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Sample records for acrylonitrile butadiene rubber-polyvinyl

  1. 21 CFR 177.1020 - Acrylonitrile/butadiene/sty-rene co-polymer.

    Science.gov (United States)

    2010-04-01

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

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

    Science.gov (United States)

    Severe, Geralda

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

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

    Science.gov (United States)

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

    2014-05-01

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

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

    Science.gov (United States)

    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.

  5. Design and Testing of Digitally Manufactured Paraffin Acrylonitrile-Butadiene-Styrene Hybrid Rocket Motors

    OpenAIRE

    McCulley, Jonathan M.

    2013-01-01

    This research investigates the application of additive manufacturing techniques for fabricating hybrid rocket fuel grains composed of porous Acrylonitrile-butadiene-styrene impregnated with paraffin wax. The digitally manufactured ABS substrate provides mechanical support for the paraffin fuel material and serves as an additional fuel component. The embedded paraffin provides an enhanced fuel regression rate while having no detrimental effect on the thermodynamic burn properties of the fuel g...

  6. STUDY ON THE EPOXY RESIN TOUGHENED BY HYDROXY-TERMINATED BUTADIENE-ACRYLONITRILE COPOLYMER

    Institute of Scientific and Technical Information of China (English)

    HAN Xiaozu; LI Shaoying; ZHANG Qingyu

    1990-01-01

    Toughened epoxy resin with excellent properties was obtained by adding organic acid anhydride curing agent and hydroxy-terminated butadiene-acrylonitrile copolymer (HTBN), which is cheaper than CTBN. The anhydride reacts with both epoxy groups on epoxy resin and hydroxyl groups on HTBN. As a result the soft long chains of HTBN and the rigid chain of epoxy resin form one network, giving the resin toughness. Two-phase structure of the toughened resin was observed by SEM and TEM.

  7. Innovative Application of Biopolymer Keratin as a Filler of Synthetic Acrylonitrile-Butadiene Rubber NBR

    OpenAIRE

    Mirosława Prochoń; Anita Przepiórkowska

    2013-01-01

    The current investigations show the influence of keratin, recovered from the tanning industry, on the thermal and mechanical properties of vulcanizates with synthetic rubber acrylonitrile-butadiene rubber NBR. The addition of waste protein to NBR vulcanizates influences the improvement of resistance at high temperatures and mechanical properties like tensile strength and hardness. The introduction of keratin to the mixes of rubber previously blended with zinc oxide (ZnO) before vulcanization ...

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

    Science.gov (United States)

    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.

  9. Electromechanical responses of poly(3-thiopheneacetic acid/acrylonitrile-butadiene rubbers

    Directory of Open Access Journals (Sweden)

    2008-12-01

    Full Text Available Acrylonitrile-butadiene rubber (NBR and blends of poly(3-thiopheneacetic acid/ acrylonitrile-butadiene rubber, P3TAA/NBR, were fabricated, and the electrorheological properties, dielectric, and electrical conductivities were investigated . The electrorheological properties were determined under an oscillatory shear mode in a frequency range of 0.1 to 100 rad/s at various electric field strengths, from 0 to 2 kV/mm, at a fixed 27°C to observe the effects of acrylonitrile content (ACN in the rubber systems and the conductive particle concentration in the blends. For the pure rubber systems, the storage modulus response (ΔG′ is linearly dependent on its dielectric constant (ε′, and increases with the ACN content. For the NBR/P3TAA blends, the storage modulus response varies nonlinearly with the dielectric constant. The bending responses of the rubbers and the blends were investigated in a vertical cantilever fixture. For the pure rubber system, the bending angle and the dielectrophoresis force vary linearly with electric field strength. For the blend system, the bending angle and the dielectrophoresis force vary nonlinearly with electric field strength.

  10. Flame Retardant Effects of Nano-Clinoptilolite on AcrylonitrileButadiene-Styrene (ABS Nano-Composite

    Directory of Open Access Journals (Sweden)

    Aboulfazl Barati

    2012-01-01

    Full Text Available In recent years, intumescent technology has found a place in polymer science as a method of providing flame retardance to polymeric materials. On heating, fire-retardant intumescent material restricts the action of the heat flux or flame. The proposed mechanism is based on charred layer acting as physical barrier, which slows down heat and mass transfer between the gas and the condensed phases. In this paper, the flammability of intumescent fire-retardant acrylonitrile-butadiene-styrene (ABS matrix composites consisting of hydromagnesite (HMg as an acid source and blowing agent, pentaerythritol (PER as a carbonisation agent and natural zeolite (clinoptilolite rich, Kansar Shargh as a synergistic agent were examined. The flammability of composites was characterized by limiting oxygen index (LOI measurement and horizontal burning tests. A synergistic effect in flame retardancy was observed when natural zeolites were used in combination with HMg and PER.

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

    Science.gov (United States)

    Krzemińska, Sylwia; Rzymski, Władysław M

    2011-01-01

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

  12. Innovative Application of Biopolymer Keratin as a Filler of Synthetic Acrylonitrile-Butadiene Rubber NBR

    Directory of Open Access Journals (Sweden)

    Mirosława Prochoń

    2013-01-01

    Full Text Available The current investigations show the influence of keratin, recovered from the tanning industry, on the thermal and mechanical properties of vulcanizates with synthetic rubber acrylonitrile-butadiene rubber NBR. The addition of waste protein to NBR vulcanizates influences the improvement of resistance at high temperatures and mechanical properties like tensile strength and hardness. The introduction of keratin to the mixes of rubber previously blended with zinc oxide (ZnO before vulcanization process leads to an increase in the cross-linking density of vulcanizates. The polymer materials received including addition of proteins will undergo biodecomposition in natural conditions. After soil test, vulcanizates with keratin especially keratin with ZnO showed much more changes on the surface area than vulcanizates without protein. In that aerobic environment, microorganisms, bacteria, and fungus digested better polymer materials containing natural additives.

  13. Thermo-Physical Properties of Kenaf-Filled Acrylonitrile Butadiene Styrene Composites

    Directory of Open Access Journals (Sweden)

    Nikmatin Siti

    2017-01-01

    Full Text Available Studies on advantageous of natural fillers incorporated into polymer composites on thermo-physical and mechanical properties are still intensively investigated. Several evidences suggest that the natural fillers with small contents combined with polymer increase their composite properties. We thus investigate thermo-physical properties of kenaf-filled acrylonitrile butadiene styrene (ABS composites. ABS with 5% kenaf microparticle size (ABS/K5, ABS with 5% kenaf short fiber (ABS/KSF5, and recycled ABS with 5% kenaf microparticle size (RABS/K5 were manufactured. Granular composites were manufactured by the twin screw extruder. Composite properties in terms of X-ray diffractions, surface morphologies, and thermal behaviors were investigated. The present work found that ABS/KSF5 has the highest degree of crystallinity compared to others. No significant difference was found in terms of thermal properties of the composites.

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

    Directory of Open Access Journals (Sweden)

    Khalil Ahmed

    2015-11-01

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

  15. Experimental Investigations on Tribological Behaviour of Alumina Added Acrylonitrile Butadiene Styrene (ABS Composites

    Directory of Open Access Journals (Sweden)

    T. Panneerselvam

    2016-09-01

    Full Text Available Composite materials are multifunctional in nature, which can be custom-made based on the nature of the applications. The challenge of composite materials lie on complementing the properties of one another i.e. materials which go in the making of composites strengthen each other by inhibiting their weaknesses. Polymers are one of the widely used materials which serve a wide spectrum of engineering needs. In the present work, the tribological behaviour of a composite containing Acrylonitrile Butadiene Styrene (ABS and traces of Alumina is experimentally investigated. Alumina is added to ABS in various percentages such as 1%, and 3% by weight in order to improve the wear resistance of the polymer. Central Composite Design was used to design the experiments and a standard Pin-On-Disk apparatus was used to conduct the experiments. It is observed from the test results that the addition of alumina significantly enhances the wear behavior of the polymer. However, adding more percentage of alumina has led to adverse effect on wear resistance of polymer materials. Abrasive wear mechanism is found to be predominant in the case of alumina added composite materials. It is also found that 1% alumina added composite exhibits excellent wear properties compared to other materials.

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

    Science.gov (United States)

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

    1997-01-01

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

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

    Science.gov (United States)

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

    2009-12-17

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

  18. Study of the Effect of Grafted Antioxidant on the Acrylonitrile-Butadiene Copolymer Properties

    Directory of Open Access Journals (Sweden)

    Abdulaziz Ibrahim Al-Ghonamy

    2010-01-01

    Full Text Available The grafting of ADPEA onto natural rubber was executed with UV radiation. Benzoyl peroxide was used to initiate the free-radical grafting copolymerization. Natural rubber-graft-N-(4-aminodiphenylether acrylamide (NR-g-ADPEA was characterized with an IR technique. The paper aims interested to determine the crosslinking density by using the ultrasonic technique. The ultrasonic velocities of both longitudinal and shear waves were measured in thermoplastic discs of NBR vulcanizates as a function of aging time. Ultrasonic velocity measurements were taken at 2 MHz ultrasonic frequency using the pulse echo method. We studied the effect of aging on the mechanical properties, crosslinking density, and the swelling and extraction phenomena for acrylonitrile-butadiene copolymer (NBR vulcanizates, which contained the prepared NR-g-ADPEA and a commercial antioxidant, N-isopropyl-−-phenyl-p-phenylenediamine. The prepared antioxidant enhanced both the mechanical properties of the NBR vulcanizates and the permanence of the ingredients in these vulcanizates.

  19. Experimental acrylonitrile butadiene styrene and polyamide evisceration implant: a rabbit clinical and histopathology study

    Directory of Open Access Journals (Sweden)

    D.C. Gomes Júnior

    Full Text Available ABSTRACT The purpose of this study was to evaluate acrylonitrile butadiene styrene (ABS and polyamide implants in rabbits submitted to evisceration at the macroscopic and microstructure level and to assess clinical response and histopathological changes as well. For the experimental study implants of 12mm diameter were prepared by rapid prototyping, weighed and the outer and inner surfaces evaluated macroscopically and by electron microscopy. In addition, a compression test was performed and ultrastructural damage was then determined. After evisceration of the left eyeball, nine New Zealand rabbits received ABS implants and nine others received polyamide implants. The animals were assessed daily for 15 days after surgery and every seven days until the end of the study (90 days. Histopathological evaluation was performed at 15, 45 and 90 days after surgery. The ABS implants weighed approximately 0.44g, while the polyamide ones weighed 0.61g. Scanning electron microscopy demonstrated that the ABS implants had regular-sized, equidistant micropores, while the polyamide ones showed micropores of various sizes. The force required to fracture the ABS implant was 14.39 ±0.60 Mpa, while for the polyamide one, it was 16.80 ±1.05 Mpa. Fifteen days after surgery, we observed centripetal tissue infiltration and scarce inflammatory infiltrate. Implants may be used in the filling of anophthalmic cavities, because they are inert, biocompatible and allow tissue integration.

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

    Science.gov (United States)

    Krzemińska, 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.

  1. Microstructure evolution and tribological properties of acrylonitrile-butadiene rubber surface modified by atmospheric plasma treatment

    Science.gov (United States)

    Shen, Ming-xue; Zhang, Zhao-xiang; Peng, Xu-dong; Lin, Xiu-zhou

    2017-09-01

    For the purpose of prolonging the service life for rubber sealing elements, the frictional behavior of acrylonitrile-butadiene rubber (NBR) surface by dielectric barrier discharge plasma treatments was investigated in this paper. Surface microstructure and chemical composition were measured by atomic force microscopy, field-emission scanning electron microscopy, and X-ray photoelectron spectroscopy, respectively. Water contact angles of the modified rubber surface were also measured to evaluate the correlation between surface wettability and tribological properties. The results show that plasma treatments can improve the properties of the NBR against friction and wear effectively, the surface microstructure and roughness of plasma-modified NBR surface had an important influence on the surface tribological behavior, and the wear depth first decreased and then increased along with the change of plasma treatment time. It was found that the wettability of the modified surface was gradually improved, which was mainly due to the change of the chemical composition after the treatment. This study suggests that the plasma treatment could effectively improve the tribological properties of the NBR surface, and also provides information for developing wear-resistant NBR for industrial applications.

  2. THERMAL DECOMPOSITION AND FLAMMABILITY OF ACRYLONITRILE-BUTADIENE-STYRENE/MULTI-WALLED CARBON NANOTUBES COMPOSITES

    Institute of Scientific and Technical Information of China (English)

    Li-fang Tong; Hai-yun Ma; Zheng-ping Fang

    2008-01-01

    Thermal and flammability properties of acrylonitrile-butadiene-styrene copolymer (ABS) with the addition of multi-walled carbon nanotubes (MWNTs) were studied. ABS/MWNTs composites were prepared via melt blending with the MWNTs content varied from 0.2% to 4.0% by mass. Thermogravimetry results showed that the addition of MWNTs accelerated the degradation of ABS during the whole process under air atmosphere, and both onset and maximum degradation temperature were lower than those of pure ABS. The destabilization effect of MWNTs on the thermal stability of the composites became unobvious under nitrogen, and the addition of MWNTs could improve the maximum degradation temperature. The heat release rate and time of ignition (tign) for the composites reduced greatly with the addition of MWNTs especially when the concentration of nanotubes was higher than 1.0%. The accumulation of carbon nanotubes with a network structure was observed and the char layer became thicker with increasing nanotubes concentration. Results from Raman spectra showed a higher degree of graphitization for the residues of ABS/MWNTs composites.

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

    Science.gov (United States)

    McCulley, Jonathan M.

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

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

    Science.gov (United States)

    Ohno, Hiroyuki; Kawamura, Yoko

    2010-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Camille Desrousseaux

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

  6. 21 CFR 177.1030 - Acrylonitrile/butadiene/styrene/methyl methacrylate copolymer.

    Science.gov (United States)

    2010-04-01

    ... as determined by a method titled “Analysis of Cycopac Resin for Residual β-(2-Hydroxyethylmercapto... the range of 13.0 to 16.0 percent as determined by Micro-Kjeldahl analysis. (2) Residual acrylonitrile... a gas chromatographic method titled “Determination of Residual Acrylonitrile and Styrene...

  7. EFFECT OF AMPHIPHILIC POLY (STYRENE-B-ETHYLENE OXIDE) DIBLOCK COPOLYMER INTERCALATED LAYERED SILICATE AS FILLER ON ACRYLONITRILE-BUTADIENE-STYRENE RESIN

    Institute of Scientific and Technical Information of China (English)

    Guo Tianying; Zhang Jie; Hao Guangjie; Song Moudao; Zhang Banghua

    2003-01-01

    The diblock copolymers intercalated layered silicate was prepared via a melt dispersion technique. Then the effect of intercalated hybrid as filler on acrylonitrile- butadiene-styrene resin was characterized by X-ray diffraction, transmission electron microscopy, stress-strain measurements in elongation.

  8. Fittings of unplasticized polyvinyl chloride (PVC-U), chlorinated polyvinyl chloride (PVC-C) or acrylonitrile/butadiene/styrene (ABS) with plain sockets for pipes under pressure - Dimensions of sockets - Metric series

    CERN Document Server

    International Organization for Standardization. Geneva

    1985-01-01

    Fittings of unplasticized polyvinyl chloride (PVC-U), chlorinated polyvinyl chloride (PVC-C) or acrylonitrile/butadiene/styrene (ABS) with plain sockets for pipes under pressure - Dimensions of sockets - Metric series

  9. 丁腈橡胶臭氧化制备羧基丁腈橡胶%Preparation of carboxylated acrylonitrile-butadiene rubber by ozonization of acrylonitrile-butadiene rubber

    Institute of Scientific and Technical Information of China (English)

    刘健; 程斌

    2011-01-01

    Carboxylated acrylnitrile-butadiene rubber(CNBR) was prepared via ozonization of acrylonitrile-butadiene rubber(NBR) in butyl acetate.Effects of reaction time, reaction temperature, the ozone flow rate and NBR concentration on intrinsic viscosity and acid value of CNBR were investigated.The results showed that higher reaction temperature,higher ozone flow rate and lower concentration of NBR could obviously increase the content of carboxylic group in CNBR and shorten the chain length of NBR. However, the factor of reaction time had a different performance. At the beginning, the intrinsic viscosity of CNBR rapidly dropped, but kept unchanged from some moment. And there was no influence of reaction time on acid value of CNBR.%以臭氧氧化丁腈橡胶合成了羧基丁腈橡胶,研究了反应时间、反应温度、臭氧通入量及丁腈橡胶胶液质量浓度对产物特性黏数和酸值的影响.结果表明,以丁腈橡胶臭氧化制备羧基丁腈橡胶,在实验范围内,反应温度升高、增大臭氧通入量和降低丁腈橡胶胶液质量浓度可以提高羧基丁腈橡胶的羧基含量,降低丁腈橡胶的相对分子质量.但是反应时间的影响较为复杂,开始时丁腈橡胶相对分子质量降低很快,到达某个时刻后保持不变.反应时间对羧基丁腈橡胶的酸值没有影响.

  10. Study on Exothermic Oxidation of Acrylonitrile-butadiene-styrene (ABS Resin Powder with Application to ABS Processing Safety

    Directory of Open Access Journals (Sweden)

    Jenq-Renn Chen

    2010-08-01

    Full Text Available Oxidative degradation of commercial grade ABS (Acrylonitrile-butadiene-styrene resin powders was studied by thermal analysis. The instabilities of ABS containing different polybutadiene (PB contents with respect to temperature were studied by Differential Scanning Calorimeter (DSC. Thermograms of isothermal test and dynamic scanning were performed. Three exothermic peaks were observed and related to auto-oxidation, degradation and oxidative decomposition, respectively. Onset temperature of the auto-oxidation was determined to be around 193 °C. However, threshold temperature of oxidation was found to be as low as 140 °C by DSC isothermal testing. Another scan of the powder after degeneration in air showed an onset temperature of 127 °C. Reactive hazards of ABS powders were verified to be the exothermic oxidation of unsaturated PB domains, not the SAN (poly(styrene-acrylonitrile matrix. Heat of oxidation was first determined to be 2,800 ± 40 J per gram of ABS or 4,720 ± 20 J per gram of PB. Thermal hazards of processing ABS powder are assessed by adiabatic temperature rise at process conditions. IR spectroscopy associated with heat of oxidation verified the oxidative mechanism, and these evidences excluded the heat source from the degradation of SAN. A specially prepared powder of ABS without adding anti-oxidant was analyzed by DSC for comparing the exothermic behaviors. Exothermic onset temperatures were determined to be 120 °C and 80 °C by dynamic scanning and isothermal test, respectively. The assessment successfully explained fires and explosions in an ABS powder dryer and an ABS extruder.

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

    Science.gov (United States)

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

    2016-05-01

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

  12. Carboxyl-terminated butadiene-acrylonitrile-toughened epoxy/carboxyl-modified carbon nanotube nanocomposites: Thermal and mechanical properties

    Directory of Open Access Journals (Sweden)

    H. F. Xie

    2012-09-01

    Full Text Available Carboxyl-modified multi-walled carbon nanotubes (MWCNT–COOHs as nanofillers were incorporated into diglycidyl ether of bisphenol A (DGEBA toughened with carboxyl-terminated butadiene-acrylonitrile (CTBN. The carboxyl functional carbon nanotubes were characterized by Fourier-transform infrared spectroscopy and thermogravimetric analysis. Furthermore, cure kinetics, glass transition temperature (Tg, mechanical properties, thermal stability and morphology of DGEBA/CTBN/MWCNT–COOHs nanocomposites were investigated by differential scanning calorimetry (DSC, dynamic mechanical analysis (DMA, universal test machine, thermogravimetric analysis and scanning electron microscopy (SEM. DSC kinetic studies showed that the addition of MWCNT–COOHs accelerated the curing reaction of the rubber-toughened epoxy resin. DMA results revealed that Tg of rubber-toughened epoxy nanocomposites lowered with MWCNT–COOH contents. The tensile strength, elongation at break, flexural strength and flexural modulus of DGEBA/CTBN/MWCNT-COOHs nanocomposites were increased at lower MWCNT-COOH concentration. A homogenous dispersion of nanocomposites at lower MWCNT–COOH concentration was observed by SEM.

  13. Hybrid joining of polyamide and hydrogenated acrylonitrile butadiene rubber through heat-resistant functional layer of silane coupling agent

    Science.gov (United States)

    Sang, Jing; Sato, Riku; Aisawa, Sumio; Hirahara, Hidetoshi; Mori, Kunio

    2017-08-01

    A simple, direct adhesion method was developed to join polyamide (PA6) to hydrogenated acrylonitrile butadiene rubber (HNBR) by grafting a functional layer of a silane coupling agent on plasma functionalized PA6 surfaces. The functional layer of the silane coupling agent was prepared using a self-assembly method, which greatly improved the heat resistance of PA6 from 153 °C up to 325 °C and the resulting PA6/HNBR joints showed excellent adhesion properties with cohesive failure between PA6 and HNBR. X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), and nanoscale infrared microscopy and chemical imaging (Nano-IR, AFM-IR) were employed to characterize the surfaces and interfaces. The Nano-IR analysis method was employed for the first time to analyze the chemical structures of the adhesion interfaces between different materials and to establish the interface formation mechanism. This study is of significant value for interface research and the study of adhesion between resins and rubbers. There is a promising future for heat-resistant functional layers on resin surfaces, with potential application in fuel hose composite materials for the automotive and aeronautical industries.

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

    Science.gov (United States)

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

    2014-12-01

    The objective of this research is flotation separation of polycarbonate (PC) and acrylonitrile-butadiene-styrene (ABS) waste plastics combined with ammonia pretreatment. The PC and ABS plastics show similar hydrophobicity, and ammonia treatment changes selectively floatability of PC plastic while ABS is insensitive to ammonia treatment. The contact angle measurement indicates the dropping of flotation recovery of PC is ascribed to a decline of contact angle. X-ray photoelectron spectroscopy demonstrates reactions occur on PC surface, which makes PC surface more hydrophilic. Separation of PC and ABS waste plastics was conducted based on the flotation behavior of single plastic. At different temperatures, PC and ABS mixtures were separated efficiently through froth flotation with ammonia pretreatment for different time (13 min at 23 °C, 18 min at 18 °C and 30 min at 23 °C). For both PC and ABS, the purity and recovery is more than 95.31% and 95.35%, respectively; the purity of PC and ABS is up to 99.72% and 99.23%, respectively. PC and ABS mixtures with different particle sizes were separated effectively, implying that ammonia treatment possesses superior applicability. Copyright © 2014 Elsevier Ltd. All rights reserved.

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

    Science.gov (United States)

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

    2013-01-01

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

  16. Properties of hydrogenated butadiene-acrylonitrile rubber plasticized by hydroxyl terminated poly (butadiene-co-acrylonitrile)%端羟基液体丁腈橡胶增塑氢化丁腈橡胶的性能

    Institute of Scientific and Technical Information of China (English)

    李再峰; 董慧民; 刘晓丹; 李敏婷; 张成龙; 熊召举

    2011-01-01

    The hydrogenated butadiene-acrylonitrile( HNBR ) was plasticized by hydroxyl terminated poly ( butadiene-co-acrylonitrile ) ( HTBN ), the structure and properties of plasticized rubber were characterized with pulsed nuclear magnetic resonance, differential scanning calorimetry, thermogravimetric analysis and stress-strain test, and the plasticization effect of HTBN was compared with plasticizer TP-95,TP-90 B and TP-759. The results indicated that HTBN worked as the common plasticizer like TP-95, TP-90 B and TP-759, resulting in the decrease of HNBR Mooney viscosity, on the other hand, it worked as a reactive species, the free radical in the vulcanization system intiated the adjacent crosslinking reaction between HTBN double bond and HNBR macromolecular backbone , thus increasing the crosslinking density, tensile strength,modulus at 100% and Shore A hardness of vulcanizates, improving the heat resistance but the glass transition temperature ( no significant change ) .When HTBN was 3 phr, the tensile strength of HNBR vulcanizate reached 41. 7 MPa, the Mooney viscosity was lower and the heat aging property was better.%利用核磁共振仪、差示扫描量热仪、热重分析仪和材料拉伸试验机等研究了端羟基液体丁腈橡胶增塑氢化丁腈橡胶的结构与性能,并与增塑剂TP-95、TP-90 B及TP-759的增塑效果进行了对比.结果表明,端羟基液体丁腈橡胶增塑氢化丁腈橡胶后,一方面起到了与TP-95、TP-90 B和TP-759类似的增塑作用,如降低了混炼胶的门尼黏度;另一方面作为一种反应性增塑剂,在体系中自由基的引发下其结构双键与氢化丁腈橡胶分子主链发生了邻接交联反应,使硫化胶的交联密度、拉伸强度、100%定伸应力和硬度都增大,耐热性能提高,而玻璃化转变温度没有变化.端羟基液体丁腈橡胶用量为3份(质量)时其所增塑氢化丁腈橡胶的拉伸强度高达41.7 MPa,且具有较低的门尼黏度和较好的热老化性能.

  17. Bacterial colonization and endotoxin content of a new renal dialysis water system composed of acrylonitrile butadiene styrene.

    Science.gov (United States)

    du Moulin, G C; Coleman, E C; Hedley-Whyte, J

    1987-06-01

    We measured endotoxin and bacterial levels in tap water, in water purified by reverse osmosis, and in dialysate samples over a 4-month period in a new 10-bed renal dialysis unit. Water treated by reverse osmosis is conducted to the 10 stations through 111 m of piping composed of acrylonitrile butadiene styrene (ABS). All determinations were made prior to the opening of the unit and after the system was purged for 35 h with all bedside station taps open. Formaldehyde disinfection of the piping system was attempted with a recommended protocol after 11 weeks by feeding 2.5 liters of 37% formaldehyde (0.85%, vol/vol) into the delivery system. Prior to water purging, 24 ng of endotoxin per ml was detected. This level decreased to 2.0 ng of endotoxin after the purging. Levels of endotoxin remained below 1.0 ng of endotoxin per ml throughout the duration of the study. In contrast, the level of viable microorganisms recovered from the treated water was approximately 3.5 X 10(4) CFU/100 ml. Even after disinfection of the system, there was no significant decrease in culturable bacteria from the water even though endotoxin levels were lower. Species isolated from the renal dialysis system were predominately pseudomonads, whereas species isolated from the tap water were Bacillus and Flavobacterium species. ABS provides a surface suitable for long-term colonization and growth of bacteria. Currently recommended decontamination protocols are ineffective in removing potentially pathogenic bacteria from ABS pipes and thus constitute an increased risk to patients undergoing dialysis.

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

    Science.gov (United States)

    Jeschke, Gunnar; Schlick, Shulamith

    2006-09-21

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

  19. Preparation of acrylonitrile butadiene rubber by soap-free emulsion polymerization%无皂乳液聚合制备丁二烯-丙烯腈橡胶

    Institute of Scientific and Technical Information of China (English)

    桂强; 梁琨; 钟启林; 马朋高; 张元寿; 王真琴

    2011-01-01

    In this paper,soap-free acrylonitrile butadiene rubber was prepared using sulfate polymerisable emulsifier KD SE-10 by emulsion copolymerization at low temperature. The article studied the influence of the amount of polymerisable emulsifier on mooney viscosity, bound acrylonitrile content, the gel ratio, tensile strength and molecular weight. And the amount of KD SE-10 was determined as 2. 7%~3.0wt%. Acrylonitrile butadiene rubber prepared has the remarkable characteristics of high-strength,excellent oil resistance and narrow molecular weight distribution.%采用硫酸盐类可聚合乳化剂烯丙氧基壬基苯氧基丙醇聚氧乙烯醚硫酸铵(KD SE-10)通过低温乳液聚合法制备无皂丁腈橡胶.详细考察了可聚合乳化剂用量对门尼粘度、结合丙烯腈含量、凝胶量、拉伸强度、相对分子质量的影响情况,并确定了KD SE-10用量为2.7%~3.0%(质量分数).制得的无皂丁腈橡胶相比普通丁腈橡胶具有显著的高强度、更优良的耐油性、相对分子质量分布窄的特点.

  20. Studies on blends of cycloaliphatic epoxy resin with varying concentrations of carboxyl terminated butadiene acrylonitrile copolymer I: Thermal and morphological properties

    Indian Academy of Sciences (India)

    Garima Tripathi; Deepak Srivastava

    2009-04-01

    Differential scanning calorimetric (DSC), thermogravimetric analysis (TGA) and dynamic mechanical analysis (DMA) of the blends of cycloaliphatic epoxy (CAE) resin toughened with liquid elastomer such as carboxyl terminated butadiene acrylonitrile copolymer (CTBN) have been carried out. Exothermal heat of reaction due to cross linking of the resin in the presence of diamino diphenyl sulphone (DDS, an amine hardener) showed a decreasing trend with increasing rubber concentration. Enhancement of thermal stability as well as lower mass loss of the epoxy–rubber blends with increasing rubber concentration have been observed in thermogravimetric analysis (TGA). Dynamic mechanical properties reflected a monotonic decrease in the storage modulus (′) with increasing rubber concentration. The loss modulus (″) and the loss tangent (tan ) values, however, showed an increasing trend with rise of temperature up to a maximum (peak) followed by a gradual fall in both cases.

  1. FINITE ELEMENT SIMULATION FOR YIELD STRESS OF HARD POLY(VINYL CHLORIDE)/ACRYLONITRILE-BUTADIENE-STYRENE BLENDS AT DIFFERENT CROSSHEAD SPEEDS

    Institute of Scientific and Technical Information of China (English)

    Pei-hua Du; Jie Yu; Peng-fei Lin; Yi-hu Song; Qiang Zneng

    2011-01-01

    Hard poly(vinyl chloride) (PVC)/acrylonitrile-butadiene-styrene (ABS) blends were prepared using injectionmolding and influence of crosshead speed on mechanical properties was examined.Based on morphology parameters obtained from transmission electron microscopy photography and the material parameters from true stress-strain curves of neat PVC and ABS,yield stresses of the blends at different crosshead speeds were simulated employing a two-dimensional nine-particle model based on the finite element analysis (FEA).The FEA results were compared with the experimental yielding stress and the good agreement validated the simulation approach.The FEA approach allowed establishing a yielding criterion related to local yielding of the interstitial matrix between ABS particles.

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

    Science.gov (United States)

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

    2009-02-01

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

  3. Preparation and Characterization of Carboxyl-terminated Poly (butadiene-co-acrylonitrile)-epoxy Resin Prepolymers for Fusion-bonded-epoxy Powder Coating

    Institute of Scientific and Technical Information of China (English)

    LIU Jingcheng; JIA Xiuli; ZHANG Shengwen; LIU Ren; LIU Xiaoya

    2012-01-01

    Liquid carboxyl-terminated poly(butadiene-co-acrylonitrile)(CTBN)-epoxy resin(EP)prepolymers were prepared with different contents of CTBN.The chemical reactions between EP and CTBN were characterized by Fourier ransform infrared (FTIR) spectroscopy and gel permeation chromatography (GPC).The scanning electron micrograph (SEM) and dynamic mechanical analysis (DMA) of curing films showed phase separation,and the rubber particles were finely dispersed in the epoxy matrix.Mechanical properties analysis of curing films showed that impact strength and elongation at break increased significantly upon the addition of CTBN,indicating good toughness of the modified epoxy resins.Thermogravimetric analysis (TGA) showed that the incorporation of CTBN had little effect on the thermal stability of EP.Fusion-bondedepoxy (FBE) powder coatings modified with CTBN-EP prepolymers were prepared.The experimental results demonstrate the ability of CTBN-EP prepolymers,toughening technology to dramatically enhance the flexibility and impact resistance of FBE coatings without compromising other key properties such as corrosion protection.

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

    Science.gov (United States)

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

    2015-01-01

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

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

    Science.gov (United States)

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

    2014-08-01

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

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

    Science.gov (United States)

    Vazquez, Yamila V; Barbosa, Silvia E

    2017-01-01

    The aim of this paper is to assess recycling process window of ABS (Acrylonitrile-Butadiene-Styrene) and HIPS (High impact Polystyrene) from WEEE (waste from electrical and electronic equipment) through a final properties/structure screening study on their blends. Main motivation is to evaluate which amount of one plastic WEEE can be included into the other at least keeping their properties. In this sense, a wider margin of error during sorting could be admitted to obtain recycling materials with similar technological application of recycled ABS and HIPS by themselves. Results are discussed in terms of final blend structure, focusing in the interaction, within blends, of copolymers phases and fillers presents in WEEE. The comparative analysis of mechanical performance and morphology of HIPS/ABS blends indicates that the addition of 50wt% HIPS to ABS even improves 50% the elongation at break maintaining the strength. On the opposite, HIPS maintains its properties with 20wt% of ABS added. This study allows enlarging composition process window of recycling plastic WEEE for similar applications. This could be a sustainable way to improve benefit of e-scrap with low costs and easy processability. In consequence, social interest in the recycling of this kind of plastic scrap could be encourage from either ecological or economical points of view. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. Poly(acrylonitrile-co-butadiene-co-styrene Reinforced with Hollow Glass Microspheres: Evaluation of Extrusion Parameters and Their Effects on the Composite Properties

    Directory of Open Access Journals (Sweden)

    Marina Panozzo Cunha

    2016-01-01

    Full Text Available Hollow glass microspheres (HGMs filled poly(acrylonitrile-co-butadiene-co-styrene (ABS composites were prepared by means of a twin-screw extruder. S038 HGMs were incorporated at different percentages of 2.5, 5.0, and 7.5 wt%. The HGMs were added into the twin-screw extruder at two different feeding zones, and the effect of HGMs loading and specific feeding zone addition on the composites produced was evaluated with regard to morphological, thermal, rheological, physical, and mechanical properties. As a result, the composite density was reduced while the thermal stability, storage modulus, complex viscosity, and tensile and flexural modulus were improved when compared with the ABS matrix. The results also indicate that the addition of 5.0 wt% of HGMs at the feeding zone closer to the die maintains the integrity of the HGMs and promotes composites with higher mechanical properties and lower density when compared with the composites obtained with the addition of HGMs closer to the hopper.

  8. Comparative acute toxicity of leachates from plastic products made of polypropylene, polyethylene, PVC, acrylonitrile-butadiene-styrene, and epoxy to Daphnia magna.

    Science.gov (United States)

    Lithner, Delilah; Nordensvan, Ildikó; Dave, Göran

    2012-06-01

    The large global production of plastics and their presence everywhere in the society and the environment create a need for assessing chemical hazards and risks associated with plastic products. The aims of this study were to determine and compare the toxicity of leachates from plastic products made of five plastics types and to identify the class of compounds that is causing the toxicity. Selected plastic types were those with the largest global annual production, that is, polypropylene, polyethylene, and polyvinyl chloride (PVC), or those composed of hazardous monomers (e.g., PVC, acrylonitrile-butadiene-styrene [ABS], and epoxy). Altogether 26 plastic products were leached in deionized water (3 days at 50°C), and the water phases were tested for acute toxicity to Daphnia magna. Initial Toxicity Identification Evaluations (C18 filtration and EDTA addition) were performed on six leachates. For eleven leachates (42%) 48-h EC50s (i.e the concentration that causes effect in 50 percent of the test organisms) were below the highest test concentration, 250 g plastic/L. All leachates from plasticized PVC (5/5) and epoxy (5/5) products were toxic (48-h EC50s ranging from 2 to 235 g plastic/L). None of the leachates from polypropylene (5/5), ABS (5/5), and rigid PVC (1/1) products showed toxicity, but one of the five tested HDPE leachates was toxic (48-h EC50 17-24 g plastic/L). Toxicity Identification Evaluations indicated that mainly hydrophobic organics were causing the toxicity and that metals were the main cause for one leachate (metal release was also confirmed by chemical analysis). Toxic chemicals leached even during the short-term leaching in water, mainly from plasticized PVC and epoxy products.

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

    Science.gov (United States)

    Chen, Tingting; Zhang, Jun

    2016-12-01

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

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

    Science.gov (United States)

    Zhao, Wenxia; Ding, Jie; Wang, Zenglin

    2013-05-21

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

  11. 液体丁腈橡胶-26特性黏数快速测定%Rapid determination of intrinsic viscosity for liquid acrylonitrile-butadiene rubber-26

    Institute of Scientific and Technical Information of China (English)

    王真琴; 吴福生; 梁滔; 龚光碧

    2012-01-01

    The intrinsic viscosity of liquid acrylonitrile-butadiene rubber - 26 was determined by dilution method with acetone as solvent,and the constants Κ,Β in Huggins and Kraemer equations were calculated. When Κ and Β met 0.180≤Κ≤0. 472,Κ+β≈0.5, the rapid method could be used to calculate intrinsic viscosity of liquid acrylonitrile - butadiene rubber -26. The relative error and the standard deviation of the rapid method were less than 3% ,0. 150%respectively.%将液体丁腈橡胶-26溶解于丙酮中,采用稀释法测定试样的特性黏数,同时计算出Huggins 方程和Kraemer方程的κ,β常数,当二者满足0.180≤κ≤0.472,κ+β≈0.5,可以用快速法计算液体丁腈橡胶-26的特性黏数.结果表明,快速法相对误差小于3%,最大标准偏差小于0.150%.

  12. 21 CFR 181.32 - Acrylonitrile copolymers and resins.

    Science.gov (United States)

    2010-04-01

    ... paragraph (b) of this section, may be safely used as follows: (1) Films. (i) Acrylonitrile/butadiene/styrene.../styrene copolymer—no restrictions. (2) Coatings. (i) Acrylonitrile/butadiene copolymer blended with... Paint Branch Pkwy., College Park, MD 20740, or available for inspection at the National Archives and...

