN R. DAHL; ROGENE F. HENDERSON; LINDA S. BIRNBAUM

    1987-01-01

    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 B6C3F1 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

  3. Biological monitoring of butadiene exposure by measurement of haemoglobin adducts

    Microsoft Academic Search

    Kevan A. Richardson; Hendricus J. J. J. Megens; James D. Webb; Nico J. van Sittert

    1996-01-01

    The measurement of haemoglobin (Hb) adducts is an important tool for monitoring exposures to industrial chemicals such as ethylene, ethylene oxide and propylene oxide. The aim of the present study was to use this method to monitor occupational exposure to butadiene. The methodology was evaluated with Hb samples obtained by reacting butadiene monoepoxide (BMO), the primary reactive metabolite of 1,3-butadiene,

  4. Rubber–pristine clay nanocomposites prepared by co-coagulating rubber latex and clay aqueous suspension

    Microsoft Academic Search

    You-Ping Wu; Yi-Qing Wang; Hui-Feng Zhang; Yi-Zhong Wang; Ding-Sheng Yu; Li-Qun Zhang; Jun Yang

    2005-01-01

    The structure of several rubber–clay nanocomposites, including styrene butadiene rubber (SBR)–clay, natural rubber (NR)–clay, nitrile butadiene rubber (NBR)–clay, carboxylated acrylonitrile butadiene rubber (CNBR)–clay nanocomposites, prepared by directly co-coagulating the rubber latex and clay aqueous suspension, were investigated. X-ray diffraction (XRD) patterns and transmission electron microscopy (TEM) micrographs showed that these nanocomposites possessed a unique structure, in which the rubber molecules

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

    EPA Science Inventory

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

  6. [Asymmetric biosynthesis of chiral styrene oxide].

    PubMed

    Wu, J; Cheng, S H; Sha, Q; Yang, L; Sun, W R

    2000-09-01

    Used styrene as the sole carbon and energy source, 12 strains of aerobic bacterial and two strains of fungi were screened from a series soil samples. These strains were able to convert styrene to styrene oxide. HPLC and chiral GC method were used for determination the substrate, product and e.e value of culture broth. There were obvious effect on the biomass and epoxidase activity under various conditions in the fermentation. Styrene epoxidation of the strain PS-1206 was studied in different reaction time. 35% of conversion yield and 80% e.e value of (R)-styrene oxide could been obtained at the optimum conditions. PMID:11191772

  7. 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 ...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  9. Multi?Wall Carbon Nanotubes\\/Styrene Butadiene Rubber (SBR) Nanocomposite

    Microsoft Academic Search

    Nazlia Girun; Suraya Abndul Rashid; Muataz Ali Atieh

    2007-01-01

    A floating catalyst chemical vapor deposition (FC?CVD) method was designed and fabricated to produce high?quality and ?quantity carbon nanotubes. The design parameters like the hydrogen flow rate; reaction time and reaction temperature were optimized to produce high yield and purity of Multi?Wall Carbon Nanotubes (MWCNTs). Multi?Walled Carbon Nanotubes (MWNTs) were used to prepare natural rubber (NR) nanocomposites. Our first efforts

  10. Uptake, Disposition, and Persistence of Acrylonitrile in Rainbow Trout

    Microsoft Academic Search

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

    1995-01-01

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

  11. Possible functional immunotoxicity of acrylonitrile (VCN).

    PubMed

    Hamada, F M; Abdel-Aziz, A H; Abd-Allah, A R; Ahmed, A E

    1998-02-01

    Acrylonitrile (vinyl cyanide, VCN), an environmental pollutant, has been shown to be an animal and human carcinogen particularly for the GIT. In a previous work done in our laboratory, VCN induced immunosuppressive effects as indicated by a decrease in plaque forming cell (PFC) response to SRBCs (sheep red blood cell) immunization, a marked depletion of spleen lymphocyte subsets by flow cytometric analysis as well as bacterial translocation of the normal flora leading to brachial lymph node abscess. This work was carried out to evaluate the systemic and/or local immunotoxic potential of VCN. Acrylonitrile (2.7 mg kg-1 day-1) was given to CD-1 mice once daily for 5, 10 and 15 days. Immunohistochemical assessment of the number of cells capable of producing IgA in different intestinal compartments (duodenum, jejunum and ileum) revealed a significant decrease following VCN treatment. On the contrary, Bromodeoxyuridine (BrdU) incorporation in gut epithelial cells (duodenum and ileum) showed a significant increase in the same VCN-treated groups of animals. On the other hand, [3H]thymidine uptake was significantly decreased in splenocytes stimulated with phytohemaglutinin (PHA), Concanavalin-A (Con-A) and Lipopolysaccharide (LPS) and derived from animals treated with VCN. The effects of VCN were started after 5 days and increased up to 15 days of daily treatment in most of the investigated parameters. The results suggested that VCN has a profound immunosuppressive effect either systemically or locally which could be a contributing factor in its GIT carcinogenicity. PMID:9572067

  12. 75 FR 9438 - Americas Styrenics, LLC-Marietta Plant a Subsidiary of Americas Styrenics, LLLC Formerly Known as...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-02

    ...workers are engaged in the production of styrene monomer and polystyrene pellets. Information shows that Americas Styrenics LLC-Marietta...affected by increased customer imports of styrene monomer and polystyrene pellets. The amended notice applicable to...

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

    PubMed Central

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

    1989-01-01

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

  14. Evidence for cellular protein covalent binding derived from styrene metabolite.

    PubMed

    Yuan, Wei; Jin, Hua; Chung, Jou-Ku; Zheng, Jiang

    2010-08-01

    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 (14)C-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 was 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 (14)C-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. PMID:20470765

  15. Mechanisms for the Induction of Oxidative Stress in Syrian Hamster Embryo Cells by Acrylonitrile

    Microsoft Academic Search

    Haizhou Zhang; Lisa M. Kamendulis; James E. Klaunig

    2002-01-01

    Chronic administration of acrylonitrile to rats resulted in an increase in the incidence of glial neoplasms of the brain. Recent studies have shown that acrylonitrile induces oxidative stress in rat brain and cultured rat glial cells. Acrylonitrile also induces morphological transformation concomitant with an increase in the formation of oxidized DNA in Syrian Hamster Embryo (SHE) cells in a dose-dependent

  16. 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...

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

    EPA Science Inventory

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

  18. Butadiene from acetylene-ethylene cross-metathesis.

    PubMed

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

    2015-04-28

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

  19. Industrial emissions of 1,3-butadiene.

    PubMed Central

    Mullins, J A

    1990-01-01

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

  20. Species differences in the disposition of inhaled butadiene.

    PubMed

    Bond, J A; Dahl, A R; Henderson, R F; Dutcher, J S; Mauderly, J L; Birnbaum, L S

    1986-07-01

    Recent chronic inhalation carcinogenicity studies of butadiene indicated that B6C3F1 mice are more sensitive to the tumorigenic effects of inhaled butadiene than are Sprague-Dawley rats. Tumors in mice included lymphomas, hemangiosarcomas, alveolar/bronchiolar adenomas and carcinomas, and hepatocellular adenomas and carcinomas whereas in rats tumors included mammary tumors, thyroid follicular cell adenomas, uterine tumors, and exocrine pancreatic adenomas. The purpose of this investigation was to determine if there were differences in the uptake and disposition of inhaled butadiene between rats and mice and if these differences were consistent with the differences in the species susceptibility to inhaled butadiene. Male Sprague-Dawley rats and B6C3F1 mice were exposed nose only to concentrations in the range of 0.14 to 13,000 micrograms [14C]butadiene/liter air (0.08 to 7100 ppm; 25 degrees C, 620 torr) for 6 hr. Blood samples were taken during exposure and urine, feces, and expired air were collected for up to 65 hr after exposure. In both rats and mice there was a significant (p less than 0.001) concentration-related decrease in the percentage of butadiene retained at the cessation of a 6-hr exposure with increasing butadiene exposure concentration, suggesting saturable metabolism of this chemical. At all concentrations of butadiene tested, mice retained about 4 to 7 times the amount (mumol/kg body wt) of butadiene and metabolites than did rats. In both species and at all butadiene concentrations tested, urine and exhaled air were the major routes of excretion of 14C, together accounting for 75 to 85% of the total 14C eliminated. In mice, for all concentrations tested, elimination of 14C in urine, feces, and exhaled air increased with increasing butadiene exposure concentration, although the increase was not proportional to exposure concentration. However, exposure of rats to 13,000 micrograms butadiene/liter air resulted in a leveling off in the amount of 14C that was eliminated in urine and a concomitant increase in exhalation of 14CO2. Analysis of blood samples taken during exposure indicated that the blood of mice contained 2 to 5 times the concentration of 1,2-epoxy-3-butene than did the blood of rats. The data from this study indicate that species differences exist in the amount retained and metabolism of inhaled butadiene. PMID:3726881

  1. Epoxidation of styrene-isoprene-styrene block copolymer and research on its reaction mechanism

    Microsoft Academic Search

    Hongqiang Li; Xingrong Zeng; Jianhua Guo

    2010-01-01

    Styrene-isoprene-styrene (SIS) block copolymer was modified into epoxidized styrene-isoprene-styrene (ESIS) block copolymer\\u000a with performic acid generated in situ from hydrogen peroxide and formic acid. The structure and property of ESIS were characterized by Fourier transform infrared\\u000a (FT-IR) spectroscopy, gel permeation chromatography (GPC), thermogravimetric\\/differential thermogravimetric (TG\\/DTG), melt\\u000a flow rate (MFR) and dynamic mechanical analysis (DMA), and the reaction mechanism in the

  2. Perforation of ABS pipes by boring bivalve Martesia striata: a case study

    Microsoft Academic Search

    H. A. Jenner; S. Rajagopal; G. Van der Velde; M. S. Daud

    2003-01-01

    Acrylonitrile butadiene styrene (ABS) pipes are considered to be immune for boring organisms. However, inspection of the offshore cooling water conduits of Lumut combined cycle power plant, Malaysia show that ABS pipes may not necessarily be immune for wood boring pholads, Martesia striata. M. striata caused heavy damage by drilling holes in ABS pipes used (about 5 years) for transportation

  3. 24 CFR 3280.611 - Vents and venting.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...methods: (i) A 11/2 inch diameter (min.) individual vent... (ii) A 11/2 inch diameter (min.) continuous vent...wet-vented, or 2-inch diameter (minimum), and each drain...acrylonitrile-butadiene-styrene, DWV grade; (ii) Stem shall be DWV grade nylon...

  4. 24 CFR 3280.611 - Vents and venting.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...methods: (i) A 11/2 inch diameter (min.) individual vent... (ii) A 11/2 inch diameter (min.) continuous vent...wet-vented, or 2-inch diameter (minimum), and each drain...acrylonitrile-butadiene-styrene, DWV grade; (ii) Stem shall be DWV grade nylon...

  5. 24 CFR 3280.803 - Power supply.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...face of the attachment-plug cap shall not be less than 21 feet...face of the attachment-plug cap to the point where the cord enters...acrylonitrile-butadiene-styrene (ABS) plastic tubing having a minimum wall...protection of the attachment-plug cap of the power supply cord...

  6. 24 CFR 3280.803 - Power supply.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...face of the attachment-plug cap shall not be less than 21 feet...face of the attachment-plug cap to the point where the cord enters...acrylonitrile-butadiene-styrene (ABS) plastic tubing having a minimum wall...protection of the attachment-plug cap of the power supply cord...

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

    NASA Astrophysics Data System (ADS)

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

    2014-04-01

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

  8. Processing strategies for thin wall injection molding

    Microsoft Academic Search

    Patraporn Tantakom

    1998-01-01

    Thin wall injection molding of a thin wall molding grade of polycarbonate and acrylonitrile butadiene styrene were examined in this research. The work investigated the effect of melt and mold temperature on part weight, orientation, tensile strength, flow front profile and flow instability. The HPM H90-V6 injection molding machine, set at its maximum injection velocity was used in the study.

  9. Metabolism of Acrylonitrile by Isolated Rat Hepatocytes1

    Microsoft Academic Search

    Lee E. Geiger; Lora L. Hogy; F. Peter Guengerich

    Several of the pathways of metabolism of the suspected carcinogen acrylonitrile (AN) were identified previously in this laboratory with the use of subcellular fractions and purified enzymes (Guengerich,F. P., Geiger, L. E., Hogy, L. L., and Wright, P. L., Cancer Res., 41: 4925-4933, 1981). In order to establishthe relativecontributionsof the variouspathwayslead ing to activated and detoxicated products, we examined AN

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

    EPA Science Inventory

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

  11. 29 CFR 1910.1051 - 1,3-Butadiene.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...the employer and the employee within 15 business days of the evaluation. The written...Whenever the employer ceases to do business, the employer shall transfer records... 5. References 5.1. “Current Intelligence Bulletin 41, 1,3-Butadiene”,...

  12. Acute Toxicity of Acrylonitrile: Effect of Diet on Tissue Nonprotein Sulfhydryl Content and Distribution of 1–14C-Acrylonitrile or Its Metabolites

    Microsoft Academic Search

    R. J. Jaeger; I. L. Cote; A. E. Rogers; E. H. Silver; S. Szabo

    1984-01-01

    The influence of diet on the acute toxicity (lethality) and distribution of glutathione as measured by tissue nonprotein sulfhydryl (NPSH) concentration following acrylonitrile (ACN) treatment was studied. The tissue distribution of radiolabeled (14C) acrylonitrile or its radioactive metabolites was also determined. The diets tested were a standard laboratory rat chow; a casein-based, complete diet; and 2 diets high in saturated

  13. Effect of alkali treatment on structure and mechanical properties of ABS\\/ bamboo fiber composites

    Microsoft Academic Search

    LI MA; HUI HE; CAN JIANG; LING ZHOU; YUANFANG LUO; DEMIN JIA

    2012-01-01

    The preparation and properties of wood-plastic composites based on acrylonitrile -butadiene-styrene (ABS) and bamboo fibers are described. Bamboo fibers were first modified by alkali treatment in order to improve their adhesion to an ABS matrix. The bamboo fiber modifications were monitored by Fourier transform infrared (FTIR) spectroscopy, X-ray photoelectron spectroscopy (XPS), thermogravimetric analysis (TGA) and scanning electron microscopy (SEM). Styrene-maleic

  14. Species-specific pharmacokinetics of styrene in rat and mouse

    Microsoft Academic Search

    Johannes G. Filser; Ursula Schweglerl; György A. Csanády; Helmut Greim; Paul E. Kreuzerl; Winfried Kessler

    1993-01-01

    The pharmacokinetics of styrene were investigated in male Sprague-Dawley rats and male B6C3F1 mice using the closed chamber technique. Animals were exposed to styrene vapors of initial concentrations ranging from 550 to 5000 ppm, or received intraperitoneal (i.p.) doses of styrene from 20 to 340 mg\\/kg or oral (p.o.) doses of styrene in olive oil from 100 to 350 mg\\/kg.

  15. PROCESS FOR MANUFACTURING GRAFT COPOLYMERS OF POLYOLEFINES AND STYRENE

    Microsoft Academic Search

    L. Callaghan; S. H. Pinner; J. F. Salmon; R. R. Smith

    1963-01-01

    A process for the manufacture of a graft copolymer derived from a ; polyolefin and styrene is patented. A polyolefin film is contacted with styrene ; in the presence of an aliphatic polyamine, which may be a polyalkylene amine such ; as tetraethylene pentamine. The contact is made at a temperature that causes the ; styrene to swell the film

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

    ERIC Educational Resources Information Center

    Amiet, R. Gary; Urban, Sylvia

    2008-01-01

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

  17. Rh-catalyzed linear hydroformylation of styrene.

    PubMed

    Boymans, Evert; Janssen, Michèle; Müller, Christian; Lutz, Martin; Vogt, Dieter

    2013-01-01

    Usually the Rh-catalyzed hydroformylation of styrene predominantly yields the branched, chiral aldehyde. An inversion of regioselectivity can be achieved using strong ?-acceptor ligands. Binaphthol-based diphosphite and bis(dipyrrolyl-phosphorodiamidite) ligands were applied in the Rh-catalyzed hydroformylation of styrene. High selectivities up to 83% of 3-phenylpropanal were obtained with 1,1-bi-2-naphthol-based bis(dipyrrolyl-phosphorodiamidite) with virtually no hydrogenation to ethyl benzene. The coordination chemistry of those ligands towards Rh(I) was investigated spectroscopically and structurally. PMID:23104326

  18. The effects of acrylonitrile on hemoglobin and red cell metabolism

    Microsoft Academic Search

    Mohammed Y. H. Farooqui; Ahmed E. Ahmed

    1983-01-01

    The effects of acrylonitrile (VCN) on hemoglobin and red cell metabolism were studied in vitro and in vivo using male Sprague?Dawley rats. Reduced glutathione (GSH) was rapidly depleted by VCN. The reaction between VCN and GSH to form S?cyanoethyl glutathione is both enzymic and nonenzymic. GSH depletion induced oxidation of considerable amount of hemoglobin to methemoglobin. Incubation of nitrite?treated erythrocytes

  19. Comparative metabolism and disposition of acrylonitrile and methacrylonitrile in rats

    Microsoft Academic Search

    Leo T. Burkal; Idalia M. Sanchez; Ahmed E. Ahmed; Burhan I. Ghanayem

    1994-01-01

    Aliphatic nitriles are a class of chemicals used in high volumes in the production of plastics and elastomers, in organic\\u000a synthesis, and in production of a number of food packaging containers. Toxicity and metabolism of acrylonitrile (AN) are well\\u000a characterized. On the other hand, minimal information is available on the toxicity or fate of structurally related, methacrylonitrile\\u000a (MAN). In an

  20. Induction of Oxidative Stress in Rat Brain by Acrylonitrile (ACN)

    Microsoft Academic Search

    Jiazhong Jiang; Yong Xu; James E. Klaunig

    1998-01-01

    Chronic treatment with acrylonitrile (ACN) has been shown to produce a dose-related increase in glial cell tumors (astrocytomas) in rats. The mechanism(s) for ACN-induced carcinogenicity remains unclear. While ACN has been reported to induce DNA damage in a number of short-term systems, evidence for a genotoxic mechanism of tumor induction is the brain is not strong. Other toxic mechanisms appear

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

    EPA Science Inventory

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

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

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-04

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

  3. Transport of styrene monomer through natural rubber

    Microsoft Academic Search

    Aji P. Mathew; S. Packirisamy; M. G. Kumaran; Sabu Thomas

    1995-01-01

    The diffusion and transport of inhibitor-free styrene through crosslinked natural rubber (NR) have been studied at various temperatures. NR has been vulcanized by conventional, efficient, peroxide and mixed vulcanization techniques. The dependence of diffusion coefficient on the crosslinking system has been studied for all the systems. The influence of temperature on the sorption and the activation energies of sorption have

  4. In Vivo Interaction of Acrylonitrile and 2-CyanoethyleneOxide with DNA in Rats1

    Microsoft Academic Search

    Lora L. Hogy; F. Peter Guengerich

    Several approaches were used to probe aspects of the mechanism of acrylonitrile carcinogenicity in rats. Acrylonitrile did not appear to in crease the rate of DNA synthesis resulting from tissue injury and regen eration in liver or brain, the latter being a target organ. The chemical did cause unscheduled DNA synthesis in rat liver but not brain. The epoxide of

  5. [An in vitro of acrylonitrile inducing early damage on buccal mucosa of murine

    PubMed

    Fu, P; Jin, W C; Jin, X J; Zhu, P

    1998-06-01

    ObJECTIVE:Understand the change and damage of rats and mice buccal mucosa tissue structure posioned by acrylonitrile and alcohol. METHODS: Using optical microscope and transmitted electron microscope (TEM) techniques, observed the structure of rats and mice buccal mucosa which posioned by acrylonitrile and alcohol for 13 weeks in different dosages. RESULTS: Acrylonitrile can damage the ultrastructure of the cells and lead to precancerous dysplasia,such as enlargement and deformation of nuclei, reducing of desmosomes and hemidesmosomes,break of basement membrane,swelling and denaturalization of mitochondrion. The degree of damage was correlated with its dosage. Alcohol can increase the damage caused by acrylonitrile. CONCLUSION: Both acrylonitrile and alcohol can destroy the ultrastructure of cells,TEM is helpful for diagnosing disease in their early stage,and buccal mucosa can be used as a window for observing the disease caused by many toxic factors. PMID:15071667

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

    SciTech Connect

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

    2014-01-03

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

  7. 40 CFR 63.500 - Back-end process provisions-carbon disulfide limitations for styrene butadiene rubber by emulsion...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...methods include, but are not limited to: (A) Use of material balances, (B) Estimation of flow rate based on physical...rubber prior to the dryers, an identification of the point and time in the process where the sulfur...

  8. 40 CFR 63.500 - Back-end process provisions-carbon disulfide limitations for styrene butadiene rubber by emulsion...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...methods include, but are not limited to: (A) Use of material balances, (B) Estimation of flow rate based on physical...rubber prior to the dryers, an identification of the point and time in the process where the sulfur...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  11. Properties of NR\\/EPDM Blends with or without Methyl Methacrylate-Butadiene-Styrene (MBS) as a Compatibilizer

    Microsoft Academic Search

    W. Arayapranee; G. L. Rempel

    Ethylene propylene diene monomer rubber (EPDM) is an excellent rubber for outdoor use. Natural rubber (NR) containing EPDM may show improved weathering resistance. EPDM was blended with natural rubber with various blend ratios, after which the processing, cure characteristics, and mechanical properties of the NR\\/EPDM blends were determined. The results of the experiments show that the tensile strength of the

  12. Hydrogenation of nitrile-butadiene rubber latex with diimide

    Microsoft Academic Search

    Xinwang Lin; Qinmin Pan; Garry L. Rempel

    2004-01-01

    Hydrogenation of nitrile-butadiene rubber latex via utilization of diimide was investigated by examining hydrogenation efficiency and hydrogenation degree. It has been found that the hydrogenation efficiency, which is defined as the ratio of the amount of hydrogen peroxide consumed for the hydrogenation to the total amount of hydrogen peroxide reacted, varies with both the type of catalyst and degree of

  13. Effect of mixing on polymerization of styrene 

    E-print Network

    Treybig, Michael Norris

    1977-01-01

    was performed by co- feeding styrene monomer, batch prepared living polystyrllithium seed and benzene. Reaction conditions such as temperature, initial monomer and polymer concentrations, residence time and mixing speed were varied to achieve different... polymerization runs, residence time distribution (RTD) studies using 30 weight percent polystyrene in benzene were conducted to determine the impeller configuration and mixing speeds required to maintain an exponential residence time distribution during...

  14. Simple replica micromolding of biocompatible styrenic elastomers.

    PubMed

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

    2013-07-21

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

  15. Cell sealant

    SciTech Connect

    Markin, C.; Book, R.J.; James, D.A.

    1988-04-26

    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.

  16. 40 CFR 721.10389 - Styrene, copolymer with acrylic acid, salt with alkoxylated alkenylamine (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

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

  17. Permeation and separation properties of polyimide membranes to 1,3-butadiene and n- butane

    Microsoft Academic Search

    Kenichi Okamoto; Kenji Noborio; Jianqiang Hao; Kazuhiro Tanaka; Hidetoshi Kita

    1997-01-01

    Single and mixed gas permeation experiments for 1,3-butadiene and n-butane were carried out for several polyimide and other glassy polymer membranes at pressures up to 1.5 atm and 323 K. They displayed large permeation coefficients to 1,3-butadiene, PC4H6, of 4–200 Barrer and very large ideal separation factors (permeability ratios of 1,3-butadiene over n-butane for single gas permeation), ?id, of 30–200

  18. Toxicokinetics of inhaled 1,3-butadiene in monkeys: Comparison to toxicokinetics in rats and mice

    Microsoft Academic Search

    A. R. Dahl; J. D. Sun; L. S. Birnbaum; J. A. Bond; W. C. Jr. Griffith; J. L. Mauderly; B. A. Muggenburg; P. J. Sabourin; R. F. Henderson

    1991-01-01

    1,3-Butadiene is a potent carcinogen in mice and a weaker carcinogen in rats. People are exposed to butadiene through its industrial use--largely in rubber production (over 3 billion pounds of butadiene were produced in 1989)--and because it is common in the environment, occurring in cigarette smoke, gasoline vapor and in the effluents from fossil fuel incineration. Epidemiological studies have provided

  19. Incorporation of radioactive wastes into styrenated polyester

    SciTech Connect

    Ikladious, N.E.; Ghattas, N.K.; Eskander, S.B.

    1986-01-01

    Styrenated polyester (poly(oxydiethylene maleate)) is examined as a medium for immobilization of simulated spent-ion exchange resin used at Inshas Reactor (Egypt). Compressive strength and hardness values illustrated the stability of the final products towards radiation. TG, DTG, and DTA diagrams showed the thermal instability of the final waste form at about 375/sup 0/C. Leaching experiment on incorporated blocks of active resin labelled with /sup 137/Cs, /sup 144/Ce, and /sup 106/Ru showed that the cumulative leaching rate for Ce is lower than those for Ru and Cs.

  20. Thermal characterization of nitrile butadiene rubber (NBR)\\/PVC blends

    Microsoft Academic Search

    F. Pruneda; J. J. Suñol; F. Andreu-Mateu; X. Colom

    2005-01-01

    Summary Nitrile butadiene rubber (NBR) and NBR\\/PVC blends were produced using 2,2,4-trimethyl-1,2-dihydroquinoline (TMQ) or not as antioxidant. Controlled ozone degradation was performed in several samples. Thermal, compositional and morphological analysis was performed by means of differential scanning calorimetry, thermogravimetry, chemical analysis and scanning electron microscopy. Thermogravimetry analysis shows four mass loss processes related to plastizicer, complex rubber degradation and metallic

  1. Site-selective participator decay of core-excited butadiene

    Microsoft Academic Search

    S. L. Sorensen; S. J. Osborne; A. Ausmees; A. Kikas; N. Correia; S. Svensson; A. Naves de Brito; P. Persson; S. Lunell

    1996-01-01

    The decay of core-excited electronic states in free 1,3 trans butadiene molecules has been studied using high-resolution synchrotron radiation and electron spectrometry. The core-level energy shift between the terminal and central carbon atoms is 0.64 eV making selective excitation of core electrons from these atoms possible. Resonant excitation to the au(?*) valence state leads to autoionizing decay channels which proceed

  2. Three-generation reproduction study of rats receiving acrylonitrile in drinking water

    Microsoft Academic Search

    M. A. Friedman; R. P. Beliles

    2002-01-01

    Acrylonitrile, a high volume organic chemical, was tested for reproductive effects in a three generation drinking water study with two matings per generation. Sprague–Dawley rats were exposed to acrylonitrile in drinking water at 0, 100, or 500 ppm. This corresponds to 0, 11±5 and 37±10 mg\\/kg, respectively, for males and 0, 20±3 and 40±8 mg\\/kg per day for the females,

  3. Plasticizer interactions with polymer and salt in propylene carbonate-poly(acrylonitrile)-lithium triflate

    Microsoft Academic Search

    Shawna Raye Starkey; Roger Frech

    1997-01-01

    A comparative infrared spectroscopic study has been undertaken in a system of poly(acrylonitrile)-propylene carbonate-lithium triflate to examine the plasticizer interactions with the polymer and salt as well as ionic association. Lithium triflate is highly associated and the lithium ion interaction is stronger with propylene carbonate (PC) than with poly(acrylonitrile) (PAN). It is hypothesized that the local structure about the lithium

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

    PubMed

    Nakano, Ryo; Ito, Shingo; Nozaki, Kyoko

    2014-04-01

    Although carbon dioxide has attracted broad interest as a renewable carbon feedstock, its use as a monomer in copolymerization with olefins has long been an elusive endeavour. A major obstacle for this process is that the propagation step involving carbon dioxide is endothermic; typically, attempted reactions between carbon dioxide and an olefin preferentially yield olefin homopolymerization. Here we report a strategy to circumvent the thermodynamic and kinetic barriers for copolymerizations of carbon dioxide and olefins by using a metastable lactone intermediate, 3-ethylidene-6-vinyltetrahydro-2H-pyran-2-one, which is formed by the palladium-catalysed condensation of carbon dioxide and 1,3-butadiene. Subsequent free-radical polymerization of the lactone intermediate afforded polymers of high molecular weight with a carbon dioxide content of 33 mol% (29 wt%). Furthermore, the protocol was applied successfully to a one-pot copolymerization of carbon dioxide and 1,3-butadiene, and one-pot terpolymerizations of carbon dioxide, butadiene and another 1,3-diene. This copolymerization technique provides access to a new class of polymeric materials made from carbon dioxide. PMID:24651200

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

    NASA Astrophysics Data System (ADS)

    Nakano, Ryo; Ito, Shingo; Nozaki, Kyoko

    2014-04-01

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

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

    PubMed Central

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

    2014-01-01

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

  7. The Rotational Spectrum of Acrylonitrile to 1.67 THz

    NASA Astrophysics Data System (ADS)

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

    2009-06-01

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

  8. 1,3-butadiene in urban and industrial areas and its role in photochemical processes

    NASA Astrophysics Data System (ADS)

    Czader, Beata; Rappenglück, Bernhard

    2015-04-01

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

  9. Monitoring of exposure to styrene oxide by GC-MS analysis of phenylhydroxyethyl esters in hemoglobin

    Microsoft Academic Search

    O. Sepai; D. Anderson; I. Bird; P. B. Farmer; E. Bailey

    1993-01-01

    Styrene oxide, which is the genotoxically active metabolite of styrene, reacts in vivo with carboxylic acid residues in hemoglobin forming phenylhydroxyethyl esters. Mild alkali hydrolysis cleaves these ester adducts, yielding styrene glycol, which in human blood labelled in vitro with14C-styrene oxide accounted for 15% of the total radioactivity covalently bound to the protein. A quantitative assay procedure has been developed

  10. Kinetics of styrene biodegradation in synthetic wastewaters using an industrial activated sludge

    Microsoft Academic Search

    R. Babaee; B. Bonakdarpour; B. Nasernejad; N. Fallah

    2010-01-01

    Kinetics of styrene biodegradation in synthetic wastewaters, containing either styrene or styrene together with ethanol, by an industrial activated sludge obtained from the wastewater treatment unit of a petrochemical complex was studied. The kinetic data could be fitted using the Haldane kinetic model. This model was previously used to predict kinetic data for biodegradation of styrene by pure or mixed

  11. Novel nanocomposite actuator based on sulfonated poly(styrene-b-ethylene-co-butylene-b-styrene) polymer.

    PubMed

    Jung, Jin-Young; Oh, Il-Kwon

    2007-11-01

    Ionic polymer metal composite (IPMC) actuators were developed with multi-walled carbon nanotubes (MWNT) and sulfonated poly(styrene-b-ethylene-co-butylene-b-styrene) (SSEBS) ionic polymers. MWNT with the diameter of 10 approximately 15 nm and length of 10 approximately 20 microm was used to enhance the mechanical and electrical performances of IPMC actuators. Ultrasonic treatment and high speed mixing were employed to disperse MWNTs homogeneously in SSEBS solution. The electroless plating method was used to make electrodes on the both side of the composite membrane. Scanning electron microscope (SEM) and transmission electron microscope (TEM) images were taken to characterize the surface and micro-structures of the composite actuators. In this study, novel nano-composite actuators were fabricated with different weight ratio of the MWNT 0.5%, 1.5% and the bending actuation performance and electrical power consumptions were investigated. PMID:18047049

  12. Phosphonium salts as catalysts for additive chlorination of 1,3-butadiene

    SciTech Connect

    Savanov, S.S.; Tolstikov, G.A.; Nizamutdinov, F.Kh.; Komissarov, V.D.

    1988-02-20

    The chlorination of 1,3-butadiene in carbon tetrachloride was investigated by catalyzing the reaction by quaternary phosphonium salts. Ethyltriphenylphosphonium bromide, tetrabutylphosphonium bromide, triphenylbenzylphosphonium chloride, triethylbenzylphosphonium chloride, and tributylbenzylphosphonium chloride were used. It was shown that, being efficient catalysts of the additive chlorination of 1,3-butadiene, phosphonium salts direct chlorine preferentially into 1,2 positions.

  13. Health risk assessment of 1,3-butadiene as a Priority Substance in Canada.

    PubMed

    Hughes, K; Meek, M E; Walker, M

    2001-06-01

    1,3-Butadiene was included in the second list of Priority Substances to be assessed under the Canadian Environmental Protection Act. Potential hazards to human health were characterized on the basis of critical examination of available data on health effects in experimental animals and occupationally exposed human populations, as well as information on mode of action. Based on consideration of all relevant data identified as of April 1998, butadiene was considered highly likely to be carcinogenic to humans, and likely to be a somatic and germ cell genotoxicant in humans. In addition, butadiene may also be a reproductive toxicant in humans. Estimates of the potency of butadiene to induce these effects have been derived on the basis of quantitation of observed exposure-response relationships for the purposes of characterization of risk to the general population in Canada exposed to butadiene in the ambient environment. PMID:11397385

  14. Hemoglobin adducts as a marker of exposure to chemical substances, especially PRTR class I designated chemical substances.

    PubMed

    Ogawa, Masanori; Oyama, Tsunehiro; Isse, Toyohi; Yamaguchi, Tetsunosuke; Murakami, Tomoe; Endo, Yoko; Kawamoto, Toshihiro

    2006-09-01

    Many new biomarkers are being studied, in addition to classical biomarkers, such as chemical substances and their metabolites in blood and urine and modified enzymes. Among these new biomarkers, hemoglobin adducts are thought to be especially useful for the estimation of chemical exposures. We review here the use of biomarkers for monitoring exposures to nine substances, mainly focusing on PRTR class I designated chemical substances, styrene, phenyloxirane (styrene oxide), 4,4'-methylendiphenyl diisocyanate (MDI), 4,4'-methylendianiline (MDA), 1,3-butadiene, ethylene oxide, propylene oxide, acrylamide and acrylonitrile. Hemoglobin adduct levels were elevated after exposures to styrene, MDI, MDA, 1, 3-butadiene, ethylene oxide, acrylamide and acrylonitrile. Moreover, hemoglobin adducts of butadiene, ethylene oxide, acrylamide and acrylonitrile have several useful advantages. For example, the hemoglobin adduct of 1,3-butadiene is an even more useful biomarker of exposure than urinary metabolites, and in the case of ethylene oxide, even though the concentration of ethylene oxide-Hb in the blood of workers did not exceed the value of the German exposure equivalent, a significant difference in it was found between workers and a control group. Also hemoglobin adducts of acrylamide and acrylonitrile can reflect their exposures because there are no urinary metabolites of acrylamide and acrylonitrile that are useful for exposure assessment. In addition to these advantages, hemoglobin adducts are superior to DNA adducts with respect to the availability of large amounts, availability of methods for chemical identification, and well-defined life spans due to the absence of repair. Hemoglobin adducts can be effective biomarkers for assessing exposure to and the effects of chemicals. PMID:17053297

  15. Clinical studies of styrene workers: initial findings.

    PubMed Central

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

    1976-01-01

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

  16. Mixed dopant conducting polyaniline reusable blend for the detection of aqueous ammonia

    Microsoft Academic Search

    S. Koul; Ramesh Chandra

    2005-01-01

    The present paper reports about the conducting polyaniline-poly(acrylonitrile–butadiene–styrene) blend films as a sensor material for aqueous ammonia. The change in resistance value of these blend films on exposure to different concentrations of aqueous ammonia shows its utility as a sensor material. The conducting blend films on exposure to 10?4, 10?5 and 10?6N aqueous ammonia show a well-defined response behaviour and

  17. Conducting polyaniline composite: a reusable sensor material for aqueous ammonia

    Microsoft Academic Search

    Sarswati Koul; R Chandra; S. K Dhawan

    2001-01-01

    The present paper reports about polyaniline–(acrylonitrile–butadiene–styrene) composite film as a sensor material for aqueous ammonia. The resistance change of the composite film on exposure to different concentrations of aqueous ammonia shows its utility as a sensor material. The composite film on exposure to 10?4 and 10?5N aqueous ammonia shows a well-defined response behaviour and this aspect has been utilized in

  18. Characterization of blended polymeric membranes for pervaporation of hydrazine hydrate

    Microsoft Academic Search

    Mrinal Kanti Mandal; Sukalyan Dutta; P. K. Bhattacharya

    2008-01-01

    Pervaporation of commercial hydrazine hydrate (at 64wt.% hydrazine) was carried out to obtain hydrazine, which in anhydrous form is an important inorganic fuel. Experimental studies were made using various laboratory prepared polymeric membranes, primarily through blending of polymers and the results are analyzed through the measurements of flux and selectivity.Acrylonitrile–butadiene–styrene (ABS) and ethyl cellulose (EC) polymers, in different ratios, were

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

    Microsoft Academic Search

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

    2008-01-01

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

  20. Strain rate effects in polycarbonate and polycarbonate\\/ABS blends

    Microsoft Academic Search

    J. P. F. Inberg; A. Takens; R. J. Gaymans

    2002-01-01

    Acrylonitrile–butadiene–styrene was blended in polycarbonate using a twin-screw extruder, producing dispersed and co-continuous blends. The blends were injection moulded into test bars. These materials were tested in single edge notch tensile tests as a function of test speed over a test speed range of 10?4–10ms?1(2.85×10?3–2.85×102s?1). Infrared measurements were made to monitor the temperature development in the material during fracture. The

  1. Toxicity of Pyrolysis Gases from Elastomers

    NASA Technical Reports Server (NTRS)

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

    1977-01-01

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

  2. Removal of organobromine compounds from the pyrolysis oils of flame retarded plastics using zeolite catalysts

    Microsoft Academic Search

    William J. Hall; Paul T. Williams

    2008-01-01

    Two flame retarded plastics have been pyrolysed in the presence of two zeolite catalysts to remove the organobromine compounds from the derived pyrolysis oil. The flame retarded plastics were, acrylonitrile–butadiene–styrene (ABS) that was flame retarded with tetrabromobisphenol A and high impact polystyrene (HIPS) that was flame retarded with decabromodiphenyl ether. The two catalysts investigated were zeolite ZSM-5 and zeolite Y-Zeolite.

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

    Microsoft Academic Search

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

    2010-01-01

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

  4. Evaluation of respiratory effects of thermal decomposition products following single and repeated exposures of guinea pigs

    Microsoft Academic Search

    Katherine Detwiler-Okabayashi; Michelle Schaper

    1995-01-01

    Groups of guinea pigs were exposed to the thermal decomposition products (TDP) released from acrylonitrile butadiene styrene\\u000a (ABS), polypropylene-polyethylene copolymer (CP), polypropylene homopolymer (HP), or plasticized polyvinyl chloride (PVC).\\u000a In single 50-min exposures to the TDP, guinea pigs exhibited sensory irritation, coughing, and airways constriction. Significant\\u000a decreases in respiratory frequency (f) occurred during TDP exposure which were magnified during CO2

  5. Enhanced biodegradation of petrochemical wastewater using ozonation and bac advanced treatment system

    Microsoft Academic Search

    Chi-Kang Lin; Tsung-Yueh Tsai; Jiunn-Ching Liu; Mei-Chih Chen

    2001-01-01

    The characteristics of degradation\\/conversion of bio-refractory and the growth of a biofilm are investigated in laboratory-scale pre-ozonation and lifted moving-bed biological activated carbon (BAC) advanced treatment processes treating phenol, benzoic acid, aminobenzoic acid and petrochemical industry wastewater which contains acrylonitrile butadiene styrene (ABS). The optimal reaction time and ozone dosage of pre-ozonation for bio-refractory conversion were determined to be 30min

  6. Characteristics of thermoplastics containing electrically conducting asymmetric particles - anisotropic electrical conductivity of injection molded parts and extrusion behavior

    Microsoft Academic Search

    Jan Martinsson; James L. White

    1986-01-01

    The characteristics of compounds of acrylonitrile-butadiene-styrene and high impact polystyrene resins filled with carbon fibers, steel fibers, carbon black, and aluminum flakes have been investigated with special emphasis on electrical conductivity and flow behavior in a capillary rheometer. Compression- and injection-molded compounds were found to be highly electrically anisotropic. The components of the electrical conductivity tensor, were measured. Generally, kappa-11,

  7. 1,3Butadiene: Biomarkers and application to risk assessment

    Microsoft Academic Search

    James A. Swenberg; Narisa K. Bordeerat; Gunnar Boysen; Sujey Carro; Nadia I. Georgieva; Jun Nakamura; John M. Troutman; Patricia B. Upton; Richard J. Albertini; Pamela M. Vacek; Vernon E. Walker; Radim J. Sram; Melissa Goggin; Natalia Tretyakova

    2011-01-01

    1,3-Butadiene (BD) is a known rodent and human carcinogen that is metabolized mainly by P450 2E1 to three epoxides, 1,2-epoxy-3-butene (EB), 1,2:3,4-diepoxybutane (DEB) and 1,2-epoxy-3,4-butanediol (EB-diol). The individual epoxides vary up to 200-fold in their mutagenic potency, with DEB being the most mutagenic metabolite. It is important to understand the internal formation of the individual epoxides to assign the relative

  8. STUDY OF NICKEL CATALYSTS IN THE STYRENE HYDROGENATION

    Microsoft Academic Search

    A. B. Gaspar; L. Salvatore

    The pyrolysis gasoline (pygas) is a product from the intermediate boiling product of naphtha steam-cracking. The hydrogenation of pygas is usually conducted in a trickle-bed reactor under mild conditions in order to remove extremely reactive unsaturated species, such as styrene, mono and di-olefins. Styrene hydrogenation is used as a representative reaction due to its slower reacting behavior in comparison to

  9. Performance of CTBN(carboxyl-terminated poly (butadiene- co -acrylonitrile))EP(diglycidyl ether of bisphenol-A (DGEBA)) prepolymers and CTBNEP\\/polyetheramine (PEA) system

    Microsoft Academic Search

    Minxian Shi; Zhixiong Huang; Yaming Li; Guorui Yang

    2009-01-01

    CTBN-EP prepolymers were synthesized from CTBN and epoxy resin under the catalysis of HTMAB. FTIR analyses indicate the formation\\u000a of ester group between the carboxyl group of CTBN and the oxirane group of epoxy resin. The viscosity of modified prepolymer\\u000a increases with CTBN content increasing, but the epoxy value of the prepolymer decreases greatly. DSC analyses verify that\\u000a CTBN affects

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

    SciTech Connect

    Corsi, P. [Dip. di Farmacologia e Fisiologia Umana, Facolta di Medicina e Chirurgia, Universita degli Studi di Bari, 70124 Italy (Italy)], E-mail: pcorsi@fisiol.uniba.it; D'Aprile, A. [Dip. di Medicina Interna e Pubblica, Facolta di Medicina e Chirurgia, Universita di Bari (Italy); Nico, B. [Dip. di Anatomia Umana e Istologia, Facolta di Medicina e Chirurgia, Universita di Bari (Italy); Costa, G.L. [Dip. di Anatomia, Farmacologia e Scienze Medico Forensi, Facolta di Medicina e Chirurgia, Universita di Parma (Italy); Assennato, G. [Dip. di Medicina Interna e Pubblica, Facolta di Medicina e Chirurgia, Universita di Bari (Italy)

    2007-10-01

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

  11. Discovery of a Novel Styrene Monooxygenase Originating from the Metagenome?

    PubMed Central

    van Hellemond, Erik W.; Janssen, Dick B.; Fraaije, Marco W.