  13. Studies on the physico-mechanical and thermal characteristics of blends of DGEBA epoxy, 3,4 epoxy cyclohexylmethyl, 3',4'-epoxycylohexane carboxylate and carboxyl terminated butadiene co-acrylonitrile (CTBN)

    Energy Technology Data Exchange (ETDEWEB)

    Tripathi, Garima [Department of Plastic Technology, H. B. Technological Institute, Kanpur 208002 (India); Srivastava, Deepak [Department of Plastic Technology, H. B. Technological Institute, Kanpur 208002 (India)], E-mail: deepak_sri92@rediffmail.com

    2008-11-25

    Toughening of blend of diglycidyl ether of bisphenol-A (DGEBA) and 3,4 epoxy cyclohexylmethyl, 3',4'-epoxycylohexane carboxylate, i.e. cycloaliphatic epoxy resin (CAE) with varying weight ratios (0-25 wt%) of carboxyl terminated butadiene acrylonitrile (CTBN) copolymer have been investigated. Fourier transform infrared (FTIR) spectroscopic analysis established that the interaction between oxirane groups of DGEBA, CAE and CTBN were responsible for characteristics peak shifts in the blends compared to their counterparts. Physico-mechanical properties of the prepared samples, e.g. tensile, flexural and impact strengths showed an optimum concentration of CTBN (15 wt%) into epoxy matrix, which offered maximum toughening. Thermal stability of the prepared samples was analyzed by dynamic thermogravimetric runs. Cross-sections of the cured samples which failed during impact testing have been critically studied through scanning electron microscopic (SEM) analysis to gain insight into the phase morphology.

  14. Ionizing radiation effect study by electron beam on acrylonitrile butadiene styrene - ABS terpolymer; Estudo do efeito da radiacao ionizante por feixe de eletrons sobre o terpolimero acrilonitrila butadieno estireno -ABS

    Energy Technology Data Exchange (ETDEWEB)

    Landi, Tania Regina Lourenco

    2003-07-01

    The great advantage in the researches involving development has as objective to increase significantly the quality of the products. The ABS (acrylonitrile, butadiene, styrene) resins are terpolymers formed by an elastomer and two thermoplastics amorphous components. The three different monomeric units from the terpolymer ABS contribute separately to the material characteristics exhibited. The molecular stiffness originating from polystyrene and the benzene ring hanging on the chain is responsible for the flexion module ABS. The acrylonitrile and the styrene incorporated butadiene exercises strong influence in the resistance to the impact because it reduces the bonding among them. The engineering use of this terpolymer became important due their mechanical properties and mainly, for the responses of this to tensions or deformations applied. The polymeric materials, when submitted to the ionizing radiation are modified by the transference of energy to these materials, introducing excitation and ionization of the molecules, generating chemical reactions that can produce permanent modifications in the polymeric physicochemical structure. The induced modifications can result in the polymeric material degradation or crosslinking, which can result in the improvement of some properties. This work has, as objective, to study the electron beam ionizing radiation effect, at different doses, in the properties of the polymer ABS. The studied properties were: tensile strength at break, elongation at break, Izod impact strength, flexural strength, melt flow index, Vicat softening temperature and the thermic distortion temperature. Also researches on Differential Scanning Calorimetry (DSC) and Thermogravimetric Analyses (TGA) were accomplished. From the experimental results, it was showed that for doses until 500 kGy, at 22.6 kGy/s dose rate, in the presence of air, the crosslinking process of ABS prevails. (author)

  15. Determination of Bound Acrylonitrile Content in Acrylonitrile-butadiene Rubber(NBR) by Infrared Spectroscopy Method%红外光谱法测定丁腈橡胶中的结合丙烯腈含量

    Institute of Scientific and Technical Information of China (English)

    高杜娟; 黄世英; 赵家琳; 刘俊保

    2015-01-01

    Infrared spectrometry in this article was used to determinate the bound acrylonitrile content in nitrile rubber( NBR). In the process of experimenting,the sample preparation conditions were determined and the stand-ard values of seven substitute standard sample were confirmed by Kjeldahl method,through which the quantitative calculation formula was get. And finally,the results were compared with the method of element analysis.%本文采用红外光谱法测定丁腈橡胶( NBR)中的结合丙烯腈含量,确定了样品前处理条件,通过凯氏定氮法确定7个代用标准胶中结合丙烯腈含量的标准值,得出了结合丙烯腈含量的定量计算公式,测试结果与元素分析法进行了对比。

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

    Science.gov (United States)

    Osterman-Golkar, S; Bond, J A

    1996-10-01

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

  17. Polybenzoxazole-filled nitrile butadiene rubber compositions

    Science.gov (United States)

    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. Toxicologic profile of acrylonitrile.

    Science.gov (United States)

    Woutersen, R A

    1998-01-01

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

  19. Study on the Preparation and Characterization of Flame-retardant Acrylonitrile-butadiene Rubber/Chlorinated Polypropylene Rubber-plastic Composites%阻燃型丁腈橡胶/氯化聚丙烯橡塑复合材料的制备与性能研究

    Institute of Scientific and Technical Information of China (English)

    彭军勇; 王曦; 苏胜培

    2012-01-01

    The flame-retardant acrylonitrile-butadiene rubber (NBR)/chlorinated polypropylene (CPP)rubber- plastic composites were prepared by adding antimony trioxide (Sb1O3) which is synergistic flame-retardant. The influences of the loading of Sb2O3 on curing characteristics, mechanical properties and flammability properties were evaluated. The experimental results showed that the processability of the blend system was not reduced with the increase of Sb2O3 loading. When the loading of Sb2O3 was at 10.0 phr., the tensile strength, 300% modulus and Shore A hardness of the composites were respectively improved by 15.7%, 112% and 10.9%. The limiting oxygen index (LOI) of the composites was increased with the increase of Sb2O3 loading. When the content of Sb2O3 was 2.5 phr, the LOI of the composites was up to 27.4%, which indicated that the inflammability of the composites was distinctly enhanced.%通过在丁腈橡胶(NBR)/氯化聚丙烯(CPP)橡塑复合材料中添加协同阻燃剂三氧化二锑,制备了阻燃型NBR/CPP橡塑复合材料,考察了三氧化二锑用量对NBR/CPP橡塑复合材料硫化特性、力学性能和燃烧性能的影响.实验结果表明:三氧化二锑的加入没有降低NBR/CPP橡塑复合材料的加工性能;当三氧化二锑用量为10.0份时,NBR/CPP橡塑复合材料的拉伸强度、300%定伸应力和邵氏硬度分别增加了15.7%、112%和10.9%;复合材料的氧指数(LOI)随三氧化二锑用量的增加逐渐增大,当三氧化二锑用量为2.5份时,复合材料氧指数为27.4%,达到自熄级阻燃效果.

  20. Acrylonitrile: a suspected human carcinogen.

    Science.gov (United States)

    Koerselman, W; van der Graaf, M

    1984-01-01

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

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

    OpenAIRE

    Osterman-Golkar, S; Bond, J. A.

    1996-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1996-10-01

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

  3. Toxicologic profile of acrylonitrile

    NARCIS (Netherlands)

    Woutersen, R.A.

    1998-01-01

    Acrylonitrile is a monomer used extensively as a raw material in the manufacturing of acrylic fibers, plastics, synthetic rubbers, and acrylamide. It has been classified as a probable human carcinogen according to the results of numerous chronic rat bioassays. The present report summarizes the toxic

  4. Toxicologic profile of acrylonitrile

    NARCIS (Netherlands)

    Woutersen, R.A.

    1998-01-01

    Acrylonitrile is a monomer used extensively as a raw material in the manufacturing of acrylic fibers, plastics, synthetic rubbers, and acrylamide. It has been classified as a probable human carcinogen according to the results of numerous chronic rat bioassays. The present report summarizes the

  5. The acrylonitrile dimer ion

    Science.gov (United States)

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

    2007-04-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Jing, Y [Iowa State Univ., Ames, IA (United States)

    2000-09-12

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

  7. Preparation and properties of adjacency crosslinked hydroxyl-terminated liquid butadiene-acrylonitrile rubber based polyurethane elastomers%邻接交联型端羟基液体丁腈橡胶基聚氨酯弹性体的制备与性能

    Institute of Scientific and Technical Information of China (English)

    董慧民; 张成龙; 彭汉修; 李再峰

    2011-01-01

    The styrene-butadiene rubber ( SBR ) / boehmite( BM) composites were prepared by directly blending. The effects of BM content and its surface modification with silane coupling agent bis-[γ-( trie-thoxysilyl) -propyl ] -tetrasulfide (Si 69 ) on mechanical properties, micro morphology, curing characteristics and dynamic mechanical properties of the composites were investigated. The results showed that BM could improve the mechanical properties of SBR vulcanizates effectively. The mechanical properties and interfacial bonding of SBR/BM composites could be further improved when BM was treated with Si 69. The scorching time and optimum curing timeof the two kinds of composites were shortened with increasing BM content at lower BM loading. Compared with the SBR/silica composites, SBR/BM composites exhibited higher mechanical loss in the low temperature range ( -20-0℃ ) and the SBR/ Si 69 modified BM exhibited lower mechanical loss in the high temperature range (50-70℃) when the filler content was the same.%以端羟基液体丁腈橡胶、二苯基甲烷二异氰酸酯及扩链剂1,4 -丁二醇为原料,加入自由基引发剂2,5-二甲基-2,5-双(过氧化叔丁基)己烷和交联助剂三烯丙基异三聚氰酸酯( TAIC),制备了邻接交联型聚氨酯弹性体(PUE),考察了 TAIC的用量对PUE力学性能的影响,并对PUE的热性能进行了研究.结果表明,随着TA IC用量的增加,PUE的交联密度增大,分子柔顺性降低,材料的力学性能逐渐提高,耐热性增强,玻璃化转变温度升高.

  8. 吸水膨胀型丙烯腈-丁二烯-苯乙烯共聚物/丁腈橡胶热塑性硫化胶的性能及微观形貌%Properties and morphology of water-swellable acrylonitrile-butadiene-styrene copolymer/nitrile rubber thermoplastic vulcanizate

    Institute of Scientific and Technical Information of China (English)

    魏东亚; 何宁; 王兆波

    2015-01-01

    以交联聚丙烯酸钠(CPNaAA)为吸水材料,通过动态硫化法制备了基于丙烯腈-丁二烯-苯乙烯共聚物(ABS)/丁腈橡胶(NBR)/氯化聚乙烯(CM)热塑性硫化胶(TPV)的吸水膨胀橡胶(WSR),考察了 CPNaAA 用量对 WSR 物理机械性能和吸水性能的影响,研究了 WSR 的微观形貌。结果表明,在实验范围内,ABS/ NBR/ CM/ CPNaAA WSR 的应力-应变行为均表现出“软而韧”的弹性体特征,随着CPNaAA 用量的增加,WSR 的拉伸强度、扯断伸长率、永久变形和撕裂强度均呈下降趋势,邵尔 A 硬度略有提高,WSR 的吸水率、吸水速率及脱水失重率提高,当 CPNaAA 用量为70份时,室温下95 h WSR即达到吸水平衡状态,此时吸水率为369.8%;与第1次的最大吸水率相比,第2次及第3次的最大吸水率仅有小幅降低,但第2次及第3次的初始吸水速率远大于第1次的初始吸水速率,脱水失重率明显降低;CPNaAA 在 TPV 中分散均匀,未出现团聚现象,但表面结构松散,与 TPV 之间的界面作用较弱;WSR吸水干燥后表面出现明显的缝隙和孔洞。%The water-swellable rubber ( WSR) was pre-pared by dynamically vulcanization with acrylonitrile-butadi-ene-styrene copolymer/ nitrile rubber/ chlorinated polyethylene thermoplastic vulcanizate (TPV) as matrix and crosslinked po-ly( sodium acrylate) ( CPNaAA) as super water-absorbent. Effects of CPNaAA amount on the mechanical properties, wa-ter-swelling behavior and morphology of the prepared WSR were investigated. The results showed that all the stress -strain curves of the WSR behaved as a typical elastomer with soft and tough characters. With increasing CPNaAA, the ten-sile strength, elongation at break, permanent set and tear strength of the WSR decreased, Shore A hardness increased slightly, and the water-swelling ratio, water-swelling rate and mass loss increased significantly. Moreover, the WSR with 70 phr CPNaAA incorporation achieved the equilibrium swell

  9. Biobased synthesis of acrylonitrile from glutamic acid

    NARCIS (Netherlands)

    Notre, le J.E.L.; Scott, E.L.; Franssen, M.C.R.; Sanders, J.P.M.

    2011-01-01

    Glutamic acid was transformed into acrylonitrile in a two step procedure involving an oxidative decarboxylation in water to 3-cyanopropanoic acid followed by a decarbonylation-elimination reaction using a palladium catalyst

  10. Biobased synthesis of acrylonitrile from glutamic acid

    NARCIS (Netherlands)

    Notre, le J.E.L.; Scott, E.L.; Franssen, M.C.R.; Sanders, J.P.M.

    2011-01-01

    Glutamic acid was transformed into acrylonitrile in a two step procedure involving an oxidative decarboxylation in water to 3-cyanopropanoic acid followed by a decarbonylation-elimination reaction using a palladium catalyst

  11. Biological monitoring of acrylonitrile exposure

    Energy Technology Data Exchange (ETDEWEB)

    Houthuijs, D.; Remijn, B.; Willems, H.; Boleij, J.; Biersteker, K.

    1982-01-01

    A study was made of the excretion pattern of acrylonitrile (AN) in urine of 15 AN-exposed workers. During a 7-day working period with the following 2 days off, the workers delivered all their urines separately. Exposure data, collected by personal monitoring, showed a mean 8-hour TWA value of 0.13 ppm. The excretion of AN in urine (AN(U) ) showed a typical pattern; concentrations peaked at the end or shortly after the end of the workday and decreased rapidly until the beginning of the next workday. A control group of 41 nonexposed workers of the same company showed a significant increase of AN(U) with increasing number of cigarettes smoked. The AN(U) concentrations of the exposed workers however were, despite the low exposure, much higher than those of the controls, both during the workdays and during the days off. Biological monitoring of AN-exposed workers by assessing AN(U) therefore seems a very sensitive exposure evaluation method, especially because it accounts for inhalation as well as skin penetration as routes for entering the body.

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

    Science.gov (United States)

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

    2006-10-01

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

  13. Starch Modification by Graft Copolymerization of Acrylonitrile

    Institute of Scientific and Technical Information of China (English)

    刘瑞贤; 李莉; 茹宗玲; 张黎明; 高建平; 田汝川

    2003-01-01

    The graft copolymerization of acrylonitrile (AN) onto starch under the initiation of potassium permanganate was investigated. The effect of various reaction conditions on the graft copolymerization was studied. The relationships between the grafting rate and the initiator concentration of potassium permanganate, monomer acrylonitrile and backbone starch, as well as reaction temperature were established. The oxidation reaction of starch with manganic ions and valence changes of manganic ions during the graft copolymerization were discussed. The results show that manganic ion Mn7+ underwent a series of valence changes during the graft copolymerization: Mn(Ⅶ) → Mn(Ⅳ) → Mn(Ⅲ) → Mn(Ⅱ). The grafting rate of the graft copolymerization of acrylonitrile onto starch is also given.

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

    Science.gov (United States)

    2014-12-01

    explores the fused deposition modeling ( FDM ) and the printing orientation as a means to quantify the potential benefits. These benefits include more cost...effective, time-efficient, in-house fabrication of designs, while optimizing the mechanical and structural integrity. In FDM , CAD software is used to...relationship to the stress experienced in a material at high-strain-rate deformation. For polymers such as ABS, the mechanical properties vary

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

    Science.gov (United States)

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

    2016-02-01

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

  16. Influence of dispersants on aging and frost elastomeric compositions based on butadiene acrylonitrile rubbers

    Directory of Open Access Journals (Sweden)

    R. M. Dolinskaya

    2016-01-01

    Full Text Available The possibility of use of dispergators of various nature for production of rubber technical products with expanded temperature conditions of operation is studied. It is investigated influences of dispergators of Dispergator FL and INT 159 on properties of rubber mixes for receiving products with high resistance to thermal aging or frost resistance. Research of influence of modifiers was conducted for rubber mixes on the basis of butadienenitrile rubbers synthetic (BNRS-18 and BNRS-28. I’s established that at addition of a dispergator of Dispergator FL the indicator of relative deformatstion of compression (RDC and respectively heat stability of rubbers increases. Introduction to structure of elastomeric composition of a dispergator of INT 159 practically doesn’t influence frost resistance, and Dispergator FL worsens her (the coefficient of frost resistance decreases by 15.4–17.8%. Possibly it is connected with the fact that at the lowered temperatures in the presence of Dispergator FL there is a bigger delay of relaxation processes and decrease in energy of the thermal movement of links of macromolecules of rubbers. It becomes insufficient for overcoming of intermolecular interaction in the modified system and commission of conformational transitions of macromolecules under the influence of external loading. Mechanical energy is to a large extent mentioned not on change of a form of macromolecules, and on their mechanodestruction. However, it increases heat stability since it that is higher, than molecular mobility is lower. INT 159 dispergator components, settling down on borders of supramolecular formations of elastomers, increase mobility of links of macromolecules of rubbers, weaken chemical bonds in them, reduce thermal stability, but at the same time INT 159 dispergator practically doesn’t reduce frost resistance therefore it is expedient to apply it when receiving frost-resistant elastomeric composition. Thus, when receiving thermostable elastomeric compositions it is necessary to use Dispergator FL, and frost-resistant – INT 159 dispergator.

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

    Science.gov (United States)

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

    2016-08-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    See, Tian Long, E-mail: tianlong.see@postgrad.manchester.ac.uk [Corrosion and Protection Centre, School of Materials, The Mill, The University of Manchester, M13 9PL Manchester (United Kingdom); Laser Processing Research Centre, School of Mechanical, Aerospace and Civil Engineering, The University of Manchester, M13 9PL Manchester (United Kingdom); Liu, Zhu [Corrosion and Protection Centre, School of Materials, The Mill, The University of Manchester, M13 9PL Manchester (United Kingdom); Li, Lin [Laser Processing Research Centre, School of Mechanical, Aerospace and Civil Engineering, The University of Manchester, M13 9PL Manchester (United Kingdom); Zhong, Xiang Li [Corrosion and Protection Centre, School of Materials, The Mill, The University of Manchester, M13 9PL Manchester (United Kingdom)

    2016-02-28

    Highlights: • Ablation threshold for excimer laser is lower compared to femtosecond laser. • Effective optical penetration depth for excimer laser is lower compared to femtosecond laser. • Two ablation characteristic regimes are observed for femtosecond laser ablation. • Reduction of C=C bond following excimer or fs laser ablation is observed. • Addition of oxygen- and nitrogen-rich functional groups is observed. - Abstract: This paper presents an investigation on the ablation characteristics of excimer laser (λ = 248 nm, τ = 15 ns) and femtosecond laser (λ = 800 nm, τ = 100 fs) on ABS polymer sheets. The laser–material interaction parameters (ablation threshold, optical penetration depth and incubation factor) and the changes in material chemical properties were evaluated and compared between the two lasers. The work shows that the ablation threshold and effective optical penetration depth values are dependent on the wavelength of laser beam (photon energy) and the pulse width. The ablation threshold value is lower for the excimer laser ablation of ABS (F{sub th} = 0.087 J/cm{sup 2}) than that for the femtosecond laser ablation of ABS (F{sub th} = 1.576 J/cm{sup 2}), demonstrating a more dominating role of laser wavelength than the pulse width in influencing the ablation threshold. The ablation depth versus the logarithmic scale of laser fluence shows two linear regions for the fs laser ablation, not previously known for polymers. The effective optical penetration depth value is lower for excimer laser ablation (α{sup −1} = 223 nm) than that for femtosecond laser ablation (α{sup −1} = 2917 nm). The ablation threshold decreases with increasing number of pulses (NOP) due to the chain scission process that shortens the polymeric chains, resulting in a weaker polymeric configuration and the dependency is governed by the incubation factor. Excimer laser treatment of ABS eliminates the C=C bond completely through the chain scission process whereas C=C bond is partially eliminated through the femtosecond laser treatment due to the difference in photon energy of the two laser beams. A reduction in the C=C bond through the chain scission process creates free radical carbons which then form crosslinks with each other or react with oxygen, nitrogen and water in air producing oxygen-rich (C−O and C=O bond) and nitrogen-rich (C−N) functional groups.

  19. Cancer occurrence among workers exposed to acrylonitrile.

    Science.gov (United States)

    Rothman, K J

    1994-10-01

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

  20. A NOVEL ACRYLONITRILE DERIVATIVE HAVING PHOTOVOLTAIC PERFORMANCE

    Directory of Open Access Journals (Sweden)

    Cigdem Yorur-Goreci

    2016-10-01

    Full Text Available A new acrylonitrile derivative 3 (BPCPFA which offer potential application as organic solar cell material was synthesized with three steps. The structures of the molecules synthesized in these steps were characterized using various spectral analyses. BPCPFA was investigated as an electron acceptor molecule in next generation organic solar cells. Theoretical prediction and experimental studies for photovoltaic performance were performed. Based on these results, it is concluded that BPCPFA with extended conjugated system has good and promising photovoltaic performance with Voc value as 0.96 V.

  1. Palladium phosphine complexes for the telomerization of butadiene

    DEFF Research Database (Denmark)

    2010-01-01

    A phosphine ligand suitable for use in telomerizing butadiene comprises two phenyl groups and a xanthene moiety.......A phosphine ligand suitable for use in telomerizing butadiene comprises two phenyl groups and a xanthene moiety....

  2. Information draft on the development of air standards for acrylonitrile

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-01-01

    Acrylonitrile is a colourless liquid with a faintly sweet and pungent odour. It is widely used as a chemical intermediate in a variety of industrial and commercial products such as acrylic and modacrylic fibres, plastics, styrene-acrylonitrile, nitrile rubber resins, and acrylamide. Although not currently produced in Canada, acrylonitrile is used in the manufacture of industrial and commercial products. Acrylonitrile levels around end-use plants have been found to be significantly higher than at producing facilities. Almost all releases of acrylonitrile are to the atmosphere and one facility is responsible for all releases in Ontario. Human exposure is through air, water and food. Acrylonitrile is absorbed by inhalation, through the mouth and to some extent through the skin. Exposure at concentrations of 7 to 45 microgram/cubic meter for 20 to 45 minutes leads to irritation of the mucous membranes, nausea, headaches, and irritability. Low-grade anaemia, leukocytosis, kidney irritation and mild jaundice have also been observed. Children are more sensitive than adults. Acrylonitrile is classified as probable human carcinogen by the US Environmental Protection Agency. The current ambient air quality criterion (AAQC) in Ontario is 100 microgram/cubic metre and the half-hour interim point of impingement (POI) standard is 300 microgram/cubic meter. Review of world-wide literature showed the existence of standards in several American states. Cancer unit risks estimates have been made by the US Environmental Protection Agency as well as by the World Health Organization. 63 refs., 1 tab., appendix.

  3. Effect of acrylonitrile on the electrode processes ivolving copper cations

    Directory of Open Access Journals (Sweden)

    Viktor F. Vargalyuk

    2016-03-01

    Full Text Available Based on the results of cyclic voltammetry and study of deposits morphology, it has been shown that acrylonitrile does not have significant effect on the mechanism of Cu2+ + 2ē → Cu0 reaction. This distinguishes acrylonitrile from the unsaturated polyfunctional organic substances (acrylic acid, acrylamide which forms stable complexes with Cu2+ ions. Acrylonitrile just inhibits cathodic process by adsorbing on the surface of electrode thus blocking its active sites. But the presence of acrylonitrile significantly changes the mechanism of the anodic process. It has been found that acrylonitrile interacts with surface copper atoms thus forming thermodynamically stable [Cu π-AN]0 π‑complexes. Ionization potential of these π‑complexes is more negative if compare to copper atoms. As the result acceleration of anodic process takes place in the low polarization area. However, since the chemisorption is a slow process the presence of acrylonitrile mainly affects dissolution of the first surface layers of copper atoms. Further ionization of copper atoms runs out directly and requires higher polarization.

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

    Science.gov (United States)

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

  5. Mutagenicity, carcinogenicity, and teratogenicity of acrylonitrile.

    Science.gov (United States)

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

    1999-05-01

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

  6. 21 CFR 177.1480 - Nitrile rubber modified acrylonitrile-methyl acrylate copolymers.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Nitrile rubber modified acrylonitrile-methyl... Nitrile rubber modified acrylonitrile-methyl acrylate copolymers. Nitrile rubber modified acrylonitrile... this chapter, subject to the provisions of this section. (a) For the purpose of this section, nitrile...

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

    Science.gov (United States)

    Liu, Guicai; Liao, Yanfen; Ma, Xiaoqian

    2017-03-01

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

  8. Resistivity and Its Anisotropy Characterization of 3D-Printed Acrylonitrile Butadiene Styrene Copolymer (ABS/Carbon Black (CB Composites

    Directory of Open Access Journals (Sweden)

    Jie Zhang

    2017-01-01

    Full Text Available The rapid printing of 3D parts with desired electrical properties enables numerous applications. Fused deposition modeling (FDM using conductive thermoplastic composites has been a valuable approach for such fabrication. The parts produced by FDM possess various controllable structural features, but the effects of the structural features on the electrical properties remain to be determined. This study investigated the effects of these features on the electrical resistivity and resistivity anisotropy of 3D-printed ABS/CB composites. The effects of the process parameters of FDM, including the layer thickness, raster width, and air gap, on the resistivity in both the vertical and horizontal directions for cubic samples were studied because the internal structure of the printed parts depended on those process parameters. The resistivities of printed parts in different parameter combinations were measured by an impedance analyzer and finite element models were created to investigate the relationship between the resistivity and the internal structure. The results indicated that the parameters remarkably affected the resistivity due to the influence of voids and the bonding condition between adjacent fibers. The resistivity in the vertical direction ranged from 70.40 ± 2.88 Ω·m to 180.33 ± 8.21 Ω·m, and the resistivity in the horizontal direction ranged from 41.91 ± 2.29 Ω·m to 58.35 ± 0.61 Ω·m at the frequency of 1 kHz. Moreover, by adjusting the resistivities in different directions, the resistivity anisotropy of the printed parts can be manipulated from 1.01 to 3.59. This research may serve as a reference to fabricate parts with sophisticated geometry with desired electrical resistivity and resistivity anisotropy.

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

    Science.gov (United States)

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

    2014-07-01

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

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

    Science.gov (United States)

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

    2016-07-01

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

  11. Commercial Application of the XYA-5 Catalyst in Acrylonitrile Unit

    Institute of Scientific and Technical Information of China (English)

    Li Zhengguang

    2008-01-01

    The XYA-5 catalyst was first applied in commercial scale on an 80-kt/a acrylonitrile unit at the Daqing Refining and Chemical Company.Test results had shown that the once-through yield of acrylonitrile exceeded 80% with the unit consumption of propylene reaching 1032 kg on each ton of acryionitrile.The product quality could be easily put under control and the distribution of reaction products was reasonable with good cleaning performance and stability of the catalyst that was suitable for use on this commercial unit.

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

    Science.gov (United States)

    Choi, Seong-Ho; Nho, Young Chang

    2000-04-01

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

  13. Polyacrylamide polymers derived from acrylonitrile without intermediate isolation

    Energy Technology Data Exchange (ETDEWEB)

    Norton, C.J.; Falk, D.O.

    1977-04-05

    Hydrolyzed and neutralized acrylonitrile is polymerized in solution without isolation to produce a high molecular weight polyacrylamide useful for mobility control in secondary recovery of petroleum. The polyacrylamide optionally may be hydrolyzed, methylolated, and sulfomethylated to further enhance its water-thickening properties. This procedure reduces the cost of making polyacrylamide. (5 claims)

  14. Oil Gels Based on Styrene Butadiene Rubber

    Institute of Scientific and Technical Information of China (English)

    ZHOU Mei-hua (周美华); XU Jing-bo(徐静波); Won-jei CHO

    2004-01-01

    Four oil absorbents based on styrene butadiene (SBR),i. e., pure SBR (PS), 4- tert-butylstyrene-SBR (PBS),EPDM-SBR network (PES) and 4-tert-butylstyrene-EPDMSBR ( PBES ), were produced from crosslinking polymerization of uncured styrene butadiene rubber (SBR),4- tert-butylstyrene ( tBS ) and ethylene-propylene-diene terpolymer (EPDM). The reaction took place in toluene using benzoyl peroxide (BPO) as an initiator. Uncured SBR was used as both a pre-polymer and a crosslink agent in this work, and the crosslinked polymer was identified by IR spectroscopy. The oil absorbency of the crosslinked polymer was evaluated with the method ASTM (F726 - 81). The order of maximum oil absorbency was PBES > PBS >PES > PS. The maximum values of oil absorbency of PBES and PBS were 74.0g/g and 69.5g/g, respectively. Gel fractions and swelling kinetic constants, however, had the opposite sequences. The swelling kinetic constant of PS evaluated by an experimental equation was 49. 97 ×10-2h-1.

  15. A New Quenching Process and Tower to Improve the Recovery of Acrylonitrile

    Institute of Scientific and Technical Information of China (English)

    甘永胜; 顾军民; 方永成

    2004-01-01

    Quenching process and design of the quenching tower in acrylonitrile production in China were studied in order to decrease the polymerization loss of acrylonitrile in the quenching tower. Based on the research of acrylonitrile polymerization in the quenching tower, a new quenching process was proposed to avoid the disadvantages of the original process. Two kinds of internals were installed to improve the performance of the quenching tower. Through a series of air-flow and real-flow model experiments, the new quenching process and new design were showed to be successful in enhancing the mass and heat transfer in the vapor-liquid system and decreasing the loss of acrylonitrile.Industrial application showed satisfactory results of decrease of the acrylonitrile loss in the quenching tower by about 4.5% and increase of the acrylonitrile recovery of the whole plant by more than 4%.

  16. Radiation initiated copolymerization of allyl alcohol with acrylonitrile

    Energy Technology Data Exchange (ETDEWEB)

    Solpan, Dilek; Guven, Olgun [Hacettepe Univ., Ankara (Turkey). Dept. of Chemistry

    1996-07-01

    Copolymerization of allyl alcohol (AA) with acrylonitrile (AN) initiated by {gamma}-rays has been investigated to determine the respective reactivity ratios. Three different experimental techniques, namely Fourier Transform Infrared (FTIR), Ultraviolet (UV/vis) and elemental analysis (EA) have been used for the determination of copolymer compositions. Fineman-Ross (FR), Kelen-Tudos (KT), Non-Linear Least Square (NLLS) Analysis and Q-e methods have been applied to the three sets of experimental data. It has been concluded that data obtained from elemental analysis as applied to the Non-Linear Least Square approach gave the most reliable reactivity ratios as 2.09 and 0.40 for acrylonitrile and allyl alcohol, respectively. (Author).

  17. Radiation initiated copolymerization of allyl alcohol with acrylonitrile

    Science.gov (United States)

    Şolpan, Dilek; Güven, Olgun

    1996-07-01

    Copolymerization of allyl alcohol (AA) with acrylonitrile (AN) initiated by γ-rays has been investigated to determine the respective reactivity ratios. Three different experimental techniques, namely Fourier Transform Infrared (FTIR), Ultraviolet (UV/vis) and elemental analysis (EA) have been used for the determination of copolymer compositions. Fineman-Ross (FR), Kelen-Tüdös (KT), Non-Linear Least Square (NLLS) Analysis and Q-e methods have been applied to the three sets of experimental data. It has been concluded that data obtained from elemental analysis as applied to the Non-Linear Least Square approach gave the most reliable reactivity ratios as 2.09 and 0.40 for acrylonitrile and allyl alcohol, respectively.

  18. Thermal Stability of Poly (acrylonitrile-methyl acrylate) Copolymers

    Institute of Scientific and Technical Information of China (English)

    HAN Na; ZHANG Xing-xiang; WANG Xue-chen

    2008-01-01

    Poly (acrylonitrile-methyl acrylate) copolymer was synthesized by water depositing polymerization and has a typical feed ratio of 85/15. And then 1 - 3 wt% lauryl alcohol maleic anhydride (LAM) was adopted as stabilizer to mix with the acrylonitrile based copolymer. The mixtures were characterized by using Fourier Transform Infrared Spectroscopy (FTIR), Nuclear Magnetic Resonance (1H NMR ), Gel Permeation Chromatography ( GPC ), Differential Scanning Calorimetry (DSC), optic microscope and Ubbelohde viscosimetryr etc. The melting point (Tm) and glass transition temperature (Tg) of the 85/15 AN/MA copolymer mixed with LAM all decrease with the increase of stabilizer content. The lowest Tg and Tm were 116.1 ℃ and 209. 1℃ respectively at the heating rate of 100℃/min when the content of LAM is 2 wt%. The 85°/15 AN/MA copolymer mixed with 1 - 3 w t% LAM possess good thermal stability up to 30 min at 220 ℃.

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

    OpenAIRE

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

    2014-01-01

    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 co...

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

    Science.gov (United States)

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

    2011-01-01

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

  1. Recent Breakthroughs in the Conversion of Ethanol to Butadiene

    Directory of Open Access Journals (Sweden)

    Guillaume Pomalaza

    2016-12-01

    Full Text Available 1,3-Butadiene is traditionally produced as a byproduct of ethylene production from steam crackers. What is unusual is that the alternative production route for this important commodity chemical via ethanol was developed a long time ago, before World War II. Currently, there is a renewed interest in the production of butadiene from biomass due to the general trend to replace oil in the chemical industry. This review describes the recent progress in the production of butadiene from ethanol (ETB by one or two-step process through intermediate production of acetaldehyde with an emphasis on the new catalytic systems. The different catalysts for butadiene production are compared in terms of structure-catalytic performance relationship, highlighting the key issues and requirements for future developments. The main difficulty in this process is that basic, acid and redox properties have to be combined in one single catalyst for the reactions of condensation, dehydration and hydrogenation. Magnesium and zirconium-based catalysts in the form of oxides or recently proposed silicates and zeolites promoted by metals are prevailing for butadiene synthesis with the highest selectivity of 70% at high ethanol conversion. The major challenge for further application of the process is to increase the butadiene productivity and to enhance the catalyst lifetime by suppression of coke deposition with preservation of active sites.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  3. 46 CFR 154.1750 - Butadiene or vinyl chloride: Refrigeration system.

    Science.gov (United States)

    2010-10-01

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

  4. On the catalytic gas phase oxidation of butadiene to furan

    Energy Technology Data Exchange (ETDEWEB)

    Kubias, B.; Rodemerck, U. [Institut fuer Angewandte Chemie Berlin-Adlershof e.V., Berlin (Germany); Ritschl, F.; Meisel, M. [Humboldt-Universitaet, Berlin (Germany). Inst. fuer Chemie

    1998-12-31

    Applying the thermochemical selectivity criterion of Hadnett et al. It is shown that the selectivity of the furan formation is not limited by a too low strength of the C-H bonds in furan when compared with the C-H bond dissociation energy in the educt molecule butadiene. In the oxidation of butadiene on a CsH{sub 2}PMo{sub 12}O{sub 40} catalyst a maximum yield of 22 mol% furan has been obtained. To improve this comparatively low furan yield oxidation activity of the catalyst must be lowered to prevent the consecutive reaction to maleic anhydride. (orig.)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1995-12-01

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

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

    Science.gov (United States)

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

    2002-07-01

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

  7. In vivo comet assay of acrylonitrile, 9-aminoacridine hydrochloride monohydrate and ethanol in rats.

    Science.gov (United States)

    Nakagawa, Yuzuki; Toyoizumi, Tomoyasu; Sui, Hajime; Ohta, Ryo; Kumagai, Fumiaki; Usumi, Kenji; Saito, Yoshiaki; Yamakage, Kohji

    2015-07-01

    As part of the Japanese Center for the Validation of Alternative Methods (JaCVAM)-initiative international validation study of the in vivo rat alkaline comet assay, we examined the ability of acrylonitrile, 9-aminoacridine hydrochloride monohydrate (9-AA), and ethanol to induce DNA damage in the liver and glandular stomach of male rats. Acrylonitrile is a genotoxic carcinogen, 9-AA is a genotoxic non-carcinogen, and ethanol is a non-genotoxic carcinogen. Positive results were obtained in the liver cells of male rats treated with known genotoxic compounds, acrylonitrile and 9-AA.

  8. Synthesis, Characterization and Photophysical Properties of Pyridine-Carbazole Acrylonitrile Derivatives

    OpenAIRE

    Gabriel Ramos-Ortiz; Enrique Pérez-Gutiérrez; José Luis Maldonado; Chapela, Víctor M.; Margarita Cerón; M. Judith Percino

    2011-01-01

    We synthesized three novel highly fluorescent compounds, 2-(2’-pyridyl)-3-(N-ethyl-(3’-carbazolyl))acrylonitrile, 2-(3”-pyridyl)-3-(N-ethyl-(3’-carbazolyl))acrylonitrile, and 2-(4-pyridyl)-3-(N-ethyl-(3’-carbazolyl))acrylonitrile by Knoevenagel condensation. The first two were synthesized without solvent in the presence of piperidine as a catalyst; the third was synthesized without a catalyst and with N,N-dimethylformamide as a solvent. In solution, the molar absorption coefficients showed ab...

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

    Science.gov (United States)

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

    2015-04-01

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

  10. Evaluation of image uniformity and radiolucency for computed tomography phantom made of 3-dimensional printing of fused deposition modeling technology by using acrylonitrile but audience styrene resin

    Energy Technology Data Exchange (ETDEWEB)

    Seoung, Youl Hun [Dept. of of Radiological Science, Cheongju University, Cheongju (Korea, Republic of)

    2016-09-15

    The purpose of this study was to evaluate the radiolucency for the phantom output to the 3D printing technology. The 3D printing technology was applied for FDM (fused deposition modeling) method and was used the material of ABS (acrylonitrile butadiene styrene) resin. The phantom was designed in cylindrical uniformity. An image uniformity was measured by a cross-sectional images of the 3D printed phantom obtained from the CT equipment. The evaluation of radiolucency was measured exposure dose by the inserted ion-chamber from the 3D printed phantom. As a results, the average of uniformity in the cross-sectional CT image was 2.70 HU and the correlation of radiolucency between PMMA CT phantom and 3D printed ABS phantom is found to have a high correlation to 0.976. In the future, this results will be expected to be used as the basis for the phantom production of the radiation quality control by used 3D printing technology.

  11. A risk assessment for acrylonitrile in consumer products.

    Science.gov (United States)

    Johnston, P K; Rock, A R

    1990-12-15

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

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

    Science.gov (United States)

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

    2014-06-01

    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.

  13. BARRIER PROPERTY AND STRUCTURE OF ACRYLONITRILE/ACRYLIC COPOLYMERS

    Institute of Scientific and Technical Information of China (English)

    YANG Zhenghua; LI Yuesheng

    1997-01-01

    A series of acrylonitrile (AN) copolymers with methyl acrylate (MA) or ethyl acrylate (EA) as comonomer (5-23 wt%) was prepared by free-radical copolymerization. The permeability coefficients of the copolymers to oxygen and carbon dioxide were measured at 1.0 MPa and at 30 ℃, and those to water vapor also measured at 100% relative humidity and at 30 ℃. All the AN/acrylic copolymers are semicrystalline. As the acrylate content increase, the permeability coefficients of the copolymers to oxygen and carbon dioxide are increased progressively, but those to water vapor are decreased progressively. The gas permeability coefficients of the polymers were correlated with free-volume fractions or the ratio of free volume to cohesive energy.

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

    Science.gov (United States)

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

    2014-10-01

    In this work, a membrane dispersion microreactor was utilized for the hydration of acrylonitrile to produce acrylamide. Through observation using a microscopy, it was found that the acrylonitrile was dispersed into the continuous phase (the aqueous phase contains nitrile hydratase (NHase)) as droplets with a diameter ranged from 25 to 35 μm, hence the mass transfer specific surface area was significantly increased, and the concentration of acrylamide reached 52.5 wt% within 50 min. By contrast, in stirred tanks, the concentration of acrylamide only got 39.5 wt% within 245 min. Moreover, only a few amounts of acrylonitrile were accumulated in this microreactor system. Through optimizing the flow rate, the concentration of acrylamide reached 45.8 wt% within 35 min, the short reaction time greatly weakened the inhibition of acrylonitrile and acrylamide on the enzyme activity, which is suitable for prolonging the life of free cell. Copyright © 2014 Elsevier Ltd. All rights reserved.

  15. KINETIC STUDIES ON THE POLYMERIZATION OF ACRYLONITRILE INITIATED BY METALLIC MAGNESIUM-NITRIC ACID SYSTEM

    Institute of Scientific and Technical Information of China (English)

    WU Chinyung

    1983-01-01

    This article reports the polymerization kinetics of acrylonitrile initiated by metallic magnesiumnitric acid system. The rate of polymerization is independent of the amount of magnesium used; when the concentration of nitric acid is higher than acrylonitrile, the equation of polymerization kinetics may be expressed as Rp=1.91 × 105e-15000/RT[Mg]0 [AN]2·2 [HNO3]0·46 The result of copolymerization of acyrlonitrile and methyl acrylate supports a free-radical mechanism.

  16. Perinatal Toxicity and Carcinogenicity Studies of Styrene –Acrylonitrile Trimer, A Ground Water Contaminant

    OpenAIRE

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

    2013-01-01

    Styrene Acrylonitrile (SAN) Trimer is a by-product in the production of acrylonitrile styrene plastics. Following a report of a childhood cancer cluster in the Toms River section of Dover Township, New Jersey, SAN Trimer was identified as one of the groundwater contaminants at Reich Farm Superfund site in the township. The contaminants from the Reich Farm site’s ground water plume impacted two wells at the Parkway well field. The National Toxicology Program (NTP) studied the toxicity and carc...

  17. EFFECTS OF SOLVENT POLARITY ON FREE RADICAL COPOLY MERIZATION OF 5-HEXENOIC ACID AND ACRYLONITRILE

    Institute of Scientific and Technical Information of China (English)

    WANG Bing; XIE Shishan; CAO Mengjiun

    1987-01-01

    The effects of solvent polarity on free radical copolymerization of 5-hexenoic acid and acrylonitrile at 60℃ were studied. It was observed that as the polarity of solvents enhanced, both the copolymerization rate and the reactivity ratios r1, r2 increased, while the alternating tendency of monomer units in copolymer chain decreased. It is believed that the solvent polarity raises the reactivities of acrylonitrile monomer and its growing chain radical, but causes no distinct variation in those of 5-hexenoic acid.

  18. Synthesis, Characterization and Photophysical Properties of Pyridine-Carbazole Acrylonitrile Derivatives

    Science.gov (United States)

    Pérez-Gutiérrez, Enrique; Percino, M. Judith; Chapela, Víctor M.; Cerón, Margarita; Maldonado, José Luis; Ramos-Ortiz, Gabriel

    2011-01-01

    We synthesized three novel highly fluorescent compounds, 2-(2’-pyridyl)-3-(N-ethyl-(3’-carbazolyl))acrylonitrile, 2-(3”-pyridyl)-3-(N-ethyl-(3’-carbazolyl))acrylonitrile, and 2-(4-pyridyl)-3-(N-ethyl-(3’-carbazolyl))acrylonitrile by Knoevenagel condensation. The first two were synthesized without solvent in the presence of piperidine as a catalyst; the third was synthesized without a catalyst and with N,N-dimethylformamide as a solvent. In solution, the molar absorption coefficients showed absorptions at 380, 378, and 396 nm, respectively; in solid state, absorptions were at 398, 390, and 442 nm, respectively. The fluorescence emission was at 540, 540 and 604 nm, respectively, the 2-(4-pyridyl)-3-(N-ethyl-(3’-carbazolyl))acrylonitrile showed a red shift in the emission of 64 nm compared to the other two compounds. The fluorescence quantum yield for the compounds in powder form showed values of 0.05, 0.14, and 0.006, respectively; compared with the value measured for the Alq3 reference, 2-(3”-pyridyl)-3-(N-ethyl-(3’-carbazolyl))acrylonitrile had a lightly higher value. The third harmonic generation measurement for 2-(2’-pyridyl)-3-(N-ethyl-(3’-carbazolyl))acrylonitrile yielded a χ(3) value of 5.5 × 10−12 esu, similar to that reported for commercial polymers. PMID:28880006

  19. Grafting of acrylonitrile onto cellulosic material derived from bamboo (Dendrocalamus strictus

    Directory of Open Access Journals (Sweden)

    2008-01-01

    Full Text Available Bamboo, a lignocellulosic biopolymer material, is of interest as feedstock for production of cellulose derivatives by chemical functionalization. Optimization of grafting of acrylonitrile onto cellulosic material (average Degree of Polymerization 816, isolated from bamboo (Dendrocalamus stictus was performed by varying the process parameters such as duration of soaking of cellulosic material in ceric ammonium nitrate solution, ceric ammonium nitrate concentration, polymerization time, temperature of reaction and acrylonitrile concentration to study their influence on percent grafting and grafting efficiency. Graft copolymerization of acrylonitrile onto cellulosic material derived from bamboo (Dendrocalamus strictus in heterogenous medium can be initiated effectively with ceric ammonium nitrate. The optimum reaction conditions obtained for grafting of acrylonitrile onto cellulosic material were: duration of dipping cellulosic material in ceric ammonium nitrate solution 1 hr, ceric ammonium nitrate concentration 0.02 M, acrylonitrile concentration 24.6 mol/anhydroglucose unit, temperature of reaction 40°C and polymerization time 4 hrs. The percent grafting for optimized samples is 210.3% and grafting efficiency is 97%. The characterization of the grafted products by means of FTIR and Scanning Electron Microscopy furnished the evidence of grafting of acrylonitrile onto the cellulosic material.

  20. Scintillation of thin tetraphenyl butadiene films under alpha particle excitation

    Energy Technology Data Exchange (ETDEWEB)

    Pollmann, Tina, E-mail: tina@owl.phy.queensu.c [Department of Physics, Engineering Physics, and Astronomy, Queens University, Kingston, Ontario, K7L 3N6 (Canada); Boulay, Mark; Kuzniak, Marcin [Department of Physics, Engineering Physics, and Astronomy, Queens University, Kingston, Ontario, K7L 3N6 (Canada)

    2011-04-11

    The alpha induced scintillation of the wavelength shifter 1,1,4,4-tetraphenyl-1,3-butadiene (TPB) was studied to improve the understanding of possible surface alpha backgrounds in the DEAP dark matter search experiment. We found that vacuum deposited thin TPB films emit 882{+-}210 photons per MeV under alpha particle excitation. The scintillation pulse shape consists of a double exponential decay with lifetimes of 11{+-}5 and 275{+-}10ns.

  1. Conversion of 2,3-butanediol to butadiene

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-09-06

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

  2. The Formation and characteristics of Acrylonitrile/Urea Inclusion Compound

    CERN Document Server

    Zou, Jun-Ting; Pang, Wen-Min; Shi, Lei; Lu, Fei

    2012-01-01

    The formation process and composition of the acrylonitrile/urea inclusion compounds (AN/UIC) with different aging times and AN/urea molar feed ratios are studied by differential scanning calorimetry (DSC) and X-ray diffraction (XRD). It is suggested that DSC could be one of the helpful methods to determine the guest/host ratio and the heat of decomposition. Meanwhile, the guest/host ratio and heat of deformation are obtained, which are 1.17 and 5361.53 J/mol, respectively. It is found that the formation of AN/UIC depends on the aging time. The formation process ends after enough aging time and the composition of AN/UIC becomes stable. It is suggested AN molecules included in urea canal lattice may be packed flat against each other. XRD results reveal that once AN molecules enter urea lattice, AN/UIC are formed, which possess the final structure. When AN molecules are sufficient, the content of AN/UIC increased as aging time prolonging until urea tunnels are saturated by AN.

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

    Science.gov (United States)

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

    2009-12-15

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

  4. Selective Vulnerability of the Cochlear Basal Turn to Acrylonitrile and Noise

    Directory of Open Access Journals (Sweden)

    B. Pouyatos

    2009-01-01

    Full Text Available Exposure to acrylonitrile, a high-production industrial chemical, can promote noise-induced hearing loss (NIHL in the rat even though this agent does not itself produce permanent hearing loss. The mechanism by which acrylonitrile promotes NIHL includes oxidative stress as antioxidant drugs can partially protect the cochlea from acrylonitrile+noise. Acrylonitrile depletes glutathione levels while noise can increase the formation of reactive oxygen species. It was previously noted that the high-frequency or basal turn of the cochlea was particularly vulnerable to the combined effects of acrylonitrile and noise when the octave band noise (OBN was centered at 8 kHz. Normally, such a noise would be expected to yield damage at a more apical region of the cochlea. The present study was designed to determine whether the basal cochlea is selectively sensitive to acrylonitrile or whether, by adjusting the frequency of the noise band, it would be possible to control the region of the auditory impairment. Rats were exposed to one of three different OBNs centered at different frequencies (4 kHz, 110 dB and 8 or 16 kHz at 97 dB for 5 days, with and without administration of acrylonitrile (50 mg/kg/day. The noise was set to cause limited NIHL by itself. Auditory function was monitored by recording distortion products, by compound action potentials, and by performing cochlear histology. While the ACN-only and noise-only exposures induced no or little permanent auditory loss, the three exposures to acrylonitrile+noise produced similar auditory and cochlear impairments above 16 kHz, despite the fact that the noise exposures covered 2 octaves. These observations show that the basal cochlea is much more sensitive to acrylonitrile+noise than the apical partition. They provide an initial basis for distinguishing the pattern of cochlear injury that results from noise exposure from that which occurs due to the combined effects of noise and a chemical

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

    Science.gov (United States)

    Page, N P; Cook, B

    1990-12-15

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

  6. Performance of CTBN(carboxyl-terminated poly (butadiene-co-acrylonitrile))-EP(diglycidyl ether of bisphenol-A(DGEBA)) Prepolymers and CTBN-EP/polyetheramine (PEA) System

    Institute of Scientific and Technical Information of China (English)

    SHI Minxian; HUANG Zhixiong; LI Yaming; YANG Guorui

    2009-01-01

    CTBN-EP prepolymers were synthesized from CTBN and epoxy resin under the catalysis of HTMAB.FTIR analyses indicate the formation of ester group between the carboxyl group of CTBN and the oxirane group of epoxy resin.The viscosity of modified prepolymer increases with CTBN content increasing,but the epoxy value of the prepolymer decreases greatly.DSC analyses verify that CTBN affects the curing process of CTBN-EP/PEA system.Mechanical testing presents the improved toughness of CTBN-EP/PEA curings for the decrease of tensile strength,flexural strength and compressive strength,and increase of impact strength and elongation-at-break with the CTBN content increasing.SEM micrographs show the rubber phase with many holes in diameter about 0.5-1.5μm is formed when CTBN content is lower than 10 phr.However,the pattern of SEM graph shows some stalactite-like strips when CTBN content is higher than 15 phr.Furthermore,the SEM image of 25 phr CTBN sample forms a kind of co-continuous structure.

  7. Synthesis of Acrylonitrile-butadiene-styrene Copolymer by Styrene-isoprene-butadiene Copolymer Latex%苯乙烯-异戊二烯-丁二烯三元集成胶乳增韧ABS树脂

    Institute of Scientific and Technical Information of China (English)

    尹国强; 李杨; 申凯华; 张峰; 张东梅; 史晶虹; 王玉荣

    2013-01-01

    采用自由基乳液聚合方法,通过苯乙烯-异戊二烯-丁二烯三元共聚合技术,设计合成了新型三元集成胶乳(SIBL)替代传统成本较高的聚丁二烯胶乳(PBL),制备丙烯腈-丁二烯-苯乙烯共聚物(ABS树脂).将高温乳液法制备的SIBL进行附聚,再经过乳液接枝法制备高胶含量的ABS粉料,最后将ABS粉料与本体苯乙烯-丙烯腈共聚物(SAN树脂)掺混、熔融挤出、造粒,制备了低成本新型ABS树脂.考察3种单体配比对SIBL聚合动力学和粒径大小、分布、凝胶含量、玻璃化转变温度(Tg)和ABS树脂性能的影响.结果表明,采用自由基乳液聚合制备三元集成胶乳的方法可行,得到的增韧ABS树脂综合性能优异,悬臂梁缺口冲击强度由139 J/m提高到233 J/m.

  8. Determination of butadiene commercial elastomers composition; Determinacao da composicao de elastomeros comerciais a base de butadieno

    Energy Technology Data Exchange (ETDEWEB)

    Tavares, M.I.B.; Mendes, L.C. [Universidade Federal, Rio de Janeiro, RJ (Brazil). Inst. de Macromoleculas

    1997-12-31

    Hydrogen-1 nuclear magnetic resonance was used in the determination of the percentile and conformational composition of commercial samples of styrene-butadiene-copolymer and poly(butadiene) homo-polymer. The results are presented and discussed 3 refs., 5 figs., 1 tab.

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

    Science.gov (United States)

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

    2012-01-01

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

  10. Genetic toxicity of 1,3-butadiene and styrene.

    Science.gov (United States)

    Norppa, H; Sorsa, M

    1993-01-01

    1,3-Butadiene and styrene (vinyl benzene) are indirect genotoxins, which require metabolic activation to an epoxide form in order to bind covalently to DNA. Styrene 7,8-oxide, the active metabolite of styrene, is a carcinogen in rodents and has been shown to be genotoxic in most in-vitro test systems and at various genetic endpoints. The few studies available on the genotoxicity of styrene 7,8-oxide in vivo have yielded negative or (in mice) weakly positive results. Styrene is not usually genotoxic in vitro in assays employing a microsomal preparation from rat liver for metabolic activation, but positive effects have been obtained when other sources of metabolic activation, such as human erythrocytes, were provided. In vivo, styrene has been found repeatedly to be weakly genotoxic in the assay for sister chromatid exchange, especially in mice. Cytogenetic damage (usually chromosomal aberrations) has been reported in many studies of workers, mainly from the reinforced plastics industry where ambient concentrations of styrene may be high (50-100 ppm), while most negative findings are associated with exposure to lower levels. Butadiene is metabolized to two reactive forms, 1,2-epoxy-3-butene and further to 1,2:3,4-diepoxybutane, both of which are genotoxic in various test systems in vitro. The lowest effective dose of the latter is 1-2 orders of magnitude higher than that of the respective monoepoxide. Butadiene itself has not been tested extensively for genotoxicity in vitro. A species-specific difference in the responses of mice and rats at various cytogenetic end-points is seen in vivo, the lowest effective concentrations in rats being clearly higher than those in mice.(ABSTRACT TRUNCATED AT 250 WORDS)

  11. Synthesis and properties of butadiene-alpha-methylstyrene thermoplastic elastomer

    Directory of Open Access Journals (Sweden)

    A. V. Firsova

    2016-01-01

    Full Text Available Butadiene-α-methylstyrene block – copolymer – a thermoplastic elastomer (TPE-R DMST occupies a special place among the ethylene – vinyl aromatic block copolymers. TPE-R DMST comprising as plastic – poly-α-methylstyrene unit and elastic – polybutadiene block. TPE-R DMST has high heat resistance, flexibility, abrasion resistance compared to butadiene-styrene thermoplastic elastomer (TPE DST. The synthesis of block copolymers of butadiene and α-methylstyrene was carried out. The process of polymerization the α-methylstyrene characterized the high speed of polymerization in polar medium and low reaction speed in hydrocarbon solvents. Anionic catalyst nbutyllithium (n-BuLi and high concentration – 60–80% α-methylstyrene in the mixture influenced by synthesis of the 1st block of TPE-R DMST, it’s technologically difficult. Found that the low temperature of polymerization α-methylstyrene (+61 o C, the reversibility of these reactions and the high concentration of residual monomer are very importance. It was revealed that a high polymerization rate α-methylstyrene can be achieved by conducting the reaction in a hydrocarbon solvent with polar additives compounds such as tetrahydrofuran (THF and methyl tert-butyl ether (MTBE. The conditions for the synthesis of P-DMST were developed. The kinetics of polymerization for the first DMST-P unit was obtained. Analysis of physical and mechanical properties DMST-P samples was conducted. The optimum content of bound α-methylstyrene block copolymer provides a good combination of properties in a relatively wide temperature range. The tensile strength at normal and elevated temperatures, the hardness and the stiffness of the polymer increased by increasing the content of bound α-methylstyrene. The elongation and the elasticity reduced by increasing the content of bound α-methylstyrene.

  12. Polynuclear hafnium polyhydrides with a 1,3-butadiene-1,4-diyl fragment from hydrogenolysis of a butadiene alkyl complex

    NARCIS (Netherlands)

    Visser, Cindy; Hende, Johannes R. van den; Meetsma, Auke; Hessen, Bart

    2003-01-01

    Hydrogenolysis of (eta(5)-C5Me5)Hf(2,3-dimethyl-1,3-butadiene)CH2SiMe3 leads to the formation of the mixed-valence tetranuclear polyhydride (eta(5)-C5Me5)(4)Hf-4-(sigma(1):sigma(1):eta(4):eta(4)C(6)H(8)(mu-H)(6) , with a central 2,3-dimethyl-1,3-butadiene-1,4-diyl fragment. The same reaction in the

  13. Excited State Spectra and Dynamics of Phenyl-Substituted Butadienes

    DEFF Research Database (Denmark)

    Wallace-Williams, Stacie E.; Schwartz, Benjamin J.; Møller, Søren

    1994-01-01

    A combination of steady-state and dynamic spectral measurements are used to provide new insights into the nature of the excited-state processes of all-trans-1,4-diphenyl-1,3-butadiene and several analogs: 1,4-diphenyl- 1,3-cyclopentadiene, 1,1,4,4-tetraphenylbutadiene, 1,2,3,4-tetraphenyl-1,3-cyc...... indicate that phenyl torsional motion is not important to the excited-state dynamics and reveal alternative excited-state reaction pathways. The results demonstrate how molecular systems that are structually similar can exhibit different electronic properties and excited-state dynamics....

  14. Study on the thermal stability of styrene butadiene rubber nanocomposites

    Science.gov (United States)

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

    2012-07-01

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

  15. Pressure dependence of the Boson peak in poly(butadiene)

    CERN Document Server

    Frick, B

    2002-01-01

    Variation of pressure and temperature in inelastic neutron scattering experiments allows us to separate density and thermal energy contributions. We summarise briefly the influence of pressure and temperature on the dynamic scattering law of the polymer glass former poly(butadiene) far below the glass transition. We also show the advantage of using a liquid-niobium pressure cell in such studies. The effect of pressure on the boson peak is to shift the peak towards higher energies and to reduce the low-frequency modes more strongly below the boson-peak maximum than above. A decrease in the Debye-Waller factor with increasing pressure is observed. (orig.)

  16. POLYMER-SUPPORTED LANTHANIDE COMPLEXES FOR THE POLYMERIZATION OF BUTADIENE

    Institute of Scientific and Technical Information of China (English)

    YU Guangqian; LI Yuliang; LIU Chongming

    1992-01-01

    The characteristics of styrene-acrylic acid copolymer supported lanthanide complexes(SAAC Ln)(Ln=La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu) were described.butadiene, a peak in activity appeared at Nd and Pr, Sm, Eu and the heavy lanthanides exhibited low or no activities. The effects of some factors on the activities were discussed. The microstructure of the polymers obtained with all the lanthanides in the series were the same and the content of cis-1,4 polybutadiene attained was more than 98%.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  18. Structure and Tunneling Dynamics of gauche-1,3-BUTADIENE

    Science.gov (United States)

    Changala, Bryan; Baraban, Joshua H.; Martin-Drumel, Marie-Aline; Eibenberger, Sandra; Patterson, David; Stanton, John F.; Ellison, Barney; McCarthy, Michael C.

    2017-06-01

    We have recently shown that gauche-1,3-butadiene is unambiguously non-planar, with a C=C-C=C dihedral angle of about 34°, and readily tunnels between two equivalent gauche structures. In this talk, subsequent microwave studies of gauche-1,3-butadiene and its isotopologues as well as the empirical equilibrium structure will be summarized. The experiments have utilized the complementary techniques of cavity enhanced Fourier transform microwave (FTMW) spectroscopy with a supersonic expansion and chirped-pulse FTMW in a cryogenic buffer gas cell. The structural characterization is complicated by the effects of facile tunneling, and full dimensional ab initio rotational-VMP2 calculations have been performed to address this issue. We will show how the tunneling splitting frequency, which ranges between about 0.5 and 2.0 cm^{-1} (depending on the isotopologue), can be extracted from the experimental spectra by careful examination of tunneling-rotation perturbations. M.-A. Martin-Drumel et al., ISMS 2016, MI11

  19. Rheological properties of styrene butadiene styrene polymer modified road bitumens

    Energy Technology Data Exchange (ETDEWEB)

    Gordon D. Airey [University of Nottingham, Nottingham (United Kingdom). Nottingham Centre for Pavement Engineering, School of Civil Engineering

    2003-10-01

    The use of polymers for the modification of bitumen in road paving applications has been growing rapidly over the last decade as government authorities and paving contractors seek to improve road life in the face of increased traffic. Currently, the most commonly used polymer for bitumen modification is the elastomer styrene butadiene styrene (SBS) followed by other polymers such as styrene butadiene rubber, ethylene vinyl acetate and polyethylene. This paper describes the polymer modification of two penetration grade bitumens with SBS. Six polymer modified bitumens (PMBs) were produced by mixing the bitumens from two crude oil sources with a linear SBS copolymer at three polymer contents. The rheological characteristics of the SBS PMBs were analysed by means of conventional as well as dynamic mechanical analysis using a dynamic shear rheometer (DSR). The results of the investigation indicate that the degree of SBS modification is a function of bitumen source, bitumen polymer compatibility and polymer concentration, with the higher polymer concentrations in a high aromatic content bitumen producing a highly elastic network which increases the viscosity, complex modulus and elastic response of the PMB, particularly at high service temperatures. However, ageing of the SBS PMBs tends to result in a reduction of the molecular size of the SBS copolymer with a decrease in the elastic response of the modified road bitumen. 25 refs., 11 figs., 6 tabs.

  20. Arylation of Acrylamide and Acrylonitrile with Arenediazonium Salts Catalyzed by Palladium Acetate

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Arylation of acrylamide and acrylonitrile were carried out with various arenediazonium tetrafluoroborates in the presence of a catalytic amount of Pd(OAc)2 in ethanol and a variety of substituted (E)-cinnamamides and (E)-cinnamonitriles were obtained in high yields under mild reaction conditions.

  1. KINETICS OF POLYMERIZATION OF ACRYLONITRILE INITIATED BY VANADIUM(V) - THIOUREA REDOX SYSTEM

    Institute of Scientific and Technical Information of China (English)

    WU Jinyuan; YANG Chaoxiong; WU Yuxian

    1990-01-01

    The kinetics of polymerization of acrylonitrile (AN) initiated by quinquevalent vanadium (V5+ )-thiourea (TU) redox system has been investigated in aqueous nitric acid in the temperature range from 30 to 50 ℃ . The polymerization rate (Rp) can be expressed as follows:Rp= 2.80×105e- 14,200/RT[AN] 2,2[V5+] 0~1/3[TU] 0~4/3[HNO3] 0.2. In the copolymerization of acrylonitrile with methyl acrylate (MA), the reactivity ratios were found to be 1.0 and 1.1, respectively. The experimental observations suggest that the initiating species is probably a complex consisting of a central ion of Lewis acid-VO+2 and the ligands of Lewis bases-acrylonitrile, thiourea, and nitrate anions, while the initiating system in lower concentration, the polymerization of acrylonitrile does not occur if the thiourea is acidified prior to its reaction with quinquevalent vanadium. This indicates that the primary radicals (or the monomeric radicals in the present article) are produced by associated thiourea rather than isothiourea.

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

    Science.gov (United States)

    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.

  3. Preparation of anionically polymerized butadiene-co-styrene copolymer-multiwalled carbon nanotubes nanocomposites

    Institute of Scientific and Technical Information of China (English)

    Zhong Guang; Wang, Jing Hua; Ling Xu

    2012-01-01

    Poly(butadiene-co-styrene) copolymer/multi-walled carbon nanotubes (SB-MWNTs) nanocomposites are prepared via terminating anionically synthesized living poly(butadiene-styryl)lithium with acyl chlorides on the MWNTs,which obtained from the carboxylation and acylation of the MWNTs.Results from the characterization of the SB-MWNTs nanocomposites,including its soluble in solvent,UV-vis and TEM of the dissolved samples,TGA and SEM of nanocomposites are presented and discussed respectively.MWNTs treated by SB can be easily distributed in the SBR (styrene-butadiene rubber) matrix.

  4. SYNTHESIS OF STYRENE-BUTADIENE STATISTIC COPOLYMERS CONTAINING MAGNESIUM INITIATOR

    Directory of Open Access Journals (Sweden)

    A. V. Firsova

    2015-01-01

    Full Text Available The article discusses the use of organomagnesium initiators in the synthesis of styrene-butadiene random copolymer (SBR obtained solution polymerization and their influence on the properties of rubber. Selected organic magnesium dialkyl initiator is combined with a modifier, which is a mixed alkoxide of an alkali and alkaline earth metals, which allows to control the micr ostructure of the diene polymer and its molecular weight characteristics. Alcohol derivatives selected high-boiling alcohols tetra (hydroxypropyl ethylenediamine (lapromol 294 and tetrahydrofurfuryl alcohol (TGFS. Selection of high-boiling alcohols due to the fact that the destruction of alkoxide with aqueous polymer degassing they do not fall into the return solvent and almost fall into the exact water. The metal components of alkoxides are lithium, sodium, potassium, magnesium and calcium. The resulting solutions are stable when stored modifier t hroughout the year even at -40 °C. The scheme of obtaining the new catalyst systems based organomagnesium and alcoxide of alkali and alkaline earth metals, which yields as functionalized SBR with a statistical and a distribution block of butadiene and styrene was developed. The process of copolymerization with styrene to butadiene organomagnesium initiators as using an organolithium compound (n-butyllithium was carried out, and without it. Found that the addition of n-butyllithium in the reaction mixture leads to a sharp increase in the rate of reaction. The results of studies of the effect of composition of the initiator system on the structure of diene polymers. It was revealed that a mixed initiator system affords a high conversion of monomers (to 90 % in 1 hour 1,2-polybutadiene content increased to 60 %. The process of polymerization of only a mixture of organomagnesium initiators and alcoxide of alkali and alkaline earth metals are not actively proceeds, conversion of the monomers reaches to 90 % in 4 hours, the microstructure

  5. Durability of styrene-butadiene latex modified concrete

    Energy Technology Data Exchange (ETDEWEB)

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

    1997-05-01

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

  6. Photodegradation Mechanisms of Tetraphenyl Butadiene Coatings for Liquid Argon Detectors

    CERN Document Server

    Jones, B J P; Conrad, J M; Pla-Dalmau, A

    2013-01-01

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

  7. A Study of the Fluorescence Response of Tetraphenyl-butadiene

    CERN Document Server

    Jerry, R; Bugel, L; Conrad, J M

    2010-01-01

    Tetraphenyl-butadiene (TPB) is a widely used fluorescent wavelength-shifter. A common application is in liquid-argon-based particle detectors, where scintillation light is produced in the UV at 128 nm. In liquid argon experiments, TPB is often employed to shift the scintillation light to the visible range in order to allow detection via standard photomultiplier tubes. This paper presents studies on the stability of TPB with time under exposure to light. We also examine batch-to-batch variations. We compare scintillation-grade TPB to 99% pure TPB response. In the 99% pure samples, we report a yellowing effect, and full degradation of the TPB emission-peak, upon extended exposure to light.

  8. Carbon nanotubes as reinforcement of styrene-butadiene rubber

    Energy Technology Data Exchange (ETDEWEB)

    De Falco, Alejandro [Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento de Fisica, LPMPyMC, Pabellon 1, Buenos Aires 1428 (Argentina); Goyanes, Silvia [Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento de Fisica, LPMPyMC, Pabellon 1, Buenos Aires 1428 (Argentina); Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET) (Argentina)], E-mail: goyanes@df.uba.ar; Rubiolo, Gerardo H. [Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento de Fisica, LPMPyMC, Pabellon 1, Buenos Aires 1428 (Argentina); Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET) (Argentina); Departamento de Materiales, CNEA, Av. del Libertador 8250, Buenos Aires 1424 (Argentina); Mondragon, Inaki [Materials and Technologies Group, Escuela Univ. Politecnica, Dpto. Ingenieria Quimica y M. Ambiente, Universidad Pais Vasco, Pza. Europa 1, 20018 Donostia-San Sebastian (Spain); Marzocca, Angel [Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento de Fisica, LPMPyMC, Pabellon 1, Buenos Aires 1428 (Argentina)

    2007-10-31

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

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

    OpenAIRE

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

    2012-01-01

    Styrene–acrylonitrile Trimer (SAN Trimer), a by-product in production of acrylonitrile styrene plastics, was identified at a Superfund site in Dover Township, NJ, where childhood cancer incidence rates were elevated for a period of several years. SAN Trimer was therefore tested by the National Toxicology Program in a 2-year perinatal carcinogenicity study in F344/N rats and a bacterial mutagenicity assay; both studies gave negative results. To further characterize its genotoxicity, SAN Trimer...

  10. Dimedone-catalyzed Addition of Amines into Cyano Group: Facile Synthesis of Thiazol-2-yl Substituted E-Acrylonitriles

    Institute of Scientific and Technical Information of China (English)

    朱伟军; 屠兴超; 冯惠; 屠蔓苏; 姜波; 吴飞跃; 屠树江

    2012-01-01

    An efficient dimedone-catalyzed synthesis of highly functionalized thiazol-2-yl substituted E-acrylonitrile derivatives has been established through two-step reaction of a-thiocyanate ketones with malononitrile and amines. The a-thiocyanate ketones were subjected with malononitrile to provide thiazol-2-ylidenemalononitrile derivatives, followed with various amines in the presence of dimedone to yield the final thiazol-2-yl substituted acrylonitrile derivatives.

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

    Science.gov (United States)

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

    2016-09-07

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

  12. Morphology Structure and Properties of Hydrogenated Acrylonitrile Butadiene Rubber/Ultra-Fine Full-Vulcanized Acrylonitrile Butadiene Rubber Powder Blends%氢化丁腈橡胶/超细全硫化粉末丁腈橡胶共混物的结构与性能研究

    Institute of Scientific and Technical Information of China (English)

    刘俊杰; 张立群; 刘力; 高富强; 肖大玲; 卢咏来

    2009-01-01

    采用熔融共混工艺制备了氢化丁腈橡胶(HNBR)/超细全硫化粉末丁腈橡胶(UFPNBR)共混物,研究了共混物相态结构、动态力学性能、力学性能及老化性能,并与HNBR/NBR共混物作了对比.透射电镜观察表明:在HNBR/UFPNBR体系中,HNBR容易形成连续相,UFPNBR为分散相;在HNBR/NBR体系中容易形成双连续相结构. DMA动态力学性能分析表明:2种共混物都只有一个tanδ峰,且相容性较好.HNBR/UFPNBR共混物在玻璃化转变区的tanδ峰值逐渐降低,而HNBR/NBR体系的tanδ峰值先减小后增大.加入适量的UFPNBR能降低HNBR/UFPNBR共混物的压缩永久变形;与常规共混胶相比,HNBR/UFPNBR具有低脆性温度和良好的耐老化性能,但力学性能略低.

  13. Nitrilase-catalysed conversion of acrylonitrile by free and immobilized cells of Streptomyces sp.

    Indian Academy of Sciences (India)

    V K Nigam; A K Khandelwal; R K Gothwal; M K Mohan; B Choudhury; A S Vidyarthi; P Ghosh

    2009-03-01

    The biotransformation of acrylonitrile was investigated using thermophilic nitrilase produced from a new isolate Streptomyces sp. MTCC 7546 in both the free and immobilized state. Under optimal conditions, the enzyme converts nitriles to acids without the formation of amides. The whole cells of the isolate were immobilized in agar-agar and the beads so formed were evaluated for 25 cycles at 50°C. The enzyme showed a little loss of activity during reuse. Seventy-one per cent of 0.5 M acrylonitrile was converted to acid at 6 h of incubation at a very low density of immobilized cells, while 100% conversion was observed at 3 h by free cells.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

  16. Synthesis, Characterization and Photophysical Properties of Pyridine-Carbazole Acrylonitrile Derivatives

    OpenAIRE

    Pérez-Gutiérrez,Enrique; Percino, M. Judith; Chapela, Víctor M.; Cerón, Margarita; Maldonado, José Luis; Ramos-Ortiz, Gabriel

    2011-01-01

    in solid state, absorptions were at 398, 390, and 442 nm, respectively. The fluorescence emission was at 540, 540 and 604 nm, respectively, the 2-(4-pyridyl)-3-(N-ethyl-(3’-carbazolyl))acrylonitrile showed a red shift in the emission of 64 nm compared to the other two compounds. The fluorescence quantum yield for the compounds in powder form showed values of 0.05, 0.14, and 0.006, respectively

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

    OpenAIRE

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

    2012-01-01

    A screening-level risk assessment was conducted for styrene-acrylonitrile (SAN) Trimer detected at the Reich Farm Superfund site in Toms River, NJ. Consistent with a screening-level approach, on-site and off-site exposure scenarios were evaluated using assumptions that are expected to overestimate actual exposures and hazards at the site. Environmental sampling data collected for soil and groundwater were used to estimate exposure point concentrations. Several exposure scenarios were evaluate...

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

    Science.gov (United States)

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

    2011-02-01

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

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

    Science.gov (United States)

    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

  20. Stepwise mechanism of oxidative ammonolysis of propane to acrylonitrile over gallium-antimony oxide catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Osipova, Z.G.; Sokolovskii, V.D.

    1979-03-01

    The stepwise mechanism of oxidative ammonolysis of propane to acrylonitrile over gallium-antimony oxide catalysts GaSb/sub 19/O/sub x/, GaSb/sub 3/Ni/sub 1.5/0/sub x/, and GaSb/sub 2.5/Ni/sub 1.5/PW/sub 0//sub 0.25/O/sub x/ was studied at 450/sup 0/ and 550/sup 0/C by introducing alternating pulses of 0.5Vertical Bar3< propane/0.6Vertical Bar3< ammonia/helium (to reduce the steady-state catalytic surface) and 0.5Vertical Bar3< propane/0.6Vertical Bar3< ammonia/1.86Vertical Bar3< oxygen/helium mixtures into a fluidized-bed catalytic reactor. Over all the catalysts studied, the rates of acrylonitrile formation during the two types of pulses were very similar, but carbon dioxide was formed much faster during the reducing pulses, particularly at 450/sup 0/C. These findings suggested that acrylonitrile is formed by a stepwise redox mechanism involving consecutive interaction of propane and ammonia with the surface oxygen of the catalysts and oxidation of the reduced catalyst surface by gas-phase oxygen. The formation of carbon dioxide proceeds by both stepwise and associative mechanisms, the latter being more important at higher temperatures. The results are similar to published results for ammoxidation of propylene and olefins.

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

    Science.gov (United States)

    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.