    2007-01-01

    Oxygenases form an interesting class of biocatalysts, as they typically perform oxygenations with exquisite chemo-, regio-, and/or enantioselectivity. It has been observed that, once heterologously expressed in Escherichia coli, some oxygenases are able to form the blue pigment indigo. We have exploited this characteristic to screen a metagenomic library derived from loam soil and identified a novel oxygenase. This oxygenase shows 50% sequence identity with styrene monooxygenases from pseudomonads (StyA). Only a limited number of homologs can be found in the genome sequence database, indicating that this biocatalyst is a member of a relatively small family of bacterial monooxygenases. The newly identified monooxygenase catalyzes the epoxidation of styrene and styrene derivatives and forms the corresponding (S)-epoxides with excellent enantiomeric excess [e.g., (S)-styrene oxide is formed with >99% enantiomeric excess, ee] and therefore is named styrene monooxgenase subunit A (SmoA). SmoA shows high enantioselectivity towards aromatic sulfides [e.g., (R)-ethyl phenyl sulfoxide is formed with 92% ee]. This excellent enantioselectivity in combination with the moderate sequence identity forms a clear indication that SmoA from a metagenomic origin represents a new enzyme within the small family of styrene monooxygenases. PMID:17644649

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

    PubMed

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

    2012-01-25

    Acrylonitrile (ACN) is a widely used intermediate in the manufacture of plastics, acrylic ?bers, synthetic rubbers and resins that are used in a variety of products including food containers and medical devices. ACN is a possible human carcinogen and a documented animal carcinogen, with the stomach being an important target of its toxicity. ACN has been previously reported to require metabolic activation to reactive intermediates and finally to cyanide (CN?). The current study aimed at exploring the potential role of neutrophils in ACN-induced gastric damage in rats. Experimental neutropenia was attained by injecting rats with methotrexate. This significantly ameliorated gastric mucosal injury induced by ACN. This is evidenced by protection against the increase in gastric ulcer index, myeloperoxidase (MPO) activity and CN? level. Also, neutropenia guarded against the decrease in prostaglandin E2 (PGE2), induction of oxidative stress and reduction of total nitrites and alleviated histopathological alterations in rat stomachs. These data indicate that neutrophil infiltration is, at least partly, involved in ACN-induced gastric damage in rats. PMID:22062130

  13. Influence of genetic polymorphisms of styrene-metabolizing enzymes on the levels of urinary biomarkers of styrene exposure.

    PubMed

    Carbonari, Damiano; Mansi, Antonella; Proietto, Anna Rita; Paci, Enrico; Bonanni, Rossana Claudia; Gherardi, Monica; Gatto, Maria Pia; Sisto, Renata; Tranfo, Giovanna

    2015-03-01

    Styrene exposure is still present in different occupational settings including manufacture of synthetic rubber, resins, polyesters and plastic. The aim of this work was to investigate the effects of polymorphic genes CYP2E1, EPHX1, GSTT1, and GSTM1 on the urinary concentrations of the styrene metabolites mandelic acid (MA), phenylglyoxylic acid (PGA) and on the concentration ratios between (MA+PGA) and urinary styrene (U-Sty) and airborne styrene (A-Sty), in 30 workers from two fiberglass-reinforced plastic manufacturing plants and 26 unexposed controls. Personal air sampling and biological monitoring results revealed that sometimes exposure levels exceeded both the threshold limit value (TLV) and the biological exposure index (BEI) suggested by the American Conference of Governmental Industrial Hygienists. A significantly reduced excretion of styrene metabolites (MA+PGA) in individuals carrying the CYP2E1*5B and CYP2E1*6 heterozygote alleles, with respect to the homozygote wild type, was observed only in the exposed group. A reduction was also detected, in the same group, in subjects carrying the slow allele EPHX1 (codon 113), through the lowering of (MA+PGA)/urinary styrene concentration ratio. In addition, the ratio between MA+PGA and the personal airborne styrene concentration appeared to be modulated by the predicted mEH activity, in the exposed group, as evidenced by univariate linear regression analysis. Our results confirm some previous hypotheses about the role of the polymorphism of genes coding for enzymes involved in the styrene detoxification pathway: this may significantly reduce the levels of excreted metabolites and therefore it must be taken into account in the interpretation of the biological monitoring results for occupational exposure. PMID:25562543

  14. Atmospheric chemistry of toxic contaminants. 3. Unsaturated aliphatics: Acrolein, acrylonitrile, maleic anhydride

    SciTech Connect

    Grosjean, D. (DGA, Inc., Ventura, CA (United States))

    1990-12-01

    Detailed mechanisms are outlined for the chemical reactions that contribute to in-situ formation and atmospheric removal of the unsaturated aliphatic contaminants acrolein, acrylonitrile, and maleic anhydride. In-situ formation of small amounts of acrolein and maleic anhydride may involve the reaction of OH (and O{sub 3}) with 1,3-dienes and the reaction of OH with aromatic hydrocarbons, respectively. There is no known pathway for in-situ formation of acrylonitrile. Rapid removal of acrolein (half-life = less than one day) and of maleic anhydride (half-life = several hours) is expected from their rapid reactions with OH (major), O{sub 3}, and NO{sub 3}. These reactions lead to formaldehyde and glyoxal from acrolein and to dicarbonyls from maleic anhydride. Acrylonitrile is removed at a slower rate (half-life = 2-7 days) by reaction with OH, leading to formaldehyde and formyl cyanide.

  15. Reliable passive-sampling method for determining outdoor 1,3-butadiene concentrations in air

    NASA Astrophysics Data System (ADS)

    Sakurai, Kenji; Miyake, Yuichi; Amagai, Takashi

    2013-12-01

    We have developed a simple and reliable passive-sampling method for determining outdoor 1,3-butadiene concentrations in air. In this method, 1,3-butadiene is adsorbed on Carboxen 1000 uniformly packed in a porous polytetrafluoroethylene tube and then analyzed by thermal desorption-gas chromatography/mass spectrometry. The amounts of 1,3-butadiene adsorbed on Carboxen 1000 were 2.8 times as high as those adsorbed on activated carbon. Much greater amounts of 1,3-butadiene were collected with the passive sampler than with an active sampler even though ozone, which reacts rapidly with 1,3-butadiene, could penetrate the passive-sampling tube. These results demonstrate that our method sensitively and reliably determines outdoor 1,3-butadiene concentrations in air, that ambient ozone slowly react with 1,3-butadiene adsorbed by the passive sampler, and that the KI ozone scrubber in an active-sampling system does not completely remove ozone from the system.

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

    PubMed

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

    2008-11-01

    We evaluated glutathione transferase (GST) activities and the levels of glutathionylated hemoglobin in the RBC of 42 workers exposed to 1,3-butadiene in a petrochemical plant, using 43 workers not exposed to 1,3-butadiene and 82 foresters as internal and external controls, respectively. Median 1,3-butadiene exposure levels were 1.5, 0.4, and 0.1 microg/m3 in 1,3-butadiene-exposed workers, in workers not directly exposed to 1,3-butadiene, and in foresters, respectively. In addition, we determined in the peripheral blood lymphocytes of the same individuals the presence of GST polymorphic genes GSTT1 and GSTM1 and the distribution of GSTP1 allelic variants. Comparing the mean values observed in petrochemical workers with those of control foresters, we found a marked decrease of GST enzymatic activity and a significant increase of glutathionylated hemoglobin in the petrochemical workers. A weak but significant negative correlation was found between levels of 1,3-butadiene exposure and GST activity, whereas a positive correlation was found between 1,3-butadiene exposure and glutathionylated hemoglobin. A negative correlation was also observed between GST activity and glutathionylated hemoglobin. No influence of confounders was observed. Using a multiple linear regression model, up to 50.6% and 41.9% of the variability observed in glutathionylated hemoglobin and GST activity, respectively, were explained by 1,3-butadiene exposure, working setting, and GSTT1 genotype. These results indicate that occupational exposure to 1,3-butadiene induces an oxidative stress that impairs the GST balance in RBC, and suggest that GST activity and glutathionylated hemoglobin could be recommended as promising biomarkers of effect in petrochemical workers. PMID:18990742

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

    PubMed

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

    2014-01-01

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

  18. Styrene emission abatement in a bathtub manufacturing plant

    SciTech Connect

    Niezgodski, D.M. [Weatherly Inc., Atlanta, GA (United States)

    1997-12-31

    EPA is moving forward on promulgating the National Emission Standard for Hazardous Air Pollutants (NESHAP-MACT) for the Reinforced Plastics/Composites Source Category which affects styrene emitters like the American Standard plant. While most composites manufacturers are taking a wait and see approach, American Standard realized the need to move foreward with the controls. Styrene has a reputation of being a difficult VOC to abate. Most adsorption technologies shy away from this monomer due to reactions that cause fires. Weatherly refined their treatment of styrene emissions with experience from installations at similar plants in Europe. Weatherly installed a 35,000 scfm concentrator/oxidation Polyad{trademark} system in 1996 at American Standard`s bathtub manufacturing plant in Salem, Ohio. The styrene emissions are captured in the spray booth exhaust and discharged to the Polyad{trademark} system. The system is achieving 93% removal efficiency on the styrene emissions. This paper will describe the Weatherly Polyad{trademark} VOC abatement system at American Standard`s Salem Ohio plant.

  19. [Degradation of styrene by coupling ultraviolet and biofiltration].

    PubMed

    Sha, Hao-Lei; Yang, Guo-Jing; Xia, Jing-Fen

    2013-12-01

    Purification of styrene by ultraviolet (UV)-biofiltration was studied in this paper. The light source and the biofilm carrier were ozone producing lamp at 185 nm and the peat, palm fiber, porous acticarbon, respectively. Styrene inlet concentration was controlled between 320-583 mg x m(-3), and the removal efficiency remained above 95% after stabilization. The UV converted styrene into more soluble and biodegradable intermediates, such as alcohol, aldehyde and acid, thus the performance of biofilter can be improved. In the stable operation stage, the variation of inlet concentration did not affect the removal efficiency when the total residence time (TRT) was long, however, the inlet concentration obviously affected the removal efficiency when the TRT decreased. The removal load of coupling system increased linearly with increasing inlet load, and the removal efficiency was higher than 95% under a TRT of 102 s. When TRT was 68 s and the inlet load was low, the variation of removal load complied with the law described above, but it gradually deviated from the straight line and tended to stabilized at a certain value when the inlet load became higher than 30 g x (m3 x h)(-). If considering the fluctuation of styrene concentration only, the contribution rate of ultraviolet photolysis to styrene removal was greater than that of the biofilter, and the removal effect could be restored on the fourth day, after closing the system for ten days and restarting. PMID:24640911

  20. 78 FR 55644 - Styrene, Copolymers with Acrylic Acid and/or Methacrylic Acid; Tolerance Exemption

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-11

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

  1. An evaluation of styrene levels emitted during cast polymer production of cultured marble building materials

    E-print Network

    Bell, Lewis Ray

    1994-01-01

    The objective of this research is to investigate and evaluate the concentration levels of styrene emitted during the production of cultured marble building materials. The manufacture of styrene monomer is generally carried out in closed systems...

  2. Rich premixed laminar methane flames doped by light unsaturated hydrocarbons. II. 1,3Butadiene

    Microsoft Academic Search

    H. A. Gueniche; P. A. Glaude; R. Fournet; F. Battin-Leclerc

    2007-01-01

    In line with the study presented in Part I of this paper, the structure of a rich premixed laminar methane flame doped with 1,3-butadiene has been investigated. The flame contains 20.7% (molar) of methane, 31.4% of oxygen, and 3.3% of 1,3-butadiene, corresponding to an equivalence ratio of 1.8, and a CâHâ\\/CHâ ratio of 16%. The flame has been stabilized on

  3. Rich methane laminar flames doped with light unsaturated hydrocarbons. Part II: 1,3butadiene

    Microsoft Academic Search

    Hadj-Ali Gueniche; Pierre-Alexandre Glaude; René Fournet; Frédérique Battin-Leclerc

    2007-01-01

    In line with the study presented in the part I of this paper, the structure of a laminar rich premixed methane flame doped with 1,3-butadiene has been investigated. The flame contains 20.7% (molar) of methane, 31.4% of oxygen and 3.3% of 1,3-butadiene, corresponding to an equivalence ratio of 1.8, and a ratio C4H6 \\/ CH4 of 16 %. The flame

  4. Biomonitoring of benzene and 1,3-butadiene exposure and early biological effects in traffic policemen

    Microsoft Academic Search

    Manaswee Arayasiri; Chulabhorn Mahidol; Panida Navasumrit; Herman Autrup; Mathuros Ruchirawat

    2010-01-01

    The objective of this study was to determine benzene and 1,3-butadiene exposure through ambient air and personal air monitoring, as well as through biomarkers of exposure, and to evaluate the potential health risk of exposure through the use of biomarkers of early biological effects in central Bangkok traffic policemen. Ambient air concentrations of benzene and 1,3-butadiene at the roadsides were

  5. Photochemistry of 1,3Butadiene : Details of the Primary Processes and Mechanism of Photopolymerization

    Microsoft Academic Search

    I. Haller; R. Srinivasan

    1964-01-01

    The photolysis of 1,3-butadiene in the vapor phase was studied in the presence of inert gases such as krypton, diethyl ether, and cyclohexane. In every instance, an increase in the pressure of the added gas led to a decrease in all of the volatile products. The behavior of 1,2-butadiene and 2-butyne were exceptional in that they showed a slight increase

  6. Detailed kinetic modeling of 1,3-butadiene oxidation at high temperatures

    Microsoft Academic Search

    Alexander Laskin; Hai Wang; Chung K. Law

    2000-01-01

    The high-temperature kinetics of 1,3-butadiene oxidation was examined with de- tailed kinetic modeling. To facilitate model validation, flow reactor experiments were carried out for 1,3-butadiene pyrolysis and oxidation over the temperature range 1035-1185 K and at atmospheric pressure, extending similar experiments found in the literature to a wider range of equivalence ratio and temperature. The kinetic model was compiled on

  7. A Physiologically Based Dosimetry Description of Acrylonitrile and Cyanoethylene Oxide in the Rat

    Microsoft Academic Search

    M. L. Gargas; M. E. Andersen; S. K. O. Teo; R. Batra; T. R. Fennell; G. L. Kedderis

    1995-01-01

    The cytochrome P450-mediated oxidation of acrylonitrile (ACN) to the mutagen 2-cyanoethylene oxide (CEO) is thought to be important for the carcinogenic effects of ACN in rats, while glutathione (GSH) conjugation of ACN and CEO is regarded as detoxication. A physiologically based dosimetry description for ACN and CEO in the male F-344 rat has been developed from in vitro data and

  8. Chemically Induced Graft Copolymerization of Acrylonitrile onto Carboxymethyl Chitosan and its Modification to Amidoxime Derivative

    Microsoft Academic Search

    Magdy W. Sabaa; Nadia A. Mohamed; Riham Ali; Soliman M. Abd El Latif

    2010-01-01

    Carboxymethyl chitosan (CMCh) was prepared and characterized by determinating its degree of substitution and elucidating its structure by elemental analyses and FTIR. Graft copolymerization of acrylonitrile (AN) onto CMCh was carried out in aqueous solution using potassium persulfate (KPS) initiator. Evidences of grafting were obtained via FTIR spectroscopy, elemental analyses, scanning electron microscopy, X-ray diffraction and the differences in swellability

  9. Physiologically Based Pharmacokinetic Model Parameter Estimation and Sensitivity and Variability Analyses for Acrylonitrile Disposition in Humans

    Microsoft Academic Search

    Lisa M. Sweeney; Michael L. Gargas; Dale E. Strother; Gregory L. Kedderis

    2003-01-01

    A physiologically based pharmacokinetic (PBPK) model of acrylonitrile (ACN) and cyanoethylene oxide (CEO) disposition in humans was developed and is based on human in vitro data and scaling from a rat model (G. L. Kedderis et al., 1996, Toxicol. Appl. Pharmacol. 140, 422- 435) for application to risk assessment. All of the major biotransformation and reactivity pathways, including metabolism of

  10. The effect of acrylonitrile on gap junctional intercellular communication in rat astrocytes

    Microsoft Academic Search

    L. M. Kamendulis; J. Jiang; H. Zhang; H. deFeijter-Rupp; J. E. Trosko; J. E. Klaunig

    1999-01-01

    Rats chronically exposed to acrylonitrile (ACN) have shown a dose-dependent increase in the incidence of astrocytomas in the brain. The mechanism(s) by which ACN induces cancer in rodents has not been established. ACN does not appear to be directly genotoxic in the brain and thus a nongenotoxic mode of action has been proposed. Inhibition of gap junctional intercellular communication (GJIC)

  11. The acute lethality of acrylonitrile is not due to brain metabolic arrest

    Microsoft Academic Search

    E. Cristian Campian; Frederick W. Benz

    2008-01-01

    Acrylonitrile (AN) is an organic compound produced in large quantities by the chemical industry and is acutely toxic. One mechanism proposed to explain the toxicity of AN is metabolism by P450 into cyanide (CN). Although blood and brain levels of CN in rats following an LD90 dose of AN are consistent with acute toxicity, blocking CN formation with P450 inhibitors

  12. Intestinal Toxicity of Acrylonitrile: In Vitro Metabolism by Intestinal Cytochrome P450 2E1

    Microsoft Academic Search

    U. Subramanian; A. E. Ahmed

    1995-01-01

    Acrylonitrile (VCN) is known to cause extensive gastrointestinal damage and tumors in rats. In this study the metabolism of VCN to cyanide (CN?) was characterized in the small intestinal mucosa. The majority of the metabolic reactivity was localized in the microsomal fraction and required reduced nicotinamide adenine dinucleotide phosphate for maximal activity. The intestinal metabolism of VCN to CN? was

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

    PubMed

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

    2013-01-01

    Twenty-eight spontaneously occurring glial tumors (previously diagnosed as astrocytomas, oligodendrogliomas, and gliomas) and eleven granular cell tumors (GCTs) were selected for evaluation using a panel of immunohistochemistry (IHC) stains (Ricinus communis agglutinin type 1 [RCA-1], ionized calcium-binding adapter molecule 1 [Iba-1], OX-6/major immunohistocompatibility complex class II, oligodendrocytes transcription factor 2 [Olig2], glial fibrillary acidic protein [GFAP], S100 beta, glutamine synthetase, neurofilament, proliferating cell nuclear antigen). In addition, nine brain tumors from a 2-year drinking water study for acrylonitrile were obtained from the Acrylonitrile Group, Inc. Based on IHC staining characteristics, Olig2+ oligodendrogliomas were the most commonly diagnosed spontaneous tumor in these animals. Many of the spontaneous tumors previously diagnosed as astrocytomas were RCA-1+, Iba-1+ and negative for GFAP, S100beta, and glutamine synthetase; the diagnosis of malignant microglial tumor is proposed for these neoplasms. Three mixed tumors were identified with Olig2+ (oligodendrocytes) and Iba-1+ (macrophage/microglia) cell populations. The term mixed glioma is not recommended for these tumors, as it is generally used to refer to oligoastrocytomas, which were not observed in this study. GCT were positive for RCA-1 and Iba-1. All acrylonitrile tumors were identified as malignant microglial tumors. These results may indicate that oligodendrogliomas are more common as spontaneous tumors, while acrylonitrile-induced neoplasms are microglial/histiocytic in origin. No astrocytomas (GFAP, S100 beta, and/or glutamine synthetase-positive neoplasms) were observed. PMID:22821367

  14. THE INFLUENCE OF REACTION CONDITIONS ON THE PROPERTIES OF GRAFTED NATURAL RUBBER WITH ACRYLONITRILE

    Microsoft Academic Search

    Charun Bunyakan; Jarun Phumnok

    The graft copolymerization of acrylonitrile onto natural rubber was successfully prepared by emulsion polymerization process using cumene hydroperoxide and tetraethylene pentamine as an initiator. The influences of initial monomer concentration, initial initiator concentration and reaction temperature on particle size, particle size distribution, 300% modulus and swelling properties of grafted NR with AN have been investigated.. The results indicated that the

  15. Sister chromatid exchanges induced in peripheral lymphocytes of workers exposed to low concentrations of styrene

    SciTech Connect

    Yager, J.W.; Paradisin, W.M.; Symanski, E.; Rappaport, S.M. (Univ. of California, Berkeley (USA))

    1990-01-01

    This study employed a longitudinal sampling design to obtain measurements of exposure and exhaled air from all members of a cohort several times over the course of one year. Styrene in exhaled air correlated well with styrene in breathing zone air. Both smoking and exposure to styrene appear to have contributed significantly and separately to increased SCEs. Early results imply that SCEs were somewhat more highly correlated with styrene in exhaled air than in breathing zone air.

  16. Bacterial degradation of styrene in waste gases using a peat filter

    Microsoft Academic Search

    M. Arnold; A. Reittu; A. von Wright; P. J. Martikainen; M.-L. Suihko

    1997-01-01

    A biofiltration process was developed for styrene-containing off-gases using peat as filter material. The average styrene\\u000a reduction ratio after 190 days of operation was 70% (max. 98%) and the mean styrene elimination capacity was 12?g m?3?h?1 (max. 30 g m?3?h?1). Efficient styrene degradation required addition of nutrients to the peat, adjustment of the pH?to a neutral level and efficient\\u000a control

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

    NASA Astrophysics Data System (ADS)

    Laowagul, Wanna; Yoshizumi, Kunio

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

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

    PubMed

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

    2014-11-21

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

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

    SciTech Connect

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

    1994-12-01

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

  20. Microbial degradation of styrene: biochemistry, molecular genetics, and perspectives for biotechnological applications

    Microsoft Academic Search

    Aisling Mooney; Patrick G. Ward; Kevin E. O’Connor

    2006-01-01

    Large quantities of the potentially toxic compound styrene are produced and used annually by the petrochemical and polymer-processing industries. It is as a direct consequence of this that significant volumes of styrene are released into the environment in both the liquid and the gaseous forms. Styrene and its metabolites are known to have serious negative effects on human health and

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

    PubMed

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

    1998-12-01

    Chronic treatment with acrylonitrile (ACN) has been shown to produce a dose-related increase in glial cell tumors (astrocytomas) in rats. The mechanism(s) for ACN-induced carcinogenicity remains unclear. While ACN has been reported to induce DNA damage in a number of short-term systems, evidence for a genotoxic mechanism of tumor induction is the brain is not strong. Other toxic mechanisms appear to participate in the induction of tumor or induce the astrocytomas solely. In particular, nongenotoxic mechanisms of carcinogen induction have been implicated in this ACN-induced carcinogenic effect in the rat brain. One major pathway of ACN metabolism is through glutathione (GSH) conjugation. Extensive utilization and depletion of GSH, an important intracellular antioxidant, by ACN may lead to cellular oxidative stress. The present study examined the ability of ACN to induce oxidative stress in male Sprague-Dawley rats. Rats were administered ACN at concentrations of 0, 5, 10, 100, or 200 ppm in the drinking water and sampled after 14, 28, or 90 days of continuous treatment. Oxidative DNA damage indicated by the presence of 8-hydroxy-2'-deoxyguanosine (OH8dG) and lipid peroxidation indicated by the presence of malondialdehyde (MDA), a lipid peroxidation product, in rat brains and livers were examined. The levels of reactive oxygen species (ROS) were also determined in different rat tissues. Both the levels of nonenzymatic antioxidants (GSH, vitamin E) and the activities of enzymatic antioxidants (catalase, superoxide dismutase, glutathione peroxidase) in rat brains and livers were measured. Increased levels of OH8dG, MDA, and ROS were found in the brains of ACN-treated rats. Decreased levels of GSH and activities of catalase and SOD were also observed in the brains of ACN-treated rats compared to the control group. Interestingly, there were no changes of these indicators of oxidative stress in the livers of ACN-treated rats. Rat liver is not a target for ACN-induced carcinogenesis. These data indicate that ACN selectively induces oxidative stress in rat brain at doses that produce carcinogenesis in chronic treatment studies. PMID:10048137

  2. Microemulsion polymerization of styrene initiated with gamma ray

    NASA Astrophysics Data System (ADS)

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

    1997-04-01

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

  3. Phase diagram and crystal phases of trans-1,3 butadiene probed by FTIR and Raman spectroscopy

    Microsoft Academic Search

    Margherita Citroni; Matteo Ceppatelli; Roberto Bini; Vincenzo Schettino

    2003-01-01

    In the present work the first spectroscopic data concerning solid butadiene are presented. FTIR and Raman spectra of solid trans-1,3 butadiene in the ordered phase I were recorded at atmospheric pressure down to 12 K. The FTIR technique was used to characterize the phase diagram of butadiene in the 0–7 GPa and 150–300 K pressure–temperature range. Besides phase I another

  4. Gas chromatographic determination of 3-butene-1,2-diol in urine samples after 1,3-butadiene exposure

    Microsoft Academic Search

    Tiina Anttinen-Klemetti; Raija Vaaranrinta; Kimmo Peltonen

    1999-01-01

    1,3-Butadiene is an important industrial chemical and a common environmental contaminant. Because of its suspected carcinogenicity butadiene-related research has gained high activity. The obvious lack of knowledge so far has been that a biomonitoring method that can detect at least one of the metabolites of butadiene from body fluids or excretas does not exist. In this communication we describe a

  5. Palladium Nanoparticles by Electrospinning from Poly(acrylonitrile-co-acrylic acid)-PdCl2 Solutions. Relations between

    E-print Network

    Yanikoglu, Berrin

    Palladium Nanoparticles by Electrospinning from Poly(acrylonitrile-co-acrylic acid)-PdCl2 Solutions Manuscript Received January 12, 2004 ABSTRACT: Catalytic palladium (Pd) nanoparticles on electrospun microscopy. Spherical Pd nanoparticles were dispersed homogeneously on the electrospun nanofibers

  6. Exploiting Framework Flexibility of a Metal-Organic Framework for Selective Adsorption of Styrene over Ethylbenzene.

    PubMed

    Mukherjee, Soumya; Joarder, Biplab; Desai, Aamod V; Manna, Biplab; Krishna, Rajamani; Ghosh, Sujit K

    2015-05-01

    The separation of styrene and ethylbenzene mixtures is industrially important and is currently performed in highly energy-intensive vacuum distillation columns. The primary objective of our investigation is to offer an energy-efficient alternative for selective adsorption of styrene by a flexible metal-organic framework, DynaMOF-100. The structural transformation of DynaMOF-100 is specifically triggered on inclusion of styrene within the framework; this structural transformation is reversible. The styrene/ethylbenzene adsorption selectivity, originated as an outcome of the framework flexibility, is found to be much superior to the only two MOFs yet reported, serving styrene/ethylbenzene separation purpose. PMID:25875678

  7. Controlled Styrene Monolayer Capping of Silicon Nanocrystals by Room Temperature Hydrosilylation.

    PubMed

    Yu, Yixuan; Korgel, Brian A

    2015-06-16

    Undecanoic acid facilitates attachment of styrene to hydride-terminated Si nanocrystals at room temperature, avoiding polymerization of styrene, yielding free-standing styrene-terminated Si nanocrystals. The nanocrystals have diamond cubic crystal structure, with photophysical properties similar to typical alkene-capped Si nanocrystals, such as bright photoluminescence with relatively long radiative lifetimes. We propose a reaction mechanism for room temperature styrene addition in which the resonance form of undecanoic acid coordinates to surface Si-H and facilitates H(-) attack at terminal C?C of styrene. PMID:26010097

  8. Rotary concentrator followed by thermal or catalytic oxidation - a hybrid approach to economical styrene abatement

    SciTech Connect

    Gupta, A. [Duerr Industries, Inc., Plymouth, MI (United States)

    1997-12-31

    There are varied challenges in deciding appropriate technology for styrene abatement. Due to high costs of using RTOs for styrene abatement the small businesses, which form the bulk of styrene emitters, are faced with economically difficult choices. The proposed Rotary Concentrator technology can reduce operating cost up to six times and reduce CO{sub 2} and NO{sub x} emissions by more than half over the currently preferred RTO technology. It is also less expensive in capital expenditure and its viability for styrene abatement has been sufficiently demonstrated by pilot studies in the US and existing installations overseas. In both cases styrene destruction of more than 95% was achieved.

  9. Mechanical, Thermal, and Rheological Properties of EPDM-graft-methyl Methacrylate and Styrene (EPDM-g-MS)\\/Methyl Methacrylate-Styrene Copolymer (MS Resin) Blends

    Microsoft Academic Search

    Yongping Zhu; Jinfeng Fu; Lianshi Wang; Anqiang Zhang

    2009-01-01

    EPDM-graft-methyl methacrylate and styrene (EPDM-g-MS) were synthesized by solution graft copolymerization of methyl methacrylate (MMA) and styrene (St) onto ethylene-propylene-diene terpolymer (EPDM). EPDM-g-MS\\/MS resin blends (MES) tht were prepared by melt blending EPDM-g-MS and methyl methacrylate-styrene copolymer (MS resin). The mechanical properties, compatibility, thermal stabilities and rheological properties of MES were studied by the pendulum impact tester and the tension

  10. Distribution and accumulation of (2,3-¹⁴C)acrylonitrile in rat after single injection

    Microsoft Academic Search

    M. Sato; F. Hirasawa; M. Ogata; Y. Takizawa; H. Kojima; T. Yoshida

    1982-01-01

    The distribution and accumulation of acrylonitrile after the single i.p. injection of (2,3-¹⁴C)acrylonitrile were examined by whole-body autoradiography and by the determination of ¹⁴C radioactivities in several tissues and subcellular fractions after a whole-body perfusion. ¹⁴C Radioactivity was seen strongly in blood, particularly in red blood cells, and in several tissues including lung, liver, and kidney. Longer retention of radioactivity

  11. Photochemical aging of in situ polymerized blends of polystyrene and poly[acrylonitrile- g-(ethylene- co-propylene- co-diene)- g-styrene] (AES)

    Microsoft Academic Search

    Emerson Lourenço; Maria Isabel Felisberti

    2006-01-01

    The influence of photochemical aging of in situ polymerized PS\\/AES blends on their mechanical properties has been studied. The PS\\/AES blends were subjected to photochemical aging for 168h and 720h. Tensile properties and Izod impact resistance of aged and non-aged samples were evaluated. The mechanical properties of the PS\\/AES blends are influenced by the polymerization temperature and blend composition and

  12. Modeling of the Microwave Initiated Emulsion Polymerization of Styrene

    Microsoft Academic Search

    Joaquín Palacios

    2005-01-01

    The emulsion polymerization of styrene, activated by microwave irradiation and conductive heating, was modeled using the Predici simulation package of CiT. Microwave activated initiation was modeled as adding a second conventional free?radical chemical initiator, whose concentration is given by the intensity of microwave irradiation, and its “decomposition” kinetic rate constant is related to the ratio of monomer concentration to the

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

    PubMed Central

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

    2011-01-01

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

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

    PubMed Central

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

    1990-01-01

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

  15. Detection of acrolein and acrylonitrile with a pulsed room temperature quantum cascade laser

    NASA Astrophysics Data System (ADS)

    Manne, J.; Jäger, W.; Tulip, J.

    2010-06-01

    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.

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

    PubMed

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

    2010-09-01

    The nitrile hydratase (NHase) of Rhodococcus rhodochrous PA-34 catalyzed the conversion of acrylonitrile to acrylamide. The resting cells (having NHase activity) (8 %; 1 mL corresponds to 22 mg dry cell mass, DCM) were immobilized in polyacrylamide gel containing 12.5 % acrylamide, 0.6 % bisacrylamide, 0.2 % diammonium persulfate and 0.4 % TEMED. The polyacrylamide entrapped cells (1.12 mg DCM/mL) completely converted acrylonitrile in 3 h at 10 °C, using 0.1 mol/L potassium phosphate buffer. In a partitioned fed batch reactor, 432 g/L acrylamide was accumulated after 1 d. The polyacrylamide discs were recycled up to 3×; 405, 210 and 170 g/L acrylamide was produced in 1st, 2nd and 3rd recycling reactions. In four cycles, a total of 1217 g acrylamide was produced by recycling the same mass of entrapped cells. PMID:20941578

  17. Formation of 8-oxodeoxyguanosine in brain DNA of rats exposed to acrylonitrile

    Microsoft Academic Search

    John Whysner; Di Chen; Carson C. Conaway; Lynne K. Verna; John P. Richie Jr.; Nusrat Ali; Gary M. Williams

    1998-01-01

    Acrylonitrile (ACN) produces tumors in rats, particularly gliomas of the brain, but tests for genotoxicity have yielded mixed\\u000a results and no ACN-DNA adducts have been identified in the brain. To examine the possibility that ACN-related brain tumors\\u000a were not a consequence of binding of ACN to brain DNA, experiments were conducted to investigate possible epigenetic mechanisms.\\u000a Male Sprague-Dawley rats were

  18. Refinement and Verification of the Physiologically Based Dosimetry Description for Acrylonitrile in Rats

    Microsoft Academic Search

    Gregory L. Kedderis; Steven K. O. Teo; Renu Batra; Sara D. Held; Michael L. Gargas

    1996-01-01

    The physiologically based dosimetry description for acrylonitrile (ACN) and its mutagenic epoxide metabolite 2-cyanoethylene oxide (CEO) in F-344 rats (M. L. Gargas, M. E. Anderson, S.K.O. Teo, R. Batra, T. R. Fennell, and G. L. Kedderis, 1995,Toxicol. Appl. Pharmacol.134,185–194) has been refined to include a physiological stomach compartment and the reactions of ACN with tissue glutathione (GSH). The second-order rate

  19. Three-generation reproduction study of rats receiving acrylonitrile in drinking water.

    PubMed

    Friedman, M A; Beliles, R P

    2002-06-24

    Acrylonitrile, a high volume organic chemical, was tested for reproductive effects in a three generation drinking water study with two matings per generation. Sprague-Dawley rats were exposed to acrylonitrile in drinking water at 0, 100, or 500 ppm. This corresponds to 0, 11+/-5 and 37+/-10 mg/kg, respectively, for males and 0, 20+/-3 and 40+/-8 mg/kg per day for the females, respectively. Water consumption was reduced in F0 rats in the 100 and 500 ppm groups. At 500 ppm, acrylonitrile reduced body weight gain and food intake of the first generation parental rats (F0). These parameters were not investigated at subsequent generations. The pup survival (both viability and lactation indices) was reduced at the 500 ppm treatment level in both matings of all three generations. Fostering the 500 ppm pups onto untreated mothers following the second mating lessened mortality, suggesting a maternal effect consistent with decreased water consumption. There was no remarkable change in the reproductive capacity in any of matings in rats at the 100 ppm concentration. In contrast, in all three generations, the body weights of the pups of the 500 ppm treatment level were reduced on Day 21 at both matings. No adverse findings were observed in the tissues of a limited number of third generation weanlings (F3b) upon gross and microscopic evaluation. No effect on the sciatic nerve was evident among the adult female rats held for 20 weeks after weaning of the second litter. There was a dose-related effect of acrylonitrile on gross masses in female rats at each parental generation held 20 weeks after the weaning of the second litter. Histopathological evaluation of these dams showed an increase in astrocytomas and zymbal gland tumors. PMID:12044706

  20. Acrylonitrile pharmacodynamics and mutagenesis. Report for 1 July 1977-30 June 1979

    Microsoft Academic Search

    1979-01-01

    A study was made of the pharmacokinetics of acrylonitrile (AN) with emphasis on routes of elimination and mechanisms of metabolism. Rats were given intraperitoneal injections of AN at 5 to 60mg\\/kg. Two AN analogues, crotononitrile (CN) and methacrylonitrile (MN), were also studied. CN and MN concentrations in blood followed a first-order kinetic elimination. AN demonstrated a biphasic kinetic elimination. An

  1. Two-year toxicity and oncogenicity study with acrylonitrile incorporated in the drinking water of rats

    Microsoft Academic Search

    John F. Quast

    2002-01-01

    Sprague–Dawley rats (80 per sex per control and 48 per sex in each treatment group) were given drinking water formulated to contain 0, 35, 100, or 300 ppm acrylonitrile (AN) for up to 2-years. An additional ten rats per sex per group were added for a 1-year interim necropsy. The equivalent doses of AN consumed were 0, 3.4, 8.5, and

  2. (Poly)acrylonitrile-based hydrogel as a therapeutic bulking agent in urology

    Microsoft Academic Search

    Pascal Ramseyer; Kathleen Meagher-Villemure; Marco Burki; Peter Frey

    2007-01-01

    Vesicoureteral reflux and urinary incontinence can be treated by endoscopic injection. Injectables such as collagen and hyaluronic acid-dextranomer are commonly used, however are not offering optimal therapeutic effect yet. In the present study a novel application for poly(acrylonitrile)-based hydrogel (Hypan®), already tested in other clinical indications, has been investigated for its aptitude as an injectable bulking agent. This non-degradable, extremely

  3. Curcumin pretreatment protects against acute acrylonitrile-induced oxidative damage in rats

    Microsoft Academic Search

    Xing Guangwei; Lu Rongzhu; Xu Wenrong; Wang Suhua; Zhao Xiaowu; Wang Shizhong; Zhang Ye; Michael Aschner; Shrinivas K. Kulkarni; Mahendra Bishnoi

    2010-01-01

    Acrylonitrile (AN) is widely used in the manufacturing of fibers, plastics and pharmaceuticals. Free radical-mediated lipid peroxidation is implicated in the toxicity of AN. The present study was designed to examine the ability of curcumin, a natural polyphenolic compound, to attenuate acute AN-induced lipid peroxidation in the brain and liver of rats. Male Sprague–Dawley rats were orally administered curcumin at

  4. Modulation of acrylonitrile-induced embryotoxicity in vitro by glutathione depletion

    Microsoft Academic Search

    Anne-Marie Saillenfait; Jean-Paul Payan; Isabelle Langonné; Dominique Beydon; Marie-Christine Grandclaude; Jean-Philippe Sabaté; Jacques de Ceaurriz

    1993-01-01

    The effects of glutathione (GSH) depletion on the embryotoxicity of acrylonitrile were assessed in vitro using the rat whole-embryo culture system. Day 10 rat embryos were cultured in rat serum medium for 6 h in the presence of 250 ?Ml-buthionine-S,R-sulfoximine (BSO), a specific inhibitor of GSH synthesis, to deplete GSH in both embryo and visceral yolk sac. Following pretreatment, conceptuses

  5. Dose Dependence of Covalent Binding of Acrylonitrile to Tissue Protein and Globin in Rats

    Microsoft Academic Search

    Frederick W. Benz; Donald E. Nerland; Junyu Li; Donna Corbett

    1997-01-01

    The dose dependence of acrylonitrile (AN) covalent binding to tissue protein, following a single acute exposure over a 100-fold range in dose, was measured. Covalent binding was a linear function of AN dose in the lower dose range (0.02–0.95 mmol AN\\/kg). The slopes of the dose–response curves indicated that tissues varied by nearly 10-fold in their reactivity with AN. The

  6. Role of glutathione modulation in acrylonitrile-induced gastric DNA damage in rats

    Microsoft Academic Search

    Ahmed E. Ahmed; Amr M. Nouraldeen; Sherif Z. Abdel-Rahman; Srinivasan Rajaraman

    1996-01-01

    Acrylonitrile (VCN) or its reactive metabolites irreversibly interact with gastric DNA in vivo and cause DNA damage. The\\u000a effect of glutathione (GSH) modulation on VCN-induced genotoxicity and unscheduled DNA repair synthesis (UDRS) in DNA of gastric\\u000a mucosal tissues was investigated. VCN-induced UDRS was determined: in control rats, rats with depleted gastric GSH contents,\\u000a and rats treated with sulfhydryl compounds. A

  7. In vivo biotransformation and biliary excretion of 1- 14 C-acrylonitrile in rats

    Microsoft Academic Search

    B. I. Ghanayem; A. E. Ahmed

    1982-01-01

    1-14C-Acrylonitrile (VCN) was given orally to rats, 27% of the given dose was excreted in bile in 6 h. When 1-14C-VCN was given to overnight fasted or cobaltous chloride treated rats, a significant increase in the biliary excretion occurred. Pretreatment of rats with phenobarbital produced no change, while diethyl maleate pretreatment significantly decreased the portion of the dose excreted in

  8. Effect of salt concentration on poly (vinyl chloride)\\/poly (acrylonitrile) based hybrid polymer electrolytes

    Microsoft Academic Search

    S. Rajendran; Ravi Shanker Babu; P. Sivakumar

    2007-01-01

    Hybrid, solid polymer electrolyte films consisting of poly (vinyl chloride) (PVC), poly (acrylonitrile) (PAN) and, propylene carbonate (PC) with different concentrations of LiClO4 are prepared by means of a using solvent-casting technique. The structure and complex formation are studied by X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy. The temperature dependence of the ionic conductivities of the polymer films

  9. Microporous poly(acrylonitrile-methyl methacrylate) membrane as a separator of rechargeable lithium battery

    Microsoft Academic Search

    S. S Zhang; M. H Ervin; K Xu; T. R Jow

    2004-01-01

    We studied microporous poly(acrylonitrile-methyl methacrylate), AMMA, membrane as the separator of Li\\/LiMn2O4 cell. The porous AMMA membrane was prepared by the phase inversion method with N,N-dimethylformamide (DMF) as the solvent and water as the non-solvent. We observed that morphology of the resulting membrane was strongly affected by the concentration of polymer solution: low concentration produced finger-like pores with dense skin

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

    Microsoft Academic Search

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

    1999-01-01

    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

  11. Acrylonitrile-induced toxicity and oxidative stress in isolated rat colonocytes

    Microsoft Academic Search

    Ahmed M. Mohamadin; Ebtehal El-Demerdash; Hesham A. El-Beshbishy; Ashraf B. Abdel-Naim

    2005-01-01

    Acrylonitrile (ACN), an environmental toxic pollutant, has been detected in drinking water, food products and occupational environment. The objective of the present work was to investigate the cytotoxic effects as well as the oxidative stress induced by ACN in cultured rat colonocytes. Colonocytes were exposed in vitro to different concentrations of ACN (0.1–2.0mM) for 60min. Also, colonocytes were incubated with

  12. Poly (acrylonitrile – co -1-vinylimidazole): A new melt processable carbon fiber precursor

    Microsoft Academic Search

    Wenjin Deng; Alexander Lobovsky; Scott T. Iacono; Tianyu Wu; Neetu Tomar; Stephen M. Budy; Timothy Long; Wesley P. Hoffman; Dennis W. Smith

    2011-01-01

    Acrylonitrile\\/1-vinylimidazole (AN\\/VIM) copolymers containing various mol% of VIM were synthesized by free radical solution polymerization. The copolymers were characterized by Attenuated Total Reflectance-Fourier Transform Infrared (ATR-FTIR) spectroscopy, 1H NMR spectroscopy, gel permeation chromatography (GPC) and differential scanning calorimetry (DSC). Char yields of the copolymers were 40–48% as determined by thermogravimetric analysis (TGA) while gel fractions were found to be 90–99%

  13. Sorption studies on Cr (VI) removal from aqueous solution using cellulose grafted with acrylonitrile monomer.

    PubMed

    Hajeeth, T; Sudha, P N; Vijayalakshmi, K; Gomathi, T

    2014-05-01

    Graft copolymerization of acrylonitrile on to cellulosic material derived from sisal fiber can be initiated effectively with ceric ammonium nitrate. The grafting conditions were optimized by changing the concentration of initiator and monomer. The change in crystallinity of the grafted polymeric samples was concluded from the XRD patterns. The prepared cellulose grafted acrylonitrile copolymer was used as an adsorbent to remove Cr (VI) ions from aqueous solutions. The efficiency of the adsorbent was identified from the variation in the percentage of adsorption with contact time, adsorbent dose and pH. From the observed results it was evident that the adsorption of metal ions increases with the increase in contact time and metal ion concentration. An optimum pH was found to be 5.0 for the removal of Cr (VI) from the aqueous solution. The results of the Langmuir, Freundlich, and pseudo first- and second-order studies revealed that the adsorption was found to fit well with Freundlich isotherm and follows pseudo second-order kinetics. From the above results, it was concluded that the cellulose-g-acrylonitrile copolymer was found to be an efficient adsorbent for the removal of Cr (VI) from aqueous waste generated from industries. PMID:24560947

  14. Theoretical study of the Diels-Alder reactions of zirconium dimer with ethylene and butadiene

    SciTech Connect

    Roszak, S.; Balasubramanian, K. [Arizona State Univ., Tempe, AZ (United States)

    1995-03-16

    A theoretical study of the symmetry concerted Diels-Alder analogue reactions of Zr{sub 2} with ethylene and 1,3-butadiene is carried out. The optimized structures of the complexes indicate breaking of one of the multiple bonds in Zr{sub 2} and 1,3-butadiene and the formation of a six-membered ring in agreement with symmetry concerted models. Thus the reaction of ethylene with Zr{sub 2} is thermally forbidden, while it is allowed for the butadiene case. This is explained based on the natural orbitals picture. The presented potential energy surfaces are useful for the interpretation of possible reactions in both ground and excited states. 26 refs., 7 figs., 3 tabs.