  2. Adsorption of Acrylonitrile on Some Soils and Minerals from Aqueous Solutions

    Institute of Scientific and Technical Information of China (English)

    WUDE-YI; N.MATSUE; 等

    1993-01-01

    Equilibrium and kinetic studies have been made on the adsorption of acrylonitrile(CH2=CHCN) on three soils and four minerals from aqueous solutions.It was shown that the organic matter was the major factor affecting the adsorption process in the soils.The conformity of the equilibrium data to linear type(one soil) and Langmuir type(two soils) isotherms indicated that different mechanisms were involved in the adsorption.This behavior appears bo be related to the hydrophobicity of soil organic matter due to their composition and E4/E6 ratio of humic acids.The adsorption kinetics were also different among the soils,indicating the difference in porosity of organic matter among the soils,and the kinetics strongly affected the adsorption capacity of soils for acrylonitrile.Acrylonitrile was slightly adsorbed from aqueous solutions on pyrophyllite with electrically neutral and hydrophobic nature,and practically not on montmorillonite and kaolinite saturated with Ca.However,much higher adsorption occurred on the zeolitized coal ash,probably caused by high organic carbon content(107g/kg).

  3. STUDY ON POLYMERIC CATALYST—PALLADIUM COMPLEX WITH RADIATION GRAFTING ACRYLONITRILE ON INORGANIC COMPOUND

    Institute of Scientific and Technical Information of China (English)

    ZHANGWanxi; CHEJitai

    1993-01-01

    Polymer bound palladium (Pd) complex catalysts with grafting acrylonitrile on inorganic compound(MgO,Y-molecular sieve and SiO2) by pre-radiation method were studies.The palladium-grafting polymers have been investigated by X-ray photoelectron spectrscopy(XPS).It is indicated that peak width of C1s and O1s spectra of MgO-g-PAN-Pd(radiation-induced graft) is wider than that of MgO-PAN-Pd(chemical method) and Peak numbers of former are one more than later.According to the report in reference,this peak is attributed to -O-C group.Thus,the graft acrylonitrile on MgO may complete through oxygen atoms im MgO and β-carbon atoms in acrylonitrile.The polymer catalyst obtained by radiation grafting is a higher active hydrogenation catalyst for olefines and better antioxic than that of one obtained by chemical method,and it has selectivity for hydrogenation catalyst.

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

    Science.gov (United States)

    Adão; Saramago; Fernandes

    1999-09-01

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

  5. Bioaccumulation factors for chlorinated benzenes, chlorinated butadienes and hexachloroethane

    Energy Technology Data Exchange (ETDEWEB)

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

    1997-08-01

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

  6. Secondary organic aerosol formation from the photooxidation of isoprene, 1,3-butadiene, and 2,3-dimethyl-1,3-butadiene under high NOx conditions

    Directory of Open Access Journals (Sweden)

    D. R. Cocker III

    2011-02-01

    Full Text Available Secondary organic aerosol (SOA formation from atmospheric oxidation of isoprene has been the subject of multiple studies in recent years; however, reactions of other conjugated dienes emitted from anthropogenic sources remain poorly understood. SOA formation from the photooxidation of isoprene, isoprene-1-13C, 1,3-butadiene, and 2,3-dimethyl-1,3-butadiene is investigated for high NOx conditions. The SOA yield measured in the 1,3-butadiene/NOx/H2O2 irradiation system (0.089–0.178 was close to or slightly higher than that measured with isoprene under similar NOx conditions (0.077–0.103, suggesting that the photooxidation of 1,3-butadiene is a possible source of SOA in urban air. In contrast, a very small amount of SOA particles was produced in experiments with 2,3-dimethyl-1,3-butadiene. Off-line liquid chromatography – mass spectrometry analysis revealed oligoesters as the major SOA products observed from all dienes investigated. The oligoesters originate from the unsaturated aldehyde gas-phase diene reaction products, which undergo oligoester formation through heterogeneous oxidation under high NOx conditions. Oligoesters produced by the dehydration reaction between nitrooxypolyol and 2-methylglyceric acid monomer or its oligomer were also discovered in these experiments with isoprene as the starting diene. These oligomers are possible sources of the 2-methyltetrols found in ambient aerosol samples collected under high NOx conditions. Furthermore, in low-temperature experiments also conducted in this study, the SOA yield measured with isoprene at 278 K was 2–3 times as high as that measured at 300 K under similar concentration conditions. Although oligomerization plays an important role in SOA formation from isoprene photooxidation, the observed temperature dependence of SOA yield is largely explained by gas/particle partitioning of semi-volatile compounds.

  7. The acrylonitrile dimer ion: A study of its dissociation via self-catalysis, self-protonation and cyclization into the pyrimidine radical cation

    NARCIS (Netherlands)

    Ervasti, H.K.; Jobst, K.J.; Burgers, P.C.; Ruttink, P.J.A.; Terlouw, J.K.

    2007-01-01

    Large energy barriers prohibit the rearrangement of solitary acrylonitrile ions, CH2CHCN+, into their more stable hydrogen-shift isomers CH2CCNH+ or CHCH–CNH+. This prompted us to examine if these isomerizations occur by self-catalysis in acrylonitrile dimer ions. Such ions, generated by chemical

  8. Control of insects with fumigants at low temperatures: toxicity of mixtures of methyl bromide and acrylonitrile to three species of insects

    Energy Technology Data Exchange (ETDEWEB)

    Bond, E.J.; Buckland, C.T.

    1976-12-15

    Acrylonitrile can be mixed with methyl bromide to increase toxicity so that the quantity of methyl bromide required for control of Sitophilus granarius (L.), Tenebrio molitor L., and Tribolium confusum Jacquelin duval is reduced by one half. Mixtures of methyl bromide and acrylonitrile are considerably more effective at low temperatures than methyl bromide alone.

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

    Science.gov (United States)

    Liu, Shusheng; Cheng, Xiansu

    2010-11-01

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

  10. Genetic effects of 1,3-butadiene on the mouse testis.

    Science.gov (United States)

    Brinkworth, M H; Anderson, D; Hughes, J A; Jackson, L I; Yu, T W; Nieschlag, E

    1998-01-16

    1,3-Butadiene is a known male mouse germ-cell mutagen, to which humans may either be occupationally or environmentally exposed. Prolonged exposure to moderate or high doses in male mice can cause dominant lethal mutations and one report has indicated that 10 week inhalation administration of low doses can result in the production of malformed foetuses. The present study had dual purposes: (a) to attempt to clarify the suspected ability of sub-chronic (6 h/day, 5 days/wk, 10 weeks) low-dose exposure to 1,3-butadiene to induce heritable mutations in mouse male germ cells: (b) investigation of the relationships between testicular DNA damage, testicular DNA repair and foetal outcome. Adult male mice were exposed to low or moderate doses of 1,3-butadiene by inhalation sub-chronically or for a single 6 h period and either used for mating (sub-chronic exposure only) or for studies of DNA damage and repair. Litter size, dominant lethality and numbers of abnormal foetuses were determined the day preceding the normal day of parturition. Testicular DNA damage and repair were assessed by the Comet assay (for DNA damage) and the unscheduled DNA synthesis assay (for DNA repair). 1,3-Butadiene caused a statistically significant increase in dominant lethality at 125 ppm but not 12.5 ppm. No significant increase in DNA repair was found with either dose level or exposure period while only 6 h exposure to 125 ppm caused a small but significant increase in DNA damage as detected by the Comet assay. These effects demonstrate the reproductive genotoxicity of (125 ppm) 1,3-butadiene but do not confirm its ability to cause abnormalities in the offspring via the sperm. It is suggested that the relationship between 1,3-butadiene-induced DNA damage, DNA repair and heritable defects in the offspring may depend on the pattern of metabolites produced.

  11. Evaporative emissions of 1,3-butadiene from petrol-fuelled motor vehicles

    Science.gov (United States)

    Ye, Y.; Galbally, I. E.; Weeks, I. A.; Duffy, B. L.; Nelson, P. F.

    This study reports the identification and quantification of 1,3-butadiene in petrol and in the evaporative emissions from Australian light-duty passenger vehicles. The mass fraction of 1,3-butadiene in each of the different grades of any brand of Australian petrol was found to be relatively constant for a given marketing area. However, the mass fractions vary significantly between the different brands (or refineries) from 0.004±0.001% to 0.047±0.008%. The measurements of the evaporative emissions of 1,3-butadiene from in-service motor vehicles were performed using standard Australian Design Rule 37/00 (ADR 37/00) Sealed Housing Evaporative Determination (SHED) tests. For post-1985 catalyst equipped vehicles fuelled with unleaded petrol, average evaporative emissions of 1,3-butadiene were 9.4 (0.7-22) and 5.0 (0.1-23) mg per test for diurnal and hot soak SHED tests, respectively. The corresponding average evaporative emissions for the older, pre-1986 non-catalyst equipped vehicles fuelled with leaded petrol were 26.5 (11.7-45.4) and 9.2 (4.3-13.1) mg per test, respectively, about double the observed emissions from newer vehicles. For the complete vehicle set (all ages), the average mass fraction of 1,3-butadiene in the total hydrocarbon (sum of C 1-C 10 hydrocarbons) emission was 0.21±0.14% from the diurnal phase and was 0.11±0.06% from the hot-soak phase. Evaporative emissions were estimated to contribute about 4% (ranging from 1-15%) of the total (exhaust and evaporative) emissions of 1,3-butadiene from Australian motor vehicles.

  12. Sequential shape-selective adsorption and photocatalytic transformation of acrylonitrile production wastewater.

    Science.gov (United States)

    Dai, Yunrong; Song, Yonghui; Tu, Xiang; Jiang, Yanpeng; Yuan, Yu

    2015-11-15

    Acrylonitrile production wastewater has been widely recognized as one type of refractory organic wastewater because of its complicated composition and low bioavailability. It usually contains plenty of micromolecular nitrile and pyridine, resulting in high chemical oxygen demand (CODCr), total organic carbon (TOC) and total nitrogen (TN) concentrations. In this study, a novel microporous zeolite, CS-Z1, was developed as an adsorbent for rapidly shape-selective adsorption of the micromolecular pollutants from the acrylonitrile production wastewater, and a visible light-driven Ti-β-Bi2O3 photocatalysis was introduced to sequentially treat the residual macromolecular pollutants for complete purification. The adsorption processes by CS-Z1 were mostly achieved within the first 5 min, and the equilibrium was reached quickly after 30 min, where the CODCr, TOC and TN removal efficiencies of the wastewater were as high as 93.5%, 92.2% and 96.8%, respectively, much higher than those by other adsorbents. Furthermore, the adsorption efficiencies of CS-Z1 were barely affected by the variation of pH value and temperature, which was mainly attributed to the shape-selective adsorption mechanism of the CS-Z1 zeolite. The Ti-β-Bi2O3 photocatalysis could remove more than 95% of the residual macromolecular pollutants in the wastewater, where a synergistic mechanism of reduction-oxidation/polymerization was proposed. In a 108 h of CS-Z1 adsorption and Ti-β-Bi2O3 photocatalysis sequential process, the CODCr, TOC and TN concentrations was reduced to below 20, 7 and 5 mg L(-1), respectively, demonstrating the excellent practical potential of the sequential treatment system for acrylonitrile production wastewater. Copyright © 2015 Elsevier Ltd. All rights reserved.

  13. Simulation of Particle Growth in Gas Phase Polymerization of Butadiene by the Multigrain Model

    Institute of Scientific and Technical Information of China (English)

    孙建中; 赵军子; 何斯征; 周其云

    2001-01-01

    Gas phase polymerization of butadiene by neodymium catalyst was modeled. The effects of mass and heat transfer resistances in the external boundary layer and within particles, sorption of butadiene in polybutadiene,and deactivation of active sites on polymer particle growth and morphology were studied. Simulation results show that the effects of intraparticle mass and heat transfer resistances on the growth rate of polymer particles are insignificant, and that there is no significant effect of mass transfer resistance on the morphology of polymer particles.The simulation results were compared with the experimental results.

  14. Azidated Ether-Butadiene-Ether Block Copolymers as Binders for Solid Propellants

    Science.gov (United States)

    Cappello, Miriam; Lamia, Pietro; Mura, Claudio; Polacco, Giovanni; Filippi, Sara

    2016-07-01

    Polymeric binders for solid propellants are usually based on hydroxyl-terminated polybutadiene (HTPB), which does not contribute to the overall energy output. Azidic polyethers represent an interesting alternative but may have poorer mechanical properties. Polybutadiene-polyether copolymers may combine the advantages of both. Four different ether-butadiene-ether triblock copolymers were prepared and azidated starting from halogenated and/or tosylated monomers using HTPB as initiator. The presence of the butadiene block complicates the azidation step and reduces the storage stability of the azidic polymer. Nevertheless, the procedure allows modifying the binder properties by varying the type and lengths of the energetic blocks.

  15. Synthesis And Properties Of Functional Ultra-High Molecular Weight Transparent Styrene-Butadiene Block Copolymer

    Institute of Scientific and Technical Information of China (English)

    GONG Guang-bi; ZHAO Xu-tao; WANG Gui-lun

    2004-01-01

    Functional ultra-high molecular weight transparent styrene-butadiene block copolymer possesses both high transparency and impact resistance and has excellent comprehensive properties prior to other transparent resins. In this paper we not only use anionic polymerization process which includes 1 time addition of initiator and 3 time addition of monomers, but also introduce functional coupling agent for the fist time to prepare mentioned functional block copolymer.The typical preparation process is described as the following: (a) Adding cyclohexane, styrene and initiator to the polymerizer, the polymerization is carried out at 50~75℃; (b) adding a mixture of styrene, butadiene and cyclohexane, the polymerization is carried out at 50~70℃ ;(c) adding a mixture of butadiene and cyclohexane, the polymerization is finished at 60~70℃ ;(d) adding coupling agent which is a substituted trimethoxysilane being expressed as N-silane, O-silane and being converted into a functional group (-NH, -OH) of mentioned block copolymer, coupling at 75~90℃ for 1 hr; (e) The amounts of coupling agent are about one sixth to one third of the initiator; (f) treating the prepared copolymer solution with some water and Carbon dioxide at 50~70℃ for 15 min.The copolymer is from three-arm to six-arm mono-modal radial block copolymer having 75~90%styrene, 10~25% butadiene and functional group of-NH or-OH. of the copolymer, Mw is from 30×104 to 120×104, Mw/Mn from 2.0 to 2.5, Izod notched impact strength 50~65 J/m,light transmission not less 87.5%, tensile strength not less 45 Mpa.The exploratory research shows that the mole ratio and feed rate of the random copolymerized styrene-butadiene, as well as the total ratio of styrene-butadiene have greater influence on the properties of the copolymer. The following model is established:Y=bo +∑3j=1 bjxj+∑3j=1bkjxkxj+∑3j=1bjjx2j (k<j)Where: Y is the light transmission, tensile strength, elongation, Izod notched impact

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1983-12-01

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

  17. STUDIES ON THE POLYMERIZATION OF ACRYLONITRILE INITIATED BY METAVANADATE- CONTAINING ANION EXCHANGER-THIOUREA REDOX SYSTEM

    Institute of Scientific and Technical Information of China (English)

    YANG Chaoxiong; WU Jinyuan; WU Yuxian

    1991-01-01

    The polymerization of acrylonitrile (AN) in aqueous nitric acid initiated by metavanadate-containing anion exchange resin (PV)-thiourea (TU) redox system at 20- 40 ℃. has been investigated. The overall rate of polymerization (Rp) is given by Rp= 1.92 × 104 e -6,860/RT [AN]1.2[PV]0.44[TU]1.0[HNO3]1.0 The kinetic parameters differed from those of V5+-TU system indicated that the generation of the primary radicals is mainly a difffusion-controlled reaction . The effect of macromolecular field arisen from the polymer matrix exerts a great influence on the polymerization process.

  18. DEPENDENCE OF ACRYLONITRILE POLYMERIZATION KINETICS ON THE COMPOSITION OF POLYAMID OXIME -THIOUREA SYSTEM

    Institute of Scientific and Technical Information of China (English)

    WU Jinyuan; YANG Chaoxiong; ZHANG Guangzhao

    1993-01-01

    The polymerization of acrylonitrile (AN) initiated by polypropylene based-polyamidoxime (PPAO)- thiourea (TU) system was investigated at [ TU]/[ PPAO] > 0.5 molar ratio. It shows that the variation of the concentrations of PPAO, thiourea and nitric acid does not exert an observable influence on the reaction rate. The overall rate of polymerization (Rp) is Rp = 2.07e - 7,800/RT[AN] 2.0The zero order dependence on PPAO and thiourea concentrations and the lowest value of the collision frequence factor were considered to be a feature of the primary radical termination.

  19. ION CONDUCTION IN COMPLEX OF ACRYLONITRILE-COPOLYMERIZED COMB POLYETHER WITH LITHIUM PERCHLORATE

    Institute of Scientific and Technical Information of China (English)

    XU Kang; DENG Zhenghua; WAN Guoxiang

    1991-01-01

    Poly ( oligoether methacrylate- co- acrylonitrile ) s, P ( MEOn- AN ), with oligoether pendants of different lengths were synthesized and the ion conduction property of their Li-salt complexes was studied as the function of polymer structure. At proper copolymer composition, lithium concentration and pendant length, the ion conductivity reaches 7.0×10-5S/cm at ambient temperature, together with improved mechanical strength. The ion transport in the polymer media is assisted by segmental relaxation ,which is confirmed both by the consistency between ion conductivity and Tg and by the study of TSC.

  20. Adsorptive removal of acrylonitrile by commercial grade activated carbon: kinetics, equilibrium and thermodynamics.

    Science.gov (United States)

    Kumar, Arvind; Prasad, B; Mishra, I M

    2008-04-01

    The potential of activated carbons--powdered (PAC) and granular (GAC), for the adsorption of acrylonitrile (AN) at different initial AN concentrations (50PAC and GAC, respectively. Error analysis also confirmed the efficacy of the R-P isotherm to best fit the experimental data. The pseudo-second order kinetic model best represents the kinetics of the adsorption of AN onto PAC and GAC. Maximum adsorption capacity of PAC and GAC at optimum conditions of AN removal (adsorbent dose approximately 20 g/l of solution, and equilibrium time approximately 5 h) was found to be 51.72 and 46.63 mg/g, respectively.

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

    Science.gov (United States)

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

    2014-07-01

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

  2. Acrylonitrile-methyl Methacrylate Copolymer Films Containing Microencapsulated n-Octadecane

    Institute of Scientific and Technical Information of China (English)

    LI Jun; HAN Na; ZHANG Xing-xiang

    2006-01-01

    Acrylonitrile-methyl methacrylate copolymer was synthesized in aqueous solution by Redox. The copolymer was mixed with 10 - 40 wt% of microencapsulated n-octadecane (MicroPCMs) in water. Copolymer films containing MicroPCMs were cast at room temperature in N, N-Dimethylformamide solution. The copolymer of acrylonitrile-methyl methacrylate and the copolymer films containing MicroPCMs were characterized by using Fourier Transform Infrared Spectroscopy (FTIR), Differential Scanning Calorimetry (DSC), Thermogravimetric Analyzer (TG), X-ray Diffrac tion (XRD) and Scanning Electron Microscopy (SEM), etc.The microcapsules in the films are evenly distributed in the copolymer matrix. The heat-absorbing temperatures and heat-evolving temperatures of the films are almost the same as that of the MicroPCMs, respectively, and fluctuate in a slight range. In addition, the enthalpy efficiency of MicroPCMs rises with the contents of MicroPCMs increasing.The crystallinity of the film increases with the contents of MicroPCMs increasing.

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

    Science.gov (United States)

    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.

  4. Theoretical study on the gas phase reaction of acrylonitrile with a hydroxyl radical.

    Science.gov (United States)

    Sun, Jingyu; Wang, Rongshun; Wang, Baoshan

    2011-10-01

    The mechanism and kinetics of the reaction of acrylonitrile (CH(2)=CHCN) with hydroxyl (OH) has been investigated theoretically. This reaction is revealed to be one of the most significant loss processes of acrylonitrile. BHandHLYP and M05-2X methods are employed to obtain initial geometries. The reaction mechanism conforms that OH addition to C[double bond, length as m-dash]C double bond or C atom of -CN group to form the chemically activated adducts, 1-IM1(HOCH(2)=CHCN), 2-IM1(CH(2)=HOCHCN), and 3-IM1(CH(2)=CHCOHN) via low barriers, and direct hydrogen abstraction paths may also occur. Temperature- and pressure-dependent rate constants have been evaluated using the Rice-Ramsperger-Kassel-Marcus theory. The calculated rate constants are in good agreement with the experimental data. At atmospheric pressure with N(2) as bath gas, 1-IM1(OHCH(2)=CHCN) formed by collisional stabilization is the major product in the temperature range of 200-1200 K. The production of CH(2)CCN and CHCHCN via hydrogen abstractions becomes dominant at high temperatures (1200-3000 K).

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

    Science.gov (United States)

    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...

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

    Science.gov (United States)

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

    2010-09-15

    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 significantly higher than in police offices used as control sites (pbutadiene (median 3.08 microg/m(3)) than office policemen (median 6.17 microg/m(3) for benzene and 0.37 microg/m(3) for 1,3-butadiene) (pbutadiene metabolite, monohydroxy-butenyl mercapturic acid. Biomarkers of early biological effects, 8-hydroxy-2'-deoxyguanosine in leukocytes (8-OHdG), DNA-strand breaks, and DNA-repair capacity, measured as an increase in gamma ray-induced chromosome aberrations were significantly higher in traffic policemen than controls (pbutadiene exposure were significantly associated with 8-OHdG and olive tail moment at pbutadiene on DNA damage. These results indicated that traffic policemen, who are exposed to benzene and 1,3-butadiene at the roadside in central Bangkok, are potentially at a higher risk for development of diseases such as cancer than office policemen.

  7. Blends of Styrene-Butadiene-Styrene Triblock Copolymer with Random Styrene-Maleic Anhydride Copolymers

    NARCIS (Netherlands)

    Piccini, Maria Teresa; Ruggeri, Giacomo; Passaglia, Elisa; Picchioni, Francesco; Aglietto, Mauro

    2002-01-01

    Blends of styrene-butadiene-styrene triblock copolymer (SBS) with random styrene-maleic anhydride copolymers (PS-co-MA), having different MA content, were prepared in a Brabender Plastigraph mixer. The presence of polystyrene (PS) blocks in the SBS copolymer and the high styrene content (93 and 86 w

  8. Emission of 1,3-butadiene from petrol-driven motor vehicles

    Science.gov (United States)

    Ye, Y.; Galbally, I. E.; Weeks, I. A.

    This study reports the measurement of 1,3-butadiene emissions from 30 petrol-driven vehicles from the Australian car fleet using the Australian Design Rule 37/00 vehicle test procedure. Six of the cars tested were not equipped with catalytic converters and used leaded petrol as fuel. The remaining 24 cars were fitted with catalytic converters and used unleaded petrol. 1,3-Butadiene in exhaust samples was found to degrade rapidly in SUMMA treated stainless steel canisters and the degradation followed first-order kinetics. The rate coefficient of the decay can be represented by a linear dependence on the concentration of nitrogen oxides in the exhaust ( r2 = 0.79, n = 43), and the gas-phase reaction of NO 2 and 1,3-butadiene may have a major role in this loss. The 1,3-butadiene concentrations used to estimate vehicle emissions were corrected for this loss using the decay rate constant either observed from replicate analyses or from the NO x concentrations in the samples. The measurements showed that 1,3-butadiene was emitted at a rate of 20.7 ± 9.2 mg km -1 from 6 non-catalyst vehicles. There was considerable scatter in the observations from catalyst equipped vehicles and we infer that this was due to the malfunction of the emission control devices on some vehicles. The 19 vehicles that appeared to have functioning catalyst emission control devices had an average emission rate of 2.1 ± 1.5 mg km -1. These emission rates are consistent with atmospheric observations and are much higher than those reported previously. We calculate that more than 90% of the 1,3-butadiene in engine exhaust comes from the common alkane and aromatic constituents of the fuel. A comparison of emissions in the different phases of the drive cycle indicates that current emission controls remove more than 90% of the 1,3-butadiene from the initial exhaust mixture.

  9. Exposure and risk assessment of 1,3-butadiene in Japan.

    Science.gov (United States)

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

    2007-03-20

    1,3-Butadiene is on the list of Substances Requiring Priority Action published by the Central Environmental Council of Japan in 1996. Emission of 1,3-butadiene has been controlled by a voluntary reduction program since 1997. Although the industrial emission of 1,3-butadiene in Japan has decreased in recent years, primarily due to a voluntary industrial emissions reduction program, the risks of exposure to it remain largely unknown. We assessed the risks and consequences of exposure to 1,3-butadiene on human health. A remarkable advantage of our risk assessment approach is the detailed assessment of exposure. Previously, we developed two different models that can be applied for the assessment of exposure: the first, the AIST-ADMER model estimates regional concentration distributions, whereas the second, the METI-LIS model estimates concentration distributions in the vicinity of factories. Both models were used for the assessment of exposure to 1,3-butadiene. Using exposure concentration and carcinogenic potency determined and reported by Environment Canada and Health Canada, we evaluated the excess lifetime cancer risk for persons exposed to 1,3-butadiene over the course of a lifetime. The results suggested that the majority of the population in Japan has an excess lifetime cancer risk of less than 10(-5), whereas a small number of people living close to industrial sources had a risk of greater than 10(-5). The results of the present assessment also showed that 1,3-butadiene in the general environment originates primarily from automobile emissions, such that a countermeasure of reducing emissions from cars is expected to be effective at reducing the total cancer risk among Japanese. On the other hand, individual risks among a population living in the vicinity of certain industrial sources were found to be significantly higher than those of the population living elsewhere, such that a reduction in emissions from a small number of specific industrial sources should be

  10. Nanostructured carbon-crystalline titania composites from microphase separation of poly(ethylene oxide-b-acrylonitrile) and titania sols.

    Science.gov (United States)

    Stefik, Morgan; Lee, Jinwoo; Wiesner, Ulrich

    2009-05-14

    A simple "one-pot" method utilizing a graphitic carbon source containing poly(ethylene oxide-b-acrylonitrile) diblock copolymer as a structure directing agent was used to synthesize carbon-crystalline titania composites as well as crystalline mesoporous titania materials after oxidative carbon removal.

  11. Absorption cross-sections of the C-h overtone of volatile organic compounds: 2 methyl-1,3-butadiene (isoprene), 1,3-butadiene, and 2,3-dimethyl-1,3-butadiene.

    Science.gov (United States)

    Cias, Pawel; Wang, Chuji; Dibble, Theodore S

    2007-02-01

    Many molecules or transient radicals have well-documented absorption cross-sections in the ultraviolet (UV) region, but their absorption cross-sections in the near-infrared (NIR) region are much less often known and are difficult to measure. We propose a method to determine the unknown NIR absorption cross-sections using the known absorption cross-sections in the UV region, in which single-path UV absorption spectroscopy and NIR continuous wave cavity ringdown spectroscopy (cw-CRDS) are employed in a cross-arm reaction chamber for simultaneous measurements. Without knowing the actual sample partial pressures (or concentrations), the NIR absorption cross-sections can be accurately determined through the two sets of measurements. The method is demonstrated by measuring the NIR absorption cross-section of the first overtone of the asymmetric C-H stretch of 2-methyl-1,3-butadiene (isoprene) (3.24 (+/-0.16) x 10(-22) cm(2) molecule(-1)) at 1651.52 nm using the known value of the absorption cross-section at 220 nm. The diode laser wavelength was calibrated by atmospheric cavity ringdown spectra of CH(4), CO(2), and H(2)O. By comparison with sample pressure measurements, this method can also be used as a pressure calibration means for the reaction chamber, and this has been demonstrated with two additional measurements of the absorption cross-sections of 1,3-butadiene and 2,3-dimethyl-1,3-butadiene (2.50 (+/- 0.08) x 10(-22) and 2.82 (+/-0.16) x 10(-22) cm(2) molecule(-1), respectively) at 1651.52 nm. The applicability of the method to determining absorption cross-sections using the simultaneous measurements of cw-CRDS and single-path absorption spectroscopy is discussed.

  12. Synthesis of novel N-, S-substituted-polyhalo-1, 3-butadienes and crystal structure of dibutadienyl homopiperazine

    Indian Academy of Sciences (India)

    Nahide Gulsah Deniz; Cemil Ibis

    2013-07-01

    Polyhalogenated-2-nitro-1, 3-butadienes are important synthetic precursors for a variety of polyfunctionalized bioactive heterocycles. Herein, we report the reactions of 1, 1, 3, 4, 4-pentachloro-2-nitro-1, 3-butadiene 1 and 4-bromo-1, 1, 3, 4-tetrachloro-2-nitro-1, 3-butadiene 2 with amino and thiol containing nucleophiles to obtain highly functionalized (E)-polyhalodiene-2-nitro-1, 3-butadiene derivatives. Most of these reactions were found to be highly selective resulting in good to high yields of the products. All new compounds have been characterized by nuclear magnetic resonance spectroscopy (NMR), mass spectrometry (MS) and Fourier transform infrared spectroscopy (FT-IR) spectroscopic data. Single crystal X-ray structure analysis of compound 8c is reported.

  13. Conversion of ethanol to 1,3-butadiene over Na doped ZnxZryOz mixed metal oxides

    Energy Technology Data Exchange (ETDEWEB)

    Baylon, Rebecca A.; Sun, Junming; Wang, Yong

    2016-01-01

    Despite numerous studies on different oxide catalysts for the ethanol to 1,3-butadiene reaction, few have identified active sites (i.e., type of acidity) correlated to the catalytic performances. In this work, the type of acidity needed for ethanol to 1,3-butadiene conversion has been studied over Zn/Zr mixed oxide catalysts. Specifically, synthesis method, Zn/Zr ratio, and Na doping have been used to control the surface acid-base properties, as confirmed by characterizations such as NH3-TPD and IR-Py techniques. The 2000 ppm Na doped Zn1Zr10Oz-H with balanced base and weak Bronsted acid sites was found to give not only high selectivity to 1,3-butadiene (47%) at near complete ethanol conversion (97%), but also exhibited a much higher 1,3-butadiene productivity than other mixed oxides studied.

  14. Comparison of cancer risks projected from animal bioassays to epidemiologic studies of acrylonitrile-exposed workers.

    Science.gov (United States)

    Ward, C E; Starr, T B

    1993-10-01

    Bioassay findings have demonstrated that acrylonitrile (ACN) is a rodent carcinogen, but the available epidemiologic evidence provides little support for the human carcinogenicity of ACN. This discordance between laboratory animal and human study findings is explored by determining post hoc the statistical power of 11 epidemiologic studies of ACN-exposed workers to detect the all-site and brain cancer excesses that are projected from rodent drinking water bioassay data. At reasonable estimates of the level and duration of exposures among the occupational cohorts, a majority of the human studies had sufficient power (> 80%) to detect the projected excesses, yet such responses were consistently absent. We conclude, subject to certain caveats, that the upper bound estimate of ACN's inhalation cancer potency of 1.5 x 10(-4) per ppm is too high to be consistent with the human ACN experience.

  15. Carcinogenicity and other health effects of acrylonitrile with reference to occupational exposure limit.

    Science.gov (United States)

    Sakurai, H

    2000-04-01

    The occupational exposure limit for acrylonitrile (AN) has been set by many organizations on the basis of its carcinogenicity. However, recent epidemiological studies do not afford evidence supporting the hypothesis that AN is carcinogenic to humans. Review of the 18 published cohort studies revealed that, although there is not adequate evidence in humans for carcinogenicity of AN, the possibility of a causal association between high exposure to AN and lung cancer in humans cannot be excluded. It was pointed out that carcinogenic potential of AN may be weak, if any, to humans, and the current occupational exposure limit (OEL) for AN of 2 ppm was evaluated as appropriate in view of AN exposure levels reported by epidemiological studies. Based also on review of the literature on health effects other than carcinogenicity, it was concluded that the current OEL for AN is a reasonable value and there is no need for a revision at present.

  16. Reversible Addition-Fragmentation Chain Transfer Polymerization of Acrylonitrile under Irradiation of Blue LED Light

    Directory of Open Access Journals (Sweden)

    Zhicheng Huang

    2016-12-01

    Full Text Available Compared to unhealthy UV or γ-ray and high-energy-consumption thermal external stimuli, the promising light emitting diode (LED external stimulus has some outstanding technological merits such as narrow wavelength distribution, low heat generation and energy consumption, and safety for human beings. In this work, a novel reversible addition-fragmentation transfer (RAFT polymerization system for acrylonitrile (AN was developed under the irradiation of blue LED light at room temperature, using 1,2,3,5-tetrakis(carbazol-9-yl-4,6-dicyanobenzene (4CzIPN as a novel radical initiator and 2-cyanoprop-2-yl-1-dithionaphthalate (CPDN as the typical chain transfer agent. Well-defined polyacrylonitrile (PAN with a controlled molecular weight and narrow molecular weight distribution was successfully synthesized. This strategy may provide another effective method for scientific researchers or the industrial community to synthesize a PAN-based precursor of carbon fibers.

  17. Efficient polymerization of acrylonitrile catalyzed by diValent lanthanide complex/sodium phenolate systems

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Four divalent lanthanide complexes Sm(ArO)2(THF)4, Yb(ArO)2(THF)3, Eu(ArO)2(THF)3 (ArO = 2,6-ditert-butyl-4-methylphenolate) and (ButCp)2Sm(THF)2 were synthesized. Their catalytic activities on the polymerization of acrylonitrile were studied. The catalytic activities were influenced by the central metal ions involved. The catalytic activities of these divalent lanthanide complexes can be greatly increased by adding NaOC~H2-2,6-But2-4-Me,NaOC6H4-4-But, or NaOC10H6-2-Me. The amount of additive has apparent effect on the catalytic activity, but the additive has no effect on the tacticity of the resulting polyacrylonitrile

  18. Improved procedure for determination of acrylonitrile in foods and its application to meat.

    Science.gov (United States)

    Page, B D; Charbonneau, C F

    1985-01-01

    The previously described headspace-gas chromatographic procedure for the determination of acrylonitrile (AN) in several foods, with N/P selective detection, has been modified to include packaged luncheon meats. The loss of AN during equilibration at 100 degrees C in meat samples as well as the previously described loss in cold pack cheese and peanut butter has been studied. The loss of AN could be prevented by the addition of 10% phosphoric acid, which increases the acidity of the food-acid-salt slurry to pH 1.2-1.5. This acidification permits detection of AN at 2 ppb (5% FSD at 16 X 10(-2) amp/mV) in all foods studied. AN was not detected in 10 samples of luncheon meat packaged in AN-based plastic which contained up to 2.6 ppm AN.

  19. A flexible Li polymer primary cell with a novel gel electrolyte based on poly(acrylonitrile)

    Science.gov (United States)

    Akashi, Hiroyuki; Tanaka, Ko-ichi; Sekai, Koji

    The performance of a Li polymer primary cell with fire-retardant poly(acrylonitrile) (PAN)-based gel electrolytes is reported. By optimizing electrodes, electrolytes, the packaging material, and the structural design of the polymer cell, we succeeded in developing a "film-like" Li polymer primary cell with sufficient performance for practical use. The cell is flexible and less than 0.5 mm thick, which makes it suitable for a power source for some smart devices, such as an IC card. Fast cation conduction in the gel electrolyte minimizes the drop of the discharge capacity even at -20 °C. The high chemical stability of the gel electrolytes and the new packaging material allow the self-discharge rate to be limited to under 4.3%, which is equivalent to that of conventional coin-shaped or cylindrical Li-MnO 2 cells.

  20. The Reproductive Effects Assessment Group's report on the mutagenicity of 1,3-butadiene and its reactive metabolites.

    Science.gov (United States)

    Rosenthal, S L

    1985-01-01

    A major data gap for assessing heritable risk from exposure to 1,3-butadiene is the lack of mammalian mutagenicity data. The data base on the mutagenic potential of 1,3-butadiene is limited to three bacterial studies from the same laboratory. Two of these studies were positive only in the presence of liver S9 mix from chemically pretreated animals. In vitro data suggest that 1,3-butadiene is metabolized to two epoxide intermediates. 3,4-Epoxybutene, one potential reactive metabolite of 1,3-butadiene, is a monofunctional alkylating agent and is a direct-acting mutagen in bacteria. In addition, unpublished data suggest that 3,4-epoxy-butene induces DNA damage and chromosomal aberrations in mice. Another potential reactive metabolite, 1,2:3,4-diepoxybutane, is a bifunctional alkylating agent and is mutagenic in a wide variety of organisms (bacteria, fungi, and the germ cells of Drosophila). This metabolite also induces DNA damage in mice and in cultured hamster cells, is clastogenic in fungi and cultured rat cells, and produces chromosome damage/breakage in Drosophila germ cells. These data, when combined with evidence that 1,3-butadiene is carcinogenic in rodent gonadal tissues and is associated with gonadal atrophy in mice, constitute suggestive evidence that 1,3-butadiene may be a human germ cell mutagen. However, because the mutagenicity of 1,3-butadiene has been studied only in bacteria, studies in mammalian test systems are needed to further characterize the mutagenic potential of 1,3-butadiene.