  15. Recoil carbon-11 atom reactions with 1,3-butadiene in the gas phase

    E-print Network

    Baltuskonis, Dennis Alan Anthony

    1975-01-01

    The fast neutron irradiation of C in butadiene yields C atoms 12. . . 11 12 * 11 from the nuclear transformation C(n , Zn) C. Products identified from the reactions of recoil carbon-11 atoms with pure 1, 3-butadiene are: CO (4/), HC=CH (58/), 1, 2, 4... of the Yields of C-labeled Products as a 11 Function of Pressure Plot of the Yields of C-l, abeled Carbon Monoxide, 11 42 52 III-3. Carbon Dioxide, and Aliene as a Function of Pressure. . . . . 55 Plot of the Yield of C-labeled Acetylene as a 11 III-4...

  16. Rich methane laminar flames doped with light unsaturated hydrocarbons. Part II: 1,3butadiene

    Microsoft Academic Search

    Hadj-Ali Gueniche; Pierre-Alexandre Glaude; René Fournet; Frédérique Battin-Leclerc

    2007-01-01

    In line with the study presented in the part I of this paper, the structure\\u000aof a laminar rich premixed methane flame doped with 1,3-butadiene has been\\u000ainvestigated. The flame contains 20.7% (molar) of methane, 31.4% of oxygen and\\u000a3.3% of 1,3-butadiene, corresponding to an equivalence ratio of 1.8, and a\\u000aratio C4H6 \\/ CH4 of 16 %. The flame

  17. Enantioselective C-H Crotylation of Primary Alcohols via Hydrohydroxyalkylation of Butadiene

    PubMed Central

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

    2012-01-01

    The direct, by-product–free conversion of basic feedstocks to products of medicinal and agricultural relevance is a broad goal of chemical research. Butadiene is a product of petroleum cracking and is produced on an enormous scale (about 12 × 106 metric tons annually). Here, with the use of a ruthenium catalyst modified by a chiral phosphate counterion, we report the direct redox-triggered carbon-carbon coupling of alcohols and butadiene to form products of carbonyl crotylation with high levels of anti-diastereoselectivity and enantioselectivity in the absence of stoichiometric by-products. PMID:22442385

  18. CC10 mRNA and protein expression in Clara cells of CD-1 mice following exposure to styrene or its metabolites styrene oxide or 4-vinylphenol.

    PubMed

    Harvilchuck, Jill A; Zurbrugg, Rebekah J; Carlson, Gary P

    2008-12-15

    Styrene, widely used in manufacturing, has both acute and chronic effects in humans. In mice, styrene is both hepato- and pneumo-toxic and causes lung tumors. The primary site for styrene metabolism and its effects in mouse lung is the Clara cell, which secretes Clara cell 10kDa protein (CC10) and surfactant protein A (SPA). Both play important roles in host defenses and inflammation prevention. The mode of action for styrene-induced lung tumor formation has yet to be elicited, yet one possibility relates to oxidative stress and decreased CC10 levels. CC10 mRNA and protein expression were measured in isolated Clara cells 3, 12, and 24h following in vivo administration of styrene (600mg/kg i.p.) or its metabolites [R-, S-, racemic styrene oxide (SO) (300mg/kg i.p.), 4-vinylphenol (100mg/kg i.p.)]. The largest decreases in CC10 mRNA expression were seen with R-SO and racemic SO at 24h. To determine if rebound effects would be seen, CC10 mRNA and protein expression were determined 48, 120, and 240h following styrene and R-SO administration. The CC10 protein level did not reach its lowest point to correlate with mRNA expression until 120h after R-SO administration. Styrene exposure caused a significant decrease in CC10 protein after 24h, rebounding through 240h. SPA protein expression showed little change from control levels, indicating a more specific effect on CC10 in the Clara cell by styrene and its metabolites. These studies demonstrate that acute changes in lung CC10 protein and mRNA expression do occur following in vivo treatment with styrene and its metabolites. These changes may be early indicators for a potential mechanism for lung tumor formation in mice as it relates to oxidative stress and the possibility deserves further study. PMID:18926891

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

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

    NASA Astrophysics Data System (ADS)

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

    2008-08-01

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

  1. Formation of styrene during the Maillard reaction is negligible

    Microsoft Academic Search

    T. Goldmann; T. Davidek; E. Gouezec; I. Blank; M.-C. Bertholet; R. Stadler

    2009-01-01

    The elucidation of chemical pathways and the identification of intermediates leading to vinylogous compounds such as acrylamide by the Maillard reaction have proven challenging. This study was conducted to assess the formation of styrene from L-phenylalanine, employing binary mixtures of the amino acid heated together with simple C3-sugar analogue (1-hydroxyacetone) or methylglyoxal. The formation of the corresponding vinylogous product, i.e.

  2. Humidity sensor using cross-linked poly(chloromethyl styrene)

    Microsoft Academic Search

    Y. Sakai; M. Matsuguchi; T. Hurukawa

    2000-01-01

    A resistive-type humidity sensor was prepared using a poly(chloromethyl styrene) (PCMS) film which was simultaneously cross-linked and quaternized. The impedance dependence on humidity for samples with various reaction degrees was measured. The sorption isotherm curves of water vapor in the cross-linked films were obtained using the quartz crystal microbalance method for the various samples. It was found that the degree

  3. Failure Analysis of AISI304 Stainless Steel Styrene Storage Tank

    Microsoft Academic Search

    Muhammad Sajid Ali Asghar; Fawad Tariq; Ashraf Ali

    2010-01-01

    This paper presents the failure analysis of AISI-304 stainless steel tank that was fabricated by welding and used for the\\u000a storage of styrene monomers. After about 13 years of satisfactory operation, significant cracking was observed adjacent to\\u000a the weld joints and in base plate near tank foundation. Weld repair was by shielded gas arc welding using AISI 308 stainless\\u000a steel filler

  4. Use of poly(styrene)-block-poly(ethyleneoxide) as emulsifier in emulsion polymerization

    Microsoft Academic Search

    Markus Berger; Walter Richtering; Rolf Miilhaupt

    1994-01-01

    Poly(styrene)-block-poly(ethyleneoxide), abbreviated as (PS-b-PEO) were used as emulsifiers in emulsion polymerization of styrene and methyl methacrylate. The block copolymers had a poly(styrene) block with Mn=1000 g\\/mol and a poly(ethyleneoxide) block with Mn=1000, 3000 or 5000 g\\/mol, respectively. Stable dispersions were obtained when the PEO block molecular weight was higher than 1000 g\\/mol. Also the amphiphilic properties of the copolymers depended

  5. Enantioselective hydrolysis of styrene oxide with the epoxide hydrolase of Sphingomonas sp. HXN-200

    Microsoft Academic Search

    Zeya Liu; Johannes Michel; Zunsheng Wang; Bernard Witholt; Zhi Li

    2006-01-01

    The soluble bacterial epoxide hydrolase (EH) from Sphingomonas sp. HXN-200 catalyzed the enantioselective hydrolysis of racemic styrene oxide to give (S)-styrene oxide with an enantiomeric ratio (E) of 21–23 in aqueous buffer, better than any reported native EHs. The ring opening of the styrene oxide with this EH was only at the terminal position for the (S)-enantiomer and at the

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

    Microsoft Academic Search

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

    2003-01-01

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

  7. Towards a Biocatalyst for (S)-Styrene Oxide Production: Characterization of the Styrene Degradation Pathway of Pseudomonas sp. Strain VLB120

    PubMed Central

    Panke, Sven; Witholt, Bernard; Schmid, Andreas; Wubbolts, Marcel G.

    1998-01-01

    In order to design a biocatalyst for the production of optically pure styrene oxide, an important building block in organic synthesis, the metabolic pathway and molecular biology of styrene degradation in Pseudomonas sp. strain VLB120 was investigated. A 5.7-kb XhoI fragment, which contained on the same strand of DNA six genes involved in styrene degradation, was isolated from a gene library of this organism in Escherichia coli by screening for indigo formation. T7 RNA polymerase expression experiments indicated that this fragment coded for at least five complete polypeptides, StyRABCD, corresponding to five of the six genes. The first two genes encoded the potential carboxy-terminal part of a sensor, named StySc, and the complete response regulator StyR. Fusion of the putative styAp promoter to a lacZ reporter indicated that StySc and StyR together regulate expression of the structural genes at the transcriptional level. Expression of styScR also alleviated a block that prevented translation of styA mRNA when a heterologous promoter was used. The structural genes styA and styB produced a styrene monooxygenase that converted styrene to styrene oxide, which was then converted to phenylacetaldehyde by StyC. Sequence homology analysis of StyD indicated a probable function as a phenylacetaldehyde dehydrogenase. To assess the usefulness of the enzymes for the production of enantiomerically pure styrene oxide, we investigated the enantiospecificities of the reactions involved. Kinetic resolution of racemic styrene oxide by styrene oxide isomerase was studied with E. coli recombinants carrying styC, which converted styrene oxide at a very high rate but with only a slight preference for the S enantiomer. However, recombinants producing styrene monooxygenase catalyzed the formation of (S)-styrene oxide from inexpensive styrene with an excellent enantiomeric excess of more than 99% at rates up to 180 U g (dry weight) of cells?1. PMID:9603811

  8. Poly(styrene-b-dimethylsiloxane-b-styrene) Membranes in Pervaporation for In Situ Product Recovery during Fermentation

    NASA Astrophysics Data System (ADS)

    Shin, Chaeyoung; Baer, Zachary; Ozcam, Ali Evren; Clark, Douglas; Balsara, Nitash

    2014-03-01

    In situ product recovery was investigated in fermentation experiments to enable the development of a continuous fermentation process. Our pervaporation membranes are based on poly(styrene-b-dimethylsiloxane-b-styrene) (SDS) block copolymers. Polydimethylsiloxane (PDMS) is the best known organophilic pervaporation membrane material and was utilized as the transporting phase for selective permeation of organic molecules. The polystyrene (PS) block added structural integrity to the membrane due to the high modulus of PS. SDS membranes were found to have both the enhanced robustness as well as comparable pervaporation performance to that of cross-linked PDMS membranes. The permeabilities of water and organic components through SDS membranes were studied to elucidate the sorption and transport phenomena in this system. Furthermore, experiments combining fermentation with pervaporation were performed, and continuous fermentation by using pervaporation as the sole means of removing products was successfully demonstrated for the first time.

  9. Gas chromatography-mass spectrometry/selected ion monitoring for screening asymmetric epoxidation of styrene.

    PubMed

    Mu, Yao; Wei, Siping; Xu, Min; Chen, Ping; Wang, Qin; Du, Xi

    2014-12-01

    A screening method by gas chromatography-mass spectrometry (GC-MS) with selected ion monitoring (SIM) has been developed for asymmetric epoxidation of styrene. All samples were analyzed by GC-MS with the mode of SIM by using ethylbenzene as the internal standard, by which styrene and styrene epoxide enantiomers were completely separated and their concentrations were accurately determined. Furthermore, this method was used to evaluate the epoxidation reaction of styrene, which was optimized by orthogonal experiment. The advantages of the method are as follows: excellent precision (RSD in the range of 1. 2% - 5. 2%, n= 5), good linearity (the correlation coefficients for styrene, (R)/(S)-styrene oxide were 0. 9997, 0. 9932 and 0. 9963, respectively) , low limits of quantitation (LOQs of styrene, (R)/(S)-styrene oxide were 1. 3, 1. 1 and 0. 7 mg/L, respectively) and reasonable recoveries (98. 2% - 108. 2%). All in all, the method provided a new way to determine the asymmetric epoxidation mixture of styrene and its homologs. PMID:25902648

  10. Influence of temperature on styrene emission from a vinyl ester resin thermoset composite material.

    PubMed

    Crawford, Shaun; Lungu, Claudiu T

    2011-08-15

    Composite materials made with vinyl ester resins are lighter, stronger and corrosion resistant compared to most metals, and are increasingly being used as building materials and in public transportation. Styrene monomer is used as both a diluent and strengthener in the production of vinyl ester resin (VER) composites. Some researchers contend that free styrene in VER composites is available to diffuse out of the material into air, perhaps leading to adverse health effects via inhalation exposures in humans, yet there is no known data on styrene emissions from these materials in the literature. In this study, a typical VER composite made with resin containing 38% by weight styrene, reinforced with E-glass fiber and formed using a vacuum assisted resin transfer method was characterized for styrene emissions by environmental test chamber (ETC) methodology. Styrene concentrations in the ETC were measured over a temperature range of 10 to 50 °C. Initial evaporative styrene emissions increase with increasing temperature. There is a nearly linear relationship in the total mass of styrene emitted and emission factor as emissions increase with increasing temperature. Styrene emission factors appear to vary for different materials, which could indicate more complex processes or the influence of material physical properties on emission rates. These results can be used to validate and improve mass transfer emission models for the prediction of volatile organic compound concentrations in indoor environments. PMID:21689842

  11. The emissions of monoaromatic hydrocarbons from small polymeric toys placed in chocolate food products.

    PubMed

    Mar?, Mariusz; Formela, Krzysztof; Klein, Marek; Namie?nik, Jacek; Zabiega?a, Bo?ena

    2015-10-15

    The article presents findings on the emissions of selected monoaromatic hydrocarbons from children's toys placed in chocolate food products. The emission test system involved the application of a new type of microscale stationary emission chamber, ?-CTE™ 250. In order to determine the type of the applied polymer in the manufacture of the tested toys, Fourier transform infrared spectroscopy and thermogravimetric analysis coupled with differential scanning calorimetry were used. It was found that the tested toy components or the whole toys (figurines) are made of two main types of polymers: polyamide and acrylonitrile-butadiene-styrene copolymer. Total number of studied small polymeric toys was 52. The average emissions of selected monoaromatic hydrocarbons from studied toys made of polyamide were as follows: benzene: 0.45±0.33ng/g; toluene: 3.3±2.6ng/g; ethylbenzene: 1.4±1.4ng/g; p,m-xylene: 2.5±4.5ng/g; and styrene: 8.2±9.9ng/g. In the case of studied toys made of acrylonitrile-butadiene-styrene copolymer the average emissions of benzene, toluene, ethylbeznene, p,m-xylene and styrene were: 0.31±0.29ng/g; 2.5±1.4ng/g; 4.6±8.9ng/g; 1.4±1.1ng/g; and 36±44ng/g, respectively. PMID:26047863

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

    EPA Science Inventory

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

  13. MUTAGENICITY AND CARCINOGENICITY ASSESSMENT OF 1,3-BUTADIENE. REVIEW DRAFT

    EPA Science Inventory

    The Mutagenicity and Carcinogenicity Assessment of 1,3-Butadiene was prepared to serve as a source document for Agency-wide use. In the development of this assessment document, the scientific literature has been inventoried, key studies have been evaluated, and the summary and co...

  14. Quantitation of DNA Adducts Induced by 1,3-Butadiene

    NASA Astrophysics Data System (ADS)

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

    2014-07-01

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

  15. Deamination and Dimroth rearrangement of deoxyadenosine-styrene oxide adducts in DNA.

    PubMed

    Barlow, T; Takeshita, J; Dipple, A

    1998-07-01

    In reactions between styrene oxide and the ring nitrogen at the 1-position of deoxyadenosine, the epoxide is opened at both the alpha- (benzylic) and beta-carbons. The 1-substituted nucleosides formed are unstable and subsequently undergo either Dimroth rearrangement to give N6-substituted deoxyadenosines or deamination to give 1-substituted deoxyinosines. alphaN6-Substituted compounds are also formed from direct reaction at the exocyclic nitrogen. Kinetic experiments revealed that relative rates of deamination of 1-substituted deoxyadenosine-styrene oxides and 1-substituted adenosine-styrene oxides were similar. However, the rate of Dimroth rearrangement in beta1-substituted adenosine-styrene oxides was approximately 2.3-fold greater than that of beta1-substituted deoxyadenosine-styrene oxides and approximately 1.5-fold greater in alpha1-substituted adenosine-styrene oxides relative to alpha1-substituted deoxyadenosine-styrene oxides. Analysis of the products formed from reactions of styrene oxide with [3H]deoxyadenosine and [3H]deoxyadenosine incorporated into native and denatured DNA showed that the double-helical DNA structure reduced the levels of adducts formed 5-fold relative to denatured DNA but did not present a complete barrier to formation of either N6-substituted deoxyadenosine- or 1-substituted deoxyinosine-styrene oxide adducts in native DNA. Additionally, in denatured and native DNA the product distributions were altered in favor of formation of beta1-substituted deoxyinosine-styrene oxide adducts with respect to reactions of the nucleoside. The ratio of retained to inverted configuration of alphaN6-substituted products was higher in DNA than in nucleoside reactions. These experiments indicate that in addition to the N6-position, the ring nitrogen at the 1-position of deoxyadenosine is available, to some extent, for reaction in native DNA. In styrene oxide-DNA reactions, formation of 1-substituted adenines can lead to deaminated products where both Watson-Crick hydrogen-bonding sites are disrupted. PMID:9671547

  16. Distribution and accumulation of (2,3-/sup 14/C)acrylonitrile in rat after single injection

    SciTech Connect

    Sato, M.; Hirasawa, F.; Ogata, M.; Takizawa, Y.; Kojima, H.; Yoshida, T.

    1982-10-01

    The distribution and accumulation of acrylonitrile after the single i.p. injection of (2,3-/sup 14/C)acrylonitrile were examined by whole-body autoradiography and by the determination of /sup 14/C radioactivities in several tissues and subcellular fractions after a whole-body perfusion. /sup 14/C Radioactivity was seen strongly in blood, particularly in red blood cells, and in several tissues including lung, liver, and kidney. Longer retention of radioactivity in brain and muscle was observed. At the subcellular level a relatively high specific radioactivity was seen in cytosol fractions of the brain, liver, and kidney.

  17. 40 CFR 721.7020 - Distillates (petroleum), C(3-6), polymers with styrene and mixed terpenes (generic name).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

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

  18. 40 CFR 721.7020 - Distillates (petroleum), C(3-6), polymers with styrene and mixed terpenes (generic name).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

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

  19. 40 CFR 721.7020 - Distillates (petroleum), C(3-6), polymers with styrene and mixed terpenes (generic name).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

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

  20. 40 CFR 721.7020 - Distillates (petroleum), C(3-6), polymers with styrene and mixed terpenes (generic name).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

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

  1. Living polymerization of butadiene at both chain ends via a bimetallic nickel initiator. Preparation of hydroxytelechelic poly(butadiene) and symmetric poly(isocyanide-b-butadiene-b-isocyanide) elastomeric triblock copolymers

    SciTech Connect

    Deming, T.J.; Novak, B.M. (Univ. of California, Berkeley, CA (United States)); Ziller, J.W. (Univ. of California, Irvine, CA (United States))

    1994-03-23

    A bifunctional nickel initiator, bis([mu]-trifluoroacetato) ([eta][sup 3]:[eta][sup 3]-2,2[prime]-biallyl)dinickel(II), IV, was synthesized to promote the living polymerization of butadiene to high cis-1,4-content polymer with both chain ends active. Other potential initiators, [1,4-phenylenebis(([eta][sup 3]-1-allyl)nickel trifluoroacetate)][sub n], II, and [1,4-cyclohexanediylbis(([eta][sup 3]-1-allyl)-nickel trifluoroacetate)][sub n], III, were found to be completely ineffective due to intermolecular carboxylate bridges which gave the complexes polymeric structures. The intramolecular bridges in IV and its molecularity were confirmed by X-ray crystallography. IV cocrystallizes in space group P[bar 1] with 0.5 equiv of 2.3-bis((trifluoroacetoxy)methyl)-1,3-butadiene in the unit cell with constants of a = 9.5600(8) [angstrom], b = 9.6554(9) [angstrom], c = 11.7615(10) [angstrom]; [alpha] = 73.711(7)[degree], [beta] = 73.537(7)[degree], [gamma]= 71.938(7)[degree]; V = 967.50(15) [angstrom][sup 3]; and Z = 2. Refinement of the model, which contained a disordered C[sub 6]H[sub 8] unit, led to convergence with R[sub F] = 5.8%, R[sub WF] = 6.9%, and GOF = 2.21 for 276 variables refined against those 2852 data with [vert bar]F[sub o][vert bar]> 3.0[sigma]/([vert bar]F[sub o][vert bar]). The living polybutadiene samples were successfully used to prepare triblock copolymers of the structure poly(1-phenylethyl isocyanide-b-butadiene-b-1-phenylethyl isocyanide). 24 refs., 5 figs., 1 tab.

  2. Comparative Disposition of Acrylonitrile and Methacrylonitrile: Quantitative Whole-Body Autoradiographic Studies in Rats

    Microsoft Academic Search

    Ahmed E. Ahmed; Sam Jacob; BURHAN I. GHANAYEMt

    1996-01-01

    Following intravenous administration of an equimolar (0.216 mmol\\/kg) radioactive dose of acrylonitrile (2-[14C]VCN, 11.5 mg\\/kg) or methacrylonitrile (2-[14C]MeVCN, 14.5 mg\\/kg), the tissue distribution, covalent interaction, and elimination were compared (at 5 min to 48 hr) in male Fischer 344 rats using whole-body autoradiography (WBA). Autoradiographs obtained from freeze-dried or acid-extracted sections of animals treated with 2-[14C]VCN showed that radioactivity accumulated

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

    Microsoft Academic Search

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

    2010-01-01

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

  4. Abstract--Plasma polymerization of styrene is widely used to synthesize polymer membranes for various applications.

    E-print Network

    Boyer, Edmond

    , in this paper, we notice that in a certain range of plasma conditions associated to a specific reactor. The plasma polymerized styrene films were prepared in a commercial capacitively coupled plasma reactor Abstract-- Plasma polymerization of styrene is widely used to synthesize polymer membranes

  5. ADDENDUM TO ASSESSMENT OF STYRENE EMISSION CONTROLS FOR FRP/C AND BOAT BUILDING INDUSTRIES

    EPA Science Inventory

    This report is an addendum to a 1996 report, Assessment of Styrene Emission Controls for FRP/C and Boat Building Industries. It presents additional evaluation of the biological treatment of styrene emissions, Dow Chemical Company's Sorbathene solvent vapor recovery system, Occupa...

  6. Enantioconvergent Production of (R)-1-Phenyl-1,2-Ethanediol From Styrene

    E-print Network

    Chen, Wilfred

    Enantioconvergent Production of (R)-1-Phenyl-1,2-Ethanediol From Styrene Oxide by Combining into the single product (R)-1-phenyl-1,2- ethanediol, which is an important intermediate for pharmaceuticals. Ech)-styrene oxide to (R)-1-phenyl-1,2-ethane- diol (2.0 Æ 0.2 mmol/min/mg), and the potato EH converts (S

  7. Letter to the Editor: Styrene-producing microbes in food-stuff

    Technology Transfer Automated Retrieval System (TEKTRAN)

    An article was published in Journal of Food Science, August 2009 (Vol. 74, Nr 6) entitled “Natural formation of styrene by cinnamon mold flora”. In the article, the authors reported on the production of styrene from several fungi typically found on cinnamon, and used cinnamic acid and similar analog...

  8. EVALUATION OF STYRENE EMISSIONS FROM A SHOWER STALL/BATHTUB MANUFACTURING FACILITY

    EPA Science Inventory

    The report gives results of emissions measurements carried out at a representative facility (Eljer Plumbingware in Wilson, NC) that manufactures polyester-resin-reinforced shower stalls and bathtubs by spraying styrene-based resins onto molds in vented, open, spray booths. Styren...

  9. 76 FR 77709 - Butyl acrylate-methacrylic acid-styrene polymer; Tolerance Exemption

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-14

    ...FRL-9327-6] Butyl acrylate-methacrylic acid-styrene polymer; Tolerance Exemption...tolerance for residues of 2-Propenoic acid, 2-methyl-, polymer with butyl 2-propenoate...also known as butyl acrylate-methacrylic acid-styrene polymer when used as an...

  10. Initiation precursors and initiators in laser-induced copolymerization of styrene and maleic anhydride in acetone

    NASA Technical Reports Server (NTRS)

    Miner, Gilda A.; Meador, Willard E.; Chang, C. Ken

    1990-01-01

    The initiation step of photopolymerized styrene/maleic anhydride copolymer was investigated at 365 nm. UV absorption measurements provide decisive evidence that the styrene/maleic anhydride charge transfer complex is the sole absorbing species; however, key laser experiments suggest intermediate reactions lead to a monoradical initiating species. A mechanism for the photoinitiation step of the copolymer is proposed.

  11. Preparation and characterization of polystyrene and styrene-butyl acrylate copolymer latices

    Microsoft Academic Search

    A. S. Badran; M. M. H. Ayoub; M. A. Abd El-Ghaffar; H. E. Naser; A. A. Abd El-Hakim

    1997-01-01

    Emulsion polymerization of styrene (S) and emulsion copolymerization of styrene with butyl acrylate (BuA) using potassium persulfate (KPS)\\/different aromatic aldehydic sodium bisulfite adducts as developed redox pair initiation systems were investigated at variable initiator, emulsifier concentrations and feed monomer compositions for studying the morphological characteristics of the obtained latices. It was found that the developed redox pair initiation system increased

  12. Diffusion and polymerization of styrene in an aqueous solution of potassium persulfate under static conditions

    Microsoft Academic Search

    A. A. Oganesyan; V. G. Boyadzhyan; I. A. Gritskova; A. V. Gukasyan; S. G. Matsoyan; A. N. Pravednikov

    1985-01-01

    The potassium persulfate-initiated polymerization of styrene in a mechanically agitated mixture of water and monomer leads to the formation of a stable, monodisperse latex. In order to explain the mechanism of the stabilization of the latex particles in this system, the authors present a detailed investigation of the polymerization of styrene in a specially constructed electrochemical cell under static conditions.

  13. AN EMPIRICAL MODEL TO PREDICT STYRENE EMISSIONS FROM FIBER-REINFORCED PLASTICS FABRICATION PROCESSES

    EPA Science Inventory

    Styrene is a designated hazardous air pollutant, per the 1990 Clean Air Act Amendments. It is also a tropospheric ozone precursor. Fiber-reinforced plastics (FRP) fabrication is the primary source of anthropogenic styrene emissions in the United States. This paper describes an em...

  14. EVALUATION OF TRICKLE-BED AIR BIOFILTER PERFORMANCE FOR STYRENE REMOVAL

    EPA Science Inventory

    A pilot-scale trickle-bed air biofilter (TBAB) was evaluated for the removal of styrene from a waste gas stream. Six-millimeter (6 mm) Celite pellets (R-635) were used as the biological attachment medium. The operating parameters considered in the study included the styrene vol...

  15. Chemical recycling of waste polystyrene into styrene over solid acids and bases

    Microsoft Academic Search

    Zhibo Zhang; Tamaki Hirose; Suehiro Nishio; Yoshio Morioka; Naoto Azuma; Akifumi Ueno; Hironobu Ohkita; Mitsunori Okada

    1995-01-01

    Catalytic degradation of waste polystyrene into styrene was studied using solid acids and bases as catalysts. Partially because of the high yield of distillates from polystyrene and partially because of the high selectivity into styrene in the distillates, solid bases were emphasized to be effective catalysts for the chemical recycling of waste polystyrene. Since there were significant differences in the

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

    EPA Science Inventory

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

  17. Depletion by Styrene of Glutathione in Plasma and Bronchioalveolar Lavage Fluid of Non-Swiss Albino (NSA) Mice

    Microsoft Academic Search

    Gary P. Carlson

    2010-01-01

    Styrene is a widely used chemical, but it is known to produce lung and liver damage in mice. This may be related to oxidative stress associated with the decrease in the levels of reduced glutathione (GSH) in the target tissues. The purpose of this study was to investigate the effect of styrene and its primary metabolites R-styrene oxide (R-SO) and

  18. Binary and ternary LLE data of the system (ethylbenzene + styrene + 1-ethyl-3-methylimidazolium thiocyanate) and binary VLE data of the system (styrene + 1-ethyl-3-methylimidazolium thiocyanate)

    Microsoft Academic Search

    Mark T. G. Jongmans; Boelo Schuur; André B. de Haan

    2012-01-01

    The distillation of close boiling mixtures may be improved by adding a proper affinity solvent, and thereby creating an extractive distillation process. An example of a close boiling mixture that may be separated by extractive distillation is the mixture ethylbenzene\\/styrene. The ionic liquid 1-ethyl-3-methylimidazolium thiocyanate ([EMIM][SCN]) is a promising solvent to separate ethylbenzene and styrene by extractive distillation. In this

  19. Mortality study of workers employed in 1,3-butadiene production units identified from a large chemical workers cohort

    Microsoft Academic Search

    Elizabeth M. Ward; John M. Fajen; Avima M. Ruder; Robert A. Rinsky; William E. Halperin; Cindy A. Fessler-Flesch

    1996-01-01

    The IARC has given the designations of “sufficient evidence” of carcinogenicity of 1,3-butadiene in experimental animals and “limited evidence” of carcinogenicity in humans. To investigate the carcinogenic effect in humans, a cohort mortality study was conducted among 364 men who were assigned to any of three 1,3-butadiene production units located within several chemical plants in the Kanawha Valley of West

  20. Occupational Styrene Exposure Induces Stress-Responsive Genes Involved in Cytoprotective and Cytotoxic Activities

    PubMed Central

    Strafella, Elisabetta; Bracci, Massimo; Staffolani, Sara; Manzella, Nicola; Giantomasi, Daniele; Valentino, Matteo; Amati, Monica; Tomasetti, Marco; Santarelli, Lory

    2013-01-01

    Objective The aim of this study was to evaluate the expression of a panel of genes involved in toxicology in response to styrene exposure at levels below the occupational standard setting. Methods Workers in a fiber glass boat industry were evaluated for a panel of stress- and toxicity-related genes and associated with biochemical parameters related to hepatic injury. Urinary styrene metabolites (MA+PGA) of subjects and environmental sampling data collected for air at workplace were used to estimate styrene exposure. Results Expression array analysis revealed massive upregulation of genes encoding stress-responsive proteins (HSPA1L, EGR1, IL-6, IL-1?, TNSF10 and TNF?) in the styrene-exposed group; the levels of cytokines released were further confirmed in serum. The exposed workers were then stratified by styrene exposure levels. EGR1 gene upregulation paralleled the expression and transcriptional protein levels of IL-6, TNSF10 and TNF? in styrene exposed workers, even at low level. The activation of the EGR1 pathway observed at low-styrene exposure was associated with a slight increase of hepatic markers found in highly exposed subjects, even though they were within normal range. The ALT and AST levels were not affected by alcohol consumption, and positively correlated with urinary styrene metabolites as evaluated by multiple regression analysis. Conclusion The pro-inflammatory cytokines IL-6 and TNF? are the primary mediators of processes involved in the hepatic injury response and regeneration. Here, we show that styrene induced stress responsive genes involved in cytoprotection and cytotoxicity at low-exposure, that proceed to a mild subclinical hepatic toxicity at high-styrene exposure. PMID:24086524

  1. Two-dimensional spectra of electron collisions with acrylonitrile and methacrylonitrile reveal nuclear dynamics

    NASA Astrophysics Data System (ADS)

    Regeta, K.; Allan, M.

    2015-05-01

    Detailed experimental information on the motion of a nuclear packet on a complex (resonant) anion potential surface is obtained by measuring 2-dimensional (2D) electron energy loss spectra. The cross section is plotted as a function of incident electron energy, which determines which resonant anion state is populated, i.e., along which normal coordinate the wave packet is launched, and of the electron energy loss, which reveals into which final states each specific resonant state decays. The 2D spectra are presented for acrylonitrile and methacrylonitrile, at the incident energy range 0.095-1.0 eV, where the incoming electron is temporarily captured in the lowest ?? orbital. The 2D spectra reveal selectivity patterns with respect to which vibrations are excited in the attachment and de-excited in the detachment. Further insight is gained by recording 1D spectra measured along horizontal, vertical, and diagonal cuts of the 2D spectrum. The methyl group in methacrylonitrile increases the resonance width 7 times. This converts the sharp resonances of acrylonitrile into boomerang structures but preserves the essence of the selectivity patterns. Selectivity of vibrational excitation by higher-lying shape resonances up to 8 eV is also reported.

  2. Membranes from acrylonitrile-based polymers for selective cultivation of human keratinocytes.

    PubMed

    Boese, Gregor; Trimpert, Christiane; Albrecht, Wolfgang; Malsch, Günter; Groth, Thomas; Lendlein, Andreas

    2007-12-01

    A cell carrier made from synthetic material supporting selective growth of keratinocytes is a promising approach to avoid the phenomenon of fibroblast overgrowth during in vitro culture of skin substitutes. Therefore, we investigated polymer membranes made of polyacrylonitrile and copolymers of acrylonitrile and N-vinylpyrrolidone (NVP) for their ability to support selectively the growth of keratinocytes. It was found that a copolymer with an NVP-content of 30% (NVP30) supports growth of human keratinocyte cell line (HaCaT) cells and inhibits fibroblast growth under serum-containing conditions. Cell proliferation of HaCaT cells was measured over 14 days. If both cell types were cultured under serum-free conditions for initial adhesion over 6 h on these NVP30 polymers, they adhered to the same extent. Long-term experiments over 7 days were performed as a coculture of both cell types showing that HaCaT cells had a growth advantage that seems to be related to the paracrine activity of contaminating fibroblasts. As a result, confluent layers of HaCaT cells were obtained with small numbers of remaining fibroblasts. The new poly [acrylonitrile-co(NVP) membranes seem to be a promising culture system for the production of epidermal transplants. PMID:17941802

  3. (Poly)acrylonitrile-based hydrogel as a therapeutic bulking agent in urology.

    PubMed

    Ramseyer, Pascal; Meagher-Villemure, Kathleen; Burki, Marco; Frey, Peter

    2007-02-01

    Vesicoureteral reflux and urinary incontinence can be treated by endoscopic injection. Injectables such as collagen and hyaluronic acid-dextranomer are commonly used, however are not offering optimal therapeutic effect yet. In the present study a novel application for poly(acrylonitrile)-based hydrogel (Hypan), already tested in other clinical indications, has been investigated for its aptitude as an injectable bulking agent. This non-degradable, extremely hydrophilic hydrogel has the capacity of a 6-fold swelling once implanted into the body, assuring the bulking effect. Deposits of this bulking agent have been implanted into the submucosal space of the bladder of 6 minipigs and the histological reaction, as well as the physical implant behavior have been studied over a time period of 6 months. The implants have developed the desired bulking effect by the above-described hydrophilic swelling. They have been enclosed into a fine fibrous tissue capsule and provoked a very limited inflammatory reaction. This study has showed that poly(acrylonitrile)-based hydrogel implants injected into the bladder are well tolerated and, due to their defined bulking ability, feasible for the treatment of vesico-ureteral reflux and urinary incontinence. To determine the therapeutic efficiency of this treatment the implants will be studied in a vesicoureteral reflux and urinary incontinence animal model. PMID:17079010

  4. Sensitive detection of acrolein and acrylonitrile with a pulsed quantum-cascade laser

    NASA Astrophysics Data System (ADS)

    Manne, J.; Lim, A.; Tulip, J.; Jäger, W.

    2012-05-01

    We report on spectroscopic measurements of acrolein and acrylonitrile at atmospheric pressure using a pulsed distributed feedback quantum-cascade laser in combination with intra- and inter-pulse techniques and compare the results. The measurements were done in the frequency region around 957 cm-1. In the inter-pulse technique, the laser is excited with short current pulses (5-10 ns), and the pulse amplitude is modulated with an external current ramp resulting in a ˜2.3 cm-1 frequency scan. In the intra-pulse technique, a linear frequency down-chirp during the pulse is used for sweeping across the absorption line. Long current pulses up to 500 ns were used for these measurements which resulted in a spectral window of ˜2.2 cm-1 during the down-chirp. These comparatively wide spectral windows facilitated the measurements of the relatively broad absorption lines (˜1 cm-1) of acrolein and acrylonitrile. The use of a room-temperature mercury-cadmium-telluride detector resulted in a completely cryogen-free spectrometer. We demonstrate ppb level detection limits within a data acquisition time of ˜10 s with these methodologies.

  5. Effect of route of administration on the disposition of acrylonitrile: quantitative whole-body autoradiographic study in rats

    Microsoft Academic Search

    Sam Jacob; Ahmed E Ahmed

    2003-01-01

    Previous studies on the effect of route of administration on acrylonitrile (VCN) toxicity in animal models indicated high rates of metabolism in rats that received an oral dose than those received an i.p. VCN dose. To evaluate the role of route of administration on the distribution of VCN, a quantitative whole-body autoradiography (QWBA) and elimination studies were conducted. Equimolar doses

  6. Radiation induced copolymerization reactivity of different allyl monomers with styrene

    NASA Astrophysics Data System (ADS)

    Yildirim, Yeliz; Balcan, Mehmet

    2012-07-01

    Radiation induced copolymerizations of electron donating such as allyl phenol (AP) and electron withdrawing such as allyl isothiocyanate (AITC) monomers with styrene (Sty) as a comonomer were studied in order to correlate the electronic behavior with copolymerization yield and molecular weight. The allyl monomers and comonomer were mixed in the same mol ratios under Ar atmosphere and copolymerized by using gamma radiation in various absorbed doses (55, 110, 165 kGy) obtained from a Co-60 source. Poly(AP-co-Sty), and poly(AITC-co-Sty) could have been prepared at all of the absorbed doses. The maximum copolymerization yields were calculated as a 16.35 and 6.52 percent for poly(AP-co-Sty) and poly(AITC-co-Sty), respectively. The molecular weights of poly(AP-co-Sty) copolymers are found to be higher in comparison to those of poly(AITC-co-Sty). Both results indicate that, under the same irradiation conditions, AP is more reactive on styrene than AITC is. Thus, the monomers having electron withdrawing (EW) substituents attached to allyl group may result in better copolymerization yield and molecular weight than those with electron donating (ED) substituents. Thermal stabilities of the poly(AP-co-Sty) copolymers are also higher than those of poly(AITC-co-Sty).

  7. Sequence analysis of styrenic copolymers by tandem mass spectrometry.

    PubMed

    Yol, Aleer M; Janoski, Jonathan; Quirk, Roderic P; Wesdemiotis, Chrys

    2014-10-01

    Styrene and smaller molar amounts of either m-dimethylsilylstyrene (m-DMSS) or p-dimethylsilylstyrene (p-DMSS) were copolymerized under living anionic polymerization conditions, and the compositions, architectures, and sequences of the resulting copolymers were characterized by matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF-MS) and tandem mass spectrometry (MS(2)). MS analysis revealed that linear copolymer chains containing phenyl-Si(CH3)2H pendants were the major product for both DMSS comonomers. In addition, two-armed architectures with phenyl-Si(CH3)2-benzyl branches were detected as minor products. The comonomer sequence in the linear chains was established by MS(2) experiments on lithiated oligomers, based on the DMSS content of fragments generated by backbone C-C bond scissions and with the help of reference MS(2) spectra obtained from a polystyrene homopolymer and polystyrene end-capped with a p-DMSS block. The MS(2) data provided conclusive evidence that copolymerization of styrene/DMSS mixtures leads to chains with a rather random distribution of the silylated comonomer when m-DMSS is used, but to chains with tapered block structures, with the silylated units near the initiator, when p-DMSS is used. Hence, MS(2) fragmentation patterns permit not only differentiation of the sequences generated in the synthesis, but also the determination of specific comonomer locations along the polymer chain. PMID:25181590

  8. [Analysis of confined crystalline behaviors of poly(styrene)-poly(ethyleneoxide)-poly(styrene) triblock copolymers by inverse gas chromatography].

    PubMed

    Chen, Sheng-zhou; Zou, Qi-chao; Zhang, Jin-zhi

    2002-01-01

    The confined crystalline behaviors of the triblock copolymers, poly(styrene)-poly(ethyleneoxide)-poly(styrene) (PS-PEO-PS), were studied by using inverse gas chromatography(IGC) probe technique, including phase-transformation of melting crystalline, crystallinity (Xc), melting temperature(Tm) and melting range of temperature. The effects of the molecule-chain length of linear alkane probes on the results are discussed. Results showed that micro-phase separation of PS-PEO-PS had a greater influence on crystallization of PEO molecule-chain. Crystalline-structure of PS-PEO-PS had interphase formed by some kinds of imperfect PEO crystal and amorphous PS. The molecule-chain length of linear alkane probes had no effect on the determination of melting temperature and melting range of temperature of PS-PEO-PS, but had a greater influence on the determination of crystallinity of PS-PEO-PS and investigation phase-transformation of melting crystalline. Crystallinity of PS-PEO-PS determined by IGC was decreased with the increase of molecule-chain length of linear alkane probes. By suitable shorter molecule-chain length of linear alkane probes, it was truer to reflect the existence of interphase of PS-PEO-PS and multi-phase-transformation of melting crystalline presenting in interphase. PMID:12541610

  9. Studies of the mutagenic effects of styrene to man: conclusions for the surveillance of styrene-exposed workers

    NASA Astrophysics Data System (ADS)

    Rothe, Roland; Schmidt, P.; Grummt, T.; Grummt, H. J.; Kersten, N.; Weigmann, Hans-Juergen

    1993-03-01

    One hundred fifty-six styrene-exposed workers had a fourfold higher rate of chromosome aberrations in peripheral lymphocytes than the control persons. The parameters of clinical chemistry (liver, kidney, and blood) remained in the normal range. Further analyses of the data of this study revealed no connections of the degree of effects in clinical chemistry and the exposure level. But a connection exists to the duration of exposure (3 - 26 years): in the comparison of the mean values (all mean values within the normal range) significant differences were found between long-term exposed workers (more than ten years) and control persons. In the higher age groups (above 45 years) also the GAP-rate differences are more pronounced. Seventy percent of the TWA-values were found to be below 85 mg/m3; the arithmetic mean of the TWA-values 72,3 mg/m3. A health surveillance program to styrene-exposed workers is to be reviewed (clinical chemistry and genetic effects). Proposals concerning both problems are presented.

  10. Estimating metabolic rate for butadiene at steady state using a Bayesian physiologically-based pharmacokinetic model

    Microsoft Academic Search

    Long Ngo; Louise M. Ryan; Maura Mezzetti; Frédéric Y. Bois; Thomas J. Smith

    2011-01-01

    In a study of 133 volunteer subjects, demographic, physiologic and pharmacokinetic data through exposure to 1,3-Butadiene\\u000a (BD) were collected in order to estimate the percentage of BD concentration metabolized at steady state, and to determine\\u000a whether this percentage varies across gender, racial, and age groups. During the 20 min of continuous exposure to 2 parts\\u000a per million (ppm) of BD, five

  11. Development of a preliminary physiologically based toxicokinetic (PBTK) model for 1,3-butadiene risk assessment

    Microsoft Academic Search

    Lisa M Sweeney; Matthew W Himmelstein; Michael L Gargas

    2001-01-01

    Potential health effects of human exposure to 1,3-butadiene (BD) are of concern due to the use of BD in industry and its low-level presence throughout the environment. Physiologically based toxicokinetic (PBTK) models of BD in rodents have been developed by multiple research groups in an effort to explain species differences in toxicity (especially carcinogenic potency) through toxicokinetics. PBTK modeling of

  12. Molecular epidemiological studies in 1,3-butadiene exposed Czech workers: Female–male comparisons

    Microsoft Academic Search

    Richard J. Albertini; Radim J. Sram; Pamela M. Vacek; Jeremiah Lynch; Pavel Rossner; Janice A. Nicklas; Jake D. McDonald; Gunnar Boysen; Nadia Georgieva; James A. Swenberg

    2007-01-01

    Results of a recent molecular epidemiological study of 1,3-butadiene (BD) exposed Czech workers, conducted to compare female to male responses, have confirmed and extended the findings of a previously reported males only study (HEI Research Report 116, 2003). The initial study found that urine concentrations of the metabolites 1,2-dihydroxy-4-(acetyl) butane (M1) and 1-dihydroxy-2-(N-acetylcysteinyl)-3-butene (M2) and blood concentrations of the hemoglobin

  13. Assessment of the peripheral, central, and autonomic nervous system function in styrene workers

    SciTech Connect

    Murata, K.; Araki, S.; Yokoyama, K. (Department of Public Health, Faculty of Medicine, University of Tokyo, (Japan))

    1991-01-01

    To investigate the effects of styrene exposure on peripheral, central, and autonomic nervous system functions in man, we measured the distribution of nerve conduction velocities (DCV), short-latency somatosensory evoked potentials (SSEP), and variability in electrocardiographic R-R interval (CVRR) as well as conventional sensory and motor median nerve conduction velocities (SCV and MCV) in eleven styrene-exposed workers. The styrene workers' urinary phenylglyoxylic acid levels ranged from 31 to 419 (mean 169) mg/g creatinine at the end of the work shift on the examination day (estimated exposure to styrene of 22 ppm in air). Control subjects, matched to each styrene worker by sex and age, were selected from healthy adults without cardiovascular, neurologic and other potentially confounding disorders. In the styrene workers, we found that the V80 velocity of the DCV, below which 80% of active nerve fibers lie, and the SCV were both significantly slowed; the CVRR was also significantly reduced. There were no significant differences in SSEP latencies, MCV, or heart rate between the exposed workers and controls. These data, despite the small sample size, suggest that styrene affects the faster myelinated fibers of the peripheral sensory nerves, and that it also affects autonomic nervous activity.

  14. Detection of phenolic metabolites of styrene in mouse liver and lung microsomal incubations.

    PubMed

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

    2010-11-01

    Metabolic activation is considered to be a critical step for styrene-induced pulmonary toxicity. Styrene-7,8-oxide is a primary oxidative metabolite generated by vinyl epoxidation of styrene. In addition, urinary 4-vinylphenol (4-VP), a phenolic metabolite formed by aromatic hydroxylation, has been detected in workers and experimental animals after exposure to styrene. In the present study, new oxidative metabolites of styrene, including 2-vinylphenol (2-VP), 3-vinylphenol (3-VP), vinyl-1,4-hydroquinone, and 2-hydroxystyrene glycol were detected in mouse liver microsomal incubations. The production rates of 2-VP, 3-VP, 4-VP, and styrene glycol were 0.0527 ± 0.0045, 0.0019 ± 0.0006, 0.0053 ± 0.0002, and 4.42 ± 0.33 nmol/(min · mg protein) in mouse liver microsomes, respectively. Both disulfiram (100 ?M) and 5-phenyl-1-pentyne (5 ?M) significantly inhibited the formation of the VPs and styrene glycol. 2-VP, 3-VP, and 4-VP were metabolized in mouse liver microsomes at rates of 2.50 ± 0.30, 2.63 ± 0.13, and 3.45 ± 0.11 nmol/(min · mg protein), respectively. The three VPs were further metabolized to vinylcatechols and/or vinyl-1,4-hydroquinone and the corresponding glycols. Pulmonary toxicity of 2-VP, 3-VP, and 4-VP was evaluated in CD-1 mice, and 4-VP was found to be more toxic than 2-VP and 3-VP. PMID:20724499

  15. Technoeconomic evaluation of bio-based styrene production by engineered Escherichia coli.

    PubMed

    Claypool, Joshua T; Raman, D Raj; Jarboe, Laura R; Nielsen, David R

    2014-08-01

    Styrene is an important commodity chemical used in polymers and resins, and is typically produced from the petrochemical feedstocks benzene and ethylene. Styrene has recently been produced biosynthetically for the first time using engineered Escherichia coli, and this bio-based route may represent a lower energy and renewable alternative to petroleum-derived styrene. However, the economics of such an approach has not yet been investigated. Using an early-stage technoeconomic evaluation tool, a preliminary economic analysis of bio-based styrene from C(6)-sugar feedstock has been conducted. Owing to styrene's limited water solubility, it was assumed that the resulting fermentation broth would spontaneously form two immiscible liquid phases that could subsequently be decanted. Assuming current C(6) sugar prices and industrially achievable biokinetic parameter values (e.g., product yield, specific growth rate), commercial-scale bio-based styrene has a minimum estimated selling price (MESP) of 1.90 USD kg(-1) which is in the range of current styrene prices. A Monte Carlo analysis revealed a potentially large (0.45 USD kg(-1)) standard deviation in the MESP, while a sensitivity analysis showed feedstock price and overall yield as primary drivers of MESP. PMID:24939174

  16. Ototoxic effects of styrene alone or in concert with other agents: A review.

    PubMed

    Morata, Thais C.; Campo, Pierre

    2002-01-01

    Styrene is an organic solvent employed in many manufacturing industries, as well as in other economic sectors. Recently, evidence is beginning to accumulate on the hazardous effects that styrene exposures have on the auditory system. In rats, a well-suited metabolic animal model for these studies, aromatic solvents seem to affect the auditory sensitivity mainly in the cochlear mid-frequency range. Outer hair cells are the primary targets within the organ of Corti, although the spiral ganglions are not spared. Therefore, styrene must be considered as an ototoxic chemical agent that can be potentially neurotoxic. Finally, noise-styrene exposures can have synergistic effects on the auditory system. The findings reported in both human and animal studies indicate that exposures to styrene, or to styrene associated to noise, may dramatically impact occupational hearing conservation practices and legislation. Human and animal studies will be summarized in discussing the effects of styrene alone or in combination with noise and other chemicals. Gaps in scientific knowledge are highlighted to assist future research. PMID:12678924

  17. Competitive hydrogenation of butadiene and butene on palladium and platinum catalysts

    SciTech Connect

    Ouchaib, T.; Massardier, J. Renouprez, A. (Institut de Recherche sur la Catalyse, Villeurbanne (France))

    1989-10-01

    In a recent study of the selective hydrogenation of butadiene to butenes, the reactivity of palladium (in the form of single crystals and of supported catalysts) was compared with that of platinum. The reactivity of single-crystal faces with (111) orientation is comparable to that of SiO{sub 2}-supported catalysts. The argument put forward to explain the comparatively lower activity of platinum was its lower hydrogen coverage under a given pressure, in the presence of the hydrocarbons, arising from a heat of adsorption smaller than that on palladium (respectively 67 and 85 kJ/mol). Concerning its poorer selectivity toward butenes, the reason invoked was a similar heat of adsorption for butadiene and butenes: the olefinic intermediate compound remains partly on the surface and the reaction proceeds to butane. A powerful kinetic method which is able to provide direct evidence for this different adsorption of dienes and butenes would be the competitive hydrogenation of these two molecules. However, to distinguish between the ethylenic hydrocarbon formed during the reaction and the molecules already present in the reactants, the experiments were performed according to the sequence: competitive hydrogenation of a butadiene-propene mixture followed by the hydrogenation of a 1-butene-propene mixture. This paper describes a study which confirms that the reason for the selectivity of palladium (after stabilization of the catalyst) can be attributed unambiguously to its capacity of adsorbing a diene more strongly than an alkene molecule.

  18. Evidence of delayed light emission of TetraPhenyl Butadiene excited by liquid Argon scintillation light

    E-print Network

    Ettore Segreto

    2015-03-29

    TetraPhenyl Butadiene is the wavelength shifter most widely used in combination with liquid Argon. The latter emits scintillation photons with a wavelength of 127 nm that need to be downshifted to be detected by photomultipliers with glass or quartz windows. TetraPhenyl Butadiene has been demonstrated to have an extremely high conversion efficiency, possibly higher than 100 % for 127 nm photons, while there is no precise information about the time dependence of its emission. It is usually assumed to be exponentially decaying with a characteristic time of the order of one ns, as an extrapolation from measurements with exciting radiation in the near UV. This work shows that TetraPhenyl Butadiene, when excited by 127 nm photons, reemits photons not only with a very short decay time, but also with slower ones due to triplet states de-excitations. This fact can strongly contribute to clarify the anomalies in liquid Argon scintillation light reported in literature since seventies, namely the inconsistency in the measured values of the long decay time constant and the appearance of an intermediate component. Similar effects should be also expected when the TPB is used in combination with Helium and Neon, that emit scintillation photons with wavelengths shorter than 127 nm.

  19. Future directions--toxicology studies of 1,3-butadiene and isoprene.

    PubMed Central

    Bird, M G

    1990-01-01

    Examination of a profile of data already existing on 1,3-butadiene shows adequate knowledge in many areas of toxicology that are conventionally required in hazard identification. However, while much progress has been made in areas of metabolism and pharmacokinetics, further studies would be worthwhile to improve mechanistic understanding such as the examination of alternate metabolic pathways, the generation of interspecies scaling factors, and an assessment of the relevance of various tumor sites. In this respect, data pertaining to repeated and pulse exposures of rodents and primates would be helpful. Another important aspect is the need to understand any human health implications of the observed 1,3-butadiene-induction of the murine leukemia virus. In this respect, studies have been pursued that include the comparison of leukemogenesis in congenetic strains, the leukemogenicity of viral isolates in rodent carcinogenicity and human cell culture studies, and the mechanisms of activation of ecotropic proviral sequences. Molecular epidemiological and toxicological research is ongoing in rodents and primates to evaluate hemoglobin adduct formation as an index of 1,3-butadiene exposure. Challenges of specificity, sensitivity, and simplification of current procedures need to be overcome. Recent mutagenicity and metabolism data suggest that structurally-related isoprene may have carcinogenic potential. The use of interstrain comparative studies and data in a second species is discussed, as well as proposed metabolism studies. PMID:2205496

  20. Styrene epoxidation over gold supported on different transition metal oxides prepared by homogeneous deposition–precipitation

    Microsoft Academic Search

    N. S. Patil; B. S. Uphade; D. G. McCulloh; S. K. Bhargava; V. R. Choudhary

    2004-01-01

    Epoxidation of styrene by anhydrous tert-butyl hydroperoxide over a number of transition metal oxide (viz. TiO2, Cr2O3, MnO2, Fe2O3, Co3O4, NiO, CuO, ZnO, Y2O3, ZrO2, La2O3 and U3O8) supported nano-size gold catalysts, prepared by the homogeneous deposition–precipitation method, has been investigated. The supported gold catalysts (except Au\\/MnO2 and Au\\/U3O8) showed good styrene conversion activity and selectivity for styrene oxide in

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

    Microsoft Academic Search

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

    2006-01-01

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

  2. Interfacing microbial styrene production with a biocompatible cyclopropanation reaction.

    PubMed

    Wallace, Stephen; Balskus, Emily P

    2015-06-01

    The introduction of new reactivity into living organisms is a major challenge in synthetic biology. Despite an increasing interest in both the development of small-molecule catalysts that are compatible with aqueous media and the engineering of enzymes to perform new chemistry in vitro, the integration of non-native reactivity into metabolic pathways for small-molecule production has been underexplored. Herein we report a biocompatible iron(III) phthalocyanine catalyst capable of efficient olefin cyclopropanation in the presence of a living microorganism. By interfacing this catalyst with E.?coli engineered to produce styrene, we synthesized non-natural phenyl cyclopropanes directly from D-glucose in single-vessel fermentations. This process is the first example of the combination of nonbiological carbene-transfer reactivity with cellular metabolism for small-molecule production. PMID:25925138

  3. Diaphragm-based fiber optic Fabry-Perot hydrophone with hydrostatic pressure compensation

    NASA Astrophysics Data System (ADS)

    Wang, Zhaogang; Zhang, Wentao; Li, Fang

    2013-09-01

    A fiber optic Fabry-Perot (FP) hydrophone with hydrostatic pressure compensation was demonstrated. A polyimide (PI) diaphragm attached on the end of an Acrylonitrile Butadiene Styrene (ABS) tube was used as the sensing element. A pair of grooves was designed in an inner ABS tube to connect the Fabry-Perot cavity with the outside environment, which made the hydrophone hydrostatic pressure compensated. The operation principle, design and testing of polyimide diaphragm-based sensor were described. Experiment results show that it has not only high stability in different hydrostatic pressures, but also flat frequency response of about 158 ±3 dB within 300-3000 Hz.

  4. Lithium-ion conduction in elastomeric binder in Li-ion batteries

    Microsoft Academic Search

    Mayumi Kaneko; Masanobu Nakayama; Masataka Wakihara

    2007-01-01

    This paper describes two kinds of elastomeric binders which are styrene–butadiene (ST–BD) copolymer and 2-ethylhexyl acrylate–acrylonitrile\\u000a (2EHA–AN) copolymer for electrode materials of rechargeable Li-ion batteries. These elastomeric binders were swollen by electrolyte\\u000a solution (EC\\/DEC=1\\/2, 1 M LiPF6), and 2EHA–AN copolymer retained larger amount of electrolyte solution than ST–BD copolymer. The Li-ionic conduction behavior\\u000a was investigated for both copolymer films swollen by

  5. Modeling and optimization of a new impact-toughened epoxy nanocomposite using response surface methodology

    Microsoft Academic Search

    Abdolreza Mirmohseni; Siamak Zavareh

    2011-01-01

    This paper reports the development of a high-impact epoxy nanocomposite toughened by the combination of poly(acrylonitrile-co-butadiene-co-styrene) (ABS) as thermoplastic, clay as layered nanofiller, and nano-TiO2 as particulate nanofiller. Response surface methodology (RSM) was applied for optimization and modeling of the impact strength\\u000a of epoxy\\/ABS\\/clay\\/TiO2 quaternary nanocomposite. A second-order mathematical model between the response (impact strength) and variables (ABS, clay\\u000a and

  6. Production of super-smooth articles

    SciTech Connect

    Duchane, D.V.

    1981-05-29

    Super-smooth rounded or formed articles made of thermoplastic materials including various poly(methyl methacrylate) or acrylonitrile-butadiene-styrene copolymers are produced by immersing the articles into a bath, the composition of which is slowly changed with time. The starting composition of the bath is made up of at least one solvent for the polymer and a diluent made up of at least one nonsolvent for the polymer and optional materials which are soluble in the bath. The resulting extremely smooth articles are useful as mandrels for laser fusion and should be useful for a wide variety of other purposes, for example lenses.

  7. Uptake of one and two molecules of 1,3-butadiene by platinum bis(dithiolene): a theoretical study.

    PubMed

    Dang, Li; Ni, Shao Fei; Hall, Michael B; Brothers, Edward N

    2014-09-15

    Platinum bis(dithiolene) complexes have reactivity toward alkenes like nickel bis(dithiolene) complexes. We examined the uptake of 1,3-butadiene by platinum bis(dithiolene) [Pt(tfd)2] (tfd = S2C2(CF3)2) via a density functional theory study; both 1,2- and 1,4-additions of 1,3-butadiene to the ligands of Pt(tfd)2 to form both interligand and intraligand adducts were studied. For single 1,3-butadiene addition, direct 1,4-addition on interligand S-S, 1,2-addition on intraligand S-S, and 1,4-addition on intraligand S-C are all feasible at room temperature and are controlled by the symmetry of the highest occupied molecular orbital of 1,3-butadiene and the lowest unoccupied molecular orbital of Pt(tfd)2. However, the formation of the interligand S-S adduct through 1,4-addition of one molecule of cis-1,3-butadiene is the most favorable route, with a reaction barrier of 9.3 kcal/mol. The other two addition processes cannot compete with this one due to both higher reaction barriers and unstable adducts. Other possible pathways, such as formation of cis-interligand S-S adduct from 1,2-addition of one molecule of 1,3-butadiene via a twisted trans-interligand S-S adduct, have higher barriers. Our calculated results show that 1,4-addition of a single molecule of 1,3-butadiene on the interligand S-S gives the kinetically stable product by a one-step pathway. But of at least equal importance is the apofacial 1,4-addition of two molecules of 1,3-butadiene on the intraligand S-C of the same ligand on Pt(tfd)2, which yields the thermodynamically stable product, obtained via a short lifetime intermediate, the 1:1 intraligand S-C adduct, being formed through several pathways. The calculated results in this study well explain the experimental observation that 1:1 interligand S-S adduct was formed in a short time, and the intraligand S-C adduct from two molecules of cis-1,3-butadiene was accumulated in 20 h at 50° and characterized by X-ray crystallography. PMID:25184506

  8. 75 FR 60444 - Certain New Chemicals; Receipt and Status Information

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-30

    ...methacrylates, polymer with alkyl acrylates, styrene, hydroxyalkyl methacrylates, epoxypropyl acrylates and polyalkene glycol hydrogen...resin (G) Epoxy modified alkyd resin, partially neutralized...styrene-butadiene- isobornyl...

  9. 77 FR 67726 - Department of State: State Department Sanctions Information and Guidance

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-11-13

    ...special naphthas, lubricants, waxes, petroleum coke, asphalt, road oil, still gas, and miscellaneous products obtained...sodium hypochlorite, styrene, tyrene acrylonite copolymer, sulfur, sulfuric acid, styrene butadiene, toluene...

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

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...specifications: Component/property Limitation Inherent viscosity 1.0-1.6 deciliter per gram.1 Styrene moiety ...Arsenic 3 parts per million maximum. 1 Inherent viscosity of a 0.25 percent (weight/volume) solution in...

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

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...specifications: Component/property Limitation Inherent viscosity 1.0-1.6 deciliter per gram.1 Styrene moiety ...Arsenic 3 parts per million maximum. 1 Inherent viscosity of a 0.25 percent (weight/volume) solution in...

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

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...specifications: Component/property Limitation Inherent viscosity 1.0-1.6 deciliter per gram.1 Styrene moiety ...Arsenic 3 parts per million maximum. 1 Inherent viscosity of a 0.25 percent (weight/volume) solution in...

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

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...specifications: Component/property Limitation Inherent viscosity 1.0-1.6 deciliter per gram.1 Styrene moiety ...Arsenic 3 parts per million maximum. 1 Inherent viscosity of a 0.25 percent (weight/volume) solution in...

  14. OCCUPATIONAL STYRENE EXPOSURE FOR TWELVE PRODUCT CATEGORIES IN THE REINFORCED-PLASTICS INDUSTRY

    EPA Science Inventory

    Approximately 1500 occupational styrene exposure values from 28 reinforced-plastic manufacturers were collected retrospectively from companies and state and federal agencies. The report describes the major types of manufacturing processes within the reinforced-plastics industry a...

  15. Preparation and characterization of emulsifier-free polyphenylsilsesquioxane-poly (styrene-butyl acrylate) hybrid particles

    NASA Astrophysics Data System (ADS)

    Bai, Ruiqin; Qiu, Teng; Han, Feng; He, Lifan; Li, Xiaoyu

    2013-10-01

    The core-shell polyphenylsilsesquioxane-poly (styrene-butyl acrylate) hybrid latex paticles with polyphenylsilsesquioxane as core and poly (styrene-butyl acrylate) as shell were successfully synthesized by seeded emulsion polymerization using polyphenylsisesquioxane (PPSQ) latex particles as seeds. X-ray diffraction (XRD) indicated that the polyphenylsilsesquioxane (PPSQ) had ladder structure, and PPSQ had incorporated into the hybrid latex particles. Transmission electron microscopy (TEM) confirmed that the resultant hybrid latex particles had the core-shell structure. TEM and dynamic light scattering (DLS) analysis indicated that the polyphenylsisesquioxane latex particles and obtained core-shell hybrid latex particles were uniform and possessed narrow size distributions. X-ray photoelectron spectroscopy (XPS) analysis also indicated that the PPSQ core particles were enwrapped by the polymer shell. In addition, compared with pure poly (styrene-butyl acrylate) latex film, the polyphenylsilsesquioxane-poly (styrene-butyl acrylate) hybrid latex film exhibited lower water uptake, higher pencil hardness and better thermal stability.

  16. Cyclopropanation of styrenes and stilbenes using lithiomethyl trimethylammonium triflate as methylene donor.

    PubMed

    Sarria Toro, Juan M; den Hartog, Tim; Chen, Peter

    2014-09-21

    Lithiomethyl trimethylammonium triflate, prepared from tetramethylammonium triflate, cyclopropanates several styrenes and stilbenes with electron-donating and selected electron-withdrawing substituents efficiently. Kinetic data support a stepwise nucleophilic addition-ring closure mechanism for this methylenation. PMID:25076071

  17. Mechanical Properties of Composites Based on Low Styrene Emission Polyester Resins for Marine Applications

    Microsoft Academic Search

    Christophe Baley; Y. Perrot; Peter Davies; A. Bourmaud; Yves Grohens

    2006-01-01

    Glass fibre reinforced polyester composites are used extensively for hulls and decks of pleasure boats. Boat-builders must\\u000a optimise manufacturing technology, not only with respect to mechanical properties but also limiting volatile organic compounds\\u000a (VOC) emissions. One way to achieve this is through modified polyester resin formulations such as low styrene content, low\\u000a styrene emission or combinations of these. The resin

  18. Electrochemical studies of gel polymer electrolytes based on methyl methacrylate-styrene copolymers

    Microsoft Academic Search

    Soo Ik Jo; Hun-Joon Sohn; Dong-Wan Kang; Dong-Won Kim

    2003-01-01

    Gel polymer electrolytes (GPEs) composed of porous methyl methacrylate-styrene copolymer membrane and electrolyte solution were prepared. The electrochemical characteristics of these polymer electrolytes were investigated in terms of copolymer composition and content of liquid electrolyte. The ionic conductivity reached 1.0×10?3S\\/cm in the gel polymer electrolyte prepared with porous methyl methacrylate-styrene copolymer membrane of which methyl methacrylate composition is 77mol%. This

  19. 1-Aza-1,3-butadiene complexes of tantalum: preparation and alkylation of TaCl 2(? 5-C 5Me 5)(? 4-1-aza-1,3-butadiene)

    Microsoft Academic Search

    Kazushi Mashima; Yutaka Matsuo; Shinya Nakahara; Kazuhide Tani

    2000-01-01

    We have synthesized half-metallocene 1-aza-1,3-butadiene (abbr. AD) complexes of tantalum and have demonstrated the unique coordination mode and reactivity of the AD ligand. Treatments of a dimeric complex [TaCl2Cp*]2 (2) (Cp*=pentamethylcyclopentadienyl) with one equivalent of 1,4-diphenyl-1-aza-1,3-butadiene (abbr. Ph-AD) and 1-p-methoxyphenyl-4-phenyl-1-aza-1,3-butadiene (abbr. p-MeOC6H4–AD) afforded purple complexes of the formula TaCl2Cp*(supine-?4-AD) (3: AD=Ph-AD; 4: AD=p-MeOC6H4–AD), whose formulation and supine-?4-coordination mode with a

  20. Real-Time Small-Angle X-ray Scattering from Rubber-Modified Thermoplastics

    NASA Astrophysics Data System (ADS)

    Bubeck, R. A.

    1997-03-01

    Real-time small-angle X-ray scattering (RTSAXS) studies have been performed on a series of rubber-modified thermoplastics. These include: High Impact Polystyrene (HIPS), (2) Acrylonitrile Butadiene Styrene copolymers (ABS), (3) weatherable ABS-type resins containing grafted rubber particles derived from acrylonitrile ethylene styrene (AES) or acrylonitrile styrene acrylate (ASA), and (4) rubber-toughened syndiotactic polystyrene (sPS). Scattering patterns were measured at successive time intervals of from 2 to 3 ms. and were analyzed to determine the plastic strain due to crazing. Simultaneous measurements of the absorption of the primary beam by the sample allowed the total plastic strain to be computed. The plastic strain due to other deformation mechanisms (e.g. particle cavitation and macroscopic shear deformation) was determined by the difference. The contribution from microscopic shear deformation was determined from video-based optical data obtained along with the RTSAXS data. One example is an experimental AES system in an SAN matrix with insufficient gel particle graft which was found to lack substantial contributions from crazing and microshear yielding mechanisms. Manipulating the graft and cross linking levels in the AES system results in a ten-fold increase in microshear yield, but not much additional cavitation and crazing.

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

    Microsoft Academic Search

    Frederick R. Johannsen; George J. Levinskas

    2002-01-01

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

  2. Dose Dependence of Covalent Binding of Acrylonitrile to Tissue Protein and Globin in Rats1-2

    Microsoft Academic Search

    FREDERICK W. BENZ; DONALD E. NERLAND; JUNYU LI; DONNA CORBETT

    LI, J., AND CORBETT, D. (1997). Fundam. Appl. ToxicoL 36, 149-156. The dose dependence of acrylonitrile (AN) covalent binding to tissue protein, following a single acute exposure over a 100-fold range in dose, was measured. Covalent binding was a linear func- tion of AN dose in the lower dose range (0.02-0.95 mmol AN\\/ kg). The slopes of the dose-response curves

  3. Cytocompatibility of poly(acrylonitrile-co- N-vinyl-2-pyrrolidone) membranes with human endothelial cells and macrophages

    Microsoft Academic Search

    Ling-Shu Wan; Zhi-Kang Xu; Xiao-Jun Huang; Xiao-Dan Huang; Ke Yao

    2007-01-01

    Polyacrylonitrile modified with N-vinyl-2-pyrrolidone (NVP) shows good hemocompatibility. This work, which aims to evaluate the cytocompatibility of membranes fabricated from poly(acrylonitrile-co-N-vinyl-2-pyrrolidone) (PANCNVP), studied the adhesion of macrophages and endothelial cell (EC) cultures. It was found that PANCNVP membranes with higher NVP content decreased the adhesion of both macrophages and ECs. Compared with polyacrylonitrile and tissue culture polystyrene control, however, these

  4. Chronic toxicity and oncogenic dose–response effects of lifetime oral acrylonitrile exposure to Fischer 344 rats

    Microsoft Academic Search

    Frederick R. Johannsen; George J. Levinskas

    2002-01-01

    Acrylonitrile (AN) was administered in the drinking water for approximately 2 years to groups of 100 male and 100 female Fischer 344 rats at nominal concentrations of 1, 3, 10, 30, and 100 ppm. Two groups, each of 100 males and 100 females, were used as untreated controls. Average daily intake was 0.1, 0.3, 0.8, 2.5 or 8.4 mg AN

  5. Preparation and characterization of gel polymer electrolytes based on acrylonitrile–methoxy polyethylene glycol (350) monoacrylate–lithium acrylate terpolymers

    Microsoft Academic Search

    Lan Zhang; Shichao Zhang

    2008-01-01

    The acrylonitrile (AN)–methoxy polyethylene glycol (350) monoacrylate (MPGA)–lithium acrylate (LiAc) copolymers (PAMGLiAc) was synthesized by emulsion polymerization. Phase inversion technique was used to prepare the PAMGLiAc microporous membrane. The gel polymer electrolytes (GPEs) with the PAMGLiAc were obtained by the copolymer microporous membrane soaking liquid electrolyte. The component and structure of the PAMGLiAc were characterized by IR, NMR and TGA\\/DSC

  6. Synergetic effect of copper-plating wastewater as a catalyst for the destruction of acrylonitrile wastewater in supercritical water oxidation

    Microsoft Academic Search

    Young Ho Shin; Hong-shik Lee; Young-Ho Lee; Jaehoon Kim; Jae-Duck Kim; Youn-Woo Lee

    2009-01-01

    A new supercritical water oxidation process for the simultaneous treatment of mixed wastewater containing wastewater from acrylonitrile manufacturing processes and copper-plating processes was investigated using a continuous tubular reactor system. Experiments were carried out at temperatures ranging from 400 to 600°C and a pressure of 25MPa. The residence time was fixed at 2s by changing the flow rates of feeds,

  7. Mortality study of workers in 1,3-butadiene production units identified from a chemical workers cohort.

    PubMed Central

    Ward, E M; Fajen, J M; Ruder, A M; Rinsky, R A; Halperin, W E; Fessler-Flesch, C A

    1995-01-01

    The International Agency for Research on Cancer has given the designations of "sufficient evidence" of carcinogenicity of 1,3-butadiene in experimental animals and "limited evidence" of carcinogenicity in humans. To investigate the carcinogenic effect in humans, we conducted a cohort mortality study among 364 men who were assigned to any of three 1,3-butadiene production units located within several chemical plants in the Kanawha Valley of West Virginia, including 277 men employed in a U.S. Rubber Reserve Plant which operated during World War II. The butadiene production units included in this study were selected from an index developed by the Union Carbide Corporation, which listed for each chemical production unit within their South Charleston, West Virginia and Institute, West Virginia, plants all products, by-products, and reactants. Departments included in the study were those where butadiene was a primary product and neither benzene nor ethylene oxide was present. A total of 185 deaths were observed; the standardized mortality ratio (SMR) for all causes of death was 91, reflecting lower mortality among the study population than the U.S. population. The study found a significantly elevated standardized mortality ratio (SMR) for lymphosarcoma and reticulosarcoma based on four observed cases (SMR = 577; 95% CI = 157-1480), which persisted in an analysis using county referent rates. An excess of lymphosarcoma and reticulosarcoma among all workers and among workers with routine exposure to 1,3-butadiene was also observed in the only other cohort of 1,3-butadiene production workers previously studied.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7556014

  8. Derivatisation of crosslinked poly(styrene-co-acryloyl chloride) for functional polymer supports and use as an electrophilic scavenger resin

    Microsoft Academic Search

    Peter Krajnc; Renata Toplak

    2002-01-01

    Poly(styrene-co-acryloyl chloride) prepared from poly(styrene-co-p-nitrophenylacrylate), crosslinked with divinylbenzene, readily reacted with N, O, S and C nucleophiles resulting in amido, hydrazido, ester, thioester and malononitryl derivatives of poly(styrene-co-acryloyl chloride). All the introduced reagents (1-propanol, 3-methyl-1-butanol, thiophenol, 3-fluoroaniline, 4-chloroaniline, 3,4-dichloroaniline, 2-aminobenzimidazole, phenylhydrazine and malononitrile) reacted under mild conditions (room temperature). No additional crosslinking was observed during processes with hydrazine or amines.

  9. An experimental system for the n-butyl-lithium initiated polymerization of styrene in a multi-sampled batch reactor 

    E-print Network

    Cox, James Harvey

    1974-01-01

    . S. , Texas A&M University Chairman of Advisory Committee: Dr. Rayford G. Anthony A complete bench scale reactor system was constructed for use in determining the kinetics of the n-butyllithium-styrene-benzene reaction system. The multi... of the various reaction mixture components. These columns lacked sufficient resolution to separate styrene and benzene in molar ratios of greater than five to one (about 1. 8 molar styrene in benzene). An adequate resolution between t-octyl disulfide...

  10. SYNTHESIS AND CRYSTAL STRUCTURE OF TRANS1,4BIS(DIPHENYLPHOSPHINO)-1,3BUTADIENE

    Microsoft Academic Search

    Alfred A. Barney; Phillip E. Fanwick; Clifford P. Kubiak

    1996-01-01

    The synthesis of trans-1,4-bis(diphenylphosphino)-1,3-butadiene (1) was accomplished via the reaction of lithium diphenylphosphide with 1,1,2,3,4,4-hexachlorobutane. Crystals suitable for X-ray diffraction were acquired by slow evaporation of solvent. Compound 1 crystallized in the monoclinic space group P2\\/n (14). a = 9.068(2) Å. b = 25.862(5) Å, c = 10.068(5) Å, ? = 107.69(3)°, V = 2249(2) Å, Z = 4. Compound

  11. Chiral Anion Dependent Inversion of Diastereo- and Enantioselectivity in Carbonyl Crotylation via Ruthenium Catalyzed Butadiene Hydrohydroxyalkylation

    PubMed Central

    McInturff, Emma L.; Yamaguchi, Eiji; Krische, Michael J.

    2012-01-01

    The ruthenium catalyst generated in situ from H2Ru(CO)(PPh3)3, (S)-SEGPHOS and a TADDOL-derived phosphoric acid promotes butadiene hydrohydroxyalkylation to form enantiomerically enriched products. Notably, the observed diastereo- and enantioselectivity is opposite of that observed using BINOL-derived phosphate counterions in combination with (S)-SEGPHOS, the same enantiomer of chiral ligand. Match-mismatch effects between chiral ligand and chiral TADDOL-phosphate counterion are described. For the first time, single crystal X-ray diffraction data is reported for a ruthenium complex modified by a chiral phosphate counterion. PMID:23234459

  12. Heat of Combustion of the Product Formed by the Reaction of Diborane with 1,3-Butadiene

    NASA Technical Reports Server (NTRS)

    Tannenbaum, Stanley; Allen, Harrison, Jr.

    1953-01-01

    The net heat of combustion of the product formed by the reaction of diborane with 1,3-butadiene was found to be 18,700+/-150 Btu per pound for the reaction of liquid fuel to gaseous carbon dioxide, gaseous water, and solid boric oxide. The measurements were made in a Parr oxygen-bomb calorimeter, and the combustion was believed to be 98 percent complete. The estimated net heat of combustion for complete combustion would therefore be 19,075+/-150 Btu per pound. Since this value is approximately the same as the heat of combustion of butadiene, it seems certain that the material is partially oxidized.

  13. Experimental study of the structure of a rich premixed 1,3-butadiene\\/CH 4 \\/O 2 \\/Ar flame

    Microsoft Academic Search

    Hadj-Ali Gueniche; Pierre-Alexandre Glaude; René Fournet; Frédérique Battin-Leclerc

    2006-01-01

    The structure of a laminar rich premixed 1,3-butadiene\\/CH4\\/O2\\/Ar flame has been investigated, 1,3-butadiene, methane, oxygen, and argon mole fractions being 0.033, 0.2073, 0.3315, and\\u000a 0.4280, respectively, for an equivalence ratio of 1.80. The flame has been stabilized on a burner at a pressure of 6.7 kPa.\\u000a The concentration profiles of stable species have been measured by gas chromatography after sampling

  14. Controlled Release of Imidacloprid from Poly Styrene-Diacetone - Nanoformulation

    NASA Astrophysics Data System (ADS)

    Qian, Kun; Guo, Yanzhen; He, Lin

    2012-01-01

    Imidacloprid is a neonicotinoids insecticide, which is important for the cash crops such as tomato, rape and so on. The conventional formulation does not only increase the loss of pesticide but also leads to environmental pollution. Controlled-release formulations of pesticide are highly desirable not only for attaining the most effective utilization of the pesticide, but also for reducing environmental pollution. Pesticide imidacloprid was incorporated in poly (styrene-diacetone crylamide)-based formulation to obtain controlled release properties, and the imidacloprid nanocontrolled release formulation was characterized by infrared (IR) and field emission scanning electron microscope (FESEM). Factors related to loading efficiency, swelling and release behaviors of the formulation were investigated. It showed that the loading efficiency could reach about 40% (w/w). The values for the diffusion exponent "n" were in the range of 0.31-0.58, which indicated that the release of imidacloprid was diffusion-controlled. The time taken for 50% of the active ingredient to be released into water, T50, was also calculated for the comparison of formulations in different conditions. The results showed that the formulation with higher temperature and more diacetone crylamide had lower value of T50, which means a quicker release of the active ingredient. This study highlighted some pieces of evidence that improved pesticide incorporation and slower release were linked to potential interactions between the pesticide and the polymer.