  1. The Effect of Uncertainty in Exposure Estimation on the Exposure-Response Relation between 1,3-Butadiene and Leukemia

    Directory of Open Access Journals (Sweden)

    George Maldonado

    2009-09-01

    Full Text Available Abstract: In a follow-up study of mortality among North American synthetic rubber industry workers, cumulative exposure to 1,3-butadiene was positively associated with leukemia. Problems with historical exposure estimation, however, may have distorted the association. To evaluate the impact of potential inaccuracies in exposure estimation, we conducted uncertainty analyses of the relation between cumulative exposure to butadiene and leukemia. We created the 1,000 sets of butadiene estimates using job-exposure matrices consisting of exposure values that corresponded to randomly selected percentiles of the approximate probability distribution of plant-, work area/job group-, and year specific butadiene ppm. We then analyzed the relation between cumulative exposure to butadiene and leukemia for each of the 1,000 sets of butadiene estimates. In the uncertainty analysis, the point estimate of the RR for the first non zero exposure category (>0–<37.5 ppm-years was most likely to be about 1.5. The rate ratio for the second exposure category (37.5–<184.7 ppm-years was most likely to range from 1.5 to 1.8. The RR for category 3 of exposure (184.7–<425.0 ppm-years was most likely between 2.1 and 3.0. The RR for the highest exposure category (425.0+ ppm-years was likely to be between 2.9 and 3.7. This range off RR point estimates can best be interpreted as a probability distribution that describes our uncertainty in RR point estimates due to uncertainty in exposure estimation. After considering the complete probability distributions of butadiene exposure estimates, the exposure-response association of butadiene and leukemia was maintained. This exercise was a unique example of how uncertainty analyses can be used to investigate and support an observed measure of effect when occupational exposure estimates are employed in the absence of direct exposure measurements.

  2. Immunoassay of haemoglobin-acrylonitrile adduct in rat as a biomarker of exposure.

    Science.gov (United States)

    L Wong Yu Ting Zheng Junyu Li Carlo H Tamburro Frederick W Benz, J

    1998-01-01

    Acrylonitrile (AN) is a rat carcinogen. Human exposure may come from chemical industries and smoking. A haemoglobin adduct of acrylonitrile (Hb-AN) has been used as a biomarker of exposure by means of gas chromatography-mass spectrometry (GC-MS) analysis. We have developed specific monoclonal antibodies (Mab) to human Hb-AN and wish to report evaluation of an immunoassay in rats using an Mab that cross-reacts with rat Hb-AN. A dose response study of LD 0, 10, 50, and 90 in Sprague-Dawley rats was undertaken, with each rat receiving \\[2,3-14C]AN at 50 Ci kg-1 sc, and Hb from an aliquot of blood was taken for covalent binding analysis by liquid scintillation spectrometry and fluorescence ELISA. The dose responses of rats at 0.25, 0.5, 1.0, and 2.0 h after AN doses of 20, 50, 80, 115 mg kg-1 were compared by both methods with Hb and globin samples. Regression analysis showed a linear relationship between immunoassay and 14C-AN binding. This indicates that an antigenic form of Hb-AN may be used as a surrogate of Hb-AN adduct. The sensitivity of ELISA was tested in rats exposed for 1 h to sub-toxic doses of AN (10-1.1 mg kg-1). Quantification of Hb-AN by immunoassay was achieved by calibration with a synthetic adduct HbAN4h, a reference adduct prepared by treating rat Hb with excess AN for 4 h. ELISA and GC-MS analysis of N-terminal valine-AN in the Hb-AN adduct were compared and similar detection levels were found. This rat study appears to have validated the new immunoassay method for biomonitoring of AN exposure.

  3. Perinatal Toxicity and Carcinogenicity Studies of Styrene –Acrylonitrile Trimer, A Ground Water Contaminant

    Science.gov (United States)

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

    2015-01-01

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

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

    Science.gov (United States)

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

    2013-12-06

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

  5. Photoinitiated decomposition of substituted ethylenes: The photodissociation of vinyl chloride and acrylonitrile at 193 nm

    Energy Technology Data Exchange (ETDEWEB)

    Blank, D.A.; Suits, A.G.; Lee, Y.T. [Lawrence Berkeley National Lab., CA (United States)] [and others

    1997-04-01

    Ethylene and its substituted analogues (H{sub 2}CCHX) are important molecules in hydrogen combustion. As the simplest {pi}-bonded hydrocarbons these molecules serve as prototypical systems for understanding the decomposition of this important class of compounds. The authors have used the technique of photofragment translational spectroscopy at beamline 9.0.2.1 to investigate the dissociation of vinyl chloride (X=Cl) and acrylonitrile (X=CN) following absorption at 193 nm. The technique uses a molecular beam of the reactant seeded in helium which is crossed at 90 degrees with the output of an excimer laser operating on the ArF transition, 193.3 nm. The neutral photoproducts which recoil out of the molecular beam travel 15.1 cm where they are photoionized by the VUV undulator radiation, mass selected, and counted as a function of time. The molecular beam source is rotatable about the axis of the dissociation laser. The authors have directly observed all four of the following dissociation channels for both systems: (1) H{sub 2}CCHX {r_arrow} H + C{sub 2}H{sub 2}X; (2) H{sub 2}CCHX {r_arrow} X + C{sub 2}H{sub 3}; (3) H{sub 2}CCHX {r_arrow} H{sub 2} + C{sub 2}HX; and (4) H{sub 2}CCHX {r_arrow} HX + C{sub 2}H{sub 2}. They measured translational energy distributions for all of the observed channels and measured the photoionization onset for many of the photoproducts which provided information about their chemical identity and internal energy content. In the case of acrylonitrile, selective product photoionization provided the ability to discriminate between channels 2 and 4 which result in the same product mass combination.

  6. Genetic and reproductive toxicity of butadiene and isoprene.

    Science.gov (United States)

    Anderson, D

    2001-06-01

    Butadiene (BD) and its 2-methyl analogue, isoprene, have been extensively studied in animals and BD in population studies. Both chemicals are metabolised by liver cytochrome P450 dependent monogenases to monoepoxide and diepoxide intermediates. The diepoxide intermediates of both compounds were mutagenic in Salmonella typhimurium. However, unlike the monoepoxide of BD, the monoepoxides of isoprene were not mutagenic. It appears that they have no alkylating capacity. BD did not induce somatic cell mutation and recombination or sex-linked recessive lethal mutation in Drosophila melanogaster and isoprene produced no increase in chromosomal aberrations in CHO cells in vitro. Comparative concentrations of haemoglobin adducts in the blood of mice and rats after exposure to BD indicated that reaction with blood may decrease the levels of reactive intermediates available to tissues in rats, but not in mice contributing to greater potency of BD in the mouse. For isoprene, the adducts reach approximately the same concentrations in both species. DNA adducts have also been detected in testicular and lung cells of mice after BD exposure. The level of epoxybutene haemoglobin adducts was significantly elevated in BD-exposed workers, but lower than in rats and mice. In conjunction with the toxicology and carcinogenesis studies for BD and isoprene, additional mice were included for the evaluation of cytogenetic effects. Both chemicals produced increases in sister chromatid exchanges in bone marrow cells and in the frequency of micronuclei in normochromatic and polychromatic erythrocytes, but only BD produced an increase in the percent of bone marrow cells with chromosomal aberrations. At similar doses, the effects with BD were 2-3 times larger than with isoprene. There were also increased hprt mutation frequencies in rats and mice after BD exposure. Biomonitoring studies with hprt mutations in lymphocytes showed conflicting results, with both positive and negative findings. BD has

  7. Synthesis and Thermal Properties of Acrylonitrile/Butyl Acrylate/Fumaronitrile and Acrylonitrile/Ethyl Hexyl Acrylate/Fumaronitrile Terpolymers as a Potential Precursor for Carbon Fiber

    Directory of Open Access Journals (Sweden)

    Siti Nurul Ain Md Jamil

    2014-09-01

    Full Text Available A synthesis of acrylonitrile (AN/butyl acrylate (BA/fumaronitrile (FN and AN/EHA (ethyl hexyl acrylate/FN terpolymers was carried out by redox polymerization using sodium bisulfite (SBS and potassium persulphate (KPS as initiator at 40 °C. The effect of comonomers, BA and EHA and termonomer, FN on the glass transition temperature (Tg and stabilization temperature was studied using Differential Scanning Calorimetry (DSC. The degradation behavior and char yield were obtained by Thermogravimetric Analysis. The conversions of AN, comonomers (BA and EHA and FN were 55%–71%, 85%–91% and 76%–79%, respectively. It was found that with the same comonomer feed (10%, the Tg of AN/EHA copolymer was lower at 63 °C compared to AN/BA copolymer (70 °C. AN/EHA/FN terpolymer also exhibited a lower Tg at 63 °C when compared to that of the AN/BA/FN terpolymer (67 °C. By incorporating BA and EHA into a PAN system, the char yield was reduced to ~38.0% compared to that of AN (~47.7%. It was found that FN reduced the initial cyclization temperature of AN/BA/FN and AN/EHA/FN terpolymers to 228 and 221 °C, respectively, in comparison to that of AN/BA and AN/EHA copolymers (~260 °C. In addition, FN reduced the heat liberation per unit time during the stabilization process that consequently reduced the emission of volatile group during this process. As a result, the char yields of AN/BA/FN and AN/EHA/FN terpolymers are higher at ~45.1% and ~43.9%, respectively, as compared to those of AN/BA copolymer (37.1% and AN/EHA copolymer (38.0%.

  8. 提高丙烯腈回收率的一种新型急冷工艺和急冷塔%A new quenching process and tower to improve the recovery of acrylonitrile

    Institute of Scientific and Technical Information of China (English)

    甘永胜; 顾军民; 方永成

    2004-01-01

    Quenching process and design of the quenching tower in acrylonitrile production in China were studied in order to decrease the polymerization loss of acrylonitrile in the quenching tower.Based on the research of acrylonitrile polymerization in the quenching tower,a new quenching process was proposed to avoid the disadvantages of the original process.Two kinds of internals were installed to improve the performance of the quenching tower.Through a series of air-flow and real-flow model experiments,the new quenching process and new design were showed to be successful in enhancing the mass and heat transfer in the vapor-liquid system and decreasing the loss of acrylonitrile.Industrial application showed satisfactory results of decrease of the acrylonitrile loss in the quenching tower by about 4.5% and increase of the acrylonitrile recovery of the whole plant by more than 4%.

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

    OpenAIRE

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

    2016-01-01

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

  10. MORPHOLOGY,INTERFACIAL INTERACTION AND PROPERTIES OF STYRENE-BUTADIENE RUBBER/MODIFIED HALLOYSITE NANOTUBE NANOCOMPOSITES

    Institute of Scientific and Technical Information of China (English)

    贾德民

    2009-01-01

    A natural nanotubular material,halloysite nanotubes(HNTs),was introduced to prepare styrene-butadiene rubber/modified halloysite nanotube(SBR/m-HNT) nanocomposites.Complex of resorcinol and hexamethylenetetramine (RH) was used as the interfacial modifier.The structure,morphology and mechanical properties of SBR/m-HNT nanocomposites,especially the interfacial interactions,were investigated.SEM and TEM observations showed that RH can not only facilitate the dispersion and orientation of HNTs in SBR matrix ...

  11. Short-term toxicity and reproduction studies in rats with hexachloro-(1,3)-butadiene

    NARCIS (Netherlands)

    Harleman, J.H.; Seinen, W.

    1979-01-01

    In rats given daily doses of 0. 0.4, 1.0, 2.5, 6.3, and 15.6 mg of hexachloro-(1,3)-buta-diene (HCBD)/kg by gavage for 13 weeks, no effect levels of 1.0 and 2.5 mg/kg were established for females and males, respectively. Inhibition of growth occurred in both sexes at the two highest doses and degene

  12. Modeling of continuous free-radical butadiene-styrene copolymerization process by the Monte Carlo method

    Directory of Open Access Journals (Sweden)

    T. A. Mikhailova

    2016-01-01

    Full Text Available In the paper the algorithm of modeling of continuous low-temperature free-radical butadiene-styrene copolymerization process in emulsion based on the Monte-Carlo method is offered. This process is the cornerstone of industrial production butadiene – styrene synthetic rubber which is the most widespread large-capacity rubber of general purpose. Imitation of growth of each macromolecule of the formed copolymer and tracking of the processes happening to it is the basis of algorithm of modeling. Modeling is carried out taking into account residence-time distribution of particles in system that gives the chance to research the process proceeding in the battery of consistently connected polymerization reactors. At the same time each polymerization reactor represents the continuous stirred tank reactor. Since the process is continuous, it is considered continuous addition of portions to the reaction mixture in the first reactor of battery. The constructed model allows to research molecular-weight and viscous characteristics of the formed copolymerization product, to predict the mass content of butadiene and styrene in copolymer, to carry out calculation of molecular-weight distribution of the received product at any moment of conducting process. According to the results of computational experiments analyzed the influence of mode of the process of the regulator introduced during the maintaining on change of characteristics of the formed butadiene-styrene copolymer. As the considered process takes place with participation of monomers of two types, besides listed the model allows to research compositional heterogeneity of the received product that is to carry out calculation of composite distribution and distribution of macromolecules for the size and structure. On the basis of the proposed algorithm created the software tool that allows you to keep track of changes in the characteristics of the resulting product in the dynamics.

  13. Thermal Stability and Flammability of Styrene-Butadiene Rubber-Based (SBR) Ceramifiable Composites

    OpenAIRE

    Rafał Anyszka; Dariusz M. Bieliński; Zbigniew Pędzich; Przemysław Rybiński; Mateusz Imiela; Mariusz Siciński; Magdalena Zarzecka-Napierała; Tomasz Gozdek; Paweł Rutkowski

    2016-01-01

    Ceramifiable styrene-butadiene (SBR)-based composites containing low-softening-point-temperature glassy frit promoting ceramification, precipitated silica, one of four thermally stable refractory fillers (halloysite, calcined kaolin, mica or wollastonite) and a sulfur-based curing system were prepared. Kinetics of vulcanization and basic mechanical properties were analyzed and added as Supplementary Materials. Combustibility of the composites was measured by means of cone calorimetry. Their t...

  14. Microstructural analysis of carbon nanomaterials produced from pyrolysis/combustion of Styrene-Butadiene-Rubber (SBR)

    OpenAIRE

    Joner Oliveira Alves; Chuanwei Zhuo; Yiannis Angelo Levendis; Jorge Alberto Soares Tenório

    2011-01-01

    Styrene-Butadiene-Rubber (SBR) is a synthetic rubber copolymer used to fabricate several products. This study aims to demonstrate the use of SBR as feedstock for carbon nanomaterials (nanofibers and nanotubes) growth, and therefore to establish a novel process for destination of waste products containing SBR. A three stage electrically heated flow reactor was used. Small pellets of rubber were pyrolyzed at a temperature of 1000 ºC. The pyrolyzates were mixed with oxygen-containing gases and w...

  15. Blending of styrene-block-butadiene-block-styrene copolymer with sulfonated vinyl aromatic polymers

    OpenAIRE

    Ruggeri, Giacomo; Passaglia, Elisa; Giorgi, Ivan; Picchioni, Francesco; Aglietto, Mauro

    2001-01-01

    Different polymers containing sulfonic groups attached to the phenyl rings were prepared by sulfonation of polystyrene (PS) and styrene-block-(ethylene-co-1-butene)-block-styrene (SEBS). The sulfonation degree (SD) was varied between 1 and 20 mol% of the styrene units. Polyphase materials containing sulfonated units were prepared by blending styrene-block-butadiene-block-styrene (SBS), with both sulfonated PS and sulfonated SEBS in a Brabender mixer. Such a procedure was performed as an alter...

  16. Palladium-catalyzed 1,4-difunctionalization of butadiene to form skipped polyenes.

    Science.gov (United States)

    McCammant, Matthew S; Liao, Longyan; Sigman, Matthew S

    2013-03-20

    A palladium-catalyzed 1,4-addition across the commodity chemical 1,3-butadiene to afford skipped polyene products is reported. Through a palladium σ → π → σ allyl isomerization, two new carbon-carbon bonds are formed with high regioselectivity and trans stereoselectivity of the newly formed alkene. The utility of this method is highlighted by the successful synthesis of the ripostatin A skipped triene core.

  17. Mechanical Properties of Injection Molded and Compression Molded Samples from Nature-Butadiene Rubber

    OpenAIRE

    Skrobak Adam; Janoštík Václav; Stanek Michal; Manas David; Ovsik Martin; Senkerik Vojtech; Reznicek Martin

    2016-01-01

    The aim of this paper is to show what extent there is an impact on the mechanical properties (tensile strength and tear strength) of a standardized testing sample made of rubber compound based on nature rubber and butadiene rubber produced by injection molding in comparison with a sample produced by classic preparation (cutting out a compression molded plate) according to the standard ISO 23529. For realization of this study it was necessary to design and produce an injection mold for all typ...

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

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Lucas N. [Instituto Federal de Educacao, Ciencia e Tecnologia de Goias-IFG,Campus Goiania, Goiania -GO (Brazil); Instituto de Pesquisas Energeticas e Nucleares -IPEN, Sao Paulo-SP (Brazil); Vieira, Silvio L. [Instituto de Fisica, Universidade Federal de Goias-UFG, Campus Samambaia, Goiania-GO (Brazil); Schimidt, Fernando [Instituto Federal de Educacao, Ciencia e Tecnologia de Goias-IFG,Campus Inhumas, Inhumas-GO (Brazil); Antonio, Patricia L.; Caldas, Linda V.E. [Instituto de Pesquisas Energeticas e Nucleares -IPEN, Sao Paulo-SP (Brazil)

    2015-07-01

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

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

    CERN Document Server

    Segreto, Ettore

    2014-01-01

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

  20. Inhalation developmental toxicology studies: Teratology study of 1,3-butadiene in mice: Final report

    Energy Technology Data Exchange (ETDEWEB)

    Hackett, P.L.; Sikov, M.R.; Mast, T.J.; Brown, M.G.; Buschbom, R.L.; Clark, M.L.; Decker, J.R.; Evanoff, J.J.; Rommereim, R.L.; Rowe, S.E.; Westerberg, R.B.

    1987-11-01

    Maternal toxicity, reproductive performance and developmental toxicology were evaluated in CD-1 mice following whole-body, inhalation exposures to 0, 40, 200 and 1000 ppM of 1,3-butadiene. The female mice, which had mated with unexposed males were exposed to the chemical for 6 hours/day on 6 through 15 dg and sacrificed on 18 dg. Maternal animals were weighed prior to mating and on 0, 6, 11 and 18 dg; the mice were observed for mortality, morbidity and signs of toxicity during exposure and examined for gross tissue abnormalities at necropsy. Live fetuses were weighed and subjected to external, visceral and skeletal examinations to detect growth retardation and morphologic anomalies. Significant concentration-related decreases were detected in a number of maternal body weight measures. There was a significant concentration-related depression of fetal body weights and placental weights. Body weights of male fetuses of all exposed groups were significantly lower than values for control fetuses; weights of female fetuses were significantly depressed in the mice exposed to 200 and 1000 ppM. In the 200- and 1000-ppM exposure groups, weights of placentas of male fetuses were significantly decreased, but placental weights of female fetuses were significantly affected only in litters exposed to the highest 1,3-butadiene concentration. This exposure regimen produced significant signs of maternal toxicity at concentrations of 200 and 1000 ppM 1,3-butadiene.

  1. An isotopic dilution approach for 1,3-butadiene tailpipe emissions and ambient air monitoring.

    Science.gov (United States)

    Riservato, Manuela; Rolla, Antonio; Davoli, Enrico

    2004-01-01

    An isotopic dilution approach for 1,3-butadiene analysis in gaseous samples is presented. The methodology is based on active sampling on sorbent tubes and subsequent analysis by thermal desorption into a gas chromatography/mass spectrometry system. By adding a perdeuterated internal standard onto the sorbent tubes before sampling, and using mass spectrometric detection, the methodology gives high accuracy for this unstable analyte. The method has been used to monitor 1,3-butadiene ambient air concentrations in a residential area in proximity to a heavy-traffic roadway over a one-week period, for comparison with other traffic-related pollutants analysed by standard procedures. It has also been used to determine tailpipe emissions of two vehicles by standard emission testing procedures in a dynamometer. These vehicles were chosen as examples of low- and high-end emission rate vehicles, i.e., an old no-catalytic converter Otto engine and a new direct-injection diesel engine with catalytic converter. Exhaust gas emissions were 0.052 and 35.85 mg/km, reflecting differences in fuel, engine design, age, and presence (or not) of a catalytic abatement system. The ambient air results showed a weekly average concentration of 1,3-butadiene of 0.53 microg/m(3).

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

    Science.gov (United States)

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

    2012-04-01

    Styrene-acrylonitrile Trimer (SAN Trimer), a by-product in production of acrylonitrile styrene plastics, was identified at a Superfund site in Dover Township, NJ, where childhood cancer incidence rates were elevated for a period of several years. SAN Trimer was therefore tested by the National Toxicology Program in a 2-year perinatal carcinogenicity study in F344/N rats and a bacterial mutagenicity assay; both studies gave negative results. To further characterize its genotoxicity, SAN Trimer was subsequently evaluated in a combined micronucleus (MN)/Comet assay in juvenile male and female F344 rats. SAN Trimer (37.5, 75, 150, or 300 mg/kg/day) was administered by gavage once daily for 4 days. Micronucleated reticulocyte (MN-RET) frequencies in blood were determined by flow cytometry, and DNA damage in blood, liver, and brain cells was assessed using the Comet assay. Highly significant dose-related increases (P exposure to SAN Trimer.

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

    Science.gov (United States)

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

    2012-01-01

    Styrene–acrylonitrile Trimer (SAN Trimer), a by-product in production of acrylonitrile styrene plastics, was identified at a Superfund site in Dover Township, NJ, where childhood cancer incidence rates were elevated for a period of several years. SAN Trimer was therefore tested by the National Toxicology Program in a 2-year perinatal carcinogenicity study in F344/N rats and a bacterial mutagenicity assay; both studies gave negative results. To further characterize its genotoxicity, SAN Trimer was subsequently evaluated in a combined micronucleus (MN)/Comet assay in juvenile male and female F344 rats. SAN Trimer (37.5, 75, 150, or 300 mg/kg/day) was administered by gavage once daily for 4 days. Micronucleated reticulocyte (MN-RET) frequencies in blood were determined by flow cytometry, and DNA damage in blood, liver, and brain cells was assessed using the Comet assay. Highly significant dose-related increases (P exposure to SAN Trimer. PMID:22351108

  4. REDUCING NONSELECTIVE PROTEIN ADSORPTION AND CELL ADHESION ON POLYACRYLONITRILE FILMS BY COPOLYMERIZATION OF ACRYLONITRILE WITH α-ALLYL GLUCOSIDE

    Institute of Scientific and Technical Information of China (English)

    Rui-qiang Kou; Chao Qu; Zhi-kang Xu; You-yi Xu; Ke Yao

    2003-01-01

    In this work, the surface properties of novel sugar-containing polymers, α-allyl glucoside (AG)/acrylonitrile (AN)copolymers, were studied by contact angle, protein adsorption and cell adhesion measurements. It was found that the contact angle of the copolymer films decreased from 68° to 30° with the increase of AG content in the copolymer. The adsorption amount of bovine serum albumin (BSA) and the adhesive macrophage onto the film surface also decreased significantly with increasing α-allyl glucoside content from 0 to 42 wt% in the copolymer. These preliminary results reveal that both the hydrophilicity and the biocompatibility of polyacrylonitrile-based membranes could be improved by copolymerizing acrylonitrile with vinyl carbohydrates.

  5. In Situ IR Spectroscopic Study on the Hydrogenation of 1,3-Butadiene on Fresh Mo2C/γ-Al2O3 Catalyst

    Institute of Scientific and Technical Information of China (English)

    Zhang Jing; Wu Weicheng; Liu Shiyang

    2014-01-01

    The surface species formed from the adsorption of 1,3-butadiene and 1,3-butadiene hydrogenation over the fresh Mo2C/γ-Al2O3 catalyst was studied by in situ IR spectroscopy. It is found that 1,3-butadiene adsorption on the Mo2C/γ-Al2O3 catalyst mainly formsπ-adsorbed butadiene (πs andπd) andσ-bonded surface species. These species are adsorbed mainly on the surface Moδ+(0<δ<2) sites as evidenced by co-adsorption of 1,3-butadiene and CO on the fresh Mo2C/γ-Al2O3 catalyst. The IR spectrometric analysis show that hydrogenation of 1,3-butadiene over fresh Mo2C/γ-Al2O3 catalyst produces mainly butane coupled with a small portion of butene. The selectivity of butene during the hydrogenation of 1,3-butadiene over fresh Mo2C/γ-Al2O3 catalyst might be explained by the adsorption mode of adsorbed 1,3-butadiene. Additionally, the active sites of the fresh Mo2C/γ-Al2O3 catalyst may be covered by coke during the hydrogenation reaction of 1,3-butadiene. The treatment with hydrogen at 673 K cannot remove the coke deposits from the surface of the Mo2C/γ-Al2O3 catalyst.

  6. Improved Method for Preparation of Amidoxime Modified Poly(acrylonitrile-co-acrylic acid: Characterizations and Adsorption Case Study

    Directory of Open Access Journals (Sweden)

    Nur Amirah Mohd Zahri

    2015-07-01

    Full Text Available Redox polymerization of poly(acrylonitrile-co-acrylic acid (poly(AN-co-AA is performed at 40 °C under N2 gas by varying the ratio of acrylonitrile (AN and acrylic acid (AA in the feed. The yield production of poly(acrylonitrile (PAN is 73% and poly(AN-co-AA with a feed ratio of 93:7 is the highest yield (72%. The PAN and poly(AN-co-AA are further chemically modify with hydroxylamine hydrochloride. The FTIR spectroscopy is used to confirm the copolymerization of poly(AN-co-AA and chemical modification of poly(AN-co-AA. Elemental microanalysis shows that the overall trend percentage of carbon, hydrogen, and nitrogen for all feed ratios are slightly decreasing as the feed ratio of AA is increasing except for poly(AN-co-AA 93:7. The SEM images shows that spherical diameter of poly(AN-co-AA is smaller compared to the PAN and amidoxime (AO modified poly(AN-co-AA. The TGA (thermogravimetric analysis analysis reveals that the poly(AN-co-AA degrades at lower temperatures compared to the PAN but higher than AO modified poly(AN-co-AA. The case study adsorption test showed that the AO modified poly(AN-co-AA 93:7 had the highest percentage removal of Cd2+ and Pb2+.

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

    Science.gov (United States)

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

    2009-05-12

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

  8. Effect of environmental friendly plasticizer cashew nut shell liquid on properties of acrylonitrile-butadiene rubber%环保型增塑剂腰果壳油对丁腈橡胶性能的影响

    Institute of Scientific and Technical Information of China (English)

    戴洪雁; 陈福林; 岑兰; 周彦豪

    2010-01-01

    研究了腰果壳油(CNSL)用量对丁腈橡胶胶料的硫化特性和硫化胶性能的影响,并与使用邻苯二甲酸二辛酯和环氧大豆油作为增塑剂进行了对比.结果表明,在0~30份(质量)用量内,加入CNSL后胶料的焦烧时间和正硫化时间有所缩短.与加入相同用量的邻苯二甲酸二辛酯和环氧大豆油的胶料及硫化胶相比,使用CNSL的胶料在硫化曲线上的最小转矩和最大转矩以及硫化胶的硬度、定伸应力和耐ASTM 1#标准油体积增加率较小;硫化胶的拉伸强度、撕裂强度、扯断伸长率和耐ASTM 3#标准油体积增加率较大;硫化胶的耐热空气老化性能较好.

  9. 2-Cyanoethylmercapturic acid (CEMA) in the urine as a possible indicator of exposure to acrylonitrile.

    Science.gov (United States)

    Jakubowski, M; Linhart, I; Pielas, G; Kopecký, J

    1987-12-01

    The aim of this study was to evaluate the efficiency of metabolism of acrylonitrile (ACN) to N-acetyl-S-(2-cyanoethyl)-L-cysteine (2-cyanoethylmercapturic acid (CEMA) in man, the kinetics of excretion of this metabolite, and the relation between the uptake of ACN and the excretion of CEMA in urine. Eleven experiments were performed on six male volunteers exposed for eight hours to ACN at concentrations of 5 or 10 mg/m3. The average respiratory retention of ACN was 52% and 21.8% of the retained ACN was excreted as CEMA in urine. Elimination approximated first order kinetics with half life of about eight hours. The best correlation between the uptake of ACN in the lungs and excretion of CEMA in urine was obtained when the concentration of CEMA in the urine fraction, collected between the sixth and eighth hours after the beginning of exposure, was adjusted to a specific gravity of 1.016 (y = 0.33x-13.3; r = 0.83). CEMA excretion, however, cannot be used as an individual index of exposure.

  10. Effects of acrylonitrile on lymphocyte lipid rafts and RAS/RAF/MAPK/ERK signaling pathways.

    Science.gov (United States)

    Li, X J; Li, B; Huang, J S; Shi, J M; Wang, P; Fan, W; Zhou, Y L

    2014-09-26

    Acrylonitrile (ACN) is a widely used chemical in the production of plastics, resins, nitriles, acrylic fibers, and synthetic rubber. Previous epidemiological investigations and animal studies have confirmed that ACN affects the lymphocytes and spleen. However, the immune toxicity mechanism is unknown. Lipid rafts are cell membrane structures that are rich in cholesterol and involved in cell signal transduction. The B cell lymophoma-10 (Bcl10) protein is a joint protein that is important in lymphocyte development and signal pathways. This study was conducted to examine the in vitro effects of ACN. We separated lipid rafts, and analyzed Bcl10 protein and caveolin. Western blotting was used to detect mitogen-activated protein kinase (MAPK) and phosphorylated MAPK levels. The results indicated that with increasing ACN concentration, the total amount of Bcl10 remained stable, but was concentrated mainly in part 4 to part 11 in electrophoretic band district which is high density in gradient centrifugation. Caveolin-1 was evaluated as a lipid raft marker protein; caveolin-1 content and position were relatively unchanged. Western blotting showed that in a certain range, MAPK protein was secreted at a higher level. At some ACN exposure levels, MAPK protein secretion was significantly decreased compared to the control group (P lipid raft structures, causing Bcl10 protein and lipid raft separation and restraining Ras-Raf-MAPK-extracellular signal-regulated kinase signaling pathways.

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

    Science.gov (United States)

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

    2013-12-01

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

  12. Induction of oxidative stress and oxidative damage in rat glial cells by acrylonitrile.

    Science.gov (United States)

    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.

  13. Weight-of-the-evidence review of acrylonitrile reproductive and developmental toxicity studies.

    Science.gov (United States)

    Neal, Barbara H; Collins, James J; Strother, Dale E; Lamb, James C

    2009-01-01

    Risk assessment of acrylonitrile (AN) toxicity to humans has focused on potential carcinogenicity and acute toxicity. Epidemiological studies from China reported reproductive and developmental effects in AN workers, including infertility, birth defects, and spontaneous abortions. A weight-of-the-evidence (WoE) evaluation of the AN database assessed study strength, characterized toxicity, and identified no-observed-adverse-effect levels (NOAELs). The epidemiological studies do not demonstrate causality and are not sufficiently robust to be used for risk assessment. Rodent developmental studies showed fetotoxicity and malformations at maternally toxic levels; there was no unique developmental susceptibility. NOAELs for oral and inhalation exposures were 10 mg/kg/day and 12 ppm (6 h/day), respectively. Drinking-water and inhalation reproductive toxicity studies showed no clear effects on reproductive performance or fertility. Maternally toxic concentrations caused decreased pup growth. The drinking-water reproductive NOAEL was 100 ppm (moderate confidence due to study limitations). The inhalation exposure reproductive and neonatal toxicity high confidence NOAEL was 45 ppm (first generation 90 ppm) (6 h/day). The inhalation reproductive toxicity study provides the most robust data for risk assessment. Based on the WoE evaluation, AN is not expected to be a developmental or reproductive toxicant in the absence of significant maternal toxicity.

  14. Peroxydisulfate initiated synthesis of potato starch-graft-poly(acrylonitrile under microwave irradiation

    Directory of Open Access Journals (Sweden)

    2007-01-01

    Full Text Available Potato starch-graft-poly(acrylonitrile could be efficiently synthesized using small concentration of ammonium peroxydisulfate (0.0014M in aqueous medium under microwave irradiation. A representative microwave synthesized graft copolymer was characterized using Fourier Transform Infrared Spectroscopy, X-ray Diffraction, Scanning Electron Microscopy and Thermogravimetric Analysis. Under microwave conditions oxygen removal from the reaction vessel was not required and the graft copolymer was obtained in high yield using very small amount of ammonium peroxydisulfate, however using the same amount of ammonium peroxydisulfate (0.0014M on thermostatic water bath no grafting was observed up to 98°C (even in inert atmosphere. Raising the concentration of the initiator to 0.24 M resulted into 10% grafting at 50 °C but in inert atmosphere.The viscosity/shear stability of the grafted starch (aqueous solution and water/saline retention ability of the microwave synthesized graft copolymer were also studied and compared with that of the native potato starch.

  15. Hg(II) adsorption using amidoximated porous acrylonitrile/itaconic copolymers prepared by suspended emulsion polymerization.

    Science.gov (United States)

    Ji, Chunnuan; Qu, Rongjun; Chen, Hou; Liu, Xiguang; Sun, Changmei; Ma, Caixia

    2016-01-01

    Initially, porous acrylonitrile/itaconic acid copolymers (AN/IA) were prepared by suspended emulsion polymerization. Successively, the cyano groups in AN/IA copolymers were converted to amidoxime (AO) groups by the reaction with hydroxylamine hydrochloride. The structures of the AN/IA and amidoximated AN/IA (AO AN/IA) were characterized by infrared spectroscopy, scanning electron microscopy, and porous structural analysis. The adsorption properties of AO AN/IA for Hg(II) were investigated. The results show that AO AN/IA has mesopores and macropores, and surface area of 11.71 m(2) g(-1). It was found that AO AN/IA has higher affinity for Hg(II), with the maximum adsorption capacity of 84.25 mg g(-1). The AO AN/IA also can effectively remove Hg(II) from different binary metal ion mixture systems. Furthermore, the adsorption kinetics and thermodynamics were studied in detail. The adsorption equilibrium can quickly be achieved in 4 h determined by an adsorption kinetics study. The adsorption process is found to belong to the second-order model, and can be described by the Freundlich model.

  16. Regenerated thermosetting styrene-co-acrylonitrile sandwich composite panels reinforced by jute fibre: structures and properties

    Indian Academy of Sciences (India)

    Jinglong Li; Qin Peng; Anrong Zeng; Junlin Li; Xiaole Wu; Xiaofei Liu

    2016-02-01

    Jute fibres-reinforced sandwich regenerated composite panels were fabricated using industrial waste thermosetting styrene-co-acrylonitrile (SAN) foam scraps via compression moulding for the purpose of recycling waste SAN foam and obtaining high physical performance. The jute fibres were, respectively, treated by heat, sodium hydroxide (NaOH) solution (5.0 wt%), and N,N-dimethylacetamide (DMAc) in order to improve the mechanical properties of the composites. The structures and mechanical properties of the composites were studied. The SAN matrix got compact and some crystalline region formed in SAN matrix via compression moulding. The composite reinforced by DMAc-treated jute fibres performed optimum mechanical properties among the regenerated panels whose impact strength, flexural strength, and compressive strength were 19.9 kJ m−2, 41.7 MPa, and 61.0 MPa, respectively. Good interfacial bonding between DMAc-treated fibres and SAN matrix was verified by peel test and exhibited in SEM photographs. Besides, the water absorption of DMAc-treated fibres composite was lower than other SAN/jute fibre-reinforced sandwich composite panels.

  17. Covalent Immobilization of Lipase on Poly ( acrylonitrile-co-maleic acid) Ultrafiltration Hollow Fiber Membrane

    Institute of Scientific and Technical Information of China (English)

    YE Peng; XU Zhi-kang; WU Jian; DENG Hong-tao; SETA Patrick

    2005-01-01

    Lipase from Candida rugosa was covalently immobilized on the surface of an ultrafiltration hollow fiber membrane fabricated from poly (acrylonitrile-co-maleic acid) (PANCMA) in which the carboxyl groups were activated with 1-ethyl-3-(dimethylaminopropyl) carbodiimide hydrochloride (EDC) and dicyclohexyl carbodiimide (DCC)/N-hydroxyl succinimide(NHS), respectively. The properties of the immobilized lipase were assayed and compared with those of the free enzyme. The maximum activities were observed in a relatively broader pH value range at high temperatures for the immobilized lipase compared to the free one. It was also found that the thermal and pH stabilities of lipase were improved upon immobilization and at 50 ℃ the thermal inactivation rate constant values are 2.1×10-2 for the free lipase, 3.2×10-3 for the immobilized lipase on the EDC-activated PANCMA membrane and 3.5×10-3 for the immobilized lipase on the DCC/NHS-activated PANCMA membrane, respectively.

  18. Cobalt-Mediated Radical Polymerization of Vinyl Acetate and Acrylonitrile in Supercritical Carbon Dioxide.

    Science.gov (United States)

    Kermagoret, Anthony; Chau, Ngoc Do Quyen; Grignard, Bruno; Cordella, Daniela; Debuigne, Antoine; Jérôme, Christine; Detrembleur, Christophe

    2016-03-01

    Cobalt-mediated radical polymerization (CMRP) of vinyl acetate (VAc) is successfully achieved in supercritical carbon dioxide (scCO2). CMRP of VAc is conducted using an alkyl-cobalt(III) adduct that is soluble in scCO2. Kinetics studies coupled to visual observations of the polymerization medium highlight that the melt viscosity and PVAc molar mass (Mn) are key parameters that affect the CMRP in scCO2. It is noticed that CMRP is controlled for Mn up to 10 000 g mol(-1), but loss of control is progressively observed for higher molar masses when PVAc precipitates in the polymerization medium. Low molar mass PVAc macroinitiator, prepared by CMRP in scCO2, is then successfully used to initiate the acrylonitrile polymerization. PVAc-b-PAN block copolymer is collected as a free flowing powder at the end of the process although the dispersity of the copolymer increases with the reaction time. Although optimization is required to decrease the dispersity of the polymer formed, this CMRP process opens new perspectives for macromolecular engineering in scCO2 without the utilization of fluorinated comonomers or organic solvents.