  15. The effect of water absorption on the viscoelastic properties of poly(styrene-block-isobutylene-block-styrene) for use in biomedical applications

    NASA Astrophysics Data System (ADS)

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

    2015-05-01

    The decrease in glass transition temperature and change in creep compliance due to water diffusion in a biocompatible thermoplastic elastomer was studied and quantified. Knowledge of the mechanical and viscoelastic performance of the styrene-isobutylene-styrene block (SIBS) copolymer is important to determine the feasibility of certain in-vivo applications. Furthermore, the deterioration in these types of properties due to the plasticizing effect of water must be well understood for long term usage. Samples were formed with an injection molding press and fully dried prior to immersion in distilled water at 37°C. Water diffusion kinetics were studied for four different SIBS copolymers of varying molecular weight and styrene content by measuring weight changes as a function of time. These gravimetric diffusion studies showed an inverse relationship between diffusivity and styrene content and molecular weight for the first thousand hours of immersion. Measurements of storage modulus, loss modulus, tangent delta, strain recovery and creep compliance were performed using a dynamic mechanical analyzer for the high molecular weight, high styrene content SIBS version at different absorbed water contents. A measurable and nearly linear decrease of the glass transition temperature and creep recovery with respect to water content was observed for the samples tested even at relatively low water content: an increase in water content of 0.27% correlated to a decrease of 4°C in glass transition temperature while a 0.16% weight increase corresponded to a 12.5% decrease in creep recovery. These quantified material properties restrict the use of SIBS in certain implantable operations that undergo cyclic strains, and in sterilization techniques that require high temperatures. As such, they are important to understand in order to determine the viability of in vivo usage of this biocompatible polymer.

  16. Thermodynamic calculations for molecules with asymmetric internal rotors--application to 1,3-butadiene.

    PubMed

    Wong, Bryan M; Raman, Sumathy

    2007-03-01

    We present quantum mechanical partition functions, free energies, entropies, and heat capacities of 1,3-butadiene derived from ab initio calculations. Our technique makes use of a reaction path-like Hamiltonian to couple all 23 vibrational modes to the large-amplitude torsion, which involves heavy asymmetric functional groups. Ab initio calculations were performed at the B3LYP, MP2, and CCSD(T) levels of theory and compared with experimental values as a reference case. By using the ab initio potentials and projected frequencies, simple perturbative expressions are presented for computing the couplings of all the vibrational modes to the large-amplitude torsion. The expressions are particularly suited for programming in the new STAR-P software platform which automatically parallelizes our codes with distributed memory via a familiar MATLAB interface. Using the efficient parallelization scheme of STAR-P, we obtain thermodynamic properties of 1,3-butadiene for temperatures ranging from 50 to 500 K. The free energies, entropies, and heat capacities obtained from our perturbative formulas are compared with conventional approximations and experimental values found in thermodynamic tables. PMID:17226834

  17. Isolable 2,3-disila-1,3-butadiene from a double sila-Peterson reaction.

    PubMed

    Motomatsu, Daiki; Ishida, Shintaro; Ohno, Koichi; Iwamoto, Takeaki

    2014-07-21

    A new 2,3-disila-1,3-butadiene (3) was synthesized as pale yellow crystals by a double sila-Peterson reaction of 1,1,2,2-tetrasilyl-1,2-dilithiodisilane with two equivalents of 2-adamantanone at 0?°C. In the solid state, the two Si=C bonds adopt a synclinal conformation with a dihedral angle of 76.8(1)°. UV/Vis spectra show two distinct absorption bands, assignable to the ?(Si=C)??*(Si=C) transition, at 371 and 322?nm and the former is considerably redshifted compared with that of structurally similar silenes. The 2,3-disilabutadiene isomerizes to the corresponding 1,3-disilabicyclo[1.1.0]butane with the activation parameters of ?H(?) = 74.5±5.4?kJ?mol(-1) and ?S(?) = -71.1±17.1?J?mol(-1) ?K(-1). DFT studies suggest that the isomerization proceeds through a conrotatory route rather than a disrotatory route. H2O and 9,10-phenanthrenequinone added across each Si=C bond in the 2,3-disila-1,3-butadiene. The UV/Vis spectrum and reactivity of 3 suggest that the interaction between the two Si=C bonds in 3 would be significant but rather small compared with that between Si=Si bonds in a synclinal tetrasilabutadiene. PMID:24986491

  18. Case study: Biofiltration of styrene and butylacetate at a dashboard manufacturer

    SciTech Connect

    McGrath, M.S.; Nieuwland, J.C.; Lith, C. van

    1999-09-30

    Holzindustie Bruchsal (HIB) was required to treat moderate levels of styrene emissions from their plastic dashboard manufacturing process. After evaluating many types of control technologies, HIB decided to install a Bioton biofiltration system from Monsanto Enviro-Chem Systems Inc. (MEC). After the installation of the Bioton biofilter, HIB and MEC learned that large amounts of butylacetate were also present in the off-gas stream. The presence of butylacetate was found to have inhibitory effects on the removal of styrene. Therefore, MEC performed a series of pilot and laboratory studies to determine if a bacteria strain could be identified that would be capable of removing styrene in the presence of butylacetate. It was found that a specific bacteria strain was capable of achieving high levels of styrene removal without inhibition from butylacetate in laboratory and pilot testing. This strain was inoculated into the full scale system. After acclimation, the full scale inoculation produced a consortium of bacteria that biologically removed the styrene from the dashboard manufacturing process in the presence of butylacetate.

  19. Styrene oxide isomerase of Rhodococcus opacus 1CP, a highly stable and considerably active enzyme.

    PubMed

    Oelschlägel, Michel; Gröning, Janosch A D; Tischler, Dirk; Kaschabek, Stefan R; Schlömann, Michael

    2012-06-01

    Styrene oxide isomerase (SOI) is involved in peripheral styrene catabolism of bacteria and converts styrene oxide to phenylacetaldehyde. Here, we report on the identification, enrichment, and biochemical characterization of a novel representative from the actinobacterium Rhodococcus opacus 1CP. The enzyme, which is strongly induced during growth on styrene, was shown to be membrane integrated, and a convenient procedure was developed to highly enrich the protein in active form from the wild-type host. A specific activity of about 370 U mg(-1) represents the highest activity reported for this enzyme class so far. This, in combination with a wide pH and temperature tolerance, the independence from cofactors, and the ability to convert a spectrum of substituted styrene oxides, makes a biocatalytic application imaginable. First, semipreparative conversions were performed from which up to 760 ?mol of the pure phenylacetaldehyde could be obtained from 130 U of enriched SOI. Product concentrations of up to 76 mM were achieved. However, due to the high chemical reactivity of the aldehyde function, SOI was shown to be the subject of an irreversible product inhibition. A half-life of 15 min was determined at a phenylacetaldehyde concentration of about 55 mM, indicating substantial limitations of applicability and the need to modify the process. PMID:22504818

  20. Structure and Reaction of Oxametallacycles Derived from Styrene Oxide on Ag(110).

    SciTech Connect

    Lukaski, Adrienne C.; Enever, Michael C.; Barteau, Mark A.

    2007-08-15

    The research described in this product was performed in part in the Environmental Molecular Sciences Laboratory, a national scientific user facility sponsored by the Department of Energy's Office of Biological and Environmental Research and located at Pacific Northwest National Laboratory. Styrene oxide forms a strongly bound oxametallacycle intermediate via activated adsorption on the Ag(110) surface. The oxametallacycle species derived from styrene oxide on Ag(110) fits well with the family of oxametallacycles identified previously in studies of nonallylic epoxides with unsaturated substituent groups on silver. Temperature-programmed reaction experiments demonstrate that styrene oxide ring opens at the substituted carbon, and Density Functional Theory calculations indicate that the phenyl ring of the resulting oxametallacycle is oriented nearly parallel to the Ag(110) surface. Interaction of the phenyl group with the silver surface stabilizes this intermediate relative to that derived from the mono-olefin epoxide, ethylene oxide. During temperature-programmed reaction, the oxametallacycle undergoes ring-closure to reform styrene oxide and isomerization to phenylacetaldehyde at 505 K on Ag(11 0). Styrene oxide-derived oxametallacycles exhibit similar ring-closure behavior on the Ag(111) surface.

  1. THE GAS PHASE REACTION OF OZONE WITH 1,3-BUTADIENE: FORMATION YIELDS OF SOME TOXIC PRODUCTS. (R826236)

    EPA Science Inventory

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

  2. Photofragment translational spectroscopy of 1,2-butadiene at 193 nm Jason C. Robinson, Weizhong Sun,a)

    E-print Network

    Neumark, Daniel M.

    Photofragment translational spectroscopy of 1,2-butadiene at 193 nm Jason C. Robinson, Weizhong Sun 94720 and Department of Chemistry, University of California, Berkeley, California 94720 Fei Qi Chemical and Department of Chemistry, University of California, Berkeley, California 94720 Received 18 July 2001; accepted

  3. Quantum chemical characterization of cycloaddition reactions between 1,3?butadiene and oxyallyl cations of varying electrophilicity

    Microsoft Academic Search

    Christopher J. Cramer; Susan E. Barrows

    2000-01-01

    Hydroxyallyl cation and lithium and sodium oxyallyl cations are predicted to react with 1,3-butadiene both in a stepwise fashion and via concerted (4 ‡ 3) cycloaddition with so-called extended stereochemistry. With hydroxyallyl cation, the stepwise process is preferred and subsequent second bond closures generate products equivalent to those that would arise from concerted (4 ‡ 3) or (3 ‡ 2)

  4. Novel enantioselective synthesis of 1,3-butadien-2-ylmethanols via tandem alkylbromide-epoxide vinylations using dimethylsulfonium methylide.

    PubMed

    Alcaraz, Lilian; Cox, Katherine; Cridland, Andrew P; Kinchin, Elizabeth; Morris, James; Thompson, Stewart P

    2005-03-31

    [reaction: see text] The treatment of chiral trans-disubstituted and trisubstituted 2,3-epoxy-1-bromides with an excess of dimethylsulfonium methylide 1 affords the corresponding 1,3-butadien-2-ylmethanols in good to excellent yields via a double one-carbon homologation. PMID:15787516

  5. Quantum-Chemical Calculations of the Structure of the Triplet Reaction Complexes in Anionic Polymerization of Butadiene

    Microsoft Academic Search

    K. K. Kalninsh; A. F. Podolskii

    2001-01-01

    A new mechanism of anionic polymerization of butadiene, radically changing the existing concepts on the structure and properties of the reaction complex, is suggested. It is stated that an elementary chemical process involves excitation into the low-lying triplet state of the “living” polymer–monomer complex, characterized as a transfer of a charge (electron) and cation (Li+ or Na+) from the terminal

  6. Dose dependence of covalent binding of acrylonitrile to tissue protein and globin in rats.

    PubMed

    Benz, F W; Nerland, D E; Li, J; Corbett, D

    1997-04-01

    The dose dependence of acrylonitrile (AN) covalent binding to tissue protein, following a single acute exposure over a 100-fold range in dose, was measured. Covalent binding was a linear function of AN dose in the lower dose range (0.02-0.95 mmol AN/kg). The slopes of the dose-response curves indicated that tissues varied by nearly 10-fold in their reactivity with AN. The relative order of covalent binding was as follows: blood > > kidney = liver > forestomach = brain > glandular stomach > > muscle. Similar dose-response behavior was observed for globin total covalent binding and for globin N-(2-cyanoethyl) valine (CEValine) adduct formation. The latter adduct was found to represent only 0.2% of the total AN adduction to globin. Regression of tissue protein binding versus globin total covalent binding or globin CEValine adduct indicated that both globin biomarkers could be used as surrogates to estimate the amount of AN bound to tissue protein. At higher AN doses, above approximately 1 mmol/kg, a sharp break in the covalent binding dose-response curve was observed. This knot value is explained by the nearly complete depletion of liver glutathione and the resultant termination of AN detoxification. The toxicity of AN is known to increase sharply above this dose. The data suggest that a comparison of specific tissue proteins labeled by AN above and below this threshold dose may provide some insight into the mechanism of AN-induced toxicity. PMID:9143484

  7. Acrylonitrile enhances H2O2-mediated DNA damage via nitrogen-centered radical formation.

    PubMed

    Murata, M; Ohnishi, S; Kawanishi, S

    2001-10-01

    Acrylonitrile (ACN) is widely used as a monomer in the polymer industry. Studies on carcinogenicity in rats exposed to ACN showed increased incidences of tumors including glial cell tumors of central nervous system and increased production of 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxo-dG) in glial cells. Using a high performance liquid chromatograph equipped with an electrochemical detector, we revealed that ACN enhanced the formation of 8-oxo-dG induced by H2O2 and Cu(II) whereas ACN itself did not cause DNA damage. The enhancing effect of ACN was much more efficient in the double-stranded DNA than that in the single-stranded DNA. Experiments with 32P-labeled DNA revealed that addition of ACN enhanced the site-specific DNA damage at guanines, particularly at 5'-site of the GG and GGG sequences while H2O2/Cu(II) induced piperidine-labile sites at thymine, cytosine, and guanine residues. An electron spin resonance spectroscopy using alpha-(4-pyridyl-1-oxide)-N-tert-butylnitrone showed that a nitrogen-centered radical was generated from ACN in the presence of H2O2 and Cu(II). It is considered that ACN enhances H2O2-mediated DNA damage via nitrogen-centered radical formation. We will discuss the mechanism of the enhancing effect on oxidative DNA damage in relation to expression of ACN carcinogenicity. PMID:11599934

  8. Covalent binding of acrylonitrile to specific rat liver glutathione S-transferases in vivo.

    PubMed

    Nerland, D E; Cai, J; Pierce, W M; Benz, F W

    2001-07-01

    Acrylonitrile (AN) is an industrial vinyl monomer that is acutely toxic. When administered to rats, AN covalently binds to tissue proteins in a dose-dependent but nonlinear manner [Benz, F. W., Nerland, D. E., Li, J., and Corbett, D. (1997) Fundam. Appl. Toxicol. 36, 149-156]. The nonlinearity in covalent binding stems from the fact that AN rapidly depletes liver glutathione after which the covalent binding to tissue proteins increases disproportionately. The identity of the tissue proteins to which AN covalently binds is unknown. The experiments described here were conducted to begin to answer this question. Male Sprague-Dawley rats were injected subcutaneously with 115 mg/kg (2.2 mmol/kg) [2,3-(14)C]AN. Two hours later, the livers were removed, homogenized, and fractionated into subcellular components, and the radioactively labeled proteins were separated on SDS-PAGE. One set of labeled proteins was found to be glutathione S-transferase (GST). Specific labeling of the mu over the alpha class was observed. Separation of the GST subunits by HPLC followed by scintillation counting showed that AN was selective for subunit rGSTM1. Mass spectral analysis of tryptic digests of the GST subunits indicated that the site of labeling was cysteine 86. The reason for the high reactivity of cysteine 86 in rGSTM1 was hypothesized to be due to its potential interaction with histidine 84, which is unique in this subunit. PMID:11453725

  9. Induction of oxidative stress and oxidative damage in rat glial cells by acrylonitrile.

    PubMed

    Kamendulis, L M; Jiang, J; Xu, Y; Klaunig, J E

    1999-08-01

    Chronic treatment of rats with acrylonitrile (ACN) resulted in a dose-related increase in glial cell tumors (astrocytomas). While the exact mechanism(s) for ACN-induced carcinogenicity remains unresolved, non-genotoxic and possibly tumor promotion modes of action appear to be involved in the induction of glial tumors. Recent studies have shown that ACN induced oxidative stress selectively in rat brain in a dose-responsive manner. The present study examined the ability of ACN to induce oxidative stress in a rat glial cell line, a target tissue, and in cultured rat hepatocytes, a non-target tissue of ACN carcinogenicity. Glial cells and hepatocytes were treated for 1, 4 and 24 h with sublethal concentrations of ACN. ACN induced an increase in oxidative DNA damage, as evidenced by increased production of 8-hydroxy-2'-deoxyguanosine (8-OH-dG) in glial cells but not in rat hepatocytes. Hydroxyl radical formation following ACN treatment was also selectively increased in glial cells. Following 1 and 4 h of ACN exposure, the levels of the non-enzymatic antioxidant glutathione, as well as the activities of the enzymatic antioxidants catalase and superoxide dismutase were significantly decreased in the rat glial cells. Lipid peroxidation and the activity of glutathione peroxidase were not affected by ACN treatment in rat glial cells. No changes in any of these biomarkers of oxidative stress were observed in hepatocytes treated with ACN. These data indicate that ACN selectively induced oxidative stress in rat glial cells. PMID:10426806

  10. Modification of fiber properties through grafting of acrylonitrile to rayon by chemical and radiation methods

    PubMed Central

    Kaur, Inderjeet; Sharma, Neelam; Kumari, Vandna

    2013-01-01

    Fibrous properties of rayon has been modified through synthesis of graft copolymers of rayon with acrylonitrile (AN) by chemical method using ceric ammonium nitrate (CAN/HNO3) as a redox initiator and gamma radiation mutual method. Percentage of grafting (Pg) was determined as a function of initiator concentration, monomer concentration, irradiation dose, temperature, time of reaction and the amount of water. Maximum percentage of grafting (160.01%) using CAN/HNO3 was obtained at [CAN] = 22.80 × 10?3 mol/L, [HNO3] = 112.68 × 10?2 mol/L and [AN] = 114.49 × 10?2 mol/L in 20 mL of water at 45 °C within 120 min while in case of gamma radiation method, maximum Pg (90.24%) was obtained at an optimum concentration of AN of 76.32 × 10?2 mol/L using 10 mL of water at room temperature with total dose exposure of 3.456 kGy/h. The grafted fiber was characterized by FTIR, SEM, TGA and XRD studies. Swelling behavior of grafted rayon in different solvents such as water, methanol, ethanol, DMF and acetone was studied and compared with the unmodified rayon. Dyeing behavior of the grafted fiber was also investigated. PMID:25685464

  11. Grafting titanium nitride surfaces with sodium styrene sulfonate thin films.

    PubMed

    Zorn, Gilad; Migonney, Véronique; Castner, David G

    2014-09-01

    The importance of titanium nitride lies in its high hardness and its remarkable resistance to wear and corrosion, which has led to its use as a coating for the heads of hip prostheses, dental implants and dental surgery tools. However, the usefulness of titanium nitride coatings for biomedical applications could be significantly enhanced by modifying their surface with a bioactive polymer film. The main focus of the present work was to graft a bioactive poly(sodium styrene sulfonate) (pNaSS) thin film from titanium nitride surfaces via a two-step procedure: first modifying the surface with 3-methacryloxypropyltrimethoxysilane (MPS) and then grafting the pNaSS film from the MPS modified titanium through free radical polymerization. X-ray photoelectron spectroscopy (XPS) and time-of-flight secondary ion mass spectrometry (ToF-SIMS) were used after each step to characterize success and completeness of each reaction. The surface region of the titanium nitride prior to MPS functionalization and NaSS grafting contained a mixture of titanium nitride, oxy-nitride, oxide species as well as adventitious surface contaminants. After MPS functionalization, Si was detected by XPS, and characteristic MPS fragments were detected by ToF-SIMS. After NaSS grafting, Na and S were detected by XPS and characteristic NaSS fragments were detected by ToF-SIMS. The XPS determined thicknesses of the MPS and NaSS overlayers were ?1.5 and ?1.7 nm, respectively. The pNaSS film density was estimated by the toluidine blue colorimetric assay to be 260?±?70 ng/cm(2). PMID:25280842

  12. The effect of plasma surface modification from a rotary plasma reactor on the styrene grafting onto a polypropylene surface

    Microsoft Academic Search

    Chi-Yuan Huang; Chun-Lung Chen

    2002-01-01

    In this investigation, the influence of an initiator, benzoyl peroxides (BPO), plasma pretreatment and grafting time of the styrene (St) grafting onto the surface of polypropylene (PP) were studied. At first, the PP pretreated by rotary glow discharge argon (Ar) plasma (PPP) and then styrene was grafted onto the PPP by using a thermal-induced grafting method with or without adding

  13. Uptake, distribution, metabolism, and elimination of styrene in man. A comparison between single exposure and co-exposure with acetone.

    PubMed Central

    Wigaeus, E; Löf, A; Nordqvist, M B

    1984-01-01

    Six male subjects were exposed for two hours during light physical exercise to 2.81 mmol/m3 (293 mg/m3) of styrene on one occasion and to a mixture of 2.89 mmol/m3 (301 mg/m3) of styrene and 21.3 mmol/m3 (1240 mg/m3) of acetone on another (combination study). About 68% of the dose (somewhat more than 4 mmol) of styrene was taken up. The arterial blood concentration of styrene reached a relatively stable level after about 75 minutes of exposure of about 18 and 20 mumol/l after the single and combined exposure, respectively. Calculated values of mean blood clearance were 1.9 l/min in the styrene study and 1.6 l/min in the combination study; the half life of styrene in blood was about 40 minutes in both studies. The concentration of non-conjugated styrene glycol increased linearly during exposure and reached about 3 mumol/l at the end of exposure and was eliminated with a half life of about 70 minutes. Styrene-7,8-oxide was detected and quantified in the blood in a complementary study. The half lives for the excretion of mandelic and phenylglyoxylic acid in the urine were about four and nine hours, respectively, in both studies. PMID:6498116

  14. Seawater ageing of low styrene emission resins for marine composites: Mechanical behaviour and nano-indentation studies

    Microsoft Academic Search

    Romain Maurin; Yves Perrot; Alain Bourmaud; Peter Davies; Christophe Baley

    2009-01-01

    Polyester resins are widely employed for pleasure boat construction. In order to satisfy new environmental legislation on styrene emissions resin suppliers have proposed modified formulations, but these show lower failure strains under tensile loading. This paper examines the influence of wet ageing on mechanical properties of low styrene polyester, together with standard polyester and vinyl ester resins, and their glass

  15. IMPACT OF AN OZONE GENERATOR AIR CLEANER ON STYRENE CONCENTRATIONS IN AN INDOOR AIR QUALITY RESEARCH CHAMBER

    EPA Science Inventory

    The paper gives results of an investigation of the impact of an ozone generator air cleaner on vapor-phase styrene concentrations in a full-scale indoor air quality test chamber. The time history of the concentrations of styrene and ozone is well predicted by a simulation model u...

  16. Vesicle Formation and Stability in Aqueous Mixtures of the Hydrolyzed Copolymer of Styrene-Maleic Anhydride and

    E-print Network

    Huang, Jianbin

    Vesicle Formation and Stability in Aqueous Mixtures of the Hydrolyzed Copolymer of Styrene of the hydrolyzed copolymer of styrene-maleic anhydride (HSMA) and a series of single-tailed cationic surfactants formed in mixtures of a series of cationic surfactants and partially hydrolyzed polyacrylamide showed

  17. Novel ETFE based radiation grafted poly(styrene sulfonic acid- co-methacrylonitrile) proton conducting membranes with increased stability

    Microsoft Academic Search

    Hicham Ben youcef; Lorenz Gubler; Selmiye Alkan Gürsel; Dirk Henkensmeier; Alexander Wokaun; Günther G. Scherer

    2009-01-01

    Styrene radiation grafted ETFE based proton conducting membranes are subject to degradation under fuel cell operating conditions and show a poor stability. Lifetimes exceeding 250h can only be achieved with crosslinked membranes. In this study, a novel approach based on the increase of the intrinsic oxidative stability of uncrosslinked membranes is reported. Hence, the co-grafting of styrene with methacrylonitrile (MAN),

  18. Relationship between the capacity to repair 8-oxoguanine, biomarkers of genotoxicity and individual susceptibility in styrene-exposed workers

    Microsoft Academic Search

    J. Slyskova; M. Dusinska; M. Kuricova; P. Soucek; L. Vodickova; S. Susova; A. Naccarati; E. Tulupova; P. Vodicka

    2007-01-01

    Genotoxic effects related to exposure to styrene have been a matter of investigation for many years by employing markers of exposure, effect and susceptibility. The role of individual DNA-repair capacity in response to exposure to styrene may explain the controversial results so far obtained, but it is still scarcely explored. In the present study, we measured capacity to repair oxidative

  19. The chemistry of dimethacrylate-styrene networks, and, Development of flame retardant, halogen-free fiber reinforced vinyl ester composites

    Microsoft Academic Search

    Astrid Christa Rosario

    2002-01-01

    One of the major classes of polymer matrix resins under consideration for structural composite applications in the infrastructure and construction industries is vinyl ester resin. Vinyl ester resin is comprised of low molecular weight poly(hydroxyether) oligomers with methacrylate endgroups diluted with styrene monomer. The methacrylate endgroups cure with styrene via free radical copolymerization to yield thermoset networks. The copolymerization behavior

  20. EVALUATION OF POLLUTION PREVENTION TECHNIQUES TO REDUCE STYRENE EMISIONS FROM OPEN CONTACT MOLDING PROCESSES - VOLUME 1. FINAL REPORT

    EPA Science Inventory

    The report gives results of a study to evaluate several pollution prevention techniques that could be used to reduce styrene emissions from open molding processes in the fiberglass-reinforced plastics/composites (FRP/C) and fiberglass boat building industries. Styrene emission...

  1. EVALUATION OF POLLUTION PREVENTION TECHNIQUES TO REDUCE STYRENE EMISSIONS FROM OPEN CONTACT MOLDING PROCESSES - VOLUME 2. APPENDICES

    EPA Science Inventory

    The report gives results of a study to evaluate several pollution prevention techniques that could be used to reduce styrene emissions from open molding processes in the fiberglass-reinforced plastics/composites (FRP/C) and fiberglass boat building industries. Styrene emissions u...

  2. Effects of Surfactants on the Properties of Mortar Containing Styrene/Methacrylate Superplasticizer

    PubMed Central

    Negim, El-Sayed; Kozhamzharova, Latipa; Khatib, Jamal; Bekbayeva, Lyazzat; Williams, Craig

    2014-01-01

    The physical and mechanical properties of mortar containing synthetic cosurfactants as air entraining agent are investigated. The cosurfactants consist of a combination of 2% dodecyl benzene sodium sulfonate (DBSS) and either 1.5% polyvinyl alcohol (PVA) or 1.5% polyoxyethylene glycol monomethyl ether (POE). Also these cosurfactants were used to prepare copolymers latex: styrene/butyl methacrylate (St/BuMA), styrene/methyl methacrylate (St/MMA), and styrene/glycidyl methacrylate (St/GMA), in order to study their effects on the properties of mortar. The properties of mortar examined included flow table, W/C ratio, setting time, water absorption, compressive strength, and combined water. The results indicate that the latex causes improvement in mortar properties compared with cosurfactants. Also polymer latex containing DBSS/POE is more effective than that containing DBSS/PVA. PMID:24955426

  3. Kinetics and mechanism of styrene epoxidation by chlorite: role of chlorine dioxide.

    PubMed

    Leigh, Jessica K; Rajput, Jonathan; Richardson, David E

    2014-07-01

    An investigation of the kinetics and mechanism for epoxidation of styrene and para-substituted styrenes by chlorite at 25 °C in the pH range of 5-6 is described. The proposed mechanism in water and water/acetonitrile includes seven oxidation states of chlorine (-I, 0, I, II, III, IV, and V) to account for the observed kinetics and product distributions. The model provides an unusually detailed quantitative mechanism for the complex reactions that occur in mixtures of chlorine species and organic substrates, particularly when the strong oxidant chlorite is employed. Kinetic control of the reaction is achieved by the addition of chlorine dioxide to the reaction mixture, thereby eliminating a substantial induction period observed when chlorite is used alone. The epoxidation agent is identified as chlorine dioxide, which is continually formed by the reaction of chlorite with hypochlorous acid that results from ClO produced by the epoxidation reaction. The overall stoichiometry is the result of two competing chain reactions in which the reactive intermediate ClO reacts with either chlorine dioxide or chlorite ion to produce hypochlorous acid and chlorate or chloride, respectively. At high chlorite ion concentrations, HOCl is rapidly eliminated by reaction with chlorite, minimizing side reactions between HOCl and Cl2 with the starting material. Epoxide selectivity (>90% under optimal conditions) is accurately predicted by the kinetic model. The model rate constant for direct reaction of styrene with ClO2(aq) to produce epoxide is (1.16 ± 0.07) × 10(-2) M(-1) s(-1) for 60:40 water/acetonitrile with 0.20 M acetate buffer. Rate constants for para substituted styrenes (R = -SO3(-), -OMe, -Me, -Cl, -H, and -NO2) with ClO2 were determined. The results support the radical addition/elimination mechanism originally proposed by Kolar and Lindgren to account for the formation of styrene oxide in the reaction of styrene with chlorine dioxide. PMID:24927381

  4. Structure and Ligand Binding Properties of the Epoxidase Component of Styrene Monooxygenase

    SciTech Connect

    Ukaegbu, Uchechi E.; Kantz, Auric; Beaton, Michelle; Gassner, George T.; Rosenzweig, Amy C. (NWU); (SFSU)

    2010-07-23

    Styrene monooxygenase (SMO) is a two-component flavoprotein monooxygenase that transforms styrene to styrene oxide in the first step of the styrene catabolic and detoxification pathway of Pseudomonas putida S12. The crystal structure of the N-terminally histidine-tagged epoxidase component of this system, NSMOA, determined to 2.3 {angstrom} resolution, indicates the enzyme exists as a homodimer in which each monomer forms two distinct domains. The overall architecture is most similar to that of p-hydroxybenzoate hydroxylase (PHBH), although there are some significant differences in secondary structure. Structural comparisons suggest that a large cavity open to the surface forms the FAD binding site. At the base of this pocket is another cavity that likely represents the styrene binding site. Flavin binding and redox equilibria are tightly coupled such that reduced FAD binds apo NSMOA {approx}8000 times more tightly than the oxidized coenzyme. Equilibrium fluorescence and isothermal titration calorimetry data using benzene as a substrate analogue indicate that the oxidized flavin and substrate analogue binding equilibria of NSMOA are linked such that the binding affinity of each is increased by 60-fold when the enzyme is saturated with the other. A much weaker {approx}2-fold positive cooperative interaction is observed for the linked binding equilibria of benzene and reduced FAD. The low affinity of the substrate analogue for the reduced FAD complex of NSMOA is consistent with a preferred reaction order in which flavin reduction and reaction with oxygen precede the binding of styrene, identifying the apoenzyme structure as the key catalytic resting state of NSMOA poised to bind reduced FAD and initiate the oxygen reaction.

  5. Identification of a Novel Self-Sufficient Styrene Monooxygenase from Rhodococcus opacus 1CP? †

    PubMed Central

    Tischler, Dirk; Eulberg, Dirk; Lakner, Silvia; Kaschabek, Stefan R.; van Berkel, Willem J. H.; Schlömann, Michael

    2009-01-01

    Sequence analysis of a 9-kb genomic fragment of the actinobacterium Rhodococcus opacus 1CP led to identification of an open reading frame encoding a novel fusion protein, StyA2B, with a putative function in styrene metabolism via styrene oxide and phenylacetic acid. Gene cluster analysis indicated that the highly related fusion proteins of Nocardia farcinica IFM10152 and Arthrobacter aurescens TC1 are involved in a similar physiological process. Whereas 413 amino acids of the N terminus of StyA2B are highly similar to those of the oxygenases of two-component styrene monooxygenases (SMOs) from pseudomonads, the residual 160 amino acids of the C terminus show significant homology to the flavin reductases of these systems. Cloning and functional expression of His10-StyA2B revealed for the first time that the fusion protein does in fact catalyze two separate reactions. Strictly NADH-dependent reduction of flavins and highly enantioselective oxygenation of styrene to (S)-styrene oxide were shown. Inhibition studies and photometric analysis of recombinant StyA2B indicated the absence of tightly bound heme and flavin cofactors in this self-sufficient monooxygenase. StyA2B oxygenates a spectrum of aromatic compounds similar to those of two-component SMOs. However, the specific activities of the flavin-reducing and styrene-oxidizing functions of StyA2B are one to two orders of magnitude lower than those of StyA/StyB from Pseudomonas sp. strain VLB120. PMID:19482928

  6. Microstructure analysis of a CO2 copolymer from styrene oxide at the diad level.

    PubMed

    Wu, Guang-Peng; Zu, Yu-Ping; Xu, Peng-Xiang; Ren, Wei-Min; Lu, Xiao-Bing

    2013-08-01

    A large amount of interesting information on the alternating copolymerization of CO2 with terminal epoxides has already been reported, such as the regiochemistry of epoxide ring-opening and the stereochemistry of the carbonate unit sequence in the polymer chain. Moreover, the microstructures of CO2 copolymers from propylene oxide and cyclohexene oxide have also been well-studied. However, the microstructure of the CO2 copolymer from styrene oxide (SO), an epoxide that contains an electron-withdrawing group, has not yet been investigated. Herein, we focus on the spectroscopic assignment of the CO2 copolymer from styrene oxide at the diad level by using three kinds of model dimer compounds, that is, T-T, H-T, and H-H. By comparing the signals in the carbonyl region, we concluded that the signals at ?=154.3, 153.8, and 153.3 ppm in the (13)C NMR spectrum of poly(styrene carbonate) were due to tail-to-tail, head-to-tail, and head-to-head carbonate linkages, respectively. Moreover, various isotactic and syndiotactic model compounds based on T-T, H-T, and H-H (dimers (R,R)-T-T, (S,S)-T-T, and (R,S)-T-T; (R,R)-H-T, (S,S)-H-T, and (R,S)-H-T; (R,R)-H-H, (S,S)-H-H, and (R,S)-H-H) were synthesized for the further spectroscopic assignment of stereospecific poly(styrene carbonate)s. We found that the carbonate carbon signals were sensitive towards the stereocenters on adjacent styrene oxide ring-opening units. These discoveries were found to be well-matched to the microstructures of the stereoregular poly(styrene carbonate)s that were prepared by using a multichiral Co(III)-based catalyst system. PMID:23712930

  7. Simultaneous determination by gas chromatography of the major metabolites in urine of toluene, xylenes and styrene.

    PubMed Central

    Van Roosmalen, P B; Drummond, I

    1978-01-01

    A gas chromatographic method has been developed to determine the following metabolites in urine simultaneously if necessary: hippuric acid from toluene or styrene; 3- and 4-methyl hippuric acids from xylenes; phenylglyoxylic acid and mandelic acid from styrene. Heptadecanoic acid is added to the urine as an internal standard and after ethyl acetate extraction from acidic solution, the trimethylsilyl (TMS) derivatives of the metabolites are formed and simultaneously analysed by gas chromatography on 3% OV-1 on 80/100 gas chrom Q (flame ionisation detector). PMID:629890

  8. Batch polymerization of styrene initiated by n-butyllithium in benzene 

    E-print Network

    Tanlak, Tayfun

    1975-01-01

    BATCH POLYMERIZATION OF STYRENE INITIATED BY n-BUTYLLITHIUM IN BENZENE A Thesis by TAYFUN TANLAK Submitted to the Graduate Co'l1ege of Texas Anil University in partial fu1fi11ment of the requirement for the degree cf MASTER OF SCIENCE... August 1975 Major Subject: Chemica1 Engineering BATCH POLYMERIZATION OF STYRENE INITIATED BY n-BUTYLLITHIUM IN BENZENE A Thesis by TAYFUN TANLAK Approved as to style and content by: Chairman of Committee Head Department Member ~ /z'1tup Member...

  9. The effect of nutrient limitation on styrene metabolism in Pseudomonas putida CA-3

    SciTech Connect

    O`Connor, K.; Dobson, A.D.W. [Univ. College, Cork (Ireland); Duetz, W.; Wind, B. [National Institute of Public Health and Environmental Protection, Bilthoven (Netherlands)

    1996-10-01

    Two main pathways for the bacterial degradation of styrene have been described as initial oxidation of the vinyl side chain and direct attach on the aromatic nucleus of the molecule. The ability of microorganisms to degrade aromatic compounds is often subject to catabolic repression. To attempt to assess the catabolic potential of Pseufomonas putida CA-3 under conditions similar to natural conditions, this study monitored the styrene degrading ability of the strain under continuous culture conditions of carbon, ammonium, and sulfate limitation in the presence or absence of primary carbon sources. 30 refs., 2 figs. 5 tabs.

  10. Acrylonitrile quenching of trp phosphorescence in proteins: a probe of the internal flexibility of the globular fold.

    PubMed

    Strambini, Giovanni B; Gonnelli, Margherita

    2010-08-01

    Quenching of Trp phosphorescence in proteins by diffusion of solutes of various molecular sizes unveils the frequency-amplitude of structural fluctuations. To cover the sizes gap between O(2) and acrylamide, we examined the potential of acrylonitrile to probe conformational flexibility of proteins. The distance dependence of the through-space acrylonitrile quenching rate was determined in a glass at 77 K, with the indole analog 2-(3-indoyl) ethyl phenyl ketone. Intensity and decay kinetics data were fitted to a rate, k(r) =k(0) exp[-(r -r(0))/r(e)], with an attenuation length r(e) = 0.03 nm and a contact rate k(0) = 3.6 x 10(10) s(-1). At ambient temperature, the bimolecular quenching rate constant (kq) was determined for a series of proteins, appositely selected to test the importance of factors such as the degree of Trp burial and structural rigidity. Relative to kq = 1.9 x 10(9) M(-1)s(-1) for free Trp in water, in proteins kq ranged from 6.5 x 10(6) M(-1)s(-1) for superficial sites to 1.3 x 10(2) M(-1)s(-1) for deep cores. The short-range nature of the interaction and the direct correlation between kq and structural flexibility attest that in the microsecond-second timescale of phosphorescence acrylonitrile readily penetrates even compact protein cores and exhibits significant sensitivity to variations in dynamical structure of the globular fold. PMID:20682273

  11. Antimony leaching in plastics from waste electrical and electronic equipment (WEEE) with various acids and gamma irradiation

    SciTech Connect

    Tostar, Sandra, E-mail: sandra.tostar@chalmers.se [Department of Industrial Materials Recycling, Chalmers University of Technology, 412 96 Gothenburg (Sweden); Stenvall, Erik; Boldizar, Antal [Department of Material and Manufacturing Technology, Chalmers University of Technology, 412 96 Gothenburg (Sweden); Foreman, Mark R. St. J. [Department of Industrial Materials Recycling, Chalmers University of Technology, 412 96 Gothenburg (Sweden)

    2013-06-15

    Highlights: • We have proposed a method to recover antimony from electronic plastics. • The most efficient acid solution was sodium hydrogen tartrate in dimethyl sulfoxide. • Gamma irradiation did not influence the antimony leaching ability. - Abstract: There has been a recent interest in antimony since the availability in readily mined areas is decreasing compared to the amounts used. It is important in many applications such as flame retardants and in the production of polyester, which can trigger an investigation of the leachability of antimony from plastics using different acids. In this paper, different types of acids are tested for their ability to leach antimony from a discarded computer housing, made of poly(acrylonitrile butadiene styrene), which is a common plastic type used in electrical and electronic equipment. The acid solutions included sodium hydrogen tartrate (0.5 M) dissolved in either dimethyl sulfoxide or water (at ca. 23 °C and heated to ca. 105 °C). The metal content after leaching was determined by inductively coupled plasma optical emission spectroscopy. The most efficient leaching medium was the heated solution of sodium hydrogen tartrate in dimethyl sulfoxide, which leached almost half of the antimony from the poly(acrylonitrile butadiene styrene). Gamma irradiation, which is proposed to improve the mechanical properties in plastics, was used here to investigate the influence of antimony leaching ability. No significant change in the amount of leached antimony could be observed.

  12. A correlation study applied to biomarkers of internal and effective dose for acrylonitrile and 4-aminobiphenyl in smokers

    PubMed Central

    Scherer, Gerhard; Newland, Kirk; Papadopoulou, Ermioni

    2014-01-01

    The urinary metabolites 2-cyanoethylmercapturic acid and 4-aminobiphenyl have been correlated with tobacco smoke exposure. Similarly, 2-cyanoethylvaline and 4-aminobiphenyl haemoglobin adducts have been used as biomarkers of effective dose for the exposure to acrylonitrile and 4-aminobiphenyl, respectively. Each pair of biomarkers is derived from the same parent chemical; however, the correlation between the urinary and the haemoglobin biomarkers has not been investigated. Using clinical study samples, we report a weak correlation between urinary and haemoglobin biomarkers due to different accumulation and elimination rates. Time course analysis showed that a reduction in exposure was paralleled by a delayed reduction in haemoglobin adducts. PMID:24754403

  13. Induction or inhibition of cytochrome P450 2E1 modifies the acute toxicity of acrylonitrile in rats: biochemical evidence

    Microsoft Academic Search

    Wang Suhua; Lu Rongzhu; Xu Wenrong; Xing Guangwei; Zhao Xiaowu; Wang Shizhong; Zhang Ye; Han Fangan; Michael Aschner

    2010-01-01

    The present study was designed to examine the effects of the inhibition or induction of CYP2E1 activity on acute acrylonitrile\\u000a (AN) toxicity in rats. Increased or decreased hepatic CYP2E1 activity was achieved by pretreatment with acetone or trans-1,2-dichloroethylene\\u000a (DCE), respectively. AN (50 mg\\/kg) was administered by intraperitoneal injection. Onset of convulsions and death were observed\\u000a in rats with increased CYP2E1 activity,

  14. Surface modification of poly(styrene-b-(ethylene-co-butylene)-b-styrene) (SEBS) elastomer via covalent immobilization of nonionic sugar-based Gemini surfactants.