  19. Nanostructured synthetic carbons obtained by pyrolysis of spherical acrylonitrile/divinylbenzene copolymers.

    Directory of Open Access Journals (Sweden)

    Danish J Malik

    Full Text Available Novel carbon materials have been prepared by the carbonization of acrylonitrile (AN/divinylbenzene (DVB suspension porous copolymers having nominal crosslinking degrees in the range of 30-70% and obtained in the presence of various amounts of porogens. The carbons were obtained by pre-oxidation of AN/DVB copolymers at 250-350°C in air followed by pyrolysis at 850°C in an N(2 atmosphere. Both processes were carried out in one furnace and the resulting material needed no further activation. Resulting materials were characterized by XPS and low temperature nitrogen adsorption/desorption. It was found that maximum pyrolysis yield was ca. 50% depending on the oxidation conditions but almost independent of the crosslinking degree of the polymers. Porous structure of the carbons was characterized for the presence of micropores and macropores, when obtained from highly crosslinked polymers or polymers oxidized at 350°C and meso- and macropores in all other cases. The latter pores are prevailing in the structure of carbons obtained from less porous AN/DVB resins. Specific surface area (BET of polymer derived carbons can vary between 440 m(2/g and 250 m(2/g depending on the amount of porogen used in the synthesis of the AN/DVB polymeric precursors.

  20. Combustion products of 1,3-butadiene inhibit catalase activity and induce expression of oxidative DNA damage repair enzymes in human bronchial epithelial cells

    OpenAIRE

    2008-01-01

    1,3-Butadiene, an important petrochemical, is commonly burned off when excess amounts need to be destroyed. This combustion process produces butadiene soot (BDS), which is composed of a complex mixture of polyaromatic hydrocarbons in particulates ranging in size from

  1. Some insights into the mode of action of butadiene by examining the genotoxicity of its metabolites.

    Science.gov (United States)

    Kligerman, A D; Hu, Y

    2007-03-20

    1,3-Butadiene (BTD) is an important commodity chemical and air pollutant that has been shown to be a potent carcinogen in mice, and to a lesser extent, a carcinogen in rats. To better assess butadiene's carcinogenic risk to humans, it is important to understand its mode of action and how this relates to differences in responses among species. In a series of in vitro experiments, lymphocytes from rats, mice, and humans were exposed to 3,4-epoxy-1-butene (EB) or 1,2:3,4-diepoxybutane (DEB) for 1h at the G(0) stage of the cell cycle, stimulated to divide, and cultured to assess the ability of these metabolites to induce sister chromatid exchange (SCE) and chromosome aberrations (CAs). EB induced no increases in SCEs or CAs in the cells from the three species. DEB was a potent SCE- and CA-inducer, with the results being similar in each rodent species. The response for SCEs seen in the human cells was more complex, with genetic polymorphism for glutathione-S-transferases (GST) possibly modulating the response. The single cell gel electrophoresis assay was used on genetically engineered V79 cell lines to investigate a possible influence of GST status. Experiments were also conducted to investigate the reason for EB's failure to induce SCEs or CAs in G(0) cells. The results indicate that EB-induced DNA damage was repaired before DNA synthesis in unstimulated lymphocytes, but EB caused a large increase in SCEs if actively cycling cells were treated. Thus, the results indicate that DEB damage is persistent in G(0) cells, and DEB is a much more potent genotoxicant than EB. The carcinogenic effect of butadiene will most likely depend on the degree to which DEB is produced and reaches target tissues, and to a lesser extent on the ability of EB to reach actively dividing or repair deficient cells.

  2. Inhalation developmental toxicology studies of 1,3-butadiene in the rat: Final report

    Energy Technology Data Exchange (ETDEWEB)

    Hackett, P.L.; Sikov, M.R.; Mast, T.J.; Brown, M.G.; Buschbom, R.L.; Clark, M.L.; Decker, J.R.; Evanoff, J.J.; Rommereim, R.L.; Rowe, S.E.; Westerberg, R.B.

    1987-11-01

    Maternal toxicity, reproductive performance and developmental toxicology were evaluated in Sprague-Dawley-derived rats during and following 6 hours/day, whole-body, inhalation exposures to 0, 40, 200, and 1000 ppM of 1,3-butadiene. The female rats (Ns = 24 to 28), which had mated with unexposed males, were exposed to the chemical from 6 through 15 dg and sacrificed on 20 dg. Maternal animals were weighed prior to mating and on 0, 6, 11, 16 and 20 dg; the rats were observed for mortality, morbidity and signs of toxicity during exposure and examined for gross tissue abnormalities at necropsy. Live fetuses were weighed and subjected to external, visceral and skeletal examinations to detect growth retardation and morphologic anomalies. There were no significant differences among treatment groups in maternal body weights or extragestational weights of rats exposed to 1,3-butadiene concentrations of 40 or 200 ppM, but, in animals exposed to 1000 ppM, significantly depressed body weight gains were observed during the first 5 days of exposure and extragestational weight gains tended to be lower than control values. These results, and the absence of clinical signs of toxicity, were considered to indicate that there was no maternal toxicity at exposure levels of 200 ppM or lower. The percentage of pregnant animals and the number of litters with live fetuses were unaffected by treatment. Under the conditions of this exposure regimen, there was no evidence for a teratogenic response to 1,3-butadiene exposure.

  3. Association of the blood/air partition coefficient of 1,3-butadiene with blood lipids and albumin.

    Science.gov (United States)

    Lin, Yu-Sheng; Smith, Thomas J; Wypij, David; Kelsey, Karl T; Sacks, Frank M

    2002-02-01

    Pulmonary gas uptake is a function of the blood solubility of a vapor, indicated by the blood/air partition coefficient. We hypothesized that blood lipid compositions are associated with the blood/air partition coefficients of lipophilic toxic vapors such as 1,3-butadiene. Our goal was to investigate cross-sectional and longitudinal relationships of blood triglycerides, total cholesterol, and albumin to the blood/air partition coefficient of butadiene. We collected blood samples from 24 subjects at three time points: a fasting baseline and 2 and 4 hr after drinking a standardized high-fat milk shake (107 g fat, 80 g sugar, and 27 g protein). The blood/air partition coefficient was determined using the closed vial-equilibrium technique. Triglycerides and total cholesterol were analyzed by an enzymatic method, and albumin was analyzed with an immunoassay technique. We used multiple linear regression and general linear models to examine the cross-sectional and longitudinal relationship, respectively. The results showed that the blood/air partition coefficient of butadiene was cross-sectionally associated only with triglycerides at baseline, and longitudinally related to baseline triglycerides, total cholesterol, and the change in triglycerides over time. The blood/air partition coefficient of butadiene increased, on average, by approximately 20% and up to 40% for subjects with borderline higher triglyceride levels after ingestion of a standardized milk shake. In addition, a time factor beyond lipids was also significant in predicting the blood/air partition coefficient of butadiene. This may represent the effects of other unmeasured parameters related to time or time of day on the blood/air partition coefficient of butadiene. Because the blood/air partition coefficient is a major determinant of gas uptake, ingestion of a high fat meal before this type of exposure may significantly increase an individual's absorbed dose, possibly increasing the risk of adverse effects.

  4. Residence time effect on fullerene yield in butadiene-based laser pyrolysis flame

    Science.gov (United States)

    Ténégal, F.; Voicu, I.; Armand, X.; Herlin-Boime, N.; Reynaud, C.

    2003-09-01

    A new route for fullerene synthesis by CO 2-laser pyrolysis of gas phase mixture is proposed. Small hydrocarbon molecules which absorb the laser radiation, such as butadiene, are mixed with nitrous oxide (N 2O) as oxidizer. Such a mixture allows avoiding the use of a photosensitizer as SF 6 which causes contamination of the reaction zone and possibly influences the growth of fullerenic structures. This Letter also confirms the strong influence of the C/O atomic ratio in the mixture on the fullerene yield, and shows that residence time of the reactants in the pyrolysis flame and pressure influence dramatically the fullerene formation.

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

    Energy Technology Data Exchange (ETDEWEB)

    Wang Qingguo [Key Laboratory of Rubber-plastics of Ministry of Education, Qingdao University of Science and Technology, Qingdao 266042 (China); School of Polymer Science and Engineering, Qingdao University of Science and Technology, Qingdao 266042 (China)], E-mail: qwang@qust.edu.cn; Wang Fenlan [School of Polymer Science and Engineering, Qingdao University of Science and Technology, Qingdao 266042 (China); Cheng Kuo [Jiangsu Dasheng Heat Shrinkable Material Co., Ltd. Wujiang city 215214 (China)

    2009-11-15

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

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

    Science.gov (United States)

    Wang, Qingguo; Wang, Fenlan; Cheng, Kuo

    2009-11-01

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

  7. Mechanical Properties of Injection Molded and Compression Molded Samples from Nature-Butadiene Rubber

    Directory of Open Access Journals (Sweden)

    Skrobak Adam

    2016-01-01

    Full Text Available The aim of this paper is to show what extent there is an impact on the mechanical properties (tensile strength and tear strength of a standardized testing sample made of rubber compound based on nature rubber and butadiene rubber produced by injection molding in comparison with a sample produced by classic preparation (cutting out a compression molded plate according to the standard ISO 23529. For realization of this study it was necessary to design and produce an injection mold for all types testing samples. Subsequently, mechanical properties such as the tensile stress-strain and tear strenght of compression molded samples and injection molded samples were studied, compared and discussed.

  8. Epigenetic Mechanisms of Mouse Interstrain Variability in Genotoxicity of the Environmental Toxicant 1,3-Butadiene

    OpenAIRE

    2011-01-01

    1,3-Butadiene (BD) is a common environmental contaminant classified as “carcinogenic to humans.” Formation of BD-induced DNA adducts plays a major role in its carcinogenicity. BD is also an epigenotoxic agent (i.e., it affects DNA and histone methylation in the liver). We used a panel of genetically diverse inbred mice (NOD/LtJ, CAST/EiJ, A/J, WSB/EiJ, PWK/PhJ, C57BL/6J, and 129S1/SvImJ) to assess whether BD-induced genotoxic and epigenotoxic events may be subject to interstrain differences. ...

  9. Study Tensile Strength and Wear Rate for Unsaturated Polyester Resin and Nitrile butadiene Rubber Polymer Blend

    Directory of Open Access Journals (Sweden)

    Entihaa G. Daway

    2015-06-01

    Full Text Available Binary polymer blend was prepared by mechanical mixing method of unsaturated polyester resin with Nitrile Butadiene Rubber (NBR with different weight ratios (0, 5, 10 and 15 % of (NBR. Tensile characteristics and wear rates of these blends were studied for all mixing ratios. The microstructure of fracture surfaces of the prepared samples were investigated by optical microscope. The results were showed that strain rates of the resin material increase after blending it with rubber while the ultimate tensile strength and Young’s modulus values of it will decrease. It is also noticed that the wear rate of resin decreases with increasing of (NBR content.

  10. New Piperazine Derivatives Synthesized from Thio-Substituted Polyhalogeno-2-nitro-1,3-butadienes

    Directory of Open Access Journals (Sweden)

    S. Goksin Aydinli

    2010-01-01

    Full Text Available It is known that polyhalogeno-nitro-1,3-butadienes are important starting materials for the synthesis of polyfunctionalized bioactive heterocycles. Novel N,S-substituted nitrobutadienes (4a-j were synthesized from the reaction of the monothio-substituted nitrodiene derivatives (2a and (2b with some piperazine derivatives. These new compounds are stable and the structures of these products were characterized by spectroscopic data. The structure of the novel N,S-substituted nitrodiene compound (4g synthesized in this study was also elucidated by single crystal x-ray analysis.

  11. Studies on Macro—kinetics of Gas Phase Polymerization of Butadiene with Rare—earch Catalyst

    Institute of Scientific and Technical Information of China (English)

    FANGDonyu; SUNJianzhong; 等

    2002-01-01

    The study of the kinetics of gas phase polymerization of butadiene with heterogeneous catalyst based on neodymium(Nd) was carried out.The effects of reaction temperature,reaction pressure,dispersing medium, and types of catalyst on kinetics of polymerization were investigated .A kinetic model with two kinds of active sites was proposed.The results show that the effects of the reaction temperature and the types of dispersing medium and catalyst on the kinetic performance of polymerization are significant,and that the combined model of first and second order decay of active site of catalyst can be used to describe the phenomena.

  12. Acrylonitrile quenching of trp phosphorescence in proteins: a probe of the internal flexibility of the globular fold.

    Science.gov (United States)

    Strambini, Giovanni B; Gonnelli, Margherita

    2010-08-04

    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.

  13. Uncertainty and variability in the exposure reconstruction of chemical incidents--the case of acrylonitrile.

    Science.gov (United States)

    Huizer, Daan; Ragas, Ad M J; Oldenkamp, Rik; van Rooij, Joost G M; Huijbregts, Mark A J

    2014-12-15

    The application of human physiologically based pharmacokinetic (PBPK) modeling combined with measured biomonitoring data, has a great potential to backtrack external exposure to chemicals during chemical incidents. So far, an important shortcoming of 'reversed dosimetry' is that uncertainty and variability in the model predictions are often neglected. The aim of this paper is to characterize the variation in predicted environmental air concentrations by means of reversed dosimetry as a result of uncertainty in chemical-specific input data and variability in physiological parameters. Human biomonitoring data (N-2-cyanoethylvaline in blood) from a chemical incident with acrylonitrile (ACN) combined with the BioNormtox PBPK model are used as a case to reconstruct the air concentration and uncertainty thereof at the time of the incident. The influence of uncertainty in chemical-specific properties and exposure duration, and interindividual variability in physiological parameters on the reconstructed air exposure concentrations were quantified via nested Monte Carlo simulation. The range in the reconstructed air concentrations of ACN during the incident was within a factor of 3. Uncertainty in the exact exposure duration directly after the chemical accident was found to have a dominant influence on the model outcomes. It was also shown that uncertainty can be further reduced by collecting human biomonitoring data as soon as possible after the incident. Finally, the collection of specific information about individual physiological parameters from the victims, such as body weight, may further reduce the variation by 5 to 20% in our case study. Future research should include the comparison of reversed dosimetry model outcomes with measured air and biological concentrations to further increase the confidence in the model approach and its implementation in practice.

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

    Science.gov (United States)

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

    2012-01-01

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

  15. Design of poly(acrylonitrile)-based gel electrolytes for high-performance lithium ion batteries.

    Science.gov (United States)

    Wang, Shih-Hong; Kuo, Ping-Lin; Hsieh, Chien-Te; Teng, Hsisheng

    2014-11-12

    The use of polyacrylonitrile (PAN) as a host for gel polymer electrolytes (GPEs) commonly produces a strong dipole-dipole interaction with the polymer. This study presents a strategy for the application of PAN in GPEs for the production of high performance lithium ion batteries. The resulting gel electrolyte GPE-AVM comprises a poly(acrylonitrile-co-vinyl acetate) copolymer blending poly(methyl methacrylate) as a host, which is swelled using a liquid electrolyte (LE) of 1 M LiPF6 in carbonate solvent. Vinyl acetate and methacrylate groups segregate the PAN chains in the GPE, which produces high ionic conductivity (3.5 × 10 (-3) S cm(-1) at 30 °C) and a wide electrochemical voltage range (>6.5 V) as well as an excellent Li(+) transference number of 0.6. This study includes GPE-AVM in a full-cell battery comprising a LiFePO4 cathode and graphite anode to promote ion motion, which reduced resistance in the battery by 39% and increased the specific power by 110%, relative to the performance of batteries based on LE. The proposed GPE-based battery has a capacity of 140 mAh g(-1) at a discharge rate of 0.1 C and is able to deliver 67 mAh g(-1) of electricity at 17 C. The proposed GPE-AVM provides a robust interface with the electrodes in full-cell batteries, resulting in 93% capacity retention after 100 charge-discharge cycles at 17 C and 63% retention after 1000 cycles.

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

    Science.gov (United States)

    Zhang, Jie; Pierce, George E

    2009-07-01

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

  17. Enhancing both the mechanical and chemical properties of paper sheet by graft co-polymerization with acrylonitrile/methyl methacrylate

    OpenAIRE

    H.M. Abd El Salam; Sayyh, S.M.; Kamal, E.H.M.

    2014-01-01

    The chemical graft copolymerization reaction of acrylonitrile (AN) and methyl methacrylate (MMA) binary mixture onto paper sheet was performed. The effect of initiator concentration, monomer concentration and temperature on the reaction rate was studied. The reaction rate equation of the graft copolymerization reaction is found to be RP = K2 [Initiator]0.795[Monomer]2.007. The apparent activation energy (Ea) of the copolymerization reaction is found to be 75.01 kJ/mol. The infrared characteri...

  18. Pre-irradiation induced emulsion co-graft polymerization of acrylonitrile and acrylic acid onto a polyethylene nonwoven fabric

    Science.gov (United States)

    Liu, Hanzhou; Yu, Ming; Ma, Hongjuan; Wang, Ziqiang; Li, Linfan; Li, Jingye

    2014-01-01

    A pre-irradiation induced emulsion co-graft polymerization method was used to introduce acrylonitrile and acrylic acid onto a PE nonwoven fabric. The use of acrylic acid is meant to improve the hydrophilicity of the modified fabric. The kinetics of co-graft polymerization were studied. The existence of polyacrylonitrile (PAN) and poly(acrylic acid) (PAAc) graft chains was proven by Fourier transform infrared spectroscopy (FTIR) analysis. The existence of the nitrile groups in the graft chains indicates that they are ready for further amidoximation and adsorption of heavy metal ions.

  19. TERMINATION AND TRANSFER OF THE CHAIN RADICALS IN THE POLYMERIZATION OF ACRYLONITRILE INITIATED BY VANADIUM(V)-THIOUREA REDOX SYSTEM

    Institute of Scientific and Technical Information of China (English)

    WU Jinyuan; YANG Chaoxiong; WU Yuxian

    1990-01-01

    The dependence of the molecular weights on the concentration of reactants in the polymerization of acrylonitrile initiated by vanadium (V)-thiourea red ox system has been investigated. It was found that the molecular weights of the polymer change nonlinearly with increasing concentrations of nitric acid and thiourea. Probably, the composition of the complexes exert a great influence on the chain initiation and termination. The reaction of "complextermination " gives rise to the decrease of the molecular weights markedly while the concentrations of thiourea and vanadium (V)in the range from one to three molar ratios.

  20. SELECTIVE SEPARATION OF WATER—ETHANOL MIXTURE THROUGH COPOLYMERIC MEMBRANES.Ⅱ.ACRYLONITRILE AND MALEIC ANHYDRIDE COPOLYMERIC MEMBRANES

    Institute of Scientific and Technical Information of China (English)

    ZHangFuyao; ZhangYifeng; 等

    1993-01-01

    Acrylonitrile(AN) and maleic anhydride(MA) copolymer has been synthesized by radical polymerization using ammonium persulfate and sodium bisulfite as initiator.The pervaporation properties of the copolymeric membranes prepared have been investigated for the first time. The dependences of pervaporation characteristics on coplymer composition,feed concentration and operating temperature have been studied.In order to improve the separation properties of the copolymeric membranes,the membranes were hydrolyzed with 10 wt% soldium hydroxide or potassium hydroxide aqueous solution.The hydrolyzed membranes containing more than 0.069MA mol fraction showed higher tensile strength and separation properties than the original membranes.

  1. Mechanistic diversity of the van Leusen reaction applied to 6-ketomorphinans and synthetic potential of the resulting acrylonitrile substructures.

    Science.gov (United States)

    Schütz, Johannes; Windisch, Petra; Kristeva, Elka; Wurst, Klaus; Ongania, Karl-Hans; Horvath, Ulrike E I; Schottenberger, Herwig; Laus, Gerhard; Schmidhammer, Helmut

    2005-06-24

    Tosylmethyl isocyanide was used to convert 7,8-didehydro-6-ketomorphinans to 6,7-didehydromorphinan-6-carbonitriles with retainment of the 4,5-epoxy ring. However, ring opening occurred in the presence of NaH giving 5,6,7,8-tetradehydromorphinan-6-carbonitriles. Addition of nucleophiles such as Li diisopropylamide or Grignard reagents to the acrylonitrile substructure yielded ring-opened 5,6-didehydro products. Seven products were characterized by X-ray crystal structure analysis and revealed insight into the mechanistic diversity of the van Leusen reaction.

  2. Performance Analysis of Styrene Butadiene Rubber-Latex on Cement Concrete Mixes.

    Directory of Open Access Journals (Sweden)

    Er. Kapil Soni

    2014-03-01

    Full Text Available To improve the performance of concrete, polymers are mixed with concrete. It has been observed that polymer-modified concrete (PMC is more durable than conventional concrete due to superior strength and high durability. In this research, effect of Styrene-Butadiene Rubber (SBR latex on compressive strength and flexural strength of concrete has been studied and also the optimum polymer (SBR-Latex content for concrete is calculated. This research was carried out to establish the effects of polymer addition on compressive and flexural strength using concrete with mix design of constant water-cement ratio at local ambient temperature. The mixes were prepared with Styrene-Butadiene Rubber (SBR latex -cement ratio of 0 %, 5%, 10%, 15% and 20%. Slump test was conducted on fresh concrete while compressive strength and flexural strength were determined at different age. A locally available Perma-Latex is used as SBR Latex. It has been observed that SBR latex has negative effect at early age while at 28 days, the addition of SBR latex in concrete results in enhancement of compressive strength and Flexural Strength. Based on the results of this study, latex modified concrete made using Perma-Latex may be recommended to be used with various types of concrete structures. However, for the mixes rich in cement, the dosage of SBR latex needs to be adjusted to maintain required workability of concrete.

  3. Exfoliated sodium-montmorillonite in nitrile butadiene rubber nanocomposites with good properties

    Institute of Scientific and Technical Information of China (English)

    WANG QingGuo; ZHANG XiaoHong; QIAO JinLiang

    2009-01-01

    We prepared and utilized a novel ultrafine fully-vulcanized powder nitrile butadiene rubber (UFPNBR)/ sodium montmorillonite (Na-MMT) nanocompound powder, in which nanoscale UFPNBR particles and nanoscale platelets of Na-MMT were isolated and stuck each other. When the UFPNBR/Na-MMT nano-compoud powder was mixed with crude nitrile butadiene rubber (NBR), UFPNBR particles could be easily dispersed in NBR matrix because of good compatibility, and nanoscale Na-MMT was also dis-persed well in NBR matrix due to the carrier aidance of UFPNBR particle, thus the NBR/UFPNBPJNa-MMT ternary nanocomposites adapting to industry was fabricated. X-ray diffraction test and scanning electron microscopy (SEM) observation indicated that nanoscale Na-MMT was dispersed well in NBR matrix. Compared with NBR/Na-MMT binary composites, NBR/UFPNBR/Na-MMT ternary nanocompo-sites have shorter vulcanization time and higher flame retardancy due to the exfoliated Na-MMT in NBR matrix.

  4. N7-guanine adducts of the epoxy metabolites of 1,3-butadiene in mice lung.

    Science.gov (United States)

    Koivisto, P; Peltonen, K

    2001-06-01

    Epoxy metabolites of 1,3-butadiene are electrophilic and can bind to nucleophilic sites in DNA forming DNA adducts. In this study, guanine N7 adducts of epoxy butene and guanine N7 adducts of epoxy butanediol were measured in lung tissues of mice inhalation exposed to various concentrations of 1,3-butadiene. 32P-postlabeling of DNA adducts were used to demonstrate that the DNA adducts derived from epoxybutene and epoxybutanediol were formed in a dose dependent manner. More than 98% of all adducts detected were formed from epoxybutanediol. Enantiomeric distribution of the adducts formed in vivo differs from that of in vitro experiments demonstrated before. In the case of epoxybutene most of the adducts were formed to the terminal carbon of the S-epoxybutene enantiomer. Most of the adducts derived from epoxybutanediol were formed from the 2S-3R enantiomer. The data demonstrates that enzymatic processes involved with activation and/or detoxification of the metabolites are enantiospecific and/or DNA repair machinery repairs the damage with stereochemical considerations. These are the crucial factors if interspecies differences in tumor sensitiveness is concerned.

  5. Aromatic ring formation in opposed-flow diffusive 1,3-butadiene flames

    KAUST Repository

    Moshammer, Kai

    2016-10-17

    This paper is concerned with the formation of one- and two-ring aromatic species in near atmospheric-pressure opposed-flow diffusion flames of 1,3-butadiene (1,3-CH). The chemical structures of two different 1,3-CH/Ar-O/Ar flames were explored using flame-sampling molecular-beam mass spectrometry with both electron and single-photon ionization. We provide mole fraction profiles of 47 components as function of distance from the fuel outlet and compare them to chemically detailed modeling results. To this end, the hierarchically developed model described by Seidel et al. [16] has been updated to accurately comprise the chemistry of 1,3-butadiene. Generally a very good agreement is observed between the experimental and modeling data, allowing for a meaningful reaction path analysis. With regard to the formation of aromatic species up to naphthalene, it was essential to improve the fulvene and the C chemistry description in the mechanism. In particular, benzene is found to be formed mainly via fulvene through the reactions of the CH isomers with CH The n-CH radical reacts with CH forming 1,3-pentadiene (CH), which is subsequently oxidized to form the naphthalene precursor cyclopentadienyl (CH). Oxidation of naphthalene is predicted to be a contributor to the formation of phenylacetylene (CH), indicating that consumption reactions can be of similar importance as molecular growth reactions.

  6. Quantum dynamics study of singlet-triplet transitions in s-trans-1,3-butadiene

    Science.gov (United States)

    Nikoobakht, Behnam; Köppel, Horst

    2016-05-01

    The intersystem crossing dynamics of s-trans-1,3-butadiene in its lowest singlet and triplet states is studied theoretically, employing a fully quantal approach for the first time. The electronic states 21Ag, 11Bu, 13Bu and 13Ag, which interact vibronically and via the spin-orbit coupling are treated in the calculation, thus covering the lowest spin-forbidden electronic transitions. Up to five nuclear degrees of freedom, including out-of-plane dihedral angles are included in our investigation. The calculation of potential energy surfaces relies on the CASPT2 method, and the evaluation of spin-orbit coupling matrix elements using the full two-electron Breit-Pauli Hamiltonian is performed by utilizing the MRCI wavefunction. The latter dependence on the nuclear coordinates is included for the first time. An electronic population transfer on the sub-picosecond time scale due to intersystem crossing is obtained, a mechanism that can contribute to the singlet-triplet transitions in the electron energy loss spectrum of s-trans-1, 3-butadiene. It is found that the dependence of the spin-orbit coupling on the out-of-plane coordinates plays a dominant role in these singlet-triplet transitions. The amount of population transfer to the 13Ag and 13Bu states is roughly of the same order of magnitude.

  7. Genetic effects of 1,3-butadiene and associated risk for heritable damage.

    Science.gov (United States)

    Pacchierotti, F; Adler, I D; Anderson, D; Brinkworth, M; Demopoulos, N A; Lähdetie, J; Osterman-Golkar, S; Peltonen, K; Russo, A; Tates, A; Waters, R

    1998-01-16

    A summary of the results of the studies conducted in the EU Project "Multi-endpoint analysis of genetic damage induced by 1,3-butadiene and its major metabolites in somatic and germ cells of mice, rats and man" is presented. Results of the project are summarized on the detection of DNA and hemoglobin adducts, on the cytotoxic and clastogenic effects in somatic and germinal cells of mice and rats, on the induction of somatic mutations at the hprt locus of experimental rodents and occupationally exposed workers, on the induction of dominant lethal mutations in mice and rats, and on heritable translocations induced in mice, after exposure to butadiene (BD) or its major metabolites, butadiene monoepoxide (BMO), diepoxybutane (DEB) and butadiene diolepoxide (BDE). The primary goal of this project was to collect experimental data on the genetic effects of BD in order to estimate the germ cell genetic risk to humans of exposure to BD. To achieve this, the butadiene exposure are based on data for heritable translocations and bone marrow micronuclei induced in mice and chromosome aberrations observed in lymphocytes of exposed workers. A doubling dose for heritable translocations in human germ cells of 4900 ppm/h is estimated, which, assuming cumulative BD exposure over the sensitive period of spermatogenesis, corresponds to 5-6 weeks of continuous exposure at the workplace to 20-25 ppm. Alternatively, the rate of heritable translocation induction per ppm/h of BD exposure is estimated to be approximately 0.8 per million live born, compared to a spontaneous incidence of balanced translocations in humans of approximately 800 per million live born. These estimates have large confidence intervals and are only intended to indicate orders of magnitude of human genetic risk. These risk estimates are based on data from germ cells of BD-exposed male mice. The demonstration that clastogenic damage was induced by DEB in preovulatory oocytes at doses which were not ovotoxic implies that

  8. Quantum chemistry and TST study of the mechanism and kinetics of the butadiene and isoprene reactions with mercapto radicals

    Science.gov (United States)

    Francisco-Márquez, Misaela; Alvarez-Idaboy, J. Raul; Galano, Annia; Vivier-Bunge, Annik

    2008-03-01

    The reactions of isoprene and butadiene with SH rad radicals have been investigated by density functional theory and ab initio molecular orbital theories. We report the thermodynamics and kinetics of four different pathways, involving addition of SH rad radicals to all double-bonded carbon atoms. Calculations have been performed on all stationary points using BHandHLYP functional, Moller-Plesset perturbation theory to second-order (MP2) and the composite CBS-QB3 method at the MP2 optimized geometries and frequencies. Pre-reactive complexes have been identified. The apparent activation energies are negative for SH rad addition at the terminal carbon atoms and are slightly smaller than those for OH rad addition at the same positions. The calculated overall rate coefficient for butadiene + SH rad reaction at 298 K is in excellent agreement with the only available experimentally measured value. Activation energies and overall rate coefficients at different temperatures are predicted for the first time for butadiene + SH rad and isoprene + SH rad reactions. The reactions of butadiene and isoprene with SH rad radicals were found to be about four times faster than with OH rad radicals.

  9. Base-free Pd/TOMPP-Catalyzed Telomerization of 1,3-Butadiene with Carbohydrates and sugar alcohols

    NARCIS (Netherlands)

    Hausoul, P.J.C.; Bruijnincx, P.C.A.; Klein Gebbink, R.J.M.; Weckhuysen, B.M.

    2009-01-01

    Sugar and alcohol - a superior combo: The telomerization activity of the Pd/TOMPP catalyst is screened using thirteen different biomass-derived carbohydrates and sugar alcohols. High substrate conversions are achieved by using low Pd loading and without the use of an added base. In terms of butadien

  10. Oxidative Dehydrogenation of n-Butenes to 1,3-Butadiene over Bismuth Molybdate and Ferrite Catalysts: A Review

    KAUST Repository

    Hong, Eunpyo

    2015-11-02

    1,3-Butadiene, an important raw material for a variety of chemical products, can be produced via the oxidative dehydrogenation (ODH) of n-butenes over multicomponent oxide catalysts based on bismuth molybdates and ferrites. In this review, the basic concept, reaction mechanism, and catalysts typically used in an ODH reaction are discussed. © 2015, Springer Science+Business Media New York.

  11. Study of conversion of butadiene to CO2 by rTiO2 nanoparticles: ZINDO/S

    Science.gov (United States)

    Mahdavian, Leila

    2017-02-01

    One of the pollutants emitted from automobile exhaust is unburned hydrocarbons that include benzene, propane, formaldehyde, butadiene, etc. Due to the carcinogenicity of these substances, eliminating and reducing them in the source of production is essential. Catalytic converters have been developed to reduce these pollutions to low-risk materials in automobile exhaust. In this study, the mechanism of converting butadiene to carbon dioxide is simulated and calculated by rutile titanium dioxide (Titania) nanoparticles ( rTiO2-NP). Then the geometric structure of simulated steps (the conversion butadiene to carbon dioxide) is optimized by DFT method and semi-empirical (ZINDO/S) method is used to calculate the thermodynamic properties. There are three different locations of physical chemistry on the rTiO2-NPs to get closer pollutants, namely Ti-O (1), Ti-O (2), and Ti-Ti. The results show the approaching possibility of butadiene to Ti-O (1) is more than other locations, because the bond length, electronegativity and spatial structure of this position are different from others.

  12. 40 CFR 63.500 - Back-end process provisions-carbon disulfide limitations for styrene butadiene rubber by emulsion...

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 9 2010-07-01 2010-07-01 false Back-end process provisions-carbon disulfide limitations for styrene butadiene rubber by emulsion processes. 63.500 Section 63.500 Protection... Pollutant Emissions: Group I Polymers and Resins § 63.500 Back-end process provisions—carbon disulfide...

  13. Palladium-Catalyzed Telomerization of 1,3-Butadiene with Biomass-based Oxygenates: Substrate Scope, Mechanism and Catalyst Heterogenization

    NARCIS (Netherlands)

    Hausoul, P.J.C.

    2013-01-01

    The catalytic activity of Pd/TOMPP (TOMPP: tris(2-methoxyphenylphosphine) in the telomerization of 1,3-butadiene was screened with carbohydrates and phenolics that can be potentially derived from lignocellulosic biomass. High conversions and selectivities were obtained and clear structure-activity r

  14. Stepwise Swelling of a Thin Film of Lamellae-Forming Poly(styrene-b-butadiene) in Cyclohexane Vapor

    DEFF Research Database (Denmark)

    Di, Zhenyu; Posselt, Dorthe; Smilgies, Detlef-M.

    2012-01-01

    We investigated the swelling of a thin film of lamellae-forming poly(styrene-b-butadiene) in cyclohexane vapor. The vapor pressure and thus the degree of swelling of the film are increased in a stepwise manner using a custom-built sample cell. The resulting structural changes during and after eac...

  15. New heterocyclic precursors for thermal generation of reactive, electron-rich 1,2-diaza-1,3-butadienes.

    Science.gov (United States)

    Boeckman, R K; Ge, P; Reed, J E

    2001-11-15

    [reaction--see text] [corrected] The preparation and thermolysis of new stable heterocyclic precursors of 1,2-diaza-1,3-butadienes is described. The resulting reactive diazadienes are trapped in situ with N-phenylmaleimide [corrected]. The effect of precursor structure on the temperature at which the diazadienes are generated is discussed.

  16. Fire and Gas Barrier Properties of Poly(styrene-co-acrylonitrile Nanocomposites Using Polycaprolactone/Clay Nanohybrid Based-Masterbatch

    Directory of Open Access Journals (Sweden)

    S. Benali

    2008-01-01

    Full Text Available Exfoliated nanocomposites are prepared by dispersion of poly(ε-caprolactone (PCL grafted montmorillonite nanohybrids used as masterbatches in poly(styrene-co-acrylonitrile (SAN. The PCL-grafted clay nanohybrids with high inorganic content are synthesized by in situ intercalative ring-opening polymerization of ε-caprolactone between silicate layers organomodified by alkylammonium cations bearing two hydroxyl functions. The polymerization is initiated by tin alcoholate species derived from the exchange reaction of tin(II bis(2-ethylhexanoate with the hydroxyl groups borne by the ammonium cations that organomodified the clay. These highly filled PCL nanocomposites (25 wt% in inorganics are dispersed as masterbatches in commercial poly(styrene-co-acrylonitrile by melt blending. SAN-based nanocomposites containing 3 wt% of inorganics are accordingly prepared. The direct blend of SAN/organomodified clay is also prepared for sake of comparison. The clay dispersion is characterized by wide-angle X-ray diffraction (WAXD, atomic force microscopy (AFM, and solid state NMR spectroscopy measurements. The thermal properties are studied by thermogravimetric analysis. The flame retardancy and gas barrier resistance properties of nanocomposites are discussed both as a function of the clay dispersion and of the matrix/clay interaction.

  17. A COMPARISON BETWEEN THE MORPHOLOGY OF SEMICRYSTALLINE POLYMER BLENDS OF POLY(EPSILON-CAPROLACTONE)/POLY(VINYL METHYL-ETHER) AND POLY(EPSILON-CAPROLACTONE)/(STYRENE-ACRYLONITRILE)

    NARCIS (Netherlands)

    OUDHUIS, AACM; THIEWES, HJ; VANHUTTEN, PF; TENBRINKE, G

    1994-01-01

    The morphology of polymer blends of poly(epsilon-caprolactone) (PCL) and poly(vinyl methyl ether) (PVME) is compared with that of PCL and a random copolymer of styrene and acrylonitrile (SAN). The main objective is to determine the influence of the glass transition temperature of the amorphous compo

  18. Accurate quantification of the mercapturic acids of acrylonitrile and its genotoxic metabolite cyanoethylene-epoxide in human urine by isotope-dilution LC-ESI/MS/MS.