    PubMed

    Xin, Zhirong; Du, Binbin; Yan, Shunjie; Du, Shanshan; Ding, Jiaotong; Yang, Zongfeng; Ren, Wanzhong

    2014-07-01

    Gemini surfactants (GS) with sugar-containing head-groups and different alkyl chains were successfully prepared. Poly(styrene-b-(ethylene-co-butylene)-b-styrene) (SEBS) elastomer was grafted with glycidyl methacrylate (GMA) by means of UV-induced graft polymerization, and then the pGMA-grafted film was chemically immobilized with the GS. The surface graft polymerization was confirmed by ATR-FTIR and XPS. The wettability and hemocompatibility of the modified surface were characterized by means of water contact angle, protein adsorption, and platelet adhesion assays. The results showed that amphiphilic surfactant-containing polymer surfaces presented protein-resistant behavior and anti-platelet adhesion after functionalization with GS, GS1 and GS2. Besides, the hemocompatibility of the modified surface deteriorated as the length of hydrophobic chain of GS increased. PMID:24854325

  15. Organometallic analogues of the Diels-Alder reaction: Molybdenum dimer + ethylene; molybdenum dimer + butadiene

    SciTech Connect

    Roszak, S.; Balasubramanian, K. [Arizona State Univ., Tempe, AZ (United States)

    1994-08-31

    A theoretical study of the symmetry-concerted Diels-Alder analogue reactions of Mo{sub 2} with 1,3-butadiene and ethylene is presented. Structure optimizations indicated elongation of the Mo-Mo and C{double_bond}C bonds in the complexes. The optimized bond distances were found to be close to one known in organomolybdenum complexes. The presented potential surfaces indicated, in agreement with symmetry-concerted models, that the Mo{sub 2}-Eth complex formation is thermally forbidden, as the reaction has to proceed in the excited state, but the Mo{sub 2}-But complex may be formed in the ground state with addition of thermal energy.

  16. Efficient bulky phosphines for the selective telomerization of 1,3-butadiene with methanol.

    PubMed

    Tschan, Mathieu J-L; García-Suárez, Eduardo J; Freixa, Zoraida; Launay, Hélène; Hagen, Henk; Benet-Buchholz, Jordi; van Leeuwen, Piet W N M

    2010-05-12

    A series of bulky phosphines containing substituted biphenyl, 2-methylnaphthyl, or 2,7-di-tert-butyl-9,9-dimethylxanthene moiety were prepared. They were used in the preparation of new monophosphine-palladium(0)-dvds complexes, which were employed as catalysts for the selective telomerization of 1,3-butadiene with methanol to obtain 1-methoxyocta-2,7-diene (1-MOD), the key intermediate in the Dow 1-octene process. Several ligands showed improved selectivity and yield compared to that of the benchmark ligand PPh(3). Especially 2,7-di-tert-butyl-9,9-dimethylxanthen-4-yl-diphenylphosphine (4, "mono-xantphos") stands out as an excellent ligand in terms of yield, selectivity, and stability. PMID:20405840

  17. Functionalized organic nanoparticles from core-crosslinked poly(4-vinylbenzocyclobutene-b-butadiene) diblock copolymer micelles

    SciTech Connect

    Sakellariou, Georgios [ORNL; Avgeropoulos, Apostolos [University of Athens, Athens, Greece; Hadjichristidis, Nikos [University of Athens, Athens, Greece; Mays, Jimmy [ORNL; Baskaran, Durairaj [University of Tennessee, Knoxville (UTK)

    2009-01-01

    Sufface-functionalized polymeric nanoparticles were prepared by: a) self~assembly of poly(4-vinylbenzocyclobutene-b-butadiene) diblock copolymer (PVBCB-b-PB) to form spherical micelles (diameter:15-48 nm) in decane, a selective solvent for PB, b) crosslinking of the PVBCB core through thermal dimerization at 200-240 ~ C, and c) cleavage of the PB corona via ozonolysis and addition of dimethyl sulfide to afford aldehyde-functionalized nanoparticles (diameter: -16-20 nm), along with agglomerated nanoparticles ranging from - 30 to -100 nm in diameter. The characterization of the diblock copolymer precursors. the intermediate micelles and the final surface-functionalized crosslinked nanoparticles was carried alit by a combination of size exclusion chromatography, static and dynamic light scattering, viscometry, thermogravimetric analysis, 1 H NMR and FfIR spectroscopy and transmission electron microscopy.

  18. The Oxidation of 1,3Butadiene: Experimental Results and Kinetic Modeling

    Microsoft Academic Search

    P. DAGAUT; M. CATHONNET

    1998-01-01

    The oxidation of 1,3-butadiene has been investigated in a jet-stirred reactor at high temperature (˜750-1250 K), variable pressure (1 and 10 atm) and variable equivalence ratio (0.25???2). Molecular species concentration profiles of O2, H2,CO,CO2,CH2O,CH4,C2H2,C2H4, C2H6, C3H4 (allene and propyne), C3H6, acrolein, 1-C4H8, 2-C4H8 (cis and trans), 1,3-C4H6, vinyla-cetylene, cyclopentadiene, and benzene were obtained by probe sampling and GC analysis. The

  19. Fluorescence Efficiency and Visible Re-emission Spectrum of Tetraphenyl Butadiene Films at Extreme Ultraviolet Wavelengths

    E-print Network

    V. M. Gehman; S. R. Seibert; K. Rielage; A. Hime; Y. Sun; D. -M. Mei; J. Maassen; D. Moore

    2011-09-22

    A large number of current and future experiments in neutrino and dark matter detection use the scintillation light from noble elements as a mechanism for measuring energy deposition. The scintillation light from these elements is produced in the extreme ultraviolet (EUV) range, from 60 - 200 nm. Currently, the most practical technique for observing light at these wavelengths is to surround the scintillation volume with a thin film of Tetraphenyl Butadiene (TPB) to act as a fluor. The TPB film absorbs EUV photons and reemits visible photons, detectable with a variety of commercial photosensors. Here we present a measurement of the re-emission spectrum of TPB films when illuminated with 128, 160, 175, and 250 nm light. We also measure the fluorescence efficiency as a function of incident wavelength from 120 to 250 nm.

  20. Homogeneous single-component betaine Ziegler-Natta catalysts derived from (butadiene)zirconocene precursors.

    PubMed

    Erker, G

    2001-04-01

    (Butadiene)zirconocene adds B(C(6)F(5))(3) at a terminal diene carbon atom to yield the zirconocene-(mu-hydrocarbyl)-borate betaine Cp(2)Zr[C(4)H(6)-B(C(6)F(5))(3)] (4). The dipolar complex 4 contains a distorted pi-allyl moiety and features an additional stabilizing Zr-F-C(arene) coordination. Under kinetic control, an isomeric betaine system is formed, characterized by an internal Zr(+).CH(2)[B](-) ion-pair interaction, that rearranges to 4 upon heating. A great variety of ansa-metallocene(butadiene) complexes and related systems cleanly form analogous metallocene-(mu-conjugated diene)-borate betaines upon treatment with B(C(6)F(5))(3) and related Lewis acids. Most of these systems represent very active homogeneous single-component Ziegler-Natta catalysts for alpha-olefin polymerization and copolymerization. In addition, these betaine catalysts are ideally suited for carrying out mechanistic studies in active Ziegler-Natta catalyst systems. They allow for an experimental observation of the first alkene insertion step at the active single-component catalyst. This feature has been used for studying the mechanism of transfer of the stereochemical information from the bent metallocene backbone and for an experimental characterization of the energy profile of the alkene addition/alkene insertion reaction sequence in active homogeneous Ziegler-Natta systems. The neutral dipolar single-component catalysts (e.g., 4) produce a polyolefin-modified R'-(CHR-CH(2))-C(4)H(6)-B(C(6)F(5))(3)(-) counterion at the end of the initiation period upon entering into the repetitive active catalytic cycle. PMID:11308305

  1. Physiologically based pharmacokinetic model parameter estimation and sensitivity and variability analyses for acrylonitrile disposition in humans.

    PubMed

    Sweeney, Lisa M; Gargas, Michael L; Strother, Dale E; Kedderis, Gregory L

    2003-01-01

    A physiologically based pharmacokinetic (PBPK) model of acrylonitrile (ACN) and cyanoethylene oxide (CEO) disposition in humans was developed and is based on human in vitro data and scaling from a rat model (G. L. Kedderis et al., 1996, TOXICOL: Appl. Pharmacol.140, 422-435) for application to risk assessment. All of the major biotransformation and reactivity pathways, including metabolism of ACN to glutathione conjugates and CEO, reaction rates of ACN and CEO with glutathione and tissues, and the metabolism of CEO by hydrolysis and glutathione conjugation, were described in the human PBPK model. Model simulations indicated that predicted blood and brain ACN and CEO concentrations were similar in rats and humans exposed to ACN by inhalation. In contrast, rats consuming ACN in drinking water had higher predicted blood concentrations of ACN than humans exposed to the same concentration in water. Sensitivity and variability analyses were conducted on the model. While many parameters contributed to the estimated variability of the model predictions, the reaction rate of CEO with glutathione, hydrolysis rate for CEO, and blood:brain partition coefficient of CEO were the parameters predicted to make the greatest contributions to variability of blood and brain CEO concentrations in humans. The main contributor to predicted variance in human blood ACN concentrations in people exposed through drinking water was the Vmax for conversion of ACN to CEO. In contrast, the main contributors for variance in people exposed by inhalation were expected to be the rate of blood flow to the liver and alveolar ventilation rate, with the brain:blood partition coefficient also contributing to variability in predicted concentrations of ACN in the brain. Expected variability in blood CEO concentrations (peak or average) in humans exposed by inhalation or drinking water was modest, with a 95th-percentile individual expected to have blood concentrations 1.8-times higher than an average individual. PMID:12520073

  2. Two-generation reproductive toxicity study of inhaled acrylonitrile vapors in Crl:CD(SD) rats.

    PubMed

    Nemec, M D; Kirkpatrick, D T; Sherman, J; Van Miller, J P; Pershing, M L; Strother, D E

    2008-01-01

    To assess the effects of acrylonitrile (AN) exposure on reproduction, Sprague-Dawley rats (25/sex/group) were exposed to vapor atmospheres of AN via whole-body inhalation at concentrations of 0, 5, 15, 45 (two offspring generations) and 90 ppm (one offspring generation), 6 h daily, 1 litter/generation, through F2 weanlings on postnatal day 28. After approximately 3 weeks of direct exposure following weaning, exposure of the F1 animals at 90 ppm was terminated due to excessive systemic toxicity in the males. There were no exposure-related mortalities in adult animals, no functional effects on reproduction or effects on reproductive organs, and no evidence of cumulative toxicity or of enhanced toxicity in pregnant and lactating dams or in developing animals. Adult systemic toxicity was limited to body weight and/or food consumption deficits in both sexes and generations (greater in males) at 45 and 90 ppm and increased liver weights in the 90 ppm F0 males and females and 45 ppm F1 males. Neonatal toxicity was expressed by F1 offspring weight decrements at 90 ppm. Clinical signs of local irritation during and immediately following exposure were observed at 90 ppm. Microscopic lesions of the rostral nasal epithelium, representing local site-of-contact irritation, were observed in some animals at 5 to 45 ppm. The no-observed-adverse-effect level (NOAEL) for reproductive toxicity over two generations and neonatal toxicity of AN administered to rats via whole-body inhalation was 45 ppm. The NOAEL for reproduction was 90 ppm for the first generation. The NOAEL for parental systemic toxicity was 15 ppm. PMID:18293209

  3. Zinc, copper, iron, and selenium levels in brain and liver of mice exposed to acrylonitrile.

    PubMed

    Rongzhu, Lu; Suhua, Wang; Guangwei, Xing; Chunlan, Ren; Fangan, Han; Junjie, Jing; Aschner, Michael

    2009-07-01

    The mechanism of toxicity of acrylonitrile (AN) has not been fully defined. The research described herein was undertaken to investigate the possible effects of AN on the levels of metallic elements in liver and brain of mice. Thirty-two mice were randomly assigned to four separate groups and treated intraperitoneal (i.p.) once daily for 1 week. Mice in the control group received normal saline, and mice in the three exposure groups received 5, 10, or 20 mg AN/kg b.w. Samples of brain and liver were collected immediately after decapitation. Tissue levels of trace elements (zinc, copper, iron) were determined with flame atomic absorption spectrophotometer or double channel atomic fluorescence absorption spectrophotometer (selenium). Mean brain weights of AN-treated mice were increased as a function of dose compared to controls, but there was no significant change in the ratio of liver/body weight in the four groups. While mean brain zinc decreased as a function of AN dosage, mean liver zinc of the low-dose group significantly increased (p < 0.05); mean liver copper in the medium-dose AN group was significantly higher compared to controls (p < 0.05); however, mean brain copper was increased, but the difference did not attain statistical significance in the three AN groups when compared with the controls (p > 0.05). Mean brain iron levels were significantly decreased in the middle-dose AN group (p < 0.05), but there were no consistent changes in liver iron. Tissue levels of selenium in brain and liver were similar for the control and AN treatment groups. AN induces significant and differential changes in the levels of zinc, copper, and iron in brain and liver. These changes likely play a pivotal role in mediating AN toxicity, most likely via changes in cellular redox status. PMID:19165426

  4. The acute lethality of acrylonitrile is not due to brain metabolic arrest.

    PubMed

    Campian, E Cristian; Benz, Frederick W

    2008-11-20

    Acrylonitrile (AN) is an organic compound produced in large quantities by the chemical industry and is acutely toxic. One mechanism proposed to explain the toxicity of AN is metabolism by P450 into cyanide (CN). Although blood and brain levels of CN in rats following an LD90 dose of AN are consistent with acute toxicity, blocking CN formation with P450 inhibitors does not prevent lethality. Another mechanism implicated in toxicity is covalent binding of AN to cysteine residues in tissue proteins. Previous work in our laboratory has shown that AN can irreversibly inactivate the catalytically active cysteine-149 in glyceraldehyde-3-phosphate dehydrogenase (GAPDH). Inactivation of GAPDH by AN would be expected to impair glycolytic ATP production and, when coupled to the inhibition of mitochondrial ATP synthesis by the AN metabolite CN, would result in metabolic arrest, particularly in brain. In this study we have measured the high energy metabolites phosphocreatine (PCr), ATP, ADP and AMP by HPLC and compared their levels in the brains of rats treated with an LD90 dose of AN, when respiration ceased, vs. controls. Two methods of rapid brain freezing in liquid nitrogen were used: funnel freezing (FF) and head immersion (HI). AN administration resulted in large decreases in PCr of 74% (FF) and 80% (HI) but relatively minor decreases in ATP of 5% (FF) and 21% (HI) and Energy Charge of 6% (FF) and 10% (HI). Thus, although substantial depletion of PCr was observed, possibly due to inhibition of creatine kinase by AN, we found no evidence that brain ATP is depleted when respiration ceases in AN-intoxicated rats. PMID:18834918

  5. Biological markers of acute acrylonitrile intoxication in rats as a function of dose and time.

    PubMed

    Benz, F W; Nerland, D E; Corbett, D; Li, J

    1997-04-01

    Three markers of acute acrylonitrile (AN) intoxication, namely, tissue glutathione (GSH), tissue cyanide (CN), and covalent binding to tissue protein, were studied as a function of dose and time. Doses administered and responses expected were 20 mg/kg (LD0), 50 mg/kg (LD10), 80 mg/kg (LD50), and 115 mg/kg (LD90). Liver GSH was the most sensitive marker of AN exposure. At 80 mg/kg AN, virtually complete depletion of liver GSH was observed within 30 min with no recovery through 120 min. Kidney GSH showed a similar, but less intense depletion; while blood and brain GSH were more refractory to AN. Whole blood and brain CN rose progressively during the first 60 min in a dose-dependent fashion. At the lowest dose, CN levels decreased thereafter, whereas, at the three higher doses, CN levels were maintained or continued to increase through 120 min. At the highest dose, blood and brain CN remained at acutely toxic levels through 240 min. Covalent binding increased rapidly in all tissues during the first 30 min at all doses. At the lowest dose, little additional covalent binding was observed beyond 30 min, while at the three higher doses, covalent binding increased, although at a slower rate. The data indicate that these three biologic markers of acute AN intoxication respond dramatically in a time-dependent manner in the toxic dosage range. Furthermore, the data provide evidence that AN toxicity is gated by GSH depletion in liver with the resultant termination of AN detoxification. PMID:9143483

  6. The effect of acrylonitrile on gap junctional intercellular communication in rat astrocytes.

    PubMed

    Kamendulis, L M; Jiang, J; Zhang, H; deFeijter-Rupp, H; Trosko, J E; Klaunig, J E

    1999-06-01

    Rats chronically exposed to acrylonitrile (ACN) have shown a dose-dependent increase in the incidence of astrocytomas in the brain. The mechanism(s) by which ACN induces cancer in rodents has not been established. ACN does not appear to be directly genotoxic in the brain and thus a nongenotoxic mode of action has been proposed. Inhibition of gap junctional intercellular communication (GJIC) has been shown to be a property of many nongenotoxic carcinogens. The present study examined the effects of ACN on GJIC in a rat astrocyte transformed cell line, DI TNC1 cells (a target cell for ACN carcinogenicity) and primary cultured hepatocytes (a nontarget cell for ACN carcinogenicity). ACN inhibited GJIC in rat astrocytes in a dose-dependent manner. Inhibition of GJIC was observed following 2 h treatment with 0.10 mmol/L and 1.00 mmol/L ACN. However, in primary cultured hepatocytes, ACN exposed did not result in inhibition of GJIC even after 48 h of continued treatment. In the astrocytes, GJIC inhibition plateaued after 4 h of treatment and remained blocked throughout the entire experimental period examined. Inhibition of GJIC in DI TNC1 cells was reversed by removal of ACN from the culture medium after 4 or 24 h of treatment. Cotreatment of astrocytes with vitamin E reduced the effect of ACN-induced inhibition of GJIC. Similarly, inhibition of GJIC was prevented by treatment with 2-oxothiazolidine-4-carboxylic acid (OTC), a precursor of glutathione synthesis. Decreasing cellular glutathione by treatment with buthionine sulfoxamine alone (without ACN) did not affect GJIC in astrocytes. Collectively, these results demonstrate that treatment with ACN caused a selective inhibition of GJIC in rat DI TNC1 astrocytes (the target cell type), but not in rat hepatocytes (a nontarget tissue). Inhibition of GJIC in astrocytes was reversed by treatment with antioxidants and suggests a potential role for oxidative stress in ACN-induced carcinogenesis. PMID:10580550

  7. Comparative disposition of acrylonitrile and methacrylonitrile: quantitative whole-body autoradiographic studies in rats.

    PubMed

    Ahmed, A E; Jacob, S; Ghanayem, B I

    1996-09-01

    Following intravenous administration of an equimolar (0.216 mmol/kg) radioactive dose of acrylonitrile (2-[14C]VCN, 11.5 mg/kg) or methacrylonitrile (2-[14C]MeVCN, 14.5 mg/kg), the tissue distribution, covalent interaction, and elimination were compared (at 5 min to 48 hr) in male Fischer 344 rats using whole-body autoradiography (WBA). Autoradiographs obtained from freeze-dried or acid-extracted sections of animals treated with 2-[14C]VCN showed that radioactivity accumulated in the liver, lung, bone marrow, adipose tissues, kidney, gastrointestinal tract, and spleen. In animals treated with 2-[14C]MeVCN, the respiratory tissues contained high levels of 14C at an early period (5 min), while the gastrointestinal mucosa, adrenal cortex, liver, and kidney contained high levels of radioactivity at later periods (8, 24, and 48 hr). Quantitatively, lower uptake and irreversible interactions of 14C were observed in autoradiographs of rats treated with 2-[14C]MeVCN compared with those treated with 2-[14C]VCN. Rats given 2-[14C]VCN eliminated only 27% of administered radioactivity (exhaled air, urine, and feces), whereas rats treated with 2-[14C]MeVCN eliminated, by all routes, 65% of the total radioactive dose. Both WBA and elimination studies indicated that 2-[14C]VCN and/or its metabolites were rapidly distributed, extensively bound, and slowly eliminated from tissues. 2-[14C]MeVCN and/or its metabolites, however, were rapidly distributed and eliminated, mostly via the lung. The study indicated that the substitution of a methyl group on the alpha-carbon of the alpha-beta unsaturated aliphatic nitrile VCN, to form MeVCN, imparted qualitative and quantitative differences in the disposition of these two compounds. PMID:8812221

  8. Selective covalent binding of acrylonitrile to Cys 186 in rat liver carbonic anhydrase III in vivo.

    PubMed

    Nerland, Donald E; Cai, Jian; Benz, Frederick W

    2003-05-01

    Covalent binding of reactive chemical species to tissue proteins is a common, but poorly understood, mechanism of toxicity. Identification of the proteins and the specific amino acid residues within the proteins that are chemically modified will aid our understanding of the toxification/detoxification mechanisms involved in covalent binding. Acrylonitrile (AN) is a commercial vinyl monomer that is acutely toxic and readily binds to tissue proteins. Total covalent binding of AN to tissue proteins is highly correlated with acute toxicity. Two-dimensional PAGE and autoradiography were used to locate proteins in male rat liver cytosol that are radiolabeled following administration of [2,3-(14)C]AN in vivo. Four intensely labeled spots were prominent in the autoradiogram and formed an apparent "charge-train" at approximately 30 kDa. Tryptic peptide mapping by matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) MS was used to identify all of the spots as carbonic anhydrase III (CAIII). HPLC of the tryptic digests combined with MALDI-TOF MS was used to localize the radiolabel to tryptic fragment T22 containing amino acids 171-187. This tryptic fragment contains two Cys residues (Cys181 and Cys186) in the rat CAIII sequence. Electrospray ionization ion-trap MS was used to sequence the peptide and establish that only Cys186 was labeled. Thus, although AN is considered to be highly reactive, our data indicate that it does not react indiscriminately with rat CAIII but rather is selective for one out of five Cys residues. Rat liver CAIII has previously been shown to protect cells against oxidative stress. Our data suggest that CAIII is also capable of scavenging reactive xenobiotics and may help prevent covalent binding to more critical macromolecules. PMID:12755587

  9. Curcumin pretreatment protects against acute acrylonitrile-induced oxidative damage in rats.

    PubMed

    Guangwei, Xing; Rongzhu, Lu; Wenrong, Xu; Suhua, Wang; Xiaowu, Zhao; Shizhong, Wang; Ye, Zhang; Aschner, Michael; Kulkarni, Shrinivas K; Bishnoi, Mahendra

    2010-01-12

    Acrylonitrile (AN) is widely used in the manufacturing of fibers, plastics and pharmaceuticals. Free radical-mediated lipid peroxidation is implicated in the toxicity of AN. The present study was designed to examine the ability of curcumin, a natural polyphenolic compound, to attenuate acute AN-induced lipid peroxidation in the brain and liver of rats. Male Sprague-Dawley rats were orally administered curcumin at doses of 0 (olive oil control), 50 or 100 mg/kg bodyweight daily for 7 consecutive days. Two hours after the last dose of curcumin, rats received an intraperitoneal injection of 50 mg AN/kg bodyweight. Acute exposure to AN significantly increased the generation of lipid peroxidation products, reflected by high levels of malondialdehyde (MDA) both in the brain and liver. These increases were accompanied by a significant decrease in reduced glutathione (GSH) content and a significant reduction in catalase (CAT) activity in the same tissues. No consistent changes in superoxide dismutase (SOD) activity were observed between the control and AN-treatment groups in both tissues. Pretreatment with curcumin reversed the AN-induced effects, reducing the levels of MDA and enhancing CAT activity and increasing reduced GSH content both in the brain and liver. Furthermore, curcumin effectively prevented AN-induced decrease in cytochrome c oxidase activity in both liver and brain. These results establish that curcumin pretreatment has a beneficial role in mitigating AN-induced oxidative stress both in the brains and livers of exposed rats and these effects are mediated independently of cytochrome P450 2E1 inhibition. Accordingly, curcumin should be considered as a potential safe and effective approach in attenuating the adverse effects produced by AN-related toxicants. PMID:19913070

  10. [Study of the termination of two acrylonitrile radicals and infrared spectrum].

    PubMed

    Li, Xin; Yang, Meng-Shi; Xu, Can; Song, Ping-An; Chen, Liang; Du, Hong-Chen; Wang, Yu

    2014-09-01

    By using the density functional theory, the study of reaction termination mechanism of two (CH3)2 (CN)C--CH2-- (CN)CH was carried out at the B3LYP/6-31G(d) level. The initiator AIBN was used. Reactants, coupled intermediates, transition states and disproportionation products were optimized at the B3LYP/6-31G(d) level. Then the total energies corrected by zero-point energy, vibrational frequencies and electronic structures were calculated, the transition states structure was also verified. The results show that it forms the energy-rich adducts a through the coupling termination. Then, the disproportionation product P[p1 (CH3)2 (CN) C-CH=CHCN + p2 (CH3)2 (CN)C-CH2-CH2CN] formed via hydrogen shift and dissociation. The reactions of coupling termination and disproportionation termination are all exothermic reactions, and the coupled product has lower energy. The rate constant of step a?TS?P k(298.15 K) = 2.71 x 10(-59) at the normal atmospheric temperature. Disproportionation termination occurs more easily with the reaction temperature rising, so the proportion of disproportionation products is increasing. Also, the analysis of infrared spectrogram of each species in reaction process shows chemical change of free radicals in the whole termination reaction. The authors give the HOMO-LUMO in this paper to verify the accuracy of biradical coupling termination and structures. It has important guiding significance to controlling the free radicals termination methods of acrylonitrile monomer. PMID:25532320

  11. Acrylonitrile-induced gastric toxicity in rats: The role of xanthine oxidase

    PubMed Central

    Al-Abbasi, Fahad A.

    2012-01-01

    Summary Background Acrylonitrile (ACN) is an extensively produced aliphatic nitrile. The gastrointestinal tract is an important target organ for ACN toxicity. The objective of the present study was to investigate the role of xanthine oxidase (XO) in ACN-induced gastric toxicity in rats. Material/Methods We assessed the effect of ACN on oxidative stress parameters as xanthine oxidase (XO) and total xanthine dehydrogenase (XD)/ XO activity, superoxide anion (O2·?) production, reduced glutathione (GSH) levels and lipid peroxidation in gastric tissues. Results A single oral dose of ACN (25 mg/kg) caused a significant enhancement in XO activity. ACN also caused a significant depletion of GSH levels, enhanced O2·? production and increased lipid peroxidation in the time-course experiment. In the dose-response experiment, ACN accelerated the conversion of XD to XO, with a significant depletion of gastric GSH in a dose-related manner. A strong negative correlation existed between the levels of GSH and the percentage enhancement in XO activity (r =?0.997). (O2·?) production and malondialdehyde (MDA) formation were significantly elevated in a dose-related manner. Pretreatment with allopurinol (50 mg/kg) significantly protected against ACN-induced rise in XO activity, depletion of GSH, and elevated production of (O2·?). However, pretreatment with diethyl maleate (DEM; 100 mg/kg) significantly aggravated the ACN-induced GSH depletion and rise in XO activity. Furthermore, DEM significantly enhanced (O2·?) and MDA production. Conclusions The present study indicates that enhancement of XO activity could be implicated in ACN-induced gastric damage in rats. PMID:22648241

  12. Alkyne as a spectator ligand for the nickel-catalyzed multicomponent connection reaction of diphenylzinc, 1,3-butadiene, aldehydes, and amines.

    PubMed

    Kimura, Masanari; Tatsuyama, Yasushi; Kojima, Keisuke; Tamaru, Yoshinao

    2007-05-10

    Under nickel catalysis, in the presence of 3-hexyne, the aldimines of aromatic amines react with Ph2Zn and one molecule of butadiene to provide 1 exclusively, while the aldimines of aliphatic amines react with Ph2Zn and two molecules of butadiene to provide 2 exclusively, where 3-hexyne serves as a spectator ligand controlling the selective formation of 1 and 2. PMID:17439222

  13. HIGH-KINETIC ENERGY FRAGMENT IONS FROM ALIPHATIC HYDROCARBONS UNDER ELECTRON IMPACT. I. MEASUREMENT AND HIGH-KINETIC ENERGY METHYL IONS FROM 1,3BUTADIENE

    Microsoft Academic Search

    Toshikazu Tsuchiya

    1962-01-01

    A conventional analytical mass spectrometer was used to study methyl ; ions with excess kinetic energy produced from six hydrocarbons: ethane, propane, ; n-butane, iso-butane, propylene, and 1,3-butadiene. An appreciable part of the m\\/; e = 15 ions of 1,3-butadiene had excess kinetic energy and is explained with a ; mechanism in which a H atom is transferred from the

  14. Comparison of breath, blood and urine concentrations in the biomonitoring of environmental exposure to 1,3-butadiene, 2,5-dimethylfuran, and benzene

    Microsoft Academic Search

    Luigi Perbellini; Andrea Princivalle; Marzia Cerpelloni; Francesco Pasini; Francesco Brugnone

    2003-01-01

    Objectives To investigate and compare alveolar, blood, and urine concentrations of 1,3-butadiene, 2,5 dimethylfuran, and benzene, in non-occupational exposure to these products. Methods Benzene, 2,5-dimethylfuran and 1,3-butadiene were measured in the breath, blood, and urine samples of 61 subjects living in small mountain villages. All 61 were regularly employed as forestry workers. Sampling was done during the long winter-season non-working

  15. Styrene–Divinyl Benzene Copolymers: Synthesis, Characterization, and Their Role in Inorganic Trace Analysis

    Microsoft Academic Search

    T. Prasada Rao; R. S. Praveen; Sobhi Daniel

    2004-01-01

    Styrene–divinyl benzene copolymers are widely used in inorganic trace analysis for solid-phase extraction preconcentration as well as other fields of application. These include nascent, ionic, and chelate incorporated polymeric materials. Furthermore, the chelate incorporation usually is achieved by surface sorption or by grafting via chemical immobilization and in situ polymerization. This review covers various synthetic approaches adopted by various researchers

  16. Durability Assessment of Styrene and Epoxy-based Shape-memory Polymer Resins

    Microsoft Academic Search

    G. P. Tandon; K. Goecke; K. Cable; J. Baur

    2009-01-01

    The present study is a baseline assessment of the durability of styrene- and epoxy-based shape memory polymer resin materials being considered for morphing applications when exposed to service environment. The approach for the experimental evaluation is a measurement of the shape memory properties and elastomeric response before and after separate environmental exposure to (i) water at 49°C for 4 days,

  17. Mechanical and Curing Properties of a Styrene-based Shape Memory Polymer

    Microsoft Academic Search

    Richard Beblo; Korey Gross; Lisa Mauck Weiland

    2010-01-01

    Presented is an experimental investigation into the characteristics of a particular styrene-based shape memory polymer, Veriflex®. Tensile, 3 point bend, and creep tests are conducted yielding the Young’s modulus, yield strength, flexural modulus, flexure strength, and creep modulus of the polymer both above and below the glass transition temperature. The results of the characterization may be used to populate a

  18. Electrolysis of sodium chloride using composite poly(styrene-co-divinylbenzene) cation exchange membranes

    Microsoft Academic Search

    Sharath Savari; Sonny Sachdeva; Anil Kumar

    2008-01-01

    Composite cation exchange membranes are prepared from cross-linked styrene-divinylbenzene copolymers for the electrolysis of sodium chloride to produce sodium hydroxide and chlorine by selective removal of sodium ions. It is prepared from a syrup of the polymer using dual initiating system and is modified with chloroacetic acid to introduce acid functional groups (COO?) on its surface. The effect of the

  19. Breath and blood levels of benzene, toluene, cumene and styrene in non-occupational exposure.

    PubMed

    Brugnone, F; Perbellini, L; Faccini, G B; Pasini, F; Maranelli, G; Romeo, L; Gobbi, M; Zedde, A

    1989-01-01

    Benzene, toluene, cumene and styrene were measured in the breath and blood of two groups of individuals. The first group included individuals belonging to a hospital staff, the second group included chemical workers who were not exposed to the abovementioned chemicals. The chemical workers were examined in plant infirmaries on the morning before the start of the workshift, and the hospital staff in the hospital infirmaries. One environmental air sample was taken in the infirmaries for each individual at the moment of the biological samplings. The environmental concentrations of benzene and styrene were significantly higher in the infirmaries of the chemical plant than in the infirmaries of the hospital. On the other hand, the environmental concentrations of toluene and cumene were not significantly different in the plant infirmaries and in the hospital infirmaries. In the hospital staff the alveolar concentrations of benzene, toluene and styrene were significantly lower than those in the chemical workers. In the hospital staff the blood concentrations of benzene, toluene and styrene were not significantly different from those in the chemical workers. Only the blood cumene concentration was significantly higher in the chemical workers. In hospital staff, smokers showed alveolar and blood concentrations of benzene and toluene that were significantly higher than those measured in the non smoker hospital staff. With reference to chemical workers, only alveolar benzene concentration was significantly higher in smokers than in non smokers.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:2707867

  20. [Significance of laboratory studies of neurobehavioral and developmental toxicities--transgenerational effects of styrene exposure].

    PubMed

    Katakura, Yoko; Kishi, Reiko

    2005-11-01

    Recently, health problems caused by environmental chemical substances present in daily life have been increasing, particularly developmental toxicities, the effects of which often become apparent only after a long developmental period. It is difficult to determine adverse transgenerational effects. Therefore, we must recognize important indices to measure neurobehavioral and developmental effects. The assessment of such effects indices, is difficult and few neurobehavioral data are available compared to teratological data. Thus, through studies using laboratory animals, analyses of the mechanisms, exposure periods, doses and neurobehavioral effects are necessary. We have reviewed studies of the volatile monomer of the organic solvent styrene with regard to reproductive and developmental toxicities in laboratory animals. The styrene monomer crosses through the placenta; however, fetal excretion is less than maternal excretion. Therefore, it seems that a dose of styrene that does not affect the mother may be toxic for the fetus. We reported that exposure to low-dose styrene results in physical and neurobehavioral developmental delays, as well as decreases in enzyme activity and neurotransmitter secretion level. To prevent neurobehavioral toxicity, we need further studies to obtain precise data on chemical-biological interactions developmental toxicity and dose-response relationships. A key step towards effective prevention can also be obtained from studies in which animals are continuously exposed to chemicals for one or more generations. Thereafter, we must extrapolate developmental toxicity data from animals to humans. In this paper, we provide the information on developmental toxicity. PMID:16370350

  1. Borohydrido rare earth complexes as precatalysts for the polymerisation of styrene

    E-print Network

    Paris-Sud XI, Université de

    Borohydrido rare earth complexes as precatalysts for the polymerisation of styrene Philippe Zinck. The activity of such catalytic systems is found to be related to the nature of the rare earth. 1 #12;Polymers rare earth complexes associated to n-butylethylmagnesium. Significative entries are reported Table 1

  2. A FLUORESCENCE BASED ASSAY FOR DNA DAMAGE INDUCED BY STYRENE OXIDE

    EPA Science Inventory

    A rapid and simple assay to detect DNA damage to calf thymus DNA caused by styrene oxide (SO) is reported. This assay is based on changes observed in the melting and annealing behavior of the damaged DNA. The melting annealing process was monitored using a fluorescence indicat...

  3. Effect of the chiral polymer chain in the anionic polymerization of styrene oxide

    Microsoft Academic Search

    Constantin Kazanskij; Michel Reix; Nicolas Spassky

    1979-01-01

    Styrene oxide of different enantiomeric compositions was polymerized in bulk using a potassium alkoxide initiator. A preferential consumption of the enantiomer in excess was observed. The magnitude of this effect depends on the enantiomeric composition of the initial monomer: the more unbalanced is the latter, the stronger is the stereoelection observed. The stereoelective effect was almost completely suppressed by addition

  4. SELECTIVE OXIDATION OF STYRENE TO ACETOPHENONE IN PRESENCE OF IONIC LIQUIDS: JOURNAL ARTICLE

    EPA Science Inventory

    NRMRL-CIN-1649 Namboodiri**, V., Varma*, R.S., Sahle-Demessie*, E., and Pillia**, U. Selective Oxidation of Styrene to Acetophenone in Presence of Ionic Liquids. Green Chemistry (White, J.D. (Ed.), Great Britain: The Royal Society of Chemistry) 4 (2):170-173 (2002). EPA/600/J-02...

  5. Composites of Single-Walled Carbon Nanotubes and Styrene-Isoprene

    E-print Network

    Resasco, Daniel

    /polymer composites involve both polymer and nano- tubes. M. L. P. Ha, B. P. Grady, G. Lolli, D. E. Resasco SchoolComposites of Single-Walled Carbon Nanotubes and Styrene-Isoprene Copolymer Latices Mai L. P. Ha the date Iijima reported about the existence of carbon nanotubes[1] (CNTs), enormous pro- gress has been

  6. ASSESSMENT OF STYRENE EMISSION CONTROLS FOR FRP/C AND BOAT BUILDING INDUSTRIES

    EPA Science Inventory

    The report gives results of an evaluation of several conventional and novel emission control technologies that have been used or could be used to treat styrene emissions from open molding processes in fiberglass-reinforced plastics/composites (FRP/C) and fiberglass boat building ...

  7. EVALUATION OF THE POLYAD FB AIR PURIFICATION AND SOLVENT RECOVERY PROCESS FOR STYRENE REMOVAL

    EPA Science Inventory

    The report gives results of a study evaluating the Polyad fluidized-bed (FB) process for controlling styrene emissions at a representative fiberglass shower stall and bath tub manufacturing plan*t. he process was evaluated using a transport able unit supplied by Weatherly, Inc., ...

  8. Styrene induces an inflammatory response in human lung epithelial cells via oxidative stress and NF-{kappa}B activation

    SciTech Connect

    Roeder-Stolinski, Carmen [UFZ - Helmholtz Centre for Environmental Research, Department of Environmental Immunology, Permoserstrasse 15, D-04318 Leipzig (Germany)], E-mail: carmen.roeder-stolinski@ufz.de; Fischaeder, Gundula [UFZ - Helmholtz Centre for Environmental Research, Department of Environmental Immunology, Permoserstrasse 15, D-04318 Leipzig (Germany)], E-mail: gundula.fischaeder@ufz.de; Oostingh, Gertie Janneke [University of Salzburg, Department of Molecular Biology, A-5020 Salzburg (Austria)], E-mail: geja.oostingh@sbg.ac.at; Feltens, Ralph [UFZ - Helmholtz Centre for Environmental Research, Department of Environmental Immunology, Permoserstrasse 15, D-04318 Leipzig (Germany)], E-mail: ralph.feltens@ufz.de; Kohse, Franziska [UFZ - Helmholtz Centre for Environmental Research, Department of Environmental Immunology, Permoserstrasse 15, D-04318 Leipzig (Germany); Bergen, Martin von [UFZ - Helmholtz Centre for Environmental Research, Department of Proteomics, Permoserstrasse 15, D-04318 Leipzig (Germany)], E-mail: martin.vonbergen@ufz.de; Moerbt, Nora [UFZ - Helmholtz Centre for Environmental Research, Department of Proteomics, Permoserstrasse 15, D-04318 Leipzig (Germany)], E-mail: nora.moerbt@ufz.de; Eder, Klaus [Martin-Luther-University Halle-Wittenberg, Institute of Agricultural and Nutritional Sciences, D-06108 Halle (Saale) (Germany)], E-mail: klaus.eder@landw.uni-halle.de; Duschl, Albert [University of Salzburg, Department of Molecular Biology, A-5020 Salzburg (Austria)], E-mail: albert.duschl@sbg.ac.at; Lehmann, Irina [UFZ - Helmholtz Centre for Environmental Research, Department of Environmental Immunology, Permoserstrasse 15, D-04318 Leipzig (Germany)], E-mail: irina.lehmann@ufz.de

    2008-09-01

    Styrene is a volatile organic compound (VOC) that is widely used as a solvent in many industrial settings. Chronic exposure to styrene can result in irritation of the mucosa of the upper respiratory tract. Contact of styrene with epithelial cells stimulates the expression of a variety of inflammatory mediators, including the chemotactic cytokine monocyte chemoattractant protein-1 (MCP-1). To characterise the underlying mechanisms of the induction of inflammatory signals by styrene, we investigated the influence of this compound on the induction of oxidative stress and the activation of the nuclear factor-kappa B (NF-{kappa}B) signalling pathway in human lung epithelial cells (A549). The results demonstrate that styrene-induced MCP-1 expression, as well as the expression of the oxidative stress marker glutathione S-transferase (GST), is associated with a concentration dependent pattern of NF-{kappa}B activity. An inhibitor of NF-{kappa}B, IKK-NBD, and the anti-inflammatory antioxidant N-acetylcysteine (NAC) were both effective in suppressing styrene-induced MCP-1 secretion. In addition, NAC was capable of inhibiting the upregulation of GST expression. Our findings suggest that the activation of the NF-{kappa}B signalling pathway by styrene is mediated via a redox-sensitive mechanism.

  9. Styrene induces an inflammatory response in human lung epithelial cells via oxidative stress and NF-kappaB activation.