    Science.gov (United States)

    Schettgen, T; Bertram, J; Kraus, T

    2012-08-30

    Acrylonitrile is a highly important industrial chemical with a high production volume worldwide, especially in the plastics industry. It is classified as a possible human carcinogen by the International Agency for Research on Cancer (IARC group 2B). During metabolism of acrylonitrile, the genotoxic metabolite cyanoethylene-epoxide is formed. The urinary mercapturic acids of acrylonitrile, namely N-acetyl-S-(2-cyanoethyl)-L-cysteine (CEMA) and cyanoethylene-epoxide, namely N-acetyl-S-(1-cyano-2-hydroxyethyl)-L-cysteine (CHEMA) are specific biomarkers for the determination of individual internal exposure to acrylonitrile and its highly reactive metabolite. We have developed and validated a sensitive method for the accurate determination of CEMA and CHEMA in human urine with a multidimensional LC/MS/MS-method using deuterium-labelled analogues for both analytes as internal standards. Analytes were stripped from urinary matrix by online extraction on a restricted access material, transferred to the analytical column and determined by tandem mass spectrometry. The limit of quantification (LOQ) for CEMA and CHEMA was 1 μg/L urine and allowed to quantify the background exposure of the (smoking) general population. Precision within and between series for CHEMA ranged from 2.6 to 8.0% at four concentrations ranging from 8.3 to 86 μg/L urine, mean accuracy was between 94 and 100%. For CEMA, precision within and between series ranged from 2.4 to 14.5% at four concentrations ranging from 15.1 to 196 μg/L urine, mean accuracy was between 91 and 104%. We applied the method to spot urine samples of 83 subjects of the general population with no known occupational exposure to acrylonitrile. Median levels (range) for CEMA and CHEMA in urine samples of non-smokers (n=47) were 1.9 μg/L (<1-16.4 μg/L) and<1 μg/L (<1-3 μg/L), while in urine samples of smokers (n=36), median levels were 184 μg/L (2-907 μg/L) and 29.3 μg/L (<1-147 μg/L), respectively. Smokers showed a

  19. CHARACTERIZATION OF IRON COMPLEXES SUPPORTED ON POLYMER AND THEIR CATALYTIC ACTIVITY IN BUTADIENE POLYMERIZATION

    Institute of Scientific and Technical Information of China (English)

    YU Guangqian; LI Yuliang; YANG Zhifan; WANG Hong

    1990-01-01

    Styrene-acrylic acid copolymer (SAAC)-supported iron complex (SAAC·Fe)was characterized and the effect of the characteristic parameters on the catalytic activity of the complex was investigated. IR spectrum suggested that the complex SAAC·Fe possesses a structure of(C) and the Fe-O bond is higher in covalency. R-C-O-Fe-O-Fe(C) The complex SAAC Fe with the structure of(C) showed a higher catalytic activity in butadiene polymerization. When Fe/- COOH molar ratio in SAAC·Fe was about 0.2 the complex gave optimum catalytic activity. The catalytic activity of SAAC Fe with the higher content of long sequence of acrylic acid units was low. When the content of the short sequence of acrylic acid units was predominant and at the same time the content of the short sequence was approximately equal to that of the long sequence for stryrene, the activity of the complex was high.

  20. Fluorescence Efficiency and Visible Re-emission Spectrum of Tetraphenyl Butadiene Films at Extreme Ultraviolet Wavelengths

    CERN Document Server

    Gehman, V M; Rielage, K; Hime, A; Sun, Y; Mei, D -M; Maassen, J; Moore, D

    2011-01-01

    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.

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

    Directory of Open Access Journals (Sweden)

    A.B. Moustafa

    2016-09-01

    Full Text Available Blends of natural rubber (NR with styrene butadiene rubber (SBR with varying ratios have been prepared. Vulcanization of the prepared blends has been induced by irradiation of gamma rays with varying doses up to 250 kGy. Mechanical properties, namely tensile strength, tensile modulus at 100% elongation, elongation at break have been followed up as a function of irradiation dose as well as blend composition. Physical properties, namely gel fraction and swelling number have been followed up using benzene as a solvent. Thermal measurements namely thermogravimetric analysis were carried out. The results indicated that the addition of NR has improved the properties of NR / SBR blends. Also NR/SBR blend is thermally stable than NR alone.

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

    Science.gov (United States)

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

    2015-01-01

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

  3. An ab initio potential function for the ν13 vibrational mode of 1,3-butadiene

    Science.gov (United States)

    Senent, M. L.

    1995-06-01

    The restricted potential of the ν13 torsional mode of 1,3-butadiene has been determined from ab initio calculations. The relative energy and geometry of the second rotamer were calculated with the optimized couple cluster method with double substitutions. This ab initio level provides that the second stable structure attaches to a gauche form situated at 140.8°. The potential energy function was obtained by fitting to a symmetry-adapted Fourier series the total electronic energies of several selected conformations. These energies were calculated by the Möller-Plesset perturbation theory up to the second order (MP2) with full and partial optimization of the geometry. Torsional Raman band positions and fundamental frequencies were determined from the periodic potentials with a good agreement with experimental data. The convenience of performing fully optimized calculations to determine the restricted function is also refuted.

  4. Synthesis and characterization of miktoarm star copolymer of styrene and butadiene using multifunctional macromolecular initiator

    Institute of Scientific and Technical Information of China (English)

    Hai Yan Zhang; Xing Ying Zhang

    2009-01-01

    A new kind of multifunctional macromolecular initiator with Sn-C bonds and polydiene arms was synthesized by living anionic polymerization.At first,polydiene-stannum chloride(PD-SnCl3)was prepared by the reaction of n-butyl-Li(n-BuLi),stannic chloride(SnCl4)and diene.Then PD-SnCl3 was used to react with the dilithium initiator to prepare the multifunctional organic macromolecular initiators.The result suggested that the initiators had a remarkable yield by GPC,nearly 90%.By using these multifunctional macromolecular initiators,styrene and butadiene were effectively polymerized via anionic polymerization,which gave birth to novel miktoarm star copolymers.The relative molecular weight and polydispersity index,microstructure contents,copolymerization components,glass transition temperature(Tg)and morphology of the miktoarm star copolymers were investigated by GPC-UV,1H NMR,DSC and TEM,respectively.

  5. Dynamic Study of Polymer Particle Growth in Gas Phase Polymerization of Butadiene

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    An experimental apparatus composed of microscope, video camera. image-processing, and mini reactor which can be used for real-time measurement of the growth of polymer particle in gas phase polymerization was built up to carry out dynamic study of gas phase polymerization of butadiene by heterogeneous catalyst based on neodymium(Nd). The studies of the shape duplication of polymer particles and catalyst particles and the growth rate of polymer particle were made. Results show that the apparatus and procedure designed can be well utilized to make dynamic observation and data collection of the growth of polymer particle in gas phase polymerization. A phenomenon of shape duplication of polymer particles and catalyst particles was observed by the real-time measurement. The result also concludes that the activity of individual catalyst particle is different, and the effect of reaction pressure on the growth of polymer particle is significant.

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

    Science.gov (United States)

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

    2016-08-01

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

  7. Biodegradation behavior of styrene butadiene rubber (SBR) reinforced with modified coconut shell powder

    Science.gov (United States)

    Sreejith, M. P.; Balan, Aparna K.; Shaniba, V.; Jinitha, T. V.; Subair, N.; Purushothaman, E.

    2017-06-01

    Biodegradation behavior of styrene butadiene rubber composites reinforced with natural filler, coconut shell powder (CSP), with different filler loadings were carried out under soil burial conditions for three to six months. The extent of biodegradation of the composites was evaluated through weight loss, tensile strength and hardness measurements. It was observed that the permanence of the composites was remarkably dependent on filler modification, size of the filler particle and filler content. Composites containing silane modified filler were found to be more resistant to attack by the microbes present in the soil. Mechanical properties such as tensile strength, Young's modulus and hardness were decreased after soil burial testing due to the microbial attack onto the samples.

  8. Microstructural analysis of carbon nanotubes produced from pyrolysis/combustion of styrene-butadiene rubber

    Energy Technology Data Exchange (ETDEWEB)

    Alves, Joner O.; Zhuo, Chuanwei; Levendis, Yannis A. [Northeastern Univ., Boston, MA (United States). Coll. of Engineering. Dept. of Mechanical and Industrial Engineering; Tenorio, Jorge A.S. [University of Sao Paulo (USP), SP (Brazil). Polytechnic School. Dept. of Metallurgical and Materials Engineering

    2010-07-01

    Styrene-Butadiene-Rubber (SBR) is a synthetic rubber copolymer used to fabricate several products. This study aims to demonstrate the use of SBR as feedstock for carbon nanotubes (CNTs) growth, and therefore to establish a novel process for destination for wastes produced from SBR. Pellets of this rubber were controlled burned at temperature of 1000 deg C, and a catalyst system was used to synthesize the nanomaterials. CNTs are materials with a wide range of potential applications due to their extraordinary mechanical, thermal and electrical properties. Produced materials were characterized by SEM and TEM, and the hydrocarbons emissions were measured using GC. Results showed that materials with diameters of 30-100 nm and lengths of about 30 {mu}m were formed. That materials presented similar structures of multi-walled CNTs. Therefore, the use of SBR to produce carbon nanotubes showed quite satisfactory and an interesting field for future investments. (author)

  9. Modification of poly(styrene-block-butadiene-block-styrene) [SBS] with phosphorus containing fire retardants

    DEFF Research Database (Denmark)

    Chernyy, Sergey; Ullah, Saif; Jomaas, Grunde;

    2015-01-01

    application of the H3PO4 modified SBS as a fire retardant additive for bitumen material, in combination with synergetic melamine species, offered 25% better self-extinguishing properties of such formulation already at a low loading level of the fire retardant components (3.5 wt.%).......An elaborate survey of the chemical modification methods for endowing highly flammable SBS with increased fire resistant properties by means of chemical modification of the polymer backbone with phosphorus containing fire retardant species is presented. Optimal conditions for free radical addition...... of the Psingle bondH containing fire retardants to a double bonds of poly(butadiene) block of SBS were found, affording varied degree of the modification (0.2–21 mol%). Alternatively, a two-step procedure based on an epoxidation step followed by hydrolysis of the epoxides with phosphoric acid was developed...

  10. Detection of far ultraviolet radiation by wavelength-shifting tetraphenyl butadiene

    Science.gov (United States)

    Graybill, Joshua R.; Shahi, Chandra B.; Coplan, Michael C.; Vest, Robert E.; Thompson, Alan K.; Clark, Charles W.

    2017-01-01

    Far ultraviolet (FUV) radiation has been used in low-energy particle physics, dark matter searches, and neutron detection, in conjuction with wavelength-shifting (WLS) materials. Tetraphenyl butadiene (TPB) has been found to have high conversion efficiency compared to other WLS fluorophores. We have spin-coated TPB films with high uniformity and optical quality on glass windows and compared the absolute efficiencies of both the spin-coated and vapor deposited films over the incident radiation wavelengths 120 nm < λ < 400 nm at the NIST SURF III Synchrotron Ultraviolet Radiation Facility. While photon efficiencies of 0.7 and 1.35, have been reported, our preliminary results indicate the absolute efficiencies to be between 0.2 and 0.5. The Neutron Observatory was used to compare conversion efficiencies in well-characterized detector platforms.

  11. Thermal recycling of polystyrene and polystyrene-butadiene dissolved in a light cycle oil

    Energy Technology Data Exchange (ETDEWEB)

    Arandes, Jose M.; Erena, Javier; Olazar, Martin; Bilbao, Javier [Departamento de Ingenieria Quimica, Universidad del Pais Vasco, Apartado 644, 48080 Bilbao (Spain); Azkoiti, Miren J. [Departamento de Ingenieria Quimica y del Medio Ambiente, Universidad del Pais Vasco, Plaza de la Casilla 3, 48012 Bilbao (Spain)

    2003-12-01

    A study has been made of the cracking on a mesoporous silica of polystyrene (PS) and polystyrene-butadiene (PS-BD) dissolved in a light cycle oil (LCO) from a product stream of a commercial fluid catalytic cracking (FCC) unit. This study has been carried out in a reactor of short contact time (3 s) in the 723-823 K range. This strategy for simultaneous valorization of plastics and solvent avoids the technological problems inherent to the treatment of solid postconsumer-plastics and the limitation to heat transfer in the process of pyrolysis. The cracking of plastics has a synergistic effect on the conversion of LCO, as it contributes to increasing the yield of gasoline (C{sub 5}-C{sub 12}). The cracking of the PS/LCO blend produces high yields of styrene, whereas the cracking of the PS-BD/LCO blend produces a stream of products with petrochemical interest.

  12. Modification of poly(styrene-block-butadiene-block-styrene) [SBS] with phosphorus containing fire retardants

    DEFF Research Database (Denmark)

    Chernyy, Sergey; Ullah, Saif; Jomaas, Grunde

    2015-01-01

    An elaborate survey of the chemical modification methods for endowing highly flammable SBS with increased fire resistant properties by means of chemical modification of the polymer backbone with phosphorus containing fire retardant species is presented. Optimal conditions for free radical addition...... resulting in 20 mol% of poly(butadiene) block modification. Based on TGA results, organophosporus-modified SBS was found to be amenable to charring – a property which correlated directly with the reduced flammability of the modified polymer observed in Cone Calorimetry tests. Furthermore, conceptually novel...... application of the H3PO4 modified SBS as a fire retardant additive for bitumen material, in combination with synergetic melamine species, offered 25% better self-extinguishing properties of such formulation already at a low loading level of the fire retardant components (3.5 wt.%)....

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

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Jen Ming, E-mail: jmyang@mail.cgu.edu.tw; Huang, Huei Tsz

    2012-08-01

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

  14. Dielectric study of Poly(styrene- co -butadiene) Composites with Carbon Black, Silica, and Nanoclay

    KAUST Repository

    Vo, Loan T.

    2011-08-09

    Dielectric spectroscopy is used to measure polymer relaxation in styrene-butadiene rubber (SBR) composites. In addition to the bulk polymer relaxation, the SBR nanocomposites also exhibit a slower relaxation attributed to polymer relaxation at the polymer-nanoparticle interface. The glass transition temperature associated with the slower relaxation is used as a way to quantify the interaction strength between the polymer and the surface. Comparisons were made among composites containing nanoclay, silica, and carbon black. The interfacial relaxation glass transition temperature of SBR-clay nanocomposites is more than 80 °C higher than the SBR bulk glass transition temperature. An interfacial mode was also observed for SBR-silica nanocomposites, but the interfacial glass transition temperature of SBR-silica nanocomposite is somewhat lower than that of clay nanocomposites. An interfacial mode is also seen in the carbon black filled system, but the signal is too weak to analyze quantitatively. The interfacial polymer relaxation in SBR-clay nanocomposites is stronger compared to both SBR-carbon black and SBR-silica composites indicating a stronger interfacial interaction in the nanocomposites containing clay. These results are consistent with dynamic shear rheology and dynamic mechanical analysis measurements showing a more pronounced reinforcement for the clay nanocomposites. Comparisons were also made among clay nanocomposites using different SBRs of varying styrene concentration and architecture. The interfacial glass transition temperature of SBR-clay nanocomposites increases as the amount of styrene in SBR increases indicating that styrene interacts more strongly than butadiene with clay. © 2011 American Chemical Society.

  15. Designing zeolite catalysts for size- and shape-selective reactions: Selective hydrogenation of acetylene in the presence of butadiene and ethylene

    Energy Technology Data Exchange (ETDEWEB)

    Corbin, D.R.; Abrams, L.; Bonifaz, C. (E.I. du Pont de Nemours Company, Wilmington, DE (USA))

    1989-02-01

    In the production of ethylene from the steam cracking of natural gas, small amounts of acetylene and butadiene are produced. Downstream, acetylene can present a hazard in a cryogenic separation process while nonselective hydrogenation removes acetylene as well as valuable ethylene and butadiene. With the aid of adsorption measurements, a selective hydrogenation catalyst has been designed. Small-pore zeolites, which serve as catalytic supports and provide reactant selective control, were ion-exchanged with Ni{sup 2+} and subsequently reduced. Compared to a commercial catalyst in which 60% of butadiene and all of the acetylene are hydrogenated, these new catalysts totally hydrogenate acetylene with only 10-20% hydrogenation of the butadiene and almost no hydrogenation of ethylene. To achieve selective hydrogenation, poisoning of the metal sites on the external zeolite surface is essential in order to obtain a product spectrum dominated by catalytic sites within the zeolite framework.

  16. Selective hydrogenation of 1,3-butadiene in presence of 1-butene under liquid phase conditions with NiPd/Al^sub 2^O3 catalysts

    National Research Council Canada - National Science Library

    Franklin J Méndez; Roger Solano; Yanet Villasana; Julia Guerra; Susana Curbelo; Marcel Inojosa; Claudio Olivera-Fuentes; Joaquín L Brito

    2016-01-01

      The catalytic performance of Al2O3-supported monometallic and bimetallic catalysts in selective hydrogenation of 1,3-butadiene in the presence of 1-butene under liquid phase conditions was studied...

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

    Science.gov (United States)

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

    2013-01-07

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

  18. Differences in Butadiene Adduct Formation between Rats and Mice Not Due to Selective Inhibition of CYP2E1 by Butadiene Metabolites

    Science.gov (United States)

    Pianalto, Kaila M.; Hartman, Jessica H.; Boysen, Gunnar; Miller, Grover P.

    2013-01-01

    CYP2E1 metabolizes 1,3-butadiene (BD) into genotoxic and possibly carcinogenic 1,2-epoxy-3-butene (EB), 1,2:3,4-diepoxybutane (DEB), and 1,2-epoxy-3,4-butanediol (EB-diol). The dose response of DNA and protein adducts derived from BD metabolites increase linearly at low BD exposures and then saturate at higher exposures in rats, but not mice. It was hypothesized that differences in adduct formation between rodents reflect more efficient BD oxidation in mice than rats. Herein, we assessed whether BD-derived metabolites selectively inhibit rat but not mouse CYP2E1 activity using B6C3F1 mouse and Fisher 344 rat liver microsomes. Basal CYP2E1 activities toward 4-nitrophenol were similar between rodents. Through IC50 studies, EB was the strongest inhibitor (IC50 54 μM, mouse; 98 μM, rat), BD-diol considerably weaker (IC50 1200 μM, mouse; 1000 μM, rat), and DEB inhibition nonexistent (IC50 >25 mM). Kinetic studies showed that in both species EB and BD-diol inhibited 4-nitrophenol oxidation through two-site mechanisms in which inhibition constants reflected trends observed in IC50 studies. None of the reactive epoxide metabolites inactivated CYP2E1 irreversibly. Thus, there was no selective inhibition or inactivation of rat CYP2E1 by BD metabolites relative to mouse Cyp2e1, and it can be inferred that CYP2E1 activity toward BD between rodent species would similarly not be impacted by the presence of BD metabolites. Inhibition of CYP2E1 by BD metabolites is then not responsible for the reported species difference in BD metabolism, formation of BD-derived DNA and protein adducts, mutagenicity and tumorigenesis. PMID:24021170

  19. ON THE KINETICS AND MECHANISM OF THE COPOLYMERIZATION OF ACRYLONITRILE WITH STYRENE IN THE PRESENCE OF COPPER CHLORIDE

    Institute of Scientific and Technical Information of China (English)

    Hiroko Sato; Hiroshi Tsuji; Hitoshi Sasaki; Shinichi Ikemura; Yasuhito Gotoh; Junzo Ishikawa; Sei-ichi Nishimoto

    2003-01-01

    The copolymerization of styrene (St) and acrylonitrile (AN) complexed with CuCl2 monomer by a free radical mechanism was performed using benzoyl peroxide as an initiator at 65℃ under N2 atmosphere for 150 min. The rate of polymerization (Rp) was found to increase linearly with the concentration (in mol/L) of CuCl2, AN and St through scaling relations. The activation energy of the copolymerization process in the presence and absence of CuCl2 was found to be 46.5 kJ/mol and 102 kJ/mol, respectively. The viscosity average molecular weight of the copolymer and the kp2/kt ratio were determired to further assess the accelerating effect of CuCl2 on the copolymerization process. The copolymerization process in the presence of CuCl2 has a radical complex mechanism.

  20. Pressure induced graft-co-polymerization of acrylonitrile onto Saccharum cilliare fibre and evaluation of some properties of grafted fibre

    Indian Academy of Sciences (India)

    A S Singha; Anjali Shama; Vijay Kumar Thakur

    2008-02-01

    In the present work, graft co-polymerization of acrylonitrile (AN) onto Saccharum cilliare fibre has been carried out in the presence of potassium persulphate and ferrous ammonium sulphate (FAS–KPS) as redox initiator. The reactions were carried out under pressure in an autoclave. Various reaction parameters such as pressure, time, pH, concentrations of initiator and monomer were optimized to get maximum graft yield (35.59%). Grafted and ungrafted Saccharum cilliare fibres were then subjected to evaluation of some of their properties like swelling behaviour in different solvents, moisture absorbance under different humidity levels, water uptake and resistance towards chemicals such as hydrochloric acid and sodium hydroxide. The characterization of the graft copolymers were carried out by FTIR spectrophotometer, X-ray diffraction (XRD) and scanning electron microscopic (SEM) studies.

  1. STUDY ON THE GASEOUS PRODUCTS OF HIGH TEMPERATURE PYROLYSIS OF ACRYLONITRILE POLYMERS BY ON-LINE FTIR METHOD

    Institute of Scientific and Technical Information of China (English)

    ZHAO Genxiang; CHEN Bangjie

    1987-01-01

    The gaseous products of high temperature pyrolysis (300℃ to 960℃) of acrylonitrile polymers were measured continuously under nitrogen atnosphere by on-line Fourier Transform Infrared Spectroscopic method (FTIR). From the variations of characteristic peaks it was found that the nitrogen of macromolecules evolved were mainly in the form of hydrogen cyanide and ammonia. During the pyrolysis amorphous carbonaceous element was formed, and crosslinked to form network structure. Three kinds of samples were used for comparison. The experimental results show that the gaseous products of volatile small molecules were HCN, NH3, CH4, C2H6 and cyanide. CO and CO2 were also formed when copolymers of PAN were thermally pyrolyzed.

  2. Free radical induced grafting of acrylonitrile on pre-treated rice straw for enhancing its durability and flame retardancy.

    Science.gov (United States)

    Mukherjee, Aparna; Halder, Seema; Datta, Deepshikha; Anupam, Kumar; Hazra, Biren; Kanti Mandal, Mrinal; Halder, Gopinath

    2017-01-01

    The present investigation highlights the feasibility of a polymer grafting process to enhance the durability and flame retardancy of rice straw towards application as a low cost roofing material. The success of this grafting methodology was perceived to depend upon a bi-step pre-treatment process encompassing delignification and inorganic salts dispersion. Subsequently free radical polymer grafting of acrylonitrile onto rice straw was implemented by immersion mechanism initiated by oxalic acid-potassium permanganate initiator. The percentage of grafting, limiting oxygen index (LOI), biodegradability of the grafted rice straw and grafting yield percentage was estimated to be 57%, 27%, 0.02% and 136.67%, respectively. The weight loss of polymer grafted rice straw implied its less biodegradability over raw straw. Thus, the process of grafting contrived in the present analysis can be a promising and reliable technique for the efficient utilization of rice straw as an inexpensive roofing element through the augmentation of its durability and flame retardancy.

  3. Poly(acrylonitrile-co-itaconic acid)–poly(3,4-ethylenedioxythiophene) and poly(3-methoxythiophene) nanoparticles and nanofibres

    Indian Academy of Sciences (India)

    HAVVA BASKAN; CEM UNSAL; HALE KARAKAS; A SEZAI SARAC

    2017-09-01

    This work aimed to produce poly(acrylonitrile-co-itaconic acid) (P(AN-co-IA)) nanocomposites with poly(3,4-ethylenedioxythiophene) (PEDOT) and poly(3-methoxythiophene) (PMOT). An anionic surfactant sodium dodecyl benzenesulphonate was used in emulsion polymerization for nanocomposite production. Incorporations of PEDOT and PMOT on the nanoparticles were characterized by scanning electron microscopy (SEM), atomic force microscopy, Fourier transforminfrared-attenuated total reflectance spectroscopy and ultra-violet spectroscopy. These nanoparticles were blended withPAN and the blends were electrospun to produce P(AN-co-IA)–polythiophene-derivative-based nanofibres, and the obtainednanofibres were characterized by SEM and energy dispersive spectroscopy. In addition, electrochemical impedance studiesconducted on nanofibres showed that PEDOT and PMOT in matrix polymer P(AN-co-IA) exhibited capacitive behaviourcomparable to that of ITO–PET. Their capacitive behaviour changed with the amount of electroactive polymer.

  4. Experimental study of the structure of rich premixed 1,3-butadiene/CH4/O2/Ar flame

    CERN Document Server

    Gueniche, Hadj-Ali; Fournet, René; Battin-Leclerc, Frédérique

    2006-01-01

    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 sampling with a quartz probe. Quantified species included carbon monoxide and dioxide, methane, oxygen, hydrogen, ethane, ethylene, acetylene, propyne, allene, propene, cyclopropane, 1,3-butadiene, butenes, 1-butyne, vinylacetylene, diacetylene, C5 compounds, benzene, and toluene. The temperature was measured thanks to a thermocouple in PtRh (6%)-PtRh (30%) settled inside the enclosure and ranged from 900 K close to the burner up to 2100 K.

  5. Resolving a Long-Standing Ambiguity: the Non-Planarity of gauche-1,3-BUTADIENE Revealed by Microwave Spectroscopy

    Science.gov (United States)

    Martin-Drumel, Marie-Aline; McCarthy, Michael C.; Patterson, David; Eibenberger, Sandra; Buckingham, Grant; Baraban, Joshua H.; Ellison, Barney; Stanton, John F.

    2016-06-01

    The preferred conformation of cis-1,3-butadiene (CH_2=CH-CH=CH_2) has been of long-standing importance in organic chemistry because of its role in Diels-Alder transition states. The molecule could adopt a planar s-cis conformation, in favor of conjugations in the carbon chain, or a non-planar gauche conformation, as a result of steric interactions between the terminal H atoms. To resolve this ambiguity, we have now measured the pure rotational spectrum of this isomer in the microwave region, unambiguously establishing a significant inertial defect, and therefore a gauche conformation. Experimental measurements of gauche-1,3-butadiene and several of its isotopologues using cavity Fourier-transform microwave (FTMW) spectroscopy in a supersonic expansion and chirped-pulse FTMW spectroscopy in a 4 K buffer gas cell will be summarized, as will new quantum chemical calculations.

  6. Dominant lethal study in CD-1 mice following inhalation exposure to 1,3-butadiene: Final technical report

    Energy Technology Data Exchange (ETDEWEB)

    Hackett, P.L.; Mast, T.J.; Brown, M.G.; Clark, M.L.; Evanoff, J.J.; Rowe, S.E.; McClanahan, B.J.; Buschbom, R.L.; Decker, J.R.; Rommereim, R.L.; Westerberg, R.B.

    1988-04-01

    The effects of whole-body inhalation exposures to 1,3-butadiene on the reproductive system was evaluated. The results of dominant lethality in CD-1 male mice that were exposed to 1,3-butadiene are described. Subsequent to exposure, males were mated with two unexposed females. Mating was continued for 8 weeks with replacement of two females each week. Gravid uteri were removed, and the total number, position and status of implantations were determined. The mice were weighed prior to exposure and at 0, 1, 2, 3, 4, 5, 6, 7, and 8 weeks after exposure and at sacrifice. The animals were observed for mortality, morbidity and signs of toxicity throughout the study. 19 refs., 5 figs., 9 tabs.

  7. Regioselective synthesis of bicyclic 1,3,5-triazepine system starting from tetrachloro-2-aza-1,3-butadienes

    OpenAIRE

    Bohdan A. Demydchuk; Rusanov, Eduard B.; Julia A. Rusanova; Volodymyr S. Brovarets

    2017-01-01

    Readily available tetrachloro-2-aza-1,3-butadienes enter into directed cyclocondensation reaction with N-phenyl-1,2-cyclopentanediamine which leads to regioselective cyclopentane annulation by the 1,3,5-triazepine. The formation of the 1,3,5-triazepine derivatives was confirmed proved by 1H- and 13C-NMR spectral study, elemental analysis and, in one case, single-crystal x-ray crystallographic study.

  8. Regioselective synthesis of bicyclic 1,3,5-triazepine system starting from tetrachloro-2-aza-1,3-butadienes

    Directory of Open Access Journals (Sweden)

    Bohdan A. Demydchuk

    2017-02-01

    Full Text Available Readily available tetrachloro-2-aza-1,3-butadienes enter into directed cyclocondensation reaction with N-phenyl-1,2-cyclopentanediamine which leads to regioselective cyclopentane annulation by the 1,3,5-triazepine. The formation of the 1,3,5-triazepine derivatives was confirmed proved by 1H- and 13C-NMR spectral study, elemental analysis and, in one case, single-crystal x-ray crystallographic study.

  9. Theoretical and experimental investigations of the 2-(4-chlorophenyl)-3-{[5-(2-cyano-2-phenylethenyl)]furan-2-yl}acrylonitrile molecule as a potential acceptor in organic solar cells

    Science.gov (United States)

    Kazici, Mehmet; Bozar, Sinem; Aydin Yuksel, Sureyya; Ongul, Fatih; Gokce, Halil; Gunes, Serap; Yorur Goreci, Cigdem

    2016-06-01

    A novel soluble asymmetric acrylonitrile derivative, 2-(4-Chlorophenyl)-3-{[5-(2-cyano-2-phenylethenyl)]furan-2-yl}acrylonitrile (CPCPFA, 3) was synthesized in three steps by Knoevenagel condensation. The structure of the CPCPFA was characterized using UV-vis, FTIR, 1H NMR, 13C NMR, and LC-MS. CPCPFA was evaluated as an electron acceptor in bulk heterojunction organic solar cells. Its optical and electronic properties as well as photovoltaic performance were investigated.

  10. DNA damage in lung cells in vivo and in vitro by 1,3-butadiene and nitrogen dioxide and their photochemical reaction products.

    Science.gov (United States)

    Walles, S A; Victorin, K; Lundborg, M

    1995-04-01

    A UV-irradiated mixture of 1,3-butadiene and nitrogen dioxide (NO2) was tested for its potency to induce DNA damage measured as single-strand breaks (SSB) in lungs of mice. Both gases were also tested separately. After 16 h exposure a UV-irradiated mixture of 40 ppm butadiene + 20 ppm NO2, but not 20 ppm butadiene + 10 ppm NO2 + UV, induced a significant increase in SSB as measured by the alkaline unwinding technique. There was no increase in the level of SSB using the alkaline elution technique during the same testing conditions. However, after 5 h exposure to 60 ppm butadiene + 30 ppm NO2 + UV both methods demonstrated a significant increase in SSB. Mice were also exposed to butadiene at 80 and 200 ppm for 16 h and at 500 ppm for 5 h. DNA damage was demonstrated in both liver and lung after 5 and 16 h (only at 200 ppm) of exposure using the unwinding technique. Using the alkaline elution assay, a significant increase in the level of SSB in lung and liver was found only after 5 h of exposure. When mice were exposed to 30 ppm NO2 for 16 h or 50 ppm for 5 h, a significant increase in SSB was found with the unwinding technique. Alveolar macrophages from mice were also exposed in vitro to the gas mixture and to butadiene and NO2 separately. In these experiments, the DNA damage was studied with the unwinding technique. A significant effect was demonstrated with 40 ppm butadiene + 20 ppm NO2 + UV. NO2 itself contributed to some extent to the increase. Reasons for the discrepancies between the unwinding and the alkaline elution techniques are discussed.

  11. Mechanical and Thermal Properties of Styrene Butadiene Rubber - Functionalized Carbon Nanotubes Nanocomposites

    KAUST Repository

    Laoui, Tahar

    2013-01-01

    The effect of reinforcing styrene butadiene rubber (SBR) with functionalized carbon nanotubes on the mechanical and thermal properties of the nanocomposite was investigated. Multi-walled carbon nanotubes (CNTs) were functionalized with phenol functional group to enhance their dispersion in SBR matrix. Surface functionalization of the CNTs was carried out using acid treatment and FTIR technique was utilized so as to ascertain the presence of phenol functional group. This was followed with the dispersion of the functionalized CNTs into a polymer solution and a subsequent evaporation of the solvent. This study has demonstrated the inherent capability of CNTs as reinforcing filler as demonstrated by the substantial improvement in Young\\'s Modulus, tensile strength and energy of absorption of the nanocomposites. The tensile strength increased from 0.17 MPa (SBR) to 0.48 MPa while the Young\\'s Modulus increased from 0.25 MPa to 0.83 MPa when 10wt% functionalized CNTs was added. With the addition of 1wt% reinforcement-a peak value of 4.1 KJ energy absorption was obtained. The homogenous dispersion of CNT-Phenol is thought to be responsible for the considerable enhancement in the reported properties. Copyright © Taylor & Francis Group, LLC.

  12. Silk Fibroin-modified Poly (butadiene) urethane Films and Their Effects on Fibroblast Viability

    Institute of Scientific and Technical Information of China (English)

    SUN Dong-hao; WU Zheng-yu; LI Ming-zhong; BAI Lun; SHENG Wei-hua

    2008-01-01

    Surface-modified poly ( butadiene) urethane (PBTU) films with silk fibroin (SF) were prepared by simple chemical method under the normal temperature.The physical properties and biological behaviour of the SF-modified PBTU film were evaluated.The results showed that the SF-modified PBTU films kept the tenacity and pliability very well, and could overcome rigid and brittle weaks of silk fibroin films.The morphology of SF in the PBTU film was dendritic aggregations, and the water-contact angle measurement indicated that the surface hydrophilicity of modified films was apparently enhanced.The biocompatibility of PBTU films was improved due to the change of surface components.The degree of platelet adhesion and the cell viability of rat embryo dermal fibrobiasts seeded on PBTU films, SF films, and SF-modified PBTU films were measured by counting platelets before and after they contacted the films and Mil assay, respectively.The results indicated that platelet adhesion resistance and cell viability on the modified film were greatly superior to those on the PBTU film and the compound interface had good stability in the air.

  13. Predicting the solubility of gases in Nitrile Butadiene Rubber in extreme conditions using molecular simulation

    Science.gov (United States)

    Khawaja, Musab; Molinari, Nicola; Sutton, Adrian; Mostofi, Arash

    In the oil and gas industry, elastomer seals play an important role in protecting sensitive monitoring equipment from contamination by gases - a problem that is exacerbated by the high pressures and temperatures found down-hole. The ability to predict and prevent such permeative failure has proved elusive to-date. Nitrile butadiene rubber (NBR) is a common choice of elastomer for seals due to its resistance to heat and fuels. In the conditions found in the well it readily absorbs small molecular weight gases. How this behaviour changes quantitatively for different gases as a function of temperature and pressure is not well-understood. In this work a series of fully atomistic simulations are performed to understand the effect of extreme conditions on gas solubility in NBR. Widom particle insertion is used to compute solubilities. The importance of sampling and allowing structural relaxation upon compression are highlighted, and qualitatively reasonable trends reproduced. Finally, while at STP it has previously been shown that the solubility of CO2 is higher than that of He in NBR, we observe that under the right circumstances it is possible to reverse this trend.

  14. FRACTAL CHARACTER OF PHASE MORPHOLOGY OF HIGH IMPACT POLYSTYRENE/POLY(cis-BUTADIENE) RUBBER BLENDS

    Institute of Scientific and Technical Information of China (English)

    Yun-yan Li; Yun-ping Han; Jing Sheng

    2006-01-01

    Evolution and fractal character of the phase morphology of high impact polystyrene/poly(cis-butadiene) rubber (HIPS/PcBR) blends during melting and mixing were investigated using scanning electron microscopy (SEM). The characteristic length L was defined as the size of particles of the dispersed phase in blends. Different fractal dimensions, Df and Dm, were introduced to study the distribution width of phase dimensions in the dimensionless region and the uniformity of the spatial distribution of particles, respectively. The results showed that the average characteristic length Lm and Df increase as the volume fraction of the dispersed phase increases, when the volume fraction of the dispersed phase is lower than 50%. In other words, the size of particles increases and their distribution in the dimensionless region becomes more uniform. Meanwhile, the uniformity of the spatial distribution becomes more perfect as the volume fraction increases. At a certain composition, Lm decreases in the initial stage of the mixing and levels off in the late stage. In the initial stage, Df becomes large rapidly with the process of blending, which means that the distribution of L in the dimensionless region becomes more uniform. Meanwhile, the spatial distribution tends to be ideal rapidly in the early stage and fluctuates in a definite range in the late stage of the mixing.

  15. EFFECTS OF STYRENE-BUTADIENE-STYRENE ON STIFFNESS OF ASPHALT CONCRETE AT DIFFERENT TRAFFIC CONDITIONS

    Directory of Open Access Journals (Sweden)

    GHOLAMALI SHAFABAKHSH

    2016-04-01

    Full Text Available The previous studies have explored the effects of Styrene-Butadiene-Styrene (SBS as the most prevalent modifier for asphalt mixtures. The current study intends to compare stiffness modulus of control and SBS modified asphalt mixtures under different traffic loadings. To this end, resilient modulus tests were performed on both conventional and SBS modified specimens. Tests were conducted at 5, 25 and 40°C with loading times of 50, 100, 300, 600 and 1000 milliseconds and 4, 9 and 30 as ratio of rest periods (between loading pulses to loading times (R/L. Using these test parameters and haversine and square loading pulses that represent vertical stress distribution at different depths within an asphalt layer, a variety of traffic densities and vehicle speeds were simulated and their effects on stiffness of asphalt concrete were determined. Results indicated that SBS modification provide higher stiffness under haversine pulse with long loading time at 40°C, so that it was about 3 times of unmodified mixture stiffness. The effect of traffic density that represented by R/L was significant only in long loading time (1000 ms especially under haversine pulse.

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

    Science.gov (United States)

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

    2012-08-01

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

  17. Natural rubber/nitrile butadiene rubber/hindered phenol composites with high-damping properties

    Directory of Open Access Journals (Sweden)

    Xiuying Zhao

    2015-10-01

    Full Text Available New natural rubber (NR/nitrile butadiene rubber (NBR/hindered phenol (AO-80 composites with high-damping properties were prepared in this study. The morphological, structural, and mechanical properties were characterized by atomic force microscopy (AFM, polarized Fourier transform infrared spectrometer (FTIR, dynamic mechanical thermal analyzer (DMTA, and a tensile tester. Each composite consisted of two phases: the NR phase and the NBR/AO-80 phase. There was partial compatibility between the NR phase and the NBR/AO-80 phase, and the NR/NBR/AO-80 (50/50/20 composite exhibited a co-continuous morphology. Strain-induced crystallization occurred in the NR phase at strains higher than 200%, and strain-induced orientation appeared in the NBR/AO-80 phase with the increase of strain from 100% to 500%. The composites had a special stress–strain behavior and mechanical properties because of the simultaneous strain-induced orientation and strain-induced crystallization. In the working temperature range of a seismic isolation bearing, the composites (especially the NR/NBR/AO-80 (50/50/20 composite presented a high loss factor, high area of loss peak (TA, and high hysteresis energy. Therefore, the NR/NBR/AO-80 rubber composites are expected to have important application as a high-performance damping material for rubber bearing.

  18. Biological monitoring to determine worker dose in a butadiene processing plant

    Energy Technology Data Exchange (ETDEWEB)

    Bechtold, W.E.; Hayes, R.B. [National Cancer Inst., Bethesda, MD (United States)

    1995-12-01

    Butadiene (BD) is a reactive gas used extensively in the rubber industry and is also found in combustion products. Although BD is genotoxic and acts as an animal carcinogen, the evidence for carcinogenicity in humans is limited. Extrapolation from animal studies on BD carcinogenicity to risk in humans has been controversial because of uncertainties regarding relative biologic exposure and related effects in humans vs. experimental animals. To reduce this uncertainty, a study was designed to characterize exposure to BD at a polymer production facility and to relate this exposure to mutational and cytogenetic effects. Biological monitoring was used to better assess the internal dose of BD received by the workers. Measurement of 1,2-dihydroxy-4-(N-acetylcysteinyl) butane (M1) in urine served as the biomarker in this study. M1 has been shown to correlate with area monitoring in previous studies. Most studies that relate exposure to a toxic chemical with its biological effects rely on exposure concentration as the dose metric; however, exposure concentration may or may not reflect the actual internal dose of the chemical.

  19. Advanced Booster Composite Case/Polybenzimidazole Nitrile Butadiene Rubber Insulation Development

    Science.gov (United States)

    Gentz, Steve; Taylor, Robert; Nettles, Mindy

    2015-01-01

    The NASA Engineering and Safety Center (NESC) was requested to examine processing sensitivities (e.g., cure temperature control/variance, debonds, density variations) of polybenzimidazole nitrile butadiene rubber (PBI-NBR) insulation, case fiber, and resin systems and to evaluate nondestructive evaluation (NDE) and damage tolerance methods/models required to support human-rated composite motor cases. The proposed use of composite motor cases in Blocks IA and II was expected to increase performance capability through optimizing operating pressure and increasing propellant mass fraction. This assessment was to support the evaluation of risk reduction for large booster component development/fabrication, NDE of low mass-to-strength ratio material structures, and solid booster propellant formulation as requested in the Space Launch System NASA Research Announcement for Advanced Booster Engineering Demonstration and/or Risk Reduction. Composite case materials and high-energy propellants represent an enabling capability in the Agency's ability to provide affordable, high-performing advanced booster concepts. The NESC team was requested to provide an assessment of co- and multiple-cure processing of composite case and PBI-NBR insulation materials and evaluation of high-energy propellant formulations.

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

    Energy Technology Data Exchange (ETDEWEB)

    Mansilla, M.A., E-mail: mmansilla@df.uba.ar [Laboratorio de Polimeros y Materiales Compuestos, Departamento de Fisica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, Pabellon 1, C1428EGA Buenos Aires (Argentina); Marzocca, A.J. [Laboratorio de Polimeros y Materiales Compuestos, Departamento de Fisica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, Pabellon 1, C1428EGA Buenos Aires (Argentina)

    2012-08-15

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

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

    Science.gov (United States)

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

    2013-12-01

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

  2. Integrated techno-economic and environmental analysis of butadiene production from biomass.

    Science.gov (United States)

    Farzad, Somayeh; Mandegari, Mohsen Ali; Görgens, Johann F

    2017-09-01

    In this study, lignocellulose biorefineries annexed to a typical sugar mill were investigated to produce either ethanol (EtOH) or 1,3-butadiene (BD), utilizing bagasse and trash as feedstock. Aspen simulation of the scenarios were developed and evaluated in terms of economic and environmental performance. The minimum selling prices (MSPs) for bio-based BD and EtOH production were 2.9-3.3 and 1.26-1.38-fold higher than market prices, respectively. Based on the sensitivity analysis results, capital investment, Internal Rate of Return and extension of annual operating time had the greatest impact on the MSP. Monte Carlo simulation demonstrated that EtOH and BD productions could be profitable if the average of ten-year historical price increases by 1.05 and 1.9-fold, respectively. The fossil-based route was found inferior to bio-based pathway across all investigated environmental impact categories, due to burdens associated with oil extraction. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Bond Characteristics of Macro Polypropylene Fiber in Cementitious Composites Containing Nanosilica and Styrene Butadiene Latex Polymer

    Directory of Open Access Journals (Sweden)

    Jae-Woong Han

    2015-01-01

    Full Text Available This study evaluated the bond properties of polypropylene (PP fiber in plain cementitious composites (PCCs and styrene butadiene latex polymer cementitious composites (LCCs at different nanosilica contents. The bond tests were evaluated according to JCI SF-8, in which the contents of nanosilica in the cement were 0, 2, 4, 6, 8, and 10 wt%, based on cement weight. The addition of nanosilica significantly affected the bond properties between macro PP fiber and cementitious composites. For PCCs, the addition of 0–2 wt% nanosilica enhanced bond strength and interface toughness, whereas the addition of 4 wt% or more reduced bond strength and interface toughness. The bond strength and interfacial toughness of LCCs also increased with the addition of up to 6% nanosilica. The analysis of the relative bond strength showed that the addition of nanosilica affects the bond properties of both PCC and LCC. This result was confirmed via microstructural analysis of the macro PP fiber surface after the bond tests, which revealed an increase in scratches due to frictional forces and fiber tearing.

  4. Degradation of Hydrogenated Nitrile-butadiene Rubber in Aqueous Solutions of H2S or HCl

    Institute of Scientific and Technical Information of China (English)

    CONG Chuan-bo; CUI Can-can; MENG Xiao-yu; LU Shao-jie; ZHOU Qiong

    2013-01-01

    The degradation of hydrogenated nitrile-butadiene rubber(HNBR) soaped in aqueous solutions of H2S and HCl was investigated.The samples unexposed and exposed to different solutions were characterized by 13C nuclear magnetic resonance(13C NMR),X-ray photoelectron and infrared spectroscopies.In contrast to those of unexposed samples and samples soaped in HCl solution,the mechanical properties of samples exposed to H2S solution significantly deteriorated,in which the new groups of C(=O)-NH2,C-S-C and C=S emerged.The mechanism of C=S and C-S-C formation was speculated,except for that of the formation of group C(=O)-NH2,which was widely discussed in acidic condition such as HC1 solution.The formation of C-S-C was due to radical reaction initiated by mercapto radical and that of C=S was due to nucleophilic reaction initiated by mercapto cations.This finding is helpful to understanding the seal failure of HNBR in working environment containing H2S.

  5. Microstructural analysis of carbon nanomaterials produced from pyrolysis/combustion of Styrene-Butadiene-Rubber (SBR

    Directory of Open Access Journals (Sweden)

    Joner Oliveira Alves

    2011-12-01

    Full Text Available Styrene-Butadiene-Rubber (SBR is a synthetic rubber copolymer used to fabricate several products. This study aims to demonstrate the use of SBR as feedstock for carbon nanomaterials (nanofibers and nanotubes growth, and therefore to establish a novel process for destination of waste products containing SBR. A three stage electrically heated flow reactor was used. Small pellets of rubber were pyrolyzed at a temperature of 1000 ºC. The pyrolyzates were mixed with oxygen-containing gases and were burned. The products of combustion were used to synthesize the carbon nanomaterials (CNMs at the presence of a catalyst. CNMs have a wide range of potential applications due to their extraordinary mechanical, thermal and electrical properties. Produced materials were characterized by SEM and TEM, whereas combustion products were assessed using GC. Results showed that CNMs with outer diameters of 30-100 nm and lengths of about 30 µm were formed. Therefore, it was demonstrated that waste products containing SBR can be used to generate CNMs which are value-added products of intense technological interest.

  6. Cytogenetic effects of butadiene metabolites in rat and mouse splenocytes following in vitro exposures.

    Science.gov (United States)

    Kligerman, A D; Doerr, C L; Milholland, V S; Tennant, A H

    1996-10-28

    As a first step in investigating the genotoxic effects of the principal metabolites of 1,3-butadiene (BD) in both rats and mice, splenocytes (which have little mixed function oxidase activity) from each specimen were exposed to a series of concentrations of either 3,4-epoxy-1-butene (EB) (20 to 931 microM) or 1,2:3,4-diepoxybutane (DEB) (2.5 to 160 microM) for 1 h. The splenocytes were then washed, cultured, and stimulated to divide with concanavalin A, and metaphases were analyzed for the induction of sister chromatid exchanges (SCEs) and chromosome aberrations (CAs). In addition, cells from some experiments were taken after exposure but before culture, and subjected to the single cell gel (SCG) assay to measure DNA damage in the form of DNA strand breakage and/or alkaline-labile sites. Initial studies indicate that EB does not induce cytogenetic damage in either rat or mouse G0 splenocytes. However, DEB was an extremely potent SCE- and CA-inducer in both species with no species differences apparent. Neither DEB nor EB produced any statistically significant DNA-damaging effects as measured by the SCG assay.

  7. Viscoelastic properties of hydroxyl-terminated poly(butadiene based composite rocket propellants

    Directory of Open Access Journals (Sweden)

    Brzić Saša J.

    2014-01-01

    Full Text Available In the present study, the viscoelastic response of three composite solid propellants based on hydroxyl-terminated poly(butadiene, ammonium perchlorate and aluminum has been investigated. The investigation was surveyed by dynamic mechanical analysis over a wide range of temperatures and frequencies. The mechanical properties of these materials are related to the macromolecular structure of the binder as well as to the content and nature of solid fillers. The storage modulus, loss modulus, loss factor and glass transition temperature for each propellant sample have been evaluated. The master curves of storage (log G' vs log ω and loss modulus (log G'' vs log ω were generated for each propellant. A comparison of logaT vs temperature curves for all propellants indicate conformance to Williams-Landel-Ferry equation. Choosing the glass transition as the reference temperature, WLF equation constants are determined. Fractional free volume at the glass transition temperature and thermal coefficient of free volume expansion values are in accordance with the consideration that Al is reinforcing filler.

  8. Biological monitoring in occupational exposure to low levels of 1,3-butadiene.

    Science.gov (United States)

    Fustinoni, S; Perbellini, L; Soleo, L; Manno, M; Foà, V

    2004-04-01

    Exposure to 1,3-butadiene (BD), a probable carcinogen to humans, was investigated in two groups of subjects working in a petrochemical plant where BD is produced and used to prepare polymers: 42 occupationally exposed workers and 43 internal non-occupationally exposed controls. BD personal exposure was very low but significantly different in the two groups (median airborne BD 1.5 and 0.4 microg/m(3) in exposed and controls, respectively). Similarly, BD in blood and urine, but not in exhaled air, was higher in the exposed workers than in controls (blood BD 3.7 ng/l versus <1.8 ng/l, urinary BD 2.4 ng/l versus <1.0 ng/l). These three biomarkers correlated significantly with personal exposure ( 0.283 < or = Pearson's r < or = 0.383) and between them (0.780 < or = r < or = 0.896). Excretion of urinary mercapturic acids N-acetyl-S-(3,4-hydroxybutyl)-l-cysteine (MI), N-acetyl-S-(1-hydroxymethyl-2-propenyl)-l-cysteine and N-acetyl-S-(2-hydroxy-3-butenyl)-l-cysteine (MII), chromosomal aberrations (CA), and sister chromatid exchanges (SCE) in peripheral blood lymphocytes were not influenced by occupational exposure. Our results show that unmetabolised BD in biological fluids, and particularly urinary BD, represents the biomarker of choice for assessing occupational exposure to low airborne concentrations of BD.

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

    Science.gov (United States)

    Sengoz, Burak; Isikyakar, Giray

    2008-01-31

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

  10. Influence of styrene-butadiene-styrene polymer modification on bitumen viscosity

    Energy Technology Data Exchange (ETDEWEB)

    Lu, X.; Isacsson, U. [Royal Institute of Technology, Stockholm (Sweden). Division of Highway Engineering

    1997-11-01

    It is reported that the effects of polymer content/structure and bitumen type on viscosity characteristics of styrene-butadiene-styrene (SBS) polymer modified bitumens were investigated. The study indicated that SBS polymers were not inert additives and increases in kinematic and dynamic viscosities of the modified bitumens were not directly proportional to polymer content; a marked viscosity increase was observed when the polymer content increased from 3 to 6% by weight of the blend. Modification with a sufficiently high polymer content also increased the degree of non-Newtonian behaviour of the bitumens. The base bitumens and modified bitumens containing 3% SBS were observed to be essentially shear rate independent, while those containing 6 to 9% SBS displayed shear-thinning behaviour. Compared to the modified bitumens with linear SBS, the modified bitumens with branched SBS demonstrated a higher degree of shear-thinning behaviour. These effects were dependent on ranges of shear rate and temperature. The increased degree of non-Newtonian behaviour was observed to influence the correlations between kinematic and dynamic viscosities. 12 refs., 7 figs., 2 tabs.

  11. Synthesis of DNA Oligodeoxynucleotides Containing Site-Specific 1,3-Butadiene- Deoxyadenosine Lesions

    Science.gov (United States)

    Wickramaratne, Susith; Seiler, Christopher L.

    2016-01-01

    Post-oligomerization synthesis is a useful technique for preparing site-specifically modified DNA oligomers. This approach involves site-specific incorporation of inherently reactive halogenated nucleobases into DNA strands using standard solid phase synthesis, followed by post-oligomerization nucleophilic aromatic substitution (SNAr) reactions with carcinogen-derived synthons. In these reactions, the inherent reactivities of DNA and carcinogen-derived species are reversed: the modified DNA nucleobase acts as an electrophile, while the carcinogen-derived species acts as a nucleophile. In the present protocol, we describe the use of the post-oligomerization approach to prepare DNA strands containing site- and stereospecific N6-adenine and N1, N6-adenine adducts induced by epoxide metabolites of the known human and animal carcinogen, 1,3-butadiene (BD). The resulting oligomers containing site specific, structurally defined DNA adducts can be used in structural and biological studies to reveal the roles of specific BD adducts in carcinogenesis and mutagenesis. PMID:26344227

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

    Science.gov (United States)

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

    2012-11-01

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

  13. Thermal Stability and Flammability of Styrene-Butadiene Rubber-Based (SBR Ceramifiable Composites

    Directory of Open Access Journals (Sweden)

    Rafał Anyszka

    2016-07-01

    Full Text Available Ceramifiable styrene-butadiene (SBR-based composites containing low-softening-point-temperature glassy frit promoting ceramification, precipitated silica, one of four thermally stable refractory fillers (halloysite, calcined kaolin, mica or wollastonite and a sulfur-based curing system were prepared. Kinetics of vulcanization and basic mechanical properties were analyzed and added as Supplementary Materials. Combustibility of the composites was measured by means of cone calorimetry. Their thermal properties were analyzed by means of thermogravimetry and specific heat capacity determination. Activation energy of thermal decomposition was calculated using the Flynn-Wall-Ozawa method. Finally, compression strength of the composites after ceramification was measured and their micromorphology was studied by scanning electron microscopy. The addition of a ceramification-facilitating system resulted in the lowering of combustibility and significant improvement of the thermal stability of the composites. Moreover, the compression strength of the mineral structure formed after ceramification is considerably high. The most promising refractory fillers for SBR-based ceramifiable composites are mica and halloysite.

  14. MORPHOLOGY, INTERFACIAL INTERACTION AND PROPERTIES OF STYRENE-BUTADIENE RUBBER/MODIFIED HALLOYSITE NANOTUBE NANOCOMPOSITES

    Institute of Scientific and Technical Information of China (English)

    Zhi-xin Jia; Yuan-fang Luo; Shu-yan Yang; Bao-chun Guo; Ming-liang Du; De-min Jia

    2009-01-01

    A natural nanotubular material, halloysite nanotubes (HNTs), was introduced to prepare styrene-butadiene rubber/modified halloysite nanotube (SBR/m-HNT) nanocomposites. Complex of resorcinol and hexamethylenetetramine (RH) was used as the interracial modifier. The structure, morphology and mechanical properties of SBR/m-HNT nanocomposites, especially the interfacial interactions, were investigated. SEM and TEM observations showed that RH can not only facilitate the dispersion and orientation of HNTs in SBR matrix at nanometer scale, but also enhance the interracial combination between HNTs and rubber matrix. FTIR and XPS investigations confirmed that a number of hydrogen bonds were formed between the phenol hydroxyl groups in resorcinol-formaldehyde resin derived from RH and the oxygen atoms in Si-O bonds or hydroxyl groups on HNTs surfaces. The m-HNTs modified with RH have significant reinforcing effect on SBR vulcanizates. RH as a good interfacial modifier can remarkably improve mechanical properties of SBR/HNT composites. The substantial improvement of comprehensive properties for SBR/m-HNT nanocomposites can be attributed to good dispersion and orientation of HNTs in SBR matrix at nanometer scale and the enhanced interracial interaction between HNTs and rubber matrix.

  15. 丙烯腈生殖毒理学研究概况%An Overview of the Study of Acrylonitrile on Reproductive Toxiocology

    Institute of Scientific and Technical Information of China (English)

    吴鑫; 金泰; 钟先玖

    2000-01-01

    @@ 丙烯腈(acrylonitrile,ACN)为有机合成工业中广泛应用的一种重要单体物质,可合成腈纶纤维,丁腈橡胶,ABS工程塑料及某些树脂.1994年全世界的ACN生产量超过30亿磅,1995年已达到100亿磅的生产能力[1].

  16. Nitrile, amide and temperature effects on amidase-kinetics during acrylonitrile bioconversion by nitrile-hydratase/amidase in situ cascade system.

    Science.gov (United States)

    Cantarella, Laura; Gallifuoco, Alberto; Spera, Agata; Cantarella, Maria

    2013-08-01

    In this study the amidase kinetics of an in situ NHase/AMase cascade system was explored as a function of operational parameters such as temperature, substrate concentration and product formation. The results indicated that controlling amidase inactivation, during acrylonitrile bioconversion, makes it possible to recover the intermediate product of the two-step reaction in almost a pure form, without using purified enzyme. It has been demonstrated, in long-term experiments performed in continuous stirred UF-membrane bioreactors, that amidase is kinetically controlled by its proper substrate, depending on the structure, and by acrylonitrile. Using acrylamide, AMase-stability is temperature dependent (5°C, kd=0.008 h(-1); 30°C kd=0.023 h(-1)). Using benzamide, amidase is thermally stable up to 50°C and no substrate inhibition/inactivation occurs. With acrylonitrile, AMase-activity and -stability remain unchanged at concentrations <200 mM but at 200 mM, 35°C, after 70 h process, 90% irreversible inactivation occurs as no AMase-activity on benzamide revives. Copyright © 2013 Elsevier Ltd. All rights reserved.

  17. IMPORTANT DESIGN POINTS FOR WASTE WATER INCINERATOR OF ACRYLONITRILE PLANT [39]%丙烯腈装置废水焚烧炉设计要点

    Institute of Scientific and Technical Information of China (English)

    丁天才

    2012-01-01

    Waste water incinerator of acryloni- trile plant treats the wastewater from the acrylo- nitrile plant to reach the environmental emission requirements and reclaims the waste heat. So it is the key equipment for the acrylonitrile plant. Taking a waste water incinerator of an acrylonitrile plant as an example, this article introduces and analyzes the process plan selection, refractory lining design and the Nox control of the waste water incinerator of acrylonitrile plant.%丙烯腈装置废水焚烧炉是丙烯腈装置的关键设备,处理来自丙烯腈装置的废水,使之达到环保的排放要求,同时回收废热,以某丙烯腈项目废水焚烧炉为例,介绍和分析了丙烯腈废水焚烧炉的工艺方案选择、耐火材料选择和NOx控制.

  18. Methods for measurement of reactive metabolites as a basis for cancer risk assessment: Application to 1,3-butadiene and isoprene

    Energy Technology Data Exchange (ETDEWEB)

    Fred, Charlotta [Stockholm Univ. (Sweden). Dept. of Environmental Chemistry

    2005-02-01

    1,3-Butadiene is a general air pollutant associated with combustion of organic matter and is also an extensively used monomer in polymer production. The cancer risk estimation of 1,3-butadiene is encumbered with large uncertainties. Extrapolation from tumour frequencies in long-term animal tests has led to a relatively high figure for the risk associated with 1,3-butadiene exposure. This is mainly based on observations of very high tumour incidences in butadiene-exposed mice, which in this respect are about 100 times more sensitive than rats. It has been hypothesized that a high cancer risk from 1,3-butadiene could be associated with its metabolism to the bifunctional 1,2:3,4-diepoxybutane (DEB) which, in comparison with monofunctional epoxides, 1,2-epoxy-3-butene (EB) and 1,2-epoxy-3,4-butanediol (EBdiol), is a highly effective mutagen, i.e. cancer initiator. Measurement of in vivo doses of DEB is therefore essential for the risk assessment of 1,3-butadiene. Reaction products with hemoglobin offer a possibility of measuring reactive metabolites in vivo. Hemoglobin adducts from EBdiol have in this study been measured with available methods, which are, however, not applicable to the bifunctional DEB, and method development was therefore needed. This work presents a procedure for measurement of a specific, ring-closed adduct, Pyr-Val, formed from the reaction of DEB with N-terminal valines in hemoglobin. It is based on LC-ESI-MS/MS analysis of the Pyr-modified N-terminal peptides enriched after trypsin digestion of globin. Mouse and rat could be compared regarding the metabolism of EB, DEB and EBdiol. From the data it was concluded that, in 1,3-butadiene exposure, about 60 times higher levels of DEB are formed in mice compared to rats. Estimates of in vivo doses in published cancer tests showed that carcinogenesis in mice is mainly due to DEB, whereas in rat, and possibly man, the monofunctional EBdiol is the predominant causative factor. Preliminarily, the cancer

  19. Melt-processable hydrophobic acrylonitrile-based copolymer systems with adjustable elastic properties designed for biomedical applications.

    Science.gov (United States)

    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

  20. Functional carbo-butadienes: nonaromatic conjugation effects through a 14-carbon, 24-π-electron backbone.

    Science.gov (United States)

    Rives, Arnaud; Maraval, Valérie; Saffon-Merceron, Nathalie; Chauvin, Remi

    2014-01-07

    A systematic study of carbo-butadiene motifs not embedded in an aromatic carbo-benzene ring is described. Dibutatrienylacetylene (DBA) targets R(1) C(R)CCC(Ph)C≡CC(Ph)CCC(R)R(2) are devised, in which R is C≡CSiiPr3 and R(1) and R(2) are R, H, or 4-X-C6 H4 , with the latter including three known representatives (X: H, NMe2 , or NH2 ). The synthesis method is based on the SnCl2 -mediated reduction of pentaynediols prepared by early or late divergent strategies; the latter allows access to a OMe-NO2 push-pull diaryl-DBA. If R(1) and R(2) are H, an over-reduced dialkynylbutatriene (DAB) with two allenyl caps was isolated instead of the unsubstituted DBA. If R(1) =R(2) =R, the tetraalkynyl-DBA target was obtained, along with an over-reduced DBA product with a 12-membered 1,2-alkylidene-1H2 ,2H2 -carbo-cyclobutadiene ring. X-ray crystallography shows that all of the acyclic DBAs adopt a planar trans-transoid-trans configuration. The maximum UV/Vis absorption wavelength is found to vary consistently with the overall π-conjugation extent and, more intriguingly, with the π-donor character of the aryl X substituents, which varies consistently with the first (reversible) reduction potential and first (irreversible) oxidation peak, as determined by voltammetry.

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

    Science.gov (United States)

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

    2011-05-01

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

  2. Analysis of butadiene urinary metabolites by liquid chromatography-triple quadrupole mass spectrometry.

    Science.gov (United States)

    McDonald, Jacob D; Bechtold, William E; Krone, Jennifer R; Blackwell, Walter B; Kracko, Dean A; Henderson, Rogene F

    2004-04-01

    1,3-Butadiene (BD) is a monomer produced in petrochemical production facilities and from several combustion sources. The United States Environmental Protection Agency has defined BD as a probable human carcinogen. Methods for assessing exposure and internal dose are therefore of critical interest, and one technique is the measurement of urinary metabolites. Here we describe methods for measuring two urinary metabolites, N-acetyl-S-(3,4-dihydroxybutyl)-L-cysteine (referred to as MI) and an isomeric mixture of the regio- and stereoisomers (R)/(S)-N-acetyl-S-(1-(hydroxymethyl)-2-propen-yl)-L-cysteine and (R)/(S)-N-acetyl-S-(2-hydroxy-3-butenyl)-L-cysteine (referred to as MII). The method is based on isolation of the metabolites by solid-phase extraction and measurement using liquid chromatography and triple quadrupole mass spectrometry (LC-MS(3)). The LC-MS(3) allowed good selectivity with minimal sample preparation. Assay accuracy was within 10% or better, with substantial improvement in accuracy accompanying the commercial availability of deuterated internal standards for both compounds. Assay precision and linearity passed rigorous validation criteria, and precision-based limits of quantitation values were 12 and 1 ng/mL for MI and MII, respectively. Data are shown from analysis of human urine from occupationally exposed individuals and rat urine from BD exposures conducted to investigate rodent metabolic profiles. Both of these data sets clearly show that this assay can discern previously described relationships between BD exposure and the production of MI/MII.

  3. Influence of metabolic genotypes on biomarkers of exposure to 1,3-butadiene in humans.

    Science.gov (United States)

    Fustinoni, Silvia; Soleo, Leonardo; Warholm, Margareta; Begemann, Petra; Rannug, Agneta; Neumann, Hans-G; Swenberg, James A; Vimercati, Luigi; Colombi, Antonio

    2002-10-01

    Carcinogenicity of 1,3-butadiene (BD) has been linked to its metabolic activation of genotoxic epoxides. The inherited variations in the activity of BD-metabolizing enzymes may be responsible for individual differences that modulate the effects of BD exposure. In this study, 40 Italian subjects (30 BD-exposed workers and 10 clerks) were investigated to evaluate the role of genetic polymorphism of cytochromes P450 2E1, microsomal epoxide hydrolase, glutathione transferases GSTM1, GSTP1, GSTT1, and alcohol dehydrogenase, on urinary N-acetyl-S-(3,4-hydroxybutyl)-L-cysteine (MI) and hemoglobin N-(2,3,4-trihydroxybutyl)-valine adducts (THBVal). Median urinary MI and THBVal levels were 1.71 mg/g creatinine and 37.0 pmol/g globin in BD-exposed workers (exposure range, 4-201 microg/m(3)) and 1.42 mg/g creatinine and 35.3 pmol/g globin in unexposed subjects. No difference between the two groups was observed. Among all subjects, MI and THBVal levels were significantly correlated (r = 0.333). Smoking positively influenced the formation of THBVal. Higher THBVal levels were found in subjects with GSTM1 null and GSTT1 null genotypes; borderline influences were also noticed for CYP2E1(G(-35)T). An additive effect of combined polymorphisms for CYP2E1, GSTM1, and GSTT1 genes on the THBVal levels was suggested. A multiple linear regression analysis, where each factor contributed significantly, correlated THBVal levels with smoking, CYP2E1(G(-35)T), GSTT1, and GSTM1 genotypes (r = 0.698). Our results indicate that the THBVal level is influenced by genotypes, and that the analysis of combined polymorphisms may be the key to a better understanding of the role played by polymorphism of BD-metabolizing enzymes.

  4. Lack of genotoxic effect in workers exposed to very low doses of 1,3-butadiene.

    Science.gov (United States)

    Lovreglio, Piero; Bukvic, Nenad; Fustinoni, Silvia; Ballini, Andrea; Drago, Ignazio; Foà, Vito; Guanti, Ginevra; Soleo, Leonardo

    2006-06-01

    1,3-Butadiene (BD), a probable carcinogen to humans, has been shown to have an ill-defined genotoxicity in occupationally exposed workers. In the present study, the influence of exposure to very low doses of BD and to cigarette smoking was investigated on some cytogenetic endpoints, namely, sister chromatid exchanges (SCE), chromosomal aberrations (CA) and cells with a high frequency of SCE (HFC), in peripheral blood lymphocytes. Twenty-seven male workers employed in a petrochemical plant and 26 matched controls were included in the study. As regards the airborne BD values, there was a significant difference between exposed (median BD value 1.5, min-max 0.2-69.0 microg/m3) and non-exposed workers (median BD value 0.4, min-max <0.1-3.8 microg/m3). Genotoxic biomarkers were not able to distinguish between the two groups. The frequency of SCE was higher in smokers than in non-smokers (p=0.001), with a positive correlation between the number of cigarettes smoked per day and both SCE (r=0.4; p=0.004) and HFC frequency (r=0.3; p=0.04). Multiple regression analysis confirmed the influence of cigarette smoking on the level of SCE and HFC, while these parameters were not affected by personal exposure to BD. Overall, the biomarkers of genotoxic effect investigated in our study were not able to discriminate between workers with a very low exposure to BD and controls, while it was possible to distinguish between smokers and non-smokers on the basis of SCE.

  5. Pharmacokinetics of Polymersomes Composed of Poly(Butadiene-Ethylene Oxide); Healthy versus Tumor-Bearing Mice.

    Science.gov (United States)

    Wang, G; de Kruijff, R M; Abou, D; Ramos, N; Mendes, E; Franken, L E; Wolterbeek, H T; Denkova, A G

    2016-02-01

    Vesicles composed of block copolymers (i.e., polymersomes) are one of the most versatile nano-carriers for medical purposes due to their tuneable physicochemical properties and the possibility to encapsulate simultaneously hydrophobic and hydrophilic substances, allowing, for instance, the combination of therapy and imaging. In cancer treatment, these vesicles need to remain long enough in the blood stream to be sufficiently taken up by tumors. Here, we have investigated the biodistribution and the pharmacokinetics of polymersomes, composed of poly(butadiene-b-ethylene oxide) having dimensions around 80 nm. The polymersomes have been radiolabeled with ¹¹¹In via the so-called active loading method achieving a loading efficiency of 92.9 ± 0.9% with radionuclide retention in mouse serum of more than 95% at 24 h. The optimized ¹¹¹In containing polymersomes have been intravenously administered in healthy and tumor bearing mice for pharmacokinetic determination using microSPECT (Single Photon Emission Computed Tomography). In healthy mice these polymersomes have been found to exhibit relatively long blood circulation (> 6 h), low liver uptake (6 ± 1.5%ID/g, 48 h p.i.) and elevated spleen uptake (188 ± 30%ID/g). The blood circulation in tumor bearing mice is dramatically reduced (< 1.5 h) most likely due to elevated splenic filtration, clearly indicating the importance of in vivo studies in diseased mice. Finally, the polymersomes have been injected subcutaneously in tumor bearing mice revealing retention of 77% in the mice, primarily accumulated at the site of injection, up to 48 hours after administration.

  6. Interaction of Chloroprene and Nitrile- Butadiene Rubber with Lubricating Greases and Base Oils

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The present communication addresses compatibility of two synthetic rubber types, chloroprene and nitrilebutadiene ones, with a number of base oils of petroleum origin and lubricating greases produced thereof. Four base oils,including three naphthenic products with varying degrees of refining and one paraffinic product,were compared with each other in terms of their effect on the rubbers. Degenerative changes occurring in the rubbers on contact with the oils and greases were studied using accelerated ageing tests. Alterations in rubber parameters, such as hardness, weight and glass transition temperature, caused by interaction with oil were monitored. The main physicochemical mechanisms standing behind the changes observed in the rubber properties were found to be (i) migration of plasticizer from rubber into the oil phase, (ii) absorption of oil by rubber,and (iii) oxidation of rubber. An increase in glass transition temperature (Tg) of rubber aged in a base oil or grease was considered as an indirect indication that the plasticizer had migrated out of rubber;the plasticizer accumulation in the oil phase being directly confirmed by gas chromatography. In order to suppress the plasticizer migration, oil additivation with dioctyl adipate (DOA), a common plasticizer used in rubber formulations, was attempted. However, the BOA-additivated oils, while reducing plasticizer migration, were found to cause more swelling than the original oils in the case of chloroprene rubber. As an alternative, replacement of BOA by an alkylated aryl phosphate in nitrile- butadiene rubber formulations was considered, but it did not solve the problem either.The results of this study suggest conclusively that the type of rubber, the plasticizer, and the base oil are all the crucial parameters that should be considered when matching rubber with oil in real- life applications. Interaction of rubber with base oils and with greases produced thereof is largely controlled by (i) solvency of the

  7. Synthesis of Ethylene or Propylene/1,3-Butadiene Copolymers Possessing Pendant Vinyl Groups with Virtually No Internal Olefins

    Directory of Open Access Journals (Sweden)

    Kenji Michiue

    2015-11-01

    Full Text Available In general, ethylene/1,3-butadiene copolymerizations provides copolymers possessing both pendant vinyls and vinylenes as olefinic moieties. We, at MCI, studied the substituent effects of C2-symmetric zirconocene complexes, rac-[Me2Si(Indenyl’2]ZrCl2 (Indenyl’ = generic substituted indenyl, after activation on the ratio of the pendant vinyls and vinylenes of the resultant copolymers. Complexes examined in this study were rac-dimethylsilylbis (1-indenylzirconium dichloride (1, rac-dimethylsilyl-bis[1-(2-methyl-4,5-benzoindenyl] zirconium dichloride (2, rac-dimethylsilyl-bis[l-(2-methyl -4-phenylindenyl]zirconium dichloride (3, rac-dimethy1si1y1- bis(2-ethyl-4-phenylindenyl zirconium dichloride (4, rac-dimethylsilyl-bis[l-(2-n-propyl -4-(1-naphthylindenyl]zirconium dichloride (5, rac-dimethylsilyl-[1-(2-ethyl-4-(5-(2,2-dimethyl-2,3-dihydro-1H-cyclopenta [a]naphthalenylindenyl][1-(2-n-propyl-4-(5-(2,2-dimethyl-2,3-dihydro-1H-cyclopenta[a] naphthalenylindenyl]zirconium dichloride (6, rac-dimethylsilyl-bis[1-(2-ethyl-4-(9-phenanthrylindenyl]zirconium dichloride (7, and rac-dimethylsilyl-bis[l-(2-n-propyl-4-(9-phenanthrylindenyl]zirconium dichloride (8. We found that the ratio of the pendant vinyls and vinylenes is strongly affected by the bulkiness of the substituent on the complexes examined. The vinyl content increased linearly in the following order, 8 > 7 > 6 > 5 > 4 > 3 > 2 > 1. Notably, complex 8/DMAO formed ethylene/1,3-butadiene copolymers possessing predominant vinyl groups, which can be crucial precursors for functionalized polyolefins. Likewise, complex 8/DMAO afforded propylene/1,3-butadiene copolymers with predominant vinyl groups.

  8. N-acetyl-S-(1-cyano-2-hydroxyethyl)-L-cysteine, a new urinary metabolite of acrylonitrile and oxiranecarbonitrile.

    Science.gov (United States)

    Linhart, I; Smejkal, J; Novák, J

    1988-01-01

    Two mercapturic acids, i.e., N-acetyl-S-(1-cyano-2-hydroxyethyl)-L-cysteine (CHEMA) and N-acetyl-S-(2-hydroxyethyl)-L-cysteine (HEMA), were isolated from the urine of rats dosed with four successive doses of oxiranecarbonitrile (glycidonitrile, GN), 5 mg/kg, a reactive metabolic intermediate of acrylonitrile (AN). GC-MS analysis of methylated urine extracts from both AN- and GN-dosed rats showed another mercapturate which was identified as N-acetyl-S-(1-cyanoethenyl)-L-cysteine (1-CEMA) methyl ester using an authentic reference sample. The mass spectrum of this compound was very similar to that of a methylated metabolite of AN tentatively identified by Langvardt et al. (1980) as N-acetyl-3-carboxy-5-cyanothiazane (ACCT). In contrast, no ACCT was found in rats dosed with either GN or AN. Hence, there is no evidence for the formation of ACCT or its isomers in rats dosed with AN or GN. The methyl ester of 1-CEMA is formed artificially by dehydration of CHEMA methyl ester in the injector of the gas chromatograph.

  9. Effect of PAHM (Poly-acrylonitrile Hollow Microsphere) addition on the Lightweight and Firing Behavior of Whiteware

    Science.gov (United States)

    Choi, H. S.; Pee, J. H.; Kim, G. H.; Kim, J. Y.; Cho, W. S.; Kim, K. J.

    2011-10-01

    The pore generation technology using PAHM (Poly-acrylonitrile Hollow Microsphere) was studied in order to reduce the weights of tableware. In this study, we verify the property of modified slurry and plasticity of green body by adding PAHM. The modified slurry was prepared by adding 25~55vol% of PAHM to the slurry for whiteware. The viscosity of slurry was controlled to be low value (25~45vol%). However, the viscosity of modified slurry increased and the plasticity of modified green body decreased inside the 45~55vol% range. The formed specimen by slip casting was fired