    PubMed

    Röder-Stolinski, Carmen; Fischäder, Gundula; Oostingh, Gertie Janneke; Feltens, Ralph; Kohse, Franziska; von Bergen, Martin; Mörbt, Nora; Eder, Klaus; Duschl, Albert; Lehmann, Irina

    2008-09-01

    Styrene is a volatile organic compound (VOC) that is widely used as a solvent in many industrial settings. Chronic exposure to styrene can result in irritation of the mucosa of the upper respiratory tract. Contact of styrene with epithelial cells stimulates the expression of a variety of inflammatory mediators, including the chemotactic cytokine monocyte chemoattractant protein-1 (MCP-1). To characterise the underlying mechanisms of the induction of inflammatory signals by styrene, we investigated the influence of this compound on the induction of oxidative stress and the activation of the nuclear factor-kappa B (NF-kappaB) signalling pathway in human lung epithelial cells (A549). The results demonstrate that styrene-induced MCP-1 expression, as well as the expression of the oxidative stress marker glutathione S-transferase (GST), is associated with a concentration dependent pattern of NF-kappaB activity. An inhibitor of NF-kappaB, IKK-NBD, and the anti-inflammatory antioxidant N-acetylcysteine (NAC) were both effective in suppressing styrene-induced MCP-1 secretion. In addition, NAC was capable of inhibiting the upregulation of GST expression. Our findings suggest that the activation of the NF-kappaB signalling pathway by styrene is mediated via a redox-sensitive mechanism. PMID:18554678

  10. Accumulation of Polyhydroxyalkanoate from Styrene and Phenylacetic Acid by Pseudomonas putida CA-3

    PubMed Central

    Ward, Patrick G.; de Roo, Guy; O'Connor, Kevin E.

    2005-01-01

    Pseudomonas putida CA-3 is capable of converting the aromatic hydrocarbon styrene, its metabolite phenylacetic acid, and glucose into polyhydroxyalkanoate (PHA) when a limiting concentration of nitrogen (as sodium ammonium phosphate) is supplied to the growth medium. PHA accumulation occurs to a low level when the nitrogen concentration drops below 26.8 mg/liter and increases rapidly once the nitrogen is no longer detectable in the growth medium. The depletion of nitrogen and the onset of PHA accumulation coincided with a decrease in the rate of substrate utilization and biochemical activity of whole cells grown on styrene, phenylacetic acid, and glucose. However, the efficiency of carbon conversion to PHA dramatically increased once the nitrogen concentration dropped below 26.8 mg/liter in the growth medium. When supplied with 67 mg of nitrogen/liter, the carbon-to-nitrogen (C:N) ratios that result in a maximum yield of PHA (grams of PHA per gram of carbon) for styrene, phenylacetic acid, and glucose are 28:1, 21:1, and 18:1, respectively. In cells grown on styrene and phenylacetic acid, decreasing the carbon-to-nitrogen ratio below 28:1 and 21:1, respectively, by increasing the nitrogen concentration and using a fixed carbon concentration leads to lower levels of PHA per cell and lower levels of PHA per batch of cells. Increasing the carbon-to-nitrogen ratio above 28:1 and 21:1 for cells grown on styrene and phenylacetic acid, respectively, by decreasing the nitrogen concentration and using a fixed carbon concentration increases the level of PHA per cell but results in a lower level of PHA per batch of cells. Increasing the carbon and nitrogen concentrations but maintaining the carbon-to-nitrogen ratio of 28:1 and 21:1 for cells grown on styrene and phenylacetic acid, respectively, results in an increase in the total PHA per batch of cells. The maximum yields for PHA from styrene, phenylacetic acid, and glucose are 0.11, 0.17, and 0.22 g of PHA per g of carbon, respectively. PMID:15812037

  11. Metabolic distribution of radioactivity in Sprague–Dawley rats and B6C3F1 mice exposed to 1,3-[2,3- 14C]–butadiene by whole body exposure

    Microsoft Academic Search

    Cindy M Swain; Ewan D Booth; William P Watson

    2003-01-01

    The uptake of 1,3-[2,3-14C]–butadiene and its disposition, measured as radioactivity in urine, faeces, exhaled volatiles and CO2 during and following 6 h whole body exposure to 20 ppm butadiene has been investigated in male Sprague–Dawley rats and B6C3F1 mice. Whilst there were similarities between the two species, the uptake and metabolic distribution of butadiene were somewhat different for rats and

  12. In vivo study of an injectable poly(acrylonitrile)-based hydrogel paste as a bulking agent for the treatment of urinary incontinence

    Microsoft Academic Search

    Pascal Ramseyer; Lionel A. Micol; Eva-Maria Engelhardt; Maria-Chiara Osterheld; Jeffrey A. Hubbell; Peter Frey

    2010-01-01

    Urinary incontinence can be treated by endoscopic injection of bulking agents, however, no optimal therapeutic effect has been achieved upon this treatment yet. In the present study, the development of a injectable poly(acrylonitrile) hydrogel paste is described, and its efficacy and histological behavior, once injected into the submucosal space of the minipig bladder, are evaluated. A device was developed to

  13. Synthesis and characterization of Cr-MSU-1 and its catalytic application for oxidation of styrene

    SciTech Connect

    Liu Hong, E-mail: liuhong@shu.edu.c [Department of Chemical Engineering, Shanghai University, Shanghai 201800 (China); Wang Zhigang [Department of Chemical Engineering, Shanghai University, Shanghai 201800 (China); Hu Hongjiu [College of Science, Shanghai University, Yanchang Road, Shanghai 200072 (China); Liang Yuguang; Wang Mengyang [Department of Chemical Engineering, Shanghai University, Shanghai 201800 (China)

    2009-07-15

    Chromium-containing mesoporous silica material Cr-MSU-1 was synthesized using lauryl alcohol-polyoxyethylene (23) ether as templating agent under the neutral pH condition by two-step method. The sample was characterized by XRD, TEM, FT-IR, UV-Vis, ESR, ICP-AES and N{sub 2} adsorption. Its catalytic performance for oxidation of styrene was studied. Effects of the solvent used, the styrene/H{sub 2}O{sub 2} mole ratio and the reaction temperature and time on the oxidation of styrene over the Cr-MSU-1 catalyst were examined. The results indicate that Cr ions have been successfully incorporated into the framework of MSU-1 and the Cr-MSU-1 material has a uniform worm-like holes mesoporous structure. After Cr-MSU-1 is calcined, most of Cr{sup 3+} is oxidized to Cr{sup 5+} and Cr{sup 6+} in tetrahedral coordination and no extra-framework Cr{sub 2}O{sub 3} is formed. The Cr-MSU-1 catalyst is highly active for the selective oxidation of styrene and the main reaction products over Cr-MSU-1 are benzaldehyde and phenylacetaldehyde. Its catalytic performance remains stable within five repeated runs and no leaching is noticed for this chromium-based catalyst. - Graphical abstract: Mesoporous Cr-MSU-1 with worm-like holes was synthesized by a novel two-step method. The Cr-MSU-1 material is highly active and stable for the selective oxidation of styrene.

  14. Theoretical study of the regioselectivity of successive 1,3-butadiene Diels-Alder cycloadditions to C{sub 60}

    SciTech Connect

    Sola, M.; Duran, M.; Mestres, J. [Universitat de Girona (Spain)] [Universitat de Girona (Spain)

    1996-09-18

    The possibility of successive Diels-Alder cycloadditions of 1,3-butadiene to C{sub 60} has been studied theoretically by means of the AM1 semiempirical method. The nine unique possible reaction pathways leading to the experimentally observed T{sub h}-symmetric hexakisadduct have been described, and the most thermodynamically favored has been analyzed in more detail. The enthalpy barrier for the cycloaddition changes from 16.2 kcal/mol in the formation of the monoadduct to 17.8 kcal/mol for the hexakisadduct, increasing slightly with successive attacks. However, once the hexakisadduct is reached, addition of a new 1,3-butadiene has an enthalpy barrier as high as 35.5 kcal/mol, in agreement with the fact that experimentally the heptakisadduct has not yet been observed. 26 refs., 2 figs., 2 tabs.

  15. Low-temperature 1,3-butadiene hydrogenation over supported Pt\\/3d\\/?-Al 2O 3 bimetallic catalysts

    Microsoft Academic Search

    William W. Lonergan; Xianjie Xing; Renyang Zheng; Suitao Qi; Benjamin Huang; Jingguang G. Chen

    2011-01-01

    Low-temperature 1,3-butadiene hydrogenation is used as a probe reaction to investigate the hydrogenation activity over several ?-Al2O3 supported Pt\\/3d (3d=Co, Ni, Cu) bimetallic catalysts. Batch and flow reactor studies are employed to quantify the kinetic activity and steady-state conversion, respectively, of each catalyst. Transmission electron microscopy (TEM) is utilized to characterize particle sizes and extended X-ray absorption fine structure (EXAFS)

  16. Low-temperature 1 3-butadiene Hydrogenation over Supported Pt\\/3d\\/gamma-Al2O3 Bimetallic Catalysts

    Microsoft Academic Search

    W Lonergan; X Xing; R Zheng; S Qi; B Huang; J Chen

    2011-01-01

    Low-temperature 1,3-butadiene hydrogenation is used as a probe reaction to investigate the hydrogenation activity over several γ-AlâOâ supported Pt\\/3d (3d = Co, Ni, Cu) bimetallic catalysts. Batch and flow reactor studies are employed to quantify the kinetic activity and steady-state conversion, respectively, of each catalyst. Transmission electron microscopy (TEM) is utilized to characterize particle sizes and extended X-ray absorption fine

  17. Time Resolved Microwave Interferometry Measurement of the Electron Density in a Pulsed 1,3Butadiene Discharge

    Microsoft Academic Search

    Ashish Kumar Jindal; Lawrence Overzet; Matthew Goeckner

    2010-01-01

    Pulsed plasmas containing organic precursors are becoming increasingly common for multiple applications. To understand the\\u000a nature of such discharges, in-situ time resolved microwave interferometry measurements of the electron density in a 60 W pulsed\\u000a inductively coupled 1,3-butadiene discharge have been made. Measurements were also made for continuous wave plasmas at 40,\\u000a 50, 60 and 70 W power for comparison. The data shows

  18. Emissions of benzene, toluene, xylenes and 1,3-butadiene from a representative portion of the Australian car fleet

    Microsoft Academic Search

    B. L Duffy; P. F Nelson; Y Ye; I. E Galbally

    1998-01-01

    The exhaust emissions of the air toxics benzene, toluene, total xylenes and 1,3-butadiene have been measured in the cold transient (CT), cold stabilised (CS) and hot transient (HT) phases of the Australian Design Rule (ADR) 37\\/00 Drive cycle for 19 pre-1986 non-catalyst-equipped vehicles fuelled with leaded petrol, and 56 post-1985 catalyst-equipped vehicles fuelled with unleaded petrol. Per vehicle exhaust emissions,

  19. Evaluation of Cancer Tests of 1,3Butadiene Using Internal Dose, Genotoxic Potency, and a Multiplicative Risk Model

    Microsoft Academic Search

    Charlotta Fred; Margareta Tornqvist; Fredrik Granath

    In cancer tests with 1,3-butadiene (BD), the mouse is much more sensitive than the rat. This is considered to be related to the metabolism of BD to the epoxide metabolites, 1,2-epoxy- 3-butene (EB), 1,2:3,4-diepoxybutane, and 1,2-epoxy-3,4- butanediol. This study evaluates whether the large difference in outcome in cancer tests with BD could be predicted quantitatively on the basis of the

  20. Refinement and verification of the physiologically based dosimetry description for acrylonitrile in rats.

    PubMed

    Kedderis, G L; Teo, S K; Batra, R; Held, S D; Gargas, M L

    1996-10-01

    The physiologically based dosimetry description for acrylonitrile (ACN) and its mutagenic epoxide metabolite 2-cyanoethylene oxide (CEO) in F-344 rats (M. L. Gargas, M. E. Anderson, S.K.O. Teo, R. Batra, T. R. Fennell, and G. L. Kedderis, 1995, Toxicol. Appl. Pharmacol. 134, 185-194) has been refined to include a physiological stomach compartment and the reactions of ACN with tissue glutathione (GSH). The second-order rate constant for reaction of ACN and GSH at pH 7.3 was measured and included in the dosimetry description. Metabolic parameters for ACN and CEO were estimated from oral bolus pharmacokinetic studies and previously obtained iv bolus data (3.4, 47, 55, or 84 mg ACN/kg). Rats were given bolus oral doses of 3, 10, or 30 mg ACN/kg in water, and blood samples were collected at selected time points. ACN and CEO blood concentrations were determined by gas chromatography. The brain and liver concentrations of ACN and CEO were also measured after 10 mg ACN/kg po. ACN elimination from blood was described by saturable P450 epoxidation (Vmax of 5.0 mg/hr/kg and K(M) of 1.5 mg/liter) and first-order GSH conjugation (73 hr(-1)/kg). CEO elimination was described by first-order GSH conjugation (500 hr(-1)/kg). The pharmacokinetic data were well simulated, although CEO blood concentrations after bolus oral dosing were somewhat overestimated. Sensitivity analysis of the dosimetry description indicated that the inhalation exposure route was much more sensitive to changes in metabolic and physiological parameters than either the iv or oral bolus routes. Therefore, inhalation pharmacokinetic data were obtained and compared to simulations of the dosimetry description. Rats were exposed to 186, 254, or 291 ppm ACN for 3 hr. ACN and CEO concentrations were measured in blood, brain, and liver at selected postexposure time points. The dosimetry description accurately simulated the ACN inhalation pharmacokinetic data, providing verification of the parameter estimates. The verified rat dosimetry description for ACN and CEO will be used as the basis for development of a dosimetry description for ACN in people. PMID:8887460

  1. Two-year toxicity and oncogenicity study with acrylonitrile incorporated in the drinking water of rats.

    PubMed

    Quast, John F

    2002-06-24

    Sprague-Dawley rats (80 per sex per control and 48 per sex in each treatment group) were given drinking water formulated to contain 0, 35, 100, or 300 ppm acrylonitrile (AN) for up to 2-years. An additional ten rats per sex per group were added for a 1-year interim necropsy. The equivalent doses of AN consumed were 0, 3.4, 8.5, and 21.3 mg/kg per day for males and 0, 4.4, 10.8, and 25.0 for females. Rats were closely monitored clinically with body weight, feed and water consumption measured at numerous intervals. Hematology, clinical chemistry, and urinalysis were evaluated six times. All rats were necropsied when moribund, found dead, or at scheduled termination, with extensive histopathology of all rats. Numerous adverse toxic and oncogenic effects were observed in both sexes of all AN treatment groups. Decreased water consumption, feed consumption, and concomitant body weight suppression occurred within days of study initiation and persisted throughout the study in all treatment groups. An early onset of Zymbal gland tumors in high dose male and female rats, and in the mammary gland of all treated groups of females, was detected in-life. Hematology, clinical chemistry, and urinalysis, repeatedly evaluated, were without significant biological effects, except for an increased urine specific gravity due to the rats lower water intake. Organ weights at study termination were not significantly affected. Mortality was high in all female treated groups, with no surviving male or female 300 ppm rats during the last 2 months of the study. The most significant findings in this study were detected following gross and microscopic examination of an extensive list of tissues from all rats in the study. Nontumorous and tumorous lesions were found at an increased and/or decreased rate in a number of tissues of both sexes at all treatment levels. The primary nontumorous histopathologic effects of AN exposure occurred in the forestomach and the central nervous system of rats of both sexes and involved all treatment groups. A statistically significant increased incidence of tumors in one or more dose levels of either sex occurred in the central nervous system, Zymbal gland, forestomach, tongue, small instestine, and mammary gland. A no-observed-effect level (NOEL) was not identified in this study for toxicity or oncogenicity in either sex. PMID:12044703

  2. Effect of equivalent weight on electrochemical mass transport properties of oxygen in proton exchange membranes based on sulfonated ?,?,?-trifluorostyrene (BAM®) and sulfonated styrene-(ethylene-butylene)-styrene triblock (DAIS-analytical) copolymers

    Microsoft Academic Search

    V. I. Basura; C. Chuy; P. D. Beattie; S. Holdcroft

    2001-01-01

    Mass transport parameters and limiting current densities are determined for a series of sulfonated ?,?,?-trifluorostyrene-co-substituted-?,?,?-trifluorostyrene (BAM®) (EW 407-735 g mol?1) and sulfonated styrene-(ethylene-butylene)-styrene copolymers (DAIS-Analytical) (EW 585–1062 g mol?1) proton exchange membranes using microelectrode techniques. These materials were investigated in an environment that mimics proton exchange membrane fuel cells. The oxygen diffusion coefficient increases with temperature, while its solubility decreases.

  3. Borane and borohydride complexes of the rare-earth elements: synthesis, structures, and butadiene polymerization catalysis.

    PubMed

    Jenter, Jelena; Meyer, Nils; Roesky, Peter W; Thiele, Sven K-H; Eickerling, Georg; Scherer, Wolfgang

    2010-05-10

    The reaction of potassium 2,5-bis[N-(2,6-diisopropylphenyl)iminomethyl]pyrrolyl [(dip(2)-pyr)K] with the borohydrides of the larger rare-earth metals, [Ln(BH(4))(3)(thf)(3)] (Ln=La, Nd), afforded the expected products [Ln(BH(4))(2)(dip(2)-pyr)(thf)(2)]. As usual, the trisborohydrides reacted like pseudohalide compounds forming KBH(4) as a by-product. To compare the reactivity with the analogous halides, the dimeric neodymium complex [NdCl(2)(dip(2)-pyr)(thf)](2) was prepared by reaction of [(dip(2)-pyr)K] with anhydrous NdCl(3). Reaction of [(dip(2)-pyr)K] with the borohydrides of the smaller rare-earth metals, [Sc(BH(4))(3)(thf)(2)] and [Lu(BH(4))(3)(thf)(3)], resulted in a redox reaction of the BH(4) (-) group with one of the Schiff base functions of the ligand. In the resulting products, [Ln(BH(4)){(dip)(dip-BH(3))-pyr}(thf)(2)] (Ln=Sc, Lu), a dinegatively charged ligand with a new amido function, a Schiff base, and the pyrrolyl function is bound to the metal atom. The by-product of the reaction of the BH(4) (-) anion with the Schiff base function (a BH(3) molecule) is trapped in a unique reaction mode in the coordination sphere of the metal complex. The BH(3) molecule coordinates in an eta(2) fashion to the metal atom. The rare-earth-metal atoms are surrounded by the eta(2)-coordinated BH(3) molecule, the eta(3)-coordinated BH(4) (-) anion, two THF molecules, and the nitrogen atoms from the Schiff base and the pyrrolyl function. All new compounds were characterized by single-crystal X-ray diffraction. Low-temperature X-ray diffraction data at 6 K were collected to locate the hydrogen atoms of [Lu(BH(4)){(dip)(dip-BH(3))-pyr}(thf)(2)]. The (DIP(2)-pyr)(-) borohydride and chloride complexes of neodymium, [Nd(BH(4))(2)(dip(2)-pyr)(thf)(2)] and [NdCl(2)(dip(2)-pyr)(thf)](2), were also used as Ziegler-Natta catalysts for the polymerization of 1,3-butadiene to yield poly(cis-1,4-butadiene). Very high activities and good cis selectivities were observed by using each of these complexes as a catalyst in the presence of various cocatalyst mixtures. PMID:20397155

  4. Rhodium-Catalyzed Alkylation of C-H Bonds in Aromatic Amides with Styrenes via Bidentate-Chelation Assistance.

    PubMed

    Shibata, Kaname; Yamaguchi, Takuma; Chatani, Naoto

    2015-07-17

    Rhodium-catalyzed alkylation reactions of aromatic C-H bonds in aromatic amides with styrene derivatives have been developed by using an 8-aminoquinoline as a bidentate directing group. C-C bond formation selectively occurred between the ortho C-H bonds in aromatic amides and the terminal carbon of the styrene derivatives. The presence of an 8-aminoquinoline moiety is essential for the success of the reaction. PMID:26125539

  5. Mild silver-mediated geminal difluorination of styrenes using an air- and moisture-stable fluoroiodane reagent.

    PubMed

    Ilchenko, Nadia O; Tasch, Boris O A; Szabó, Kálmán J

    2014-11-17

    An air- and moisture-stable fluoroiodane in the presence of AgBF4 is suitable for selective geminal difluorination of styrenes under mild reaction conditions. One of the C?F bonds is formed by transfer of electrophilic fluorine from the hypervalent iodine reagent, while the other one arises from the tetrafluoroborate counterion of silver. Deuterium-isotope-labelling experiments and rearrangement of methyl styrene substrates suggest that the reaction proceeds through a phenonium ion intermediate. PMID:25335468

  6. Determination of migration monomer styrene from GPPS (general purpose polystyrene) and HIPS (high impact polystyrene) cups to hot drinks.

    PubMed

    Khaksar, Mohammad-Reza; Ghazi-Khansari, Mahmoud

    2009-03-01

    In this study, 162 samples were analysed for monomer styrene content with using high performance liquid chromatography (HPLC) method in hot tea, milk, cocoa milk. The monomer styrene content, expressed in microg/l of drink and the level of migration of styrene monomer were varied from 0.61 to 8.15 for hot tea, from 0.65 to 8.30 for hot milk, from 0.71 to 8.65 for hot cocoa milk in GPPS (general purpose polystyrene), from 0.48 to 6.85 for hot tea, from 0.61 to 7.65 for hot milk, from 0.72 to 7.78 for hot cocoa milk in HIPS (high performance polystyrene) cups in different temperatures and times. The estimated limit of detection of (HPLC) method for all samples was 0.001 mg/kg. There is linear regression for styrene monomer from 1 to 10 ng/ml. Several samples spiked with a known amount of styrene monomer. The results of the recovery in study for styrene monomer were determinate to be mean, 96.1 +/- 1.92 to 99.7 +/- 1.15%. The results of this study indicate that styrene monomer from polystyrene disposable into hot and fat drinks was migrated and this migration was highly dependent on fat content and temperature of drinks. The derived concentration of styrene monomer in this study was above the EPA (Environmental protection agency) recommended level, especially in MCLG (Maximum contaminant level goal) standard. More study is needed to further elucidate this finding. PMID:19750020

  7. Determination of migration monomer styrene from GPPS (general purpose polystyrene) and HIPS (high impact polystyrene) cups to hot drinks

    PubMed Central

    Khaksar, Mohammad-Reza; Ghazi-Khansari, Mahmoud

    2009-01-01

    In this study, 162 samples were analysed for monomer styrene content with using high performance liquid chromatography (HPLC) method in hot tea, milk, cocoa milk. The monomer styrene content, expressed in ?g/l of drink and the level of migration of styrene monomer were varied from 0.61 to 8.15 for hot tea, from 0.65 to 8.30 for hot milk, from 0.71 to 8.65 for hot cocoa milk in GPPS (general purpose polystyrene), from 0.48 to 6.85 for hot tea, from 0.61 to 7.65 for hot milk, from 0.72 to 7.78 for hot cocoa milk in HIPS (high performance polystyrene) cups in different temperatures and times. The estimated limit of detection of (HPLC) method for all samples was 0.001 mg/kg. There is linear regression for styrene monomer from 1 to 10 ng/ml. Several samples spiked with a known amount of styrene monomer. The results of the recovery in study for styrene monomer were determinate to be mean, 96.1 ± 1.92 to 99.7 ± 1.15%. The results of this study indicate that styrene monomer from polystyrene disposable into hot and fat drinks was migrated and this migration was highly dependent on fat content and temperature of drinks. The derived concentration of styrene monomer in this study was above the EPA (Environmental protection agency) recommended level, especially in MCLG (Maximum contaminant level goal) standard. More study is needed to further elucidate this finding. PMID:19750020

  8. 40 CFR Table 5 to Subpart Jjj of... - Group 1 Storage Vessels at New Affected Sources Producing the Listed Thermoplastics

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...Thermoplastics Thermoplastic Chemical a Vessel capacity(cubic meters) Vapor pressure b (kilopascals) ASA/AMSAN c Styrene/ acrylonitrile mixture ? 3.78 ? 0.47 Acrylonitrile ? 75.7 ? 1.62 SAN, continuous d All...

  9. Synthesis of lanthanum-doped MCM-48 molecular sieves and its catalytic performance for the oxidation of styrene.

    PubMed

    Zhan, Wangcheng; Guo, Yanglong; Wang, Yanqin; Liu, Xiaohui; Guo, Yun; Wang, Yunsong; Zhang, Zhigang; Lu, Guanzhong

    2007-10-25

    Lanthanum-doped MCM-48 molecular sieves with different La contents were synthesized hydrothermally and characterized by X-ray diffraction (XRD), nitrogen sorption, transmission electron microscopy (TEM), UV-visible spectroscopy, and Fourier transform infrared (FT-IR) spectroscopy. The results show that the majority of La cations have been incorporated into the framework of MCM-48 molecular sieves. When the molar ratio of La/Si is >0.039 in the sample, some of lanthanum species exist in the extraframework. Compared with pure silicate MCM-48, lanthanum-doped MCM-48 samples show the medium strong acidity that is due to the incorporation of La in the framework of silica. In the oxidation of styrene with H(2)O(2) as the oxidant over the lanthanum-doped MCM-48 catalysts, benzaldehyde is the main product with a small amount of styrene oxide. The La content in the catalysts, reaction temperature, reaction time, and solvent affect greatly the catalytic oxidation of styrene. The conversion of styrene and the selectivity to styrene oxide increase noticeably when a small amount of NaOH aqueous solution is added into the reaction mixture. Ln-doped MCM-48 catalysts with 14 kinds of rare earth elements were synthesized hydrothermally and evaluated for the oxidation of styrene. The results show that their catalytic performance is tremendously different and depends on the nature of rare earth elements doped in the MCM-48 mesoporous materials. PMID:17914798

  10. Enhanced styrene recovery from waste polystyrene pyrolysis using response surface methodology coupled with Box-Behnken design.

    PubMed

    Mo, Yu; Zhao, Lei; Wang, Zhonghui; Chen, Chia-Lung; Tan, Giin-Yu Amy; Wang, Jing-Yuan

    2014-04-01

    A work applied response surface methodology coupled with Box-Behnken design (RSM-BBD) has been developed to enhance styrene recovery from waste polystyrene (WPS) through pyrolysis. The relationship between styrene yield and three selected operating parameters (i.e., temperature, heating rate, and carrier gas flow rate) was investigated. A second order polynomial equation was successfully built to describe the process and predict styrene yield under the study conditions. The factors identified as statistically significant to styrene production were: temperature, with a quadratic effect; heating rate, with a linear effect; carrier gas flow rate, with a quadratic effect; interaction between temperature and carrier gas flow rate; and interaction between heating rate and carrier gas flow rate. The optimum conditions for the current system were determined to be at a temperature range of 470-505°C, a heating rate of 40°C/min, and a carrier gas flow rate range of 115-140mL/min. Under such conditions, 64.52% WPS was recovered as styrene, which was 12% more than the highest reported yield for reactors of similar size. It is concluded that RSM-BBD is an effective approach for yield optimization of styrene recovery from WPS pyrolysis. PMID:24491383

  11. Quaternized poly (styrene-co-vinylbenzyl chloride) anion exchange membranes for alkaline water electrolysers

    NASA Astrophysics Data System (ADS)

    Vengatesan, S.; Santhi, S.; Jeevanantham, S.; Sozhan, G.

    2015-06-01

    In this study, poly (ST-co-VBC) based anion exchange membranes with different styrene to VBC ratios (1: 0.16, 1: 0.33 and 1: 1) have been prepared via chloromethylation-free synthetic route using aromatic vinyl monomers. The synthesized co-polymers are identified by FTIR and 1H-NMR analysis. Hydroxide (OH-) ion conductivity of the anion exchange membrane with styrene to VBC ratio of 1: 0.33 is as high as 6.8 × 10-3 S cm-1 in de-ionised water at 25 °C. The membrane also acquires the ion-exchange capacity of 2.14 meq. g-1, and the water uptake of 127%. Membrane-electrode-assembly (MEA) using the anion exchange membrane and Ni - foam catalyst demonstrate the current density of 40 mA cm-2 at 2.3 V in a water electrolyser cell.

  12. Damage Resistance of Composites Based on Glass Fibre Reinforced Low Styrene Emission Resins for Marine Applications

    NASA Astrophysics Data System (ADS)

    Perrot, Y.; Baley, C.; Grohens, Y.; Davies, P.

    2007-01-01

    Composites based on glass fiber reinforced low styrene emission polyester resins have been widely used over the last 10 years, in order to meet increasingly strict safety regulations, particularly in the pleasure boat industry. Previous studies of their mechanical properties suggested that although these resins are generally more brittle than traditional orthophthalic polyester resins this did not adversely affect the properties commonly used for quality control (short beam shear and tensile failure strength of mat reinforced composites). In the present paper results from a more detailed study of damage behaviour are presented. Tests include fracture toughness (K Ic ) tests on resins, fibre/matrix interface energy, detection of composite damage initiation in tension by acoustic emission, composite delamnation (G Ic and G IIc ), and low energy impact. Overall the results indicate that the low failure strain of low styrene emission resins results in significantly lower composite damage resistance.

  13. Use of the glycophorin A human mutation assay to study workers exposed to styrene

    SciTech Connect

    Compton-Quintana, P.J.E.; Smith, M.T.; Rappaport, S.M. (Univ. of California, Berkeley (United States)); Jensen, R.H.; Bigbee, W.L.; Grant, S.G.; Langlois, R.G. (Lawrence Livermore National Lab., CA (United States))

    1993-03-01

    The glycophorin A (GPA) assay is a human mutation assay that is potentially useful for large epidemiological studies. The assay is rapid and requires a minimal amount of blood, which can be stored before analysis. The data presented here were collected from workers exposed to styrene in a boat manufacturing plant. This study was the first to apply the GPA assay to an occupationally exposed population. Subjects with a mean styrene exposure of 30 ppM had a higher frequency of GPA N[Phi] variant cells than subjects with mean exposure of 1 ppM, but the subjects differed in respect to smoking and age distribution. Results indicate that the original 1-W-1 version of the assay many not be suitable for studies of small numbers of exposed subjects due to variability and artifacts. The newer BR6 version, however, has much lower variability and shows promise for use in the occupational setting. 15 refs., 3 figs.

  14. Synthesis and properties study of the uniform nonspherical styrene/methacrylic acid copolymer latex particles.

    PubMed

    Wang, Wenqin; Ren, Guohong; Yang, Yanqiong; Cai, Wujin; Chen, Tao

    2015-01-13

    A facile method to prepare the nonspherical amphiphilic random copolymer of poly(styrene-co-methacrylic acid) (poly(St-co-PMAA)) latex particles with well-defined shapes and high yields by one-step batch emulsifier-free polymerization was demonstrated. In our strategy, only varying the molar ratio of styrene (St) to methacrylic acid (MAA), no seed-particles, no cross-linker, and no multistep control procedures were needed. Due to the presence of carboxyl groups on the surface of (poly(St-co-PMAA) latex particles, these latex particles can be used as templates for fabricating core-shell nonspherical functional materials, such as poly(St-co-PMAA)@SiO2 and poly(St-co-PMAA)@polypyrrole). The corresponding nonspherical hollow structures (SiO2 and polypyrrole) could be obtained after removal of the templates. In addition, poly(St-co-PMAA) latex particles exhibit interesting morphologies in ethanol. PMID:25513835

  15. Diffusion and polymerization of styrene in an aqueous solution of potassium persulfate under static conditions

    SciTech Connect

    Oganesyan, A.A.; Boyadzhyan, V.G.; Gritskova, I.A.; Gukasyan, A.V.; Matsoyan, S.G.; Pravednikov, A.N.

    1985-10-01

    The potassium persulfate-initiated polymerization of styrene in a mechanically agitated mixture of water and monomer leads to the formation of a stable, monodisperse latex. In order to explain the mechanism of the stabilization of the latex particles in this system, the authors present a detailed investigation of the polymerization of styrene in a specially constructed electrochemical cell under static conditions. A schematic of the cell is shown. Results show that the capacity of the electrical double layer on the platinum electrode remains constant with time in a system containing only a solution of electrolyte, either K/sub 2/SO/sub 4/ or K/sub 2/S/sub 2/O/sub 8/.

  16. Modification on liquid retention property of cassava starch by radiation grafting with acrylonitrile. I. Effect of ?-irradiation on grafting parameters

    NASA Astrophysics Data System (ADS)

    Kiatkamjornwong, S.; Chvajarernpun, J.; Nakason, C.

    1993-07-01

    Radiation modification on liquid retention properties of native cassava starch, gelatinized at 85°C, by graft copolymerization with acrylonitrile was carried out by mutual irradiation to gamma-rays. A thin aluminum foil was used to cover the inner wall of the reaction vessel, so that the homopolymer concentration was reduced to be less than 1.0% with a distilled water retention value of 665 g/g of the dry weight of the saponified grafted product. Confirmation of graft copolymerization and saponification reactions was made by the infrared spectrophotometric technique. The combined effect of radiation parameters in terms of an irradiation time and a dose rate to the total dose on the extent of the grafting reaction expressed in terms of grafting parameters which directly influenced liquid retention values was evaluated in conjunction with statistical analysis.

  17. Hydrosilylation of n-alkenes and allyl chloride over platinum supported on styrene–divinylbenzene copolymer

    Microsoft Academic Search

    Agata Wawrzy?czak; Micha? Dutkiewicz; Jacek Guli?ski; Hieronim Maciejewski; Bogdan Marciniec; Ryszard Fiedorow

    2011-01-01

    Catalytic performance of styrene–divinylbenzene copolymer-supported platinum catalyst of high crosslinking degree and high surface area was studied in reactions of hydrosilylation of allyl chloride, 1-octene and 1-butene. The catalyst has shown considerably greater stability of catalytic activity than classical active carbon-supported catalyst. In experiments on repeated use of catalysts, the decrease in catalytic activity for hydrosilylation of liquid double bond-containing

  18. Nonisothermal Co-Polymerizing Behavior and Thermal Properties of Methylacyloxylpropyl-POSS with Styrene

    Microsoft Academic Search

    Jungang Gao; Yuanyuan Zhang; Caiyun Zhang

    2010-01-01

    The methylacryloylpropyl-polyhedral oligomeric silsesquioxanes (MAP-POSS) was introduced into the PSt by copolymerization. The copolymerizing kinetics was investigated by non-isothermal DSC. The mechanical loss peak temperature Tp and thermal properties were determined by DMA and TGA. The results show that the compatibility of MAP-POSS with styrene is very well and can copolymerization. The relationship of polymerization Ea and conversion ? be

  19. Thermal degradation of blends of phenyl methacrylate–styrene copolymers with aluminium ethoxide

    Microsoft Academic Search

    Shagufta Zulfiqar; Khalid Masud; Q Ameer

    2002-01-01

    The thermal behaviour of phenyl methacrylate–styrene (PMA–ST) copolymers was studied in the presence of aluminium ethoxide [Al(OC2H5)3]. The blends were investigated in an inert atmosphere using thermogravimetry–differential thermogravimetry (TG–DTG) and under vacuum using thermal volatilisation analysis (TVA). The condensable volatile degradation products from the TVA experiments were separated by sub-ambient TVA and characterized by IR spectroscopy and gas chromatography–mass spectrometry

  20. Selective Oxidation of Styrene in Ionic Liquid and its Reaction Kinetics

    Microsoft Academic Search

    Zhang Zhang; Li Hui; Liu Yürong; Ye Yühua

    2009-01-01

    Selective oxidation of styrene to benzaldehyde by molecular oxygen was investigated, while the brönsted ionic liquid was used as solvent, and the Mn(III)-salen complex as the catalyst, the products obtained were detected by GC. The best process conditions were [Bmim]PF6 to be the solvent and T = 343K, P = 0.5MPa with 0.1% (n\\/n) catalysts. Furthermore, the dynamic model was

  1. Styrene Solubilization and Adsolubilization on an Aluminum Oxide Surface Using Linker Molecules and Extended Surfactants

    Microsoft Academic Search

    Ampira Charoensaeng; David A. Sabatini; Sutha Khaodhiar

    2008-01-01

    The impact of lipophilic linker and extended surfactant properties on admicelle formation and styrene adsolubilization were\\u000a evaluated through adsorption and adsolubilization studies on aluminum oxide. While linker-based systems achieved a higher\\u000a maximum adsorption than extended surfactants, the extended surfactants reached maximum adsorption at a lower aqueous surfactant\\u000a concentration. Results of solubilization and adsolubilization studies are summarized by the extent of

  2. Chronic Toxicity\\/Oncogenicity Study of Styrene in CD Rats by Inhalation Exposure for 104 Weeks

    Microsoft Academic Search

    George Cruzan; Janette R. Cushman; Larry S. Andrews; Geoffrey C. Granville; Keith A. Johnson; Colin J. Hardy; Derek W. Coombs; Pamela A. Mullins; W. Ray Brown

    1998-01-01

    Groups of 70 male and 70 female Charles River CD (Sprague–Dawley-derived) rats were exposed whole body to styrene vapor at 0, 50, 200, 500, or 1000 ppm 6 h\\/day 5 days\\/week for 104 weeks. The rats were observed daily, body weights and food and water consumption were measured periodically, and a battery of hematologic and clinical pathology examinations was conducted

  3. Efficient Synthesis of Octahydrophenanthrene Derivatives with Mild Cascade Reactions of Isochromenylium Tetrafluoroborates and Bifunctional Styrenes.

    PubMed

    Mo, Lei; Wu, Lin-Lin; Wang, Shaozhong; Yao, Zhu-Jun

    2015-07-01

    A highly efficient catalyst-free cascade reaction of air-stable isochromenylium tetrafluoroborates and bifunctional styrenes containing a 1,3-diketone moiety has been developed, affording the corresponding single diastereomeric ocatahydrophenanthrene derivatives (21 examples, up to 86% yield). A cascade process of [4 + 2]-cyclization and subsequent intramolecular nucleophilic addition is proposed to generate the three new C-C bonds diastereoselectively in the reactions. PMID:26098712

  4. Alkyl methacrylate and styrene terpolymers as lubricating oil viscosity index improvers

    Microsoft Academic Search

    Ante Jukic; Elvira Vidovic; Zvonimir Janovic

    2007-01-01

    The properties of styrene\\/dodecyl methacrylate\\/octadecyl methacrylate terpolymers as viscosity index improvers of lubricating\\u000a mineral oils were investigated. Terpolymers of different composition and molar mass were prepared by peroxide-initiated polymerization\\u000a of the monomer mixture in a mineral base oil solution. All the terpolymer solutions in base oil exhibited high kinematic viscosity\\u000a and viscosity index values (> 130), proving their high thickening

  5. Preparation of styrene-acrylate latex used in ultralow VOC building internal wall coating

    Microsoft Academic Search

    Lijun Chen; Fengqin Wu; Xinyu Zhuang; Jian Yang; Rongxian Li

    2008-01-01

    Styrene-acrylate latex with high glass transition temperature (T\\u000a g), low minimum film forming temperature(MFT) and good stability was prepared via core-shell emulsion polymerization. With\\u000a semicontinuous process, high conversion rate of monomer and low gel rate were achieved. The weight ratio of core monomer to\\u000a shell monomer was approximately 1.35. It is found that many factors such as emulsifiers, initiators, reaction

  6. Thermal properties of polymer concrete using glycerol methacrylate\\/styrene system at low temperature

    Microsoft Academic Search

    Akihiro Moriyoshi; Tohru Hirano; Akira Ogasawara; Katsuya Tokumitsu; Shigeki Nagata

    1996-01-01

    This paper describes the results of thermal fracture test and flexural test of polymer concrete using glycerol methacrylate\\/styrene system (GM\\/St) as binder. This concrete can harden at low temperatures. The test also includes polymer concrete using unsaturated polyester resin(UP) and cement concrete. The thermal fracture test was carried out at a constant rate of cooling in order to record stress-temperature

  7. Design and evaluation of a monolithic drug-in-adhesive patch for testosterone based on styrene-isoprene-styrene block copolymer.

    PubMed

    Ma, Jianfang; Wang, Chengxiao; Luo, Huafei; Zhu, Zhuangzhi; Wu, Yubo; Wang, Hao

    2013-07-01

    The purpose of the present study was to design and evaluate a monolithic drug-in-adhesive patch with a novel pressure-sensitive adhesive (PSA) matrix based on styrene-isoprene-styrene (SIS) block copolymer. Testosterone was selected as the model drug. The orthogonal array design for ternary mixtures was employed to optimize the amounts of SIS, C-5 hydrocarbon resin, and liquid paraffin. The drug release percentage, water vapor permeability, adhesive properties were chosen as response variables. The patch formulation was optimized by investigating the effects of the drug loading capacity, the type, and amount of permeation enhancer on the adhesive properties and skin permeation. The compositions of the optimal matrix were: 120 g of SIS copolymer, 120 g of C-5 hydrocarbon resin, 60 g of liquid paraffin. An optimized formulation with maximum skin permeation and acceptable adhesive properties was developed incorporating 2% testosterone and 6% isopropyl myristate. No significant differences for in vitro release, skin permeation, and in vivo absorption were observed between the optimal formulation and Testopatch®. The stability evaluation showed that the patches were stable at 25°C/60% relative humidity for 6 months. The result indicated that SIS copolymer was a suitable and compatible polymer for the development of PSA. PMID:23650152

  8. Local Structure and Ion Transport in Glassy Poly(ethylene oxide styrene) Copolymers

    NASA Astrophysics Data System (ADS)

    Yang, Han-Chang; Mays, Jimmy; Sokolov, Alexei P.; Winey, Karen I.

    2014-03-01

    Polymer electrolytes have attracted attention for a wide variety of applications in energy production such as lithium-ion batteries and fuel cells. The concept of free volume provides important information about ion mobility and chain dynamics in the polymer matrix. Researchers have recently demonstrated that ion transport in glassy polymer can be improved by designing a system with high free volume. We have studied the effect of temperature and humidity on the intermolecular correlations of poly(ethylene oxide styrene-block-styrene) (PEOSt- b-St) block copolymer and poly(ethylene oxide styrene) (PEOSt) homopolymer using in situ multi-angle x-ray scattering across a wide range of scattering angles (q = 0.007-1.5 Å-1) . An increase in backbone-to-backbone distance is observed, indicating an increase in free volume between different polymer main chains. Structural characterization of the polymer segments will be discussed together with conductivity and dielectric results to better understand the ion transport mechanism in the local environment of the polymer system. Department of Chemistry, University of Tennessee.

  9. Pyrolysis of polystyrene - polyphenylene oxide to recover styrene and useful products

    DOEpatents

    Evans, Robert J. (Lakewood, CO); Chum, Helena L. (Arvada, CO)

    1995-01-01

    A process of using fast pyrolysis in a carrier gas to convert a polystyrene and polyphenylene oxide plastic waste to a given polystyrene and polyphenylene oxide prior to pyrolysis of other plastic components therein comprising: selecting a first temperature range to cause pyrolysis of given polystyrene and polyphenylene oxide and its high value monomeric constituent prior to a temperature range that causes pyrolysis of other plastic components; selecting a catalyst and a support and treating the feed stream with the catalyst to affect acid or base catalyzed reaction pathways to maximize yield or enhance separation of high value monomeric constituent of styrene from polystyrene and polyphenylene oxide in the first temperature range; differentially heating the feed stream at a heat rate within the first temperature range to provide differential pyrolysis for selective recovery of the high value monomeric constituent of styrene from polystyrene and polyphenylene oxide prior to pyrolysis of other plastic components; separating the high value monomer constituent of styrene; selecting a second higher temperature range to cause pyrolysis to a different derived high value product of polyphenylene oxide from the plastic waste and differentially heating the feed stream at the higher temperature range to cause pyrolysis of the plastic into a polyphenylene oxide derived product; and separating the different derived high value polyphenylene oxide product.

  10. Ion transport in a chemically prepared polypyrrole/poly(styrene-4-sulfonate) composite

    SciTech Connect

    Li, G.; Pickup, P.G.

    1999-11-18

    The electrochemistry of a chemically prepared polypyrrole/poly(styrene-4-sulfonate) powder has been investigated by cyclic voltammetry and impedance spectroscopy in a variety of aqueous electrolytes. The facile p-doping/undoping of thick layers of the polymer composite is shown to be due to the high ionic conductivity imparted by electrolyte solution in pores. As a consequence, the ionic conductivities of the polymer layers are strongly dependent on the concentration and conductivity of the electrolyte solution used but relatively insensitive to the doping level of the polymer. In contrast, electrochemically prepared polypyrrole/poly(styrene-4-sulfonate) films show much lower ionic conductivities with a pronounced dependence on doping level. It is concluded that layers of the chemically prepared material are approximately 10 times more porous than the electrochemically prepared films. High ionic conductivities previously obtained for polypyrrole/poly(styrene-4-sulfonate) layers bonded to Nafion membranes have been shown to be due to HNO{sub 3} generated in pores by ion exchange of residual Fe{sup 3+} with H{sup +} in the Nafion.

  11. Polymerization of styrene in microemulsions and water-in-oil-in-water emulsions

    SciTech Connect

    Johnson, P.L.

    1984-01-01

    Two types of emulsion polymerization media were studied in the formation of polystyrene: two O/W microemulsions and a WOW emulsion. The microemulsions and isolated polystyrene were studied using photon correlation spectroscopy and time-averaged light scattering. GPC verified the polymer's size distribution and FTIR determined the polymer's end groups. Photomicroscopy was used to size the WOW emulsion droplets. The effect of an oil-soluble, azoisobisbutyronitrile (AIBN), versus water-soluble, potassium persulfate (KPS), free-radical generator in the polymerization of styrene in microemulsions was investigated. The microemulsions contained styrene, brine, sodium dodecyl sulfate (SDS), and pentanol. Under the dilute conditions the microemulsions and lattices were stable and the droplets independent of each other. Both AIBN and KPS produced polystyrene containing two different size fractions; the molecular weight of the two fractions were of the order of magnitude of 10{sup 5} and 10{sup 6}. End group analysis indicated that initiator fragments and alcohol fragments were present in the polystyrene. The WOW emulsions contained styrene, water, Tween 80, and Span 80. The multiple phase emulsion had a polydisperse droplet size distribution with globule diameters ranging from 1 {mu}m to 190 {mu}m. Both single and multiple phase globules were present in the emulsion due to < 100% yield. WOW emulsion polymerization was slower than microemulsion polymerization and the reaction never reached completion. The isolated polymer showed a wide size distribution with an average molecular weight of {approximately} 4.6 {times} 10{sup 5}.

  12. Oxidative Stress Due to (R)Styrene Oxide Exposure and The Role of Antioxidants in Non-Swiss Albino (NSA) Mice

    Microsoft Academic Search

    Anna Meszka-Jordan; Riina Mahlapuu; Ursel Soomets; Gary P. Carlson

    2009-01-01

    Styrene produces lung and liver damage that may be related to oxidative stress. The purpose of this study was to investigate the toxicity of (R)-styrene oxide (R-SO), the more active enantiomeric metabolite of styrene, and the protective properties of the antioxidants glutathione (GSH), N-acetylcysteine (NAC), and 4-methoxy-L-tyrosinyl-?-L-glutamyl-L-cysteinyl-glycine (UPF1) against R-SO-induced toxicity in non-Swiss Albino (NSA) mice. UPF1 is a synthetic

  13. Styrene oxide DNA adducts: in vitro reaction and sensitive detection of modified oligonucleotides using capillary zone electrophoresis interfaced to electrospray mass spectrometry

    Microsoft Academic Search

    Wolfgang Schrader; Michael Linscheid

    1997-01-01

    Styrene is one of the most important synthetic chemicals in the world and is subject to investigations concerning carcinogenicity\\u000a and mutagenicity due to the active metabolite, styrene-7,8-oxide. This epoxide shows a tendency to react, among others, with\\u000a DNA and DNA constituents. The in vitro reaction of styrene oxide with DNA was investigated by cleaving incubated calf thymus\\u000a DNA with two

  14. Microbial production of the aromatic building-blocks (S)-styrene oxide and (R)-1,2-phenylethanediol from renewable resources.

    PubMed

    McKenna, Rebekah; Pugh, Shawn; Thompson, Brian; Nielsen, David R

    2013-12-01

    (S)-Styrene oxide and (R)-1,2-phenylethanediol are chiral aromatic molecular building blocks used commonly as precursors to pharmaceuticals and other specialty chemicals. Two pathways have been engineered in Escherichia coli for their individual biosynthesis directly from glucose. The novel pathways each constitute extensions of the previously engineered styrene pathway, developed by co-expressing either styrene monooxygenase (SMO) or styrene dioxygenase (SDO) to convert styrene to (S)-styrene oxide and (R)-1,2-phenylethanediol, respectively. StyAB from Pseudomonas putida S12 was determined to be the most effective SMO. SDO activity was achieved using NahAaAbAcAd of Pseudomonas sp. NCIB 9816-4, a naphthalene dioxygenase with known broad substrate specificity. Production of phenylalanine, the precursor to both pathways, was systematically enhanced through a number of mutations, most notably via deletion of tyrA and over-expression of tktA. As a result, (R)-1,2-phenylethanediol reached titers as high as 1.23 g/L, and at 1.32 g/L (S)-styrene oxide titers already approach their toxicity limit. As with other aromatics, product toxicity was strongly correlated with a model of membrane accumulation and disruption. This study additionally demonstrates that greater flux through the styrene pathway can be achieved if its toxicity is addressed, as achieved in this case by reacting styrene to less toxic products. PMID:23801570

  15. Mortality, morbidity, and haematological results from a cohort of long-term workers involved in 1,3-butadiene monomer production.

    PubMed Central

    Cowles, S R; Tsai, S P; Snyder, P J; Ross, C E

    1994-01-01

    A retrospective mortality analysis and prospective morbidity and haematological analyses were performed for Shell Deer Park Manufacturing Complex (DPMC) male employees who worked in jobs with potential exposure to 1,3-butadiene from 1948 to 1989. 614 employees qualified for the mortality study (1948-89), 438 of those were still employed during the period of the morbidity study (1982-9), and 429 of those had haematological data available for analysis. Industrial hygiene data from 1979 to 1992 showed that most butadiene exposures did not exceed 10 ppm (eight-hour time weighted average (8 hour TWA)), and most were below 1 ppm, with an arithmetic mean of 3.5 ppm. 24 deaths occurred during the mortality study period. For all causes of death, the standardised mortality ratio (SMR) was 48 (95% confidence interval (95% CI) = 31-72), and the all cancer SMR was 34 (95% CI = 9-87). There were only two deaths due to lung cancer (SMR 42, 95% CI = 5-151) and none due to lymphohaematopoietic cancer (expected = 1.2). Morbidity (illness absence) events of six days or more for the 438 butadiene employees were compared with the rest of the complex. No cause of morbidity was in excess for this group; the all cause standardised morbidity ratio (SMbR) was 85 (95% CI = 77-93) and the all neoplasms SMbR was 51 (95% CI = 22-100). Haematological results for the 429 with laboratory data were compared with results for the rest of the complex. No significant differences occurred between the two groups and the distributions of results between butadiene and non-butadiene groups were virtually identical. These results suggest that butadiene exposures at concentrations common at DPMC in the past 10-20 years do not pose a health hazard to employees. PMID:8199682

  16. Products of the gas-phase reactions of 1,3-butadiene with OH and NO{sub 3} radicals

    SciTech Connect

    Tuazon, E.C.; Alvarado, A.; Aschmann, S.M.; Atkinson, R.; Arey, J.

    1999-10-15

    1,3-Butadiene is emitted into the atmosphere from a number of sources including combustion sources and is listed in the US as a hazardous air pollutant. In the atmosphere, 1,3-butadiene reacts with OH radicals, NO{sub 3} radicals, and O{sub 3} with the dominant tropospheric removal processes being daytime reaction with the OH radical and nighttime reaction with the NO{sub 3} radical. The authors have used gas chromatography, in situ Fourier transform infrared (FT-IR) absorption spectroscopy, and in situ atmospheric pressure ionization tandem mass spectrometry (API-MS) to identify and quantify the products formed from the reactions of 1,3-butadiene with OH radicals (in the presence of NO) and NO{sub 3} radicals. Acrolein, formaldehyde, and furan were identified and quantified from the OH radical-initiated reaction, with formation yields of 0.58 {+-} 0.04, 0.62 {+-} 0.05, and 0.03--0.04, respectively. Organic nitrates were observed by FT-IR spectroscopy with an estimated yield of 0.07 {+-} 0.03, and the API-MS analyses indicated that these organic nitrates are mainly the hydroxynitrate HOCH{sub 2}CH=CHCH{sub 2}ONO{sub 2} and/or its isomers. API-MS analyses showed the formation of a hydroxycarbonyl with the formula C{sub 4}H{sub 6}O{sub 2}, attributed to HOCH{sub 2}CH=CHCHO and/or its isomers. The major products of the NO{sub 3} radical-initiated reaction were organic nitrates; the API-MS analyses indicated the formation of acrolein, 1,2-epoxy-3-butene, and unsaturated C{sub 4}-hydroxycarbonyls, hydroxynitrates, carbonyl nitrates, and nitrooxyhydroperoxides. Acrolein, HCHO, and furan were again quantified by gas chromatographic and FT-IR analyses. The data is compared with previous literature studies, and detailed reaction mechanisms are presented and discussed.

  17. Experimental study of the structure of rich premixed 1,3-butadiene\\/CH4\\/O2\\/Ar flame

    Microsoft Academic Search

    Hadj-Ali Gueniche; Pierre-Alexandre Glaude; René Fournet; Frédérique Battin-Leclerc

    2007-01-01

    The structure of a laminar rich premixed 1,3-C4H6\\/CH4\\/O2\\/Ar flame have been investigated. 1,3-Butadiene, methane, oxygen and argon mole fractions are 0.033; 0.2073; 0.3315, and 0.4280, respectively, for an equivalent ratio of 1.80. The flame has been stabilized on a burner at a pressure of 6.7 kPa (50 Torr). The concentration profiles of stable species were measured by gas chromatography after

  18. Deacetylation and further metabolism of the mercapturic acid of hexachloro-1,3-butadiene by rat kidney cytosol in vitro

    Microsoft Academic Search

    Iona S. Pratt; Edward A. Lock

    1988-01-01

    Hexachloro-1,3-butadiene (HCBD) is more nephrotoxic to female than male rats. Metabolism of HCBD involves conjugation with glutathione followed by formation of the cysteine conjugate S-(pentachloro-1,3-butadienyl) cysteine (PCBD-CYS) and then the mercapturic acid N-acetyl-S-pentachloro-1,3-butadienyl-cysteine (PCBD-NAC). PCBD-NAC is also more nephrotoxic to female rats than male rats. The deacetylation of [14C]-PCBD-NAC to PCBD-CYS and the binding of radiolabelled metabolites to protein has

  19. 32P-postlabeling of 1,3-butadiene and 4-vinyl-1-cyclohexene metabolite-DNA adducts: in vitro and in vivo applications

    Microsoft Academic Search

    Nathalie Mabon; Kurt Randerath

    1996-01-01

    Epoxides of 1,3-butadiene i.e. 1,2-epoxy-3-butene and 1,2:3,4-diepoxybutane are DNA-reactive metabolites. No methods have been reported for detecting DNA adducts of these compounds in exposed animals or humans. The purpose of this study has been to develop a 32P-postlabeling assay for adducts of 1,3-butadiene and its dimer, 4-vinyl-1-cyclohexene. The assay was applied to skin DNA of mice exposed topically to diepoxides

  20. Effects of 1,3-Butadiene, Isoprene, and Their Photochemical Degradation Products on Human Lung Cells

    PubMed Central

    Doyle, Melanie; Sexton, Kenneth G.; Jeffries, Harvey; Bridge, Kevin; Jaspers, Ilona

    2004-01-01

    Because of potential exposure both in the workplace and from ambient air, the known carcinogen 1,3-butadiene (BD) is considered a priority hazardous air pollutant. BD and its 2-methyl analog, isoprene (ISO), are chemically similar but have very different toxicities, with ISO showing no significant carcinogenesis. Once released into the atmosphere, reactions with species induced by sunlight and nitrogen oxides convert BD and ISO into several photochemical reaction products. In this study, we determined the relative toxicity and inflammatory gene expression induced by exposure of A549 cells to BD, ISO, and their photochemical degradation products in the presence of nitric oxide. Gas chromatography and mass spectrometry analyses indicate the initial and major photochemical products produced during these experiments for BD are acrolein, acetaldehyde, and formaldehyde, and products for ISO are methacrolein, methyl vinyl ketone, and formaldehyde; both formed < 200 ppb of ozone. After exposure the cells were examined for cytotoxicity and interleukin-8 (IL-8) gene expression, as a marker for inflammation. These results indicate that although BD and ISO alone caused similar cytotoxicity and IL-8 responses compared with the air control, their photochemical products significantly enhanced cytotoxicity and IL-8 gene expression. This suggests that once ISO and BD are released into the environment, reactions occurring in the atmosphere transform these hydrocarbons into products that induce potentially greater adverse health effects than the emitted hydrocarbons by themselves. In addition, the data suggest that based on the carbon concentration or per carbon basis, biogenic ISO transforms into products with proinflammatory potential similar to that of BD products. PMID:15531432

  1. Quantitative analysis of trihydroxybutyl mercapturic acid, a urinary metabolite of 1, 3-butadiene, in humans

    PubMed Central

    Kotapati, Srikanth; Matter, Brock A.; Grant, Amy L.; Tretyakova, Natalia Y.

    2011-01-01

    1,3-butadiene (BD)* is a known human carcinogen present in cigarette smoke and in automobile exhaust, leading to widespread exposure of human populations. BD requires cytochrome P450-mediated metabolic activation to electrophilic species, e.g. 3,4-epoxy-1-butene (EB), hydroxymethylvinylketone (HMVK), and 3,4-epoxy-1,2-diol (EBD), which form covalent adducts with DNA. EB, HMVK, and EBD can be conjugated with glutathione and ultimately excreted in urine as monohydroxybutenyl mercapturic acid (MHBMA), dihydroxybutyl mercapturic acid (DHBMA), and trihydroxybutyl mercapturic acid (THBMA), respectively, which can serve as biomarkers of BD exposure and metabolic processing. While MHBMA and DHBMA have been found in smokers and non-smokers, THBMA has not been previously detected in humans. In the present work, an isotope dilution HPLC-ESI?-MS/MS methodology was developed and employed to quantify THBMA in urine of known smokers and non-smokers (19–27 per group). The new method has excellent sensitivity (LOQ, 1 ng/mL urine) and achieves accurate quantitation using a small sample volume (100 µl). Mean urinary THBMA concentrations in smokers and non-smokers were found to be 21.6 and 13.7 ng/mg creatinine, respectively, suggesting that there are sources of THBMA other than exposure to tobacco smoke in humans, as is also the case for DHBMA. However, THBMA concentrations are significantly greater in urine of smokers than that of non-smokers (p < 0.01). Furthermore, THBMA amounts in human urine declined 25–50 % following smoking cessation, suggesting that smoking is an important source of this metabolite in humans. The HPLC-ESI?-MS/MS methodology developed in the present work will be useful for future epidemiological studies of BD exposure and metabolism. PMID:21749114

  2. Evaluation of frequencies of HPRT mutant lymphocytes in butadiene polymer workers in a Southeast Texas facility

    PubMed Central

    Wickliffe, Jeffrey K.; Ammenheuser, Marinel M.; Adler, P. Jene; Abdel-Rahman, Sherif Z.; Ward, Jonathan B.

    2009-01-01

    We examined the frequency of mutant lymphocytes (VFs) in workers (n = 30) occupationally exposed to the petrochemical, 1,3-butadiene (BD), using the autoradiographic HPRT mutant lymphocyte assay. Current exposures were determined with organic vapor monitors that had a 12-hour method detection limit (MDL) of 2.5 parts per billion (ppb). HPRT VFs were analyzed with respect to current exposure estimates, age in years, and occupational longevity (OL; defined as years working in the BD industry at this facility). Current exposures were low (mean 93.5 ppb, median 2.5 ppb) with only one individual's estimate (1,683.5 ppb) exceeding the Occupational Safety and Health Administration's permissible exposure limit of 1,000 ppb. The majority (>50%) of current exposures were below the MDL. HPRT VFs were not significantly associated with current exposures (n = 29), and they were not significantly associated with age (n = 29). HPRT VFs were, however, significantly associated with OL (n = 29, R2 = 0.107, p < 0.046). This result suggests that chronic and/or past, high-level exposures might leave a mutagenic signature that is revealed by the HPRT assay, possibly through the retention of mutant, long-term memory T-cells. While it is encouraging that current occupational exposures to BD in this facility do not appear to be increasing the frequency of mutant T-lymphocytes, evidence from workers with a lengthy history in the industry (?30 years in this case) indicates that these individuals likely require additional biomonitoring for possible mutagenic effects resulting from chronic, past exposures. PMID:19107895

  3. Vapor-liquid equilibria for copolymer+solvent systems: Effect of intramolecular repulsion

    SciTech Connect

    Gupta, R.B.; Prausnitz, J.M.

    1995-03-01

    Role of intramolecular interactions in blend miscibility is well documented for polymer+copolymer mixtures. Some copolymer+polymer mixtures are miscible although their corresponding homopolymers are not miscible; for example, over a range of acrylonitrile content, styrene/acrylonitrile copolymers are miscible with poly(methyl methacrylate) but neither polystyrene nor polyacrylonitrile is miscible with poly(methyl methacrylate). Similarly, over a composition range, butadiene/acrylonitrile copolymers are miscible with poly(vinyl chloride) while none of the binary combinations of the homopolymers [polybutadiene, polyacrylonitrile, and poly(vinyl chloride)] are miscible. This behavior has been attributed to ``intramolecular repulsion`` between unlike copolymer segments. We have observed similar behavior in vapor-liquid equilibria (VLE) of copolymer+solvent systems. We find that acrylonitrile/butadiene copolymers have higher affinity for acetonitrile solvent than do polyacrylonitrile or polybutadiene. We attribute this non-intuitive behavior to ``intramolecular repulsion`` between unlike segments of the copolymer. This repulsive interaction is weakened when acetonitrile molecules are in the vicinity of unlike copolymer segments, favoring copolymer+solvent miscibility. We find similar behavior when acetonitrile is replaced by methyl ethyl ketone. To best knowledge, this effect has not been reported previously for VLE. We have obtained VLE data for mixtures containing a solvent and a copolymer as a function of copolymer composition. It appears that, at a given solvent partial pressure, there may be copolymer composition that yields maximum absorption of the solvent. This highly non-ideal VLE phase behavior may be useful for optimum design of a membrane for a separation process.

  4. In vivo study of an injectable poly(acrylonitrile)-based hydrogel paste as a bulking agent for the treatment of urinary incontinence.

    PubMed

    Ramseyer, Pascal; Micol, Lionel A; Engelhardt, Eva-Maria; Osterheld, Maria-Chiara; Hubbell, Jeffrey A; Frey, Peter

    2010-06-01

    Urinary incontinence can be treated by endoscopic injection of bulking agents, however, no optimal therapeutic effect has been achieved upon this treatment yet. In the present study, the development of a injectable poly(acrylonitrile) hydrogel paste is described, and its efficacy and histological behavior, once injected into the submucosal space of the minipig bladder, are evaluated. A device was developed to mix poly(acrylonitrile) hydrogel powder with glycerin, used as carrier, prior to injection into the submucosal space of the bladder. Several paste deposits, depending on the size of the bladder, were injected per animal. The implants were harvested at days 7, 14, 21, 28, 84 and 168 and analyzed morphologically and by histology. The persistence of the implants was demonstrated. However, at later time points the implants were split up and surrounded by granulomatous tissue, which was gradually replaced by histiocytes and adipocytes. Transitory focal urothelial metaplasia was observed only at day 7 and moderate foreign body reaction was detected predominantly between the second and fifth week. This study demonstrated the feasibility to develop an injectable paste of poly(acrylonitrile) hydrogel thought to provide the expected bulking effect, necessary for the treatment of urinary incontinence. PMID:20303170

  5. Bioconversion of Styrene to Poly(hydroxyalkanoate) (PHA) by the New Bacterial Strain Pseudomonas putida NBUS12

    PubMed Central

    Tan, Giin-Yu Amy; Chen, Chia-Lung; Ge, Liya; Li, Ling; Tan, Swee Ngin; Wang, Jing-Yuan

    2015-01-01

    Styrene is a toxic pollutant commonly found in waste effluents from plastic processing industries. We herein identified and characterized microorganisms for bioconversion of the organic eco-pollutant styrene into a valuable biopolymer medium-chain-length poly(hydroxyalkanoate) (mcl-PHA). Twelve newly-isolated styrene-degrading Pseudomonads were obtained and partial phaC genes were detected by PCR in these isolates. These isolates assimilated styrene to produce mcl-PHA, forming PHA contents between 0.05±0.00 and 23.10±3.25% cell dry mass (% CDM). The best-performing isolate was identified as Pseudomonas putida NBUS12. A genetic analysis of 16S rDNA and phaZ genes revealed P. putida NBUS12 as a genetically-distinct strain from existing phenotypically-similar bacterial strains. This bacterium achieved a final biomass of 1.28±0.10 g L?1 and PHA content of 32.49±2.40% CDM. The extracted polymer was mainly comprised of 3-hydroxyhexanoate (C6 ), 3-hydroxyoctanoate (C8 ), 3-hydroxydecanoate (C10 ), 3-hydroxydodecanoate (C12 ), and 3-hydroxytetradecanoate (C14 ) monomers at a ratio of 2:42:1257:17:1. These results collectively suggested that P. putida NBUS12 is a promising candidate for the biotechnological conversion of styrene into mcl-PHA. PMID:25740622

  6. Chronic toxicity and three-generation reproduction study of styrene monomer in the drinking water of rats

    SciTech Connect

    Beliles, R.P.; Butala, J.H.; Stack, C.R.; Makris, S.

    1985-10-01

    Chronic toxicity and reproductive performance were evaluated in groups of rats receiving styrene monomer in their drinking water at nominal concentrations of 0, 125, or 250 ppm. Fifty male and 70 female rats in each test group and 76 males and 104 females in the control group were placed on a 2-year study and followed for observations of general health which included measurement of body weight, food and water consumption, hemograms, clinical chemistries, urinalysis, and histopathological examination. Ten males and 20 females from each group in the study were mated to produce F1 pups. These pups were subsequently mated to produce three generations of offspring, all maintained on styrene-treated drinking water. For each generation, the following were evaluated: fertility, litter size, pup viability, pup survival, sex ratio, pup body weight, weanling liver and kidney weight, and marrow cytogenetics. Except for a statistically significant reduction in water consumption for styrene-treated rats, no treatment-related changes, including mortality patterns, were reported for animals in the chronic study. The data evaluated for reproductive performance also showed no evidence of styrene-related changes. It was concluded that the administration of styrene in the drinking water of rats for 2 years produced no deleterious dose-related effects or decrements in reproductive performance.

  7. Low-temperature 1 3-butadiene Hydrogenation over Supported Pt/3d/gamma-Al2O3 Bimetallic Catalysts

    SciTech Connect

    W Lonergan; X Xing; R Zheng; S Qi; B Huang; J Chen

    2011-12-31

    Low-temperature 1,3-butadiene hydrogenation is used as a probe reaction to investigate the hydrogenation activity over several {gamma}-Al{sub 2}O{sub 3} supported Pt/3d (3d = Co, Ni, Cu) bimetallic catalysts. Batch and flow reactor studies are employed to quantify the kinetic activity and steady-state conversion, respectively, of each catalyst. Transmission electron microscopy (TEM) is utilized to characterize particle sizes and extended X-ray absorption fine structure (EXAFS) measurements are performed to verify the Pt-3d bimetallic bond formation. Pulse carbon monoxide chemisorption measurements are also performed to characterize the number of active sites. Additionally, density functional theory (DFT) calculations are included to determine the binding energies of 1,3-butadiene and atomic hydrogen on the corresponding model surfaces. The binding energies of the adsorbates are found to correlate with the hydrogenation activity, allowing for use of such correlation to potentially predict hydrogenation catalysts with enhanced activity based on the binding energies of the adsorbates of interest.

  8. NIOSH comments to DOL on occupational exposure to 1,3-butadiene by J. D. Millar, February 10, 1992

    SciTech Connect

    Not Available

    1992-02-10

    The post hearing brief concerned the viewpoints of NIOSH regarding laboratory experiments using animals to determine the effects of 1,3-butadiene (106990) (BD). The first area of concern was the use of quantitative risk estimates for butadiene which the Chemical Manufacturers Association (CMA) indicated should be based on the International Institute of Synthetic Rubber Producers, Inc. rat study rather than the low dose National Toxicology Program mouse study. The second point considered was that CMA considered studies of BD uptake which demonstrated that primates retain only 1/10 or 1/30 as much BD as B6C3F1-mice on a per kilogram basis to indicate that humans would be 1/10 or 1/30 as sensitive to BD induced cancers as B6C3F1-mice. The third concern was that CMA concluded that since 1,2-epoxybutene-3 levels are about 500 times lower in primates than in B6C3F1-mice, humans would be expected to be 500 times less susceptible to BD induced cancer. The last point was the advisability of using BW(3/4) scaling from B6C3F1-mice to humans.

  9. Development of a treatment solution for reductive dechlorination of hexachloro-1,3-butadiene in vadose zone soil.

    PubMed

    Yee, Lachlan H; Aagaard, Vibeke; Johnstone, Angela; Lee, Matthew; Kjelleberg, Staffan J; Manefield, Mike

    2010-11-01

    The biodegradation of chlorinated organics in vadose zone soils is challenging owing to the presence of oxygen, which inhibits reductive dehalogenation reactions and consequently the growth of dehalorespiring microbes. In addition, the hydraulic conductivity of vadose zone soils is typically high, hence attempts to remediate such zones with biostimulation solutions are often unsuccessful due to the short residence times for these solutions to act upon the native bacterial community. In this study we have identified sodium alginate as a hydrogel polymer that can be used to increase the residence time of a nutrient solution in an unsaturated sandy soil. Additionally we have identified neutral red as a redox active compound that can catalyse the reductive dechlorination of the chlorinated organic hexachloro-1,3-butadiene by activated sludge fed with lactate and acetate. Finally we have shown that a nutrient solution amended with neutral red and sodium alginate can lower the redox potential and reduce hexachloro-1,3-butadiene concentrations in a contaminated vadose zone soil. PMID:20383654

  10. Melt-processable hydrophobic acrylonitrile-based copolymer systems with adjustable elastic properties designed for biomedical applications.

    PubMed

    Cui, J; Trescher, K; Kratz, K; Jung, F; Hiebl, B; Lendlein, A

    2010-01-01

    Acrylonitrile-based polymer systems (PAN) are comprehensively explored as versatile biomaterials having various potential biomedical applications, such as membranes for extra corporal devices or matrixes for guided skin reconstruction. The surface properties (e.g. hydrophilicity or charges) of such materials can be tailored over a wide range by variation of molecular parameters such as different co-monomers or their sequence structure. Some of these materials show interesting biofunctionalities such as capability for selective cell cultivation. So far, the majority of AN-based copolymers, which were investigated in physiological environments, were processed from the solution (e.g. membranes), as these materials are thermo-sensitive and might degrade when heated. In this work we aimed at the synthesis of hydrophobic, melt-processable AN-based copolymers with adjustable elastic properties for preparation of model scaffolds with controlled pore geometry and size. For this purpose a series of copolymers from acrylonitrile and n-butyl acrylate (nBA) was synthesized via free radical copolymerisation technique. The content of nBA in the copolymer varied from 45 wt% to 70 wt%, which was confirmed by 1H-NMR spectroscopy. The glass transition temperatures (Tg) of the P(AN-co-nBA) copolymers determined by differential scanning calorimetry (DSC) decreased from 58 degrees C to 20 degrees C with increasing nBA-content, which was in excellent agreement with the prediction of the Gordon-Taylor equation based on the Tgs of the homopolymers. The Young's modulus obtained in tensile tests was found to decrease significantly with rising nBA-content from 1062 MPa to 1.2 MPa. All copolymers could be successfully processed from the melt with processing temperatures ranging from 50 degrees C to 170 degrees C, whereby thermally induced decomposition was only observed at temperatures higher than 320 degrees C in thermal gravimetric analysis (TGA). Finally, the melt processed P(AN-co-nBA) biomaterials were sterilized with ethylene oxide and tested for cytotoxicity in direct contact tests with L929 cells according to the EN DIN ISO standard 10993-5. All tested samples exhibited non-toxic effects on the functional integrity of the cell membrane and the mitochondrial activity. However, the morphology of the cells on the samples was different from that observed on polystyrene as control, indicating slightly cytotoxic effects according to the evaluation guide of the US Pharmacopeial Convention. Thus, the melt-processable, hydrophobic P(AN-co-nBA) copolymers with adjustable mechanical properties are promising candidates for in vitro investigations of tissue growth kinetics. PMID:20675924

  11. Engineering of Pseudomonas taiwanensis VLB120 for Constitutive Solvent Tolerance and Increased Specific Styrene Epoxidation Activity

    PubMed Central

    Volmer, Jan; Neumann, Christoph; Schmid, Andreas

    2014-01-01

    The application of whole cells as biocatalysts is often limited by the toxicity of organic solvents, which constitute interesting substrates/products or can be used as a second phase for in situ product removal and as tools to control multistep biocatalysis. Solvent-tolerant bacteria, especially Pseudomonas strains, are proposed as promising hosts to overcome such limitations due to their inherent solvent tolerance mechanisms. However, potential industrial applications suffer from tedious, unproductive adaptation processes, phenotypic variability, and instable solvent-tolerant phenotypes. In this study, genes described to be involved in solvent tolerance were identified in Pseudomonas taiwanensis VLB120, and adaptive solvent tolerance was proven by cultivation in the presence of 1% (vol/vol) toluene. Deletion of ttgV, coding for the specific transcriptional repressor of solvent efflux pump TtgGHI gene expression, led to constitutively solvent-tolerant mutants of P. taiwanensis VLB120 and VLB120?C. Interestingly, the increased amount of solvent efflux pumps enhanced not only growth in the presence of toluene and styrene but also the biocatalytic performance in terms of stereospecific styrene epoxidation, although proton-driven solvent efflux is expected to compete with the styrene monooxygenase for metabolic energy. Compared to that of the P. taiwanensis VLB120?C parent strain, the maximum specific epoxidation activity of P. taiwanensis VLB120?C?ttgV doubled to 67 U/g of cells (dry weight). This study shows that solvent tolerance mechanisms, e.g., the solvent efflux pump TtgGHI, not only allow for growth in the presence of organic compounds but can also be used as tools to improve redox biocatalysis involving organic solvents. PMID:25128338

  12. Influence of 2,2,6,6-tetramethylpiperidine and of 2,2,6,6-tetramethylpiperidine-N-oxide on radically induced styrene polymerization

    Microsoft Academic Search

    Manfred L. Hallensleben; Thomas S. Wibowo; Hellmuth Wurm

    1990-01-01

    The influence of 2, 2, 6, 6-tetramethylpiperidine TMP and the corresponding N-oxide TEMPO on the kinetics of the radical polymerization of styrene in bulk is described. Results reveal that the piperidine TMP acts as a chain transfer agent with ctr=0.014 whereas TEMPO is a strong polymerization inhibitor. TEMPO is formed from TMP during polymerization in air saturated styrene.

  13. A case of acute psychosis in a patient following exposure to a single high dose of styrene.

    PubMed

    Moon, Eunsoo; Suh, Hwagyu; Lee, Byung Dae; Park, Je Min; Lee, Young Min; Jeong, Hee Jeong

    2015-09-01

    We report a case of acute psychotic symptoms following exposure to a single high dose of styrene monomer. The 24-year-old male patient showed psychotic and cognitive symptoms immediately after exposure. His psychotic symptoms included auditory hallucinations and delusions of reference. Brain magnetic resonance imaging, electroencephalography, and laboratory examinations were performed to evaluate any other causes. The clinical, neuroimaging, and laboratory review in this case suggested that the suddenly developed psychotic symptoms that led to chronic deterioration were caused by the single exposure to styrene monomer. This is the first recent report in which acute psychotic symptoms developed from a single high dose of styrene suffocation compared with previous findings showing symptoms because of long-term low-dose exposure. PMID:26184570

  14. Catalytic and hydrodynamic properties of styrene monooxygenases from Rhodococcus opacus 1CP are modulated by cofactor binding.

    PubMed

    Riedel, Anika; Heine, Thomas; Westphal, Adrie H; Conrad, Catleen; Rathsack, Philipp; van Berkel, Willem J H; Tischler, Dirk

    2015-12-01

    Styrene monooxygenases (SMOs) are flavoenzymes catalyzing the epoxidation of styrene into styrene oxide. SMOs are composed of a monooxygenase (StyA) and a reductase (StyB). The latter delivers reduced FAD to StyA on the expense of NADH. We identified Rhodococcus opacus 1CP as the first microorganism to possess three different StyA isoforms occurring in two systems StyA1/StyA2B and StyA/StyB, respectively. The hydrodynamic properties of StyA isozymes were found to be modulated by the binding of the (reduced) FAD cofactor. StyA1 and SyA2B mainly occur as dimers in their active forms while StyA is a monomer. StyA1 showed the highest epoxidation activity and excellent enantioselectivity in aromatic sulfoxidation. The hydrodynamic and biocatalytic properties of SMOs from strain 1CP are of relevance for investigation of possible industrial applications. PMID:26054733

  15. Batch polymerization of styrene and isoprene by n-butyl lithium initiator 

    E-print Network

    Hasan, Sayeed

    1970-01-01

    ler) CP3 MV gse P . January 1970 9&ZS&8 ABSTRACT Batch Polymerization of Styrene and Isoprene By n-Butyl Lithium Initiator. (January 1970) Sayeed 1Iasan, B. Sc. , East Pakistan University of Engineering and Technology, Dacca Directed by: Dr... of his graduate committee. Sincere appreciation is also expressed to Fir. William H. Smii. h, Jr. for his help and suggestions during the purification of the mono- mers and the solvents. Thanks are expressed to Nr. Frank P. Smith, I'ii. ss Sheral L...

  16. Sequencing and functional analysis of styrene catabolism genes from Pseudomonas fluorescens ST.

    PubMed Central

    Beltrametti, F; Marconi, A M; Bestetti, G; Colombo, C; Galli, E; Ruzzi, M; Zennaro, E

    1997-01-01

    The nucleotide sequence of the 4,377-bp chromosomal region of Pseudomonas fluorescens ST that codes for the oxidation of styrene to phenylacetic acid was determined. Four open reading frames, named styA, styB, styC, and styD, were identified in this region. Sequence analysis and biotransformation assays, performed with batch and continuous cultures, allowed us to identify the functions of the sequenced genes. styA and styB encode a styrene monooxygenase responsible for the transformation of styrene to epoxystyrene; styC codes for the second enzyme of the pathway, an epoxystyrene isomerase that converts epoxystyrene to phenylacetaldehyde; and the styD gene produces a phenylacetaldehyde dehydrogenase that oxidizes phenylacetaldehyde to phenylacetic acid. StyA, 415-amino-acids long, was found to be weakly homologous to p-hydroxybenzoate hydroxylase from both P. fluorescens and P. aeruginosa and to salicylate hydroxylase from P. putida, suggesting that it might be a flavin adenine dinucleotide-binding monooxygenase. StyB was found to be partially homologous to the carboxyterminal part of the 2,4-dichlorophenol-6-monooxygenase encoded by plasmid pJP4, while the styC product did not share significant homology with any known proteins. The fourth open reading frame, styD, could encode a protein of 502 amino acids and was strongly homologous to several eukaryotic and prokaryotic aldehyde dehydrogenases. The order of the genes corresponds to that of the catabolic steps. The previously suggested presence of the gene for epoxystyrene reductase, which directly converts epoxystyrene to 2-phenylethanol (A.M. Marconi, F. Beltrametti, G. Bestetti, F. Solinas, M. Ruzzi, E. Galli, and E. Zennaro, Appl. Environ. Microbiol. 61:121-127, 1996), has not been confirmed by sequencing and by biotransformation assays performed in continuous cultures. A copy of the insertion sequence ISI162, belonging to the IS21-like family of elements, was identified immediately downstream of the styrene catabolic genes. PMID:9172343

  17. Scale invariance of the density fluctuations in films and macromolecular aggregates in poly(styrene) solutions

    NASA Astrophysics Data System (ADS)

    Novikov, D. V.; Krasovski?, A. N.; Osmolovskaya, N. A.; Efremov, V. I.

    2007-02-01

    The specific features of the transformation of a polymer solution into a solid state (film) of an amorphous polymer are investigated using electron microscopy. The correspondence between the characteristics of fractal macromolecular aggregates in a solution and the parameters of the spatial distribution of density fluctuations at the surface of the film is established using a linear atactic poly(styrene) as an example. The correspondence exists under the condition that the packing density of coils does not exceed a critical value at the liquid-solid phase transition point and the polymer concentration in the solution provides the formation of a continuous network of entangled macromolecules.

  18. Batch polymerization of styrene and isoprene by n-butyl lithium initiator

    E-print Network

    Hasan, Sayeed

    1970-01-01

    ler) CP3 MV gse P . January 1970 9&ZS&8 ABSTRACT Batch Polymerization of Styrene and Isoprene By n-Butyl Lithium Initiator. (January 1970) Sayeed 1Iasan, B. Sc. , East Pakistan University of Engineering and Technology, Dacca Directed by: Dr...-VI 22 50 51 52 53 55 ?JOE&'M~ 3 CC"VFRSION VS 'O'AJTIJ(F PJOT M01'1OMER CONVI", RS'1('X) VS. REAITI?(F, PLOT FOR RUN-II 57 1. 0 MON)0?iIER CONVERSION VS. REAJTII'!E )Pl. OT FOR R(JN- I. I I IJONOiill'. 'R CONV]. ':RSIO?) VS. Ri'AJ, TIME PLOT...

  19. Interception and characterization of alkyl and acyl complexes in rhodium-catalyzed hydroformylation of styrene.

    PubMed

    Nelsen, Eleanor R; Landis, Clark R

    2013-07-01

    Reaction of [Rh(H)(CO)2(BDP)] (BDP = bis(diazaphospholane)) with styrene at low temperatures enables detailed NMR characterization of four- and five-coordinate rhodium alkyl complexes [Rh(styrenyl)(CO)n(BDP)] presumed to be intermediates in rhodium-catalyzed hydroformylation. The five-coordinate acyl complexes [Rh(C(O)styrenyl)(CO)2(BDP)] are also observed and characterized. The equilibrium distribution of these species suggests an inversion of thermodynamic preference for branched vs linear species from the alkyl to the acyl stage. PMID:23786304

  20. Mössbauer spectroscopic study of FeII-doped sulphonated poly(ether-urethane)—styrene-acrylate copolymer

    NASA Astrophysics Data System (ADS)

    Kamnev, A. A.; Grigoryeva, O. P.; Fainleib, A. M.; Kuzmann, E.

    2013-04-01

    Thermoplastic linear ionomer based on sulphonated poly(ether-urethane)—styrene-acrylate copolymer, doped with natural Fe2 + , was studied by Mössbauer spectroscopy at T = 78 and 290 K to monitor the chemical state of Fe species. The Fe2 + added to aqueous suspension of the system was only partly oxidised in the course of polymer film preparation and drying in air. The oxidised part comprised a magnetic phase (~19 % of total Fe both at T = 78 and 298 K) and a quadrupole doublet (~40 %), while FeII (over 40 %) stabilised in two types of microenvironments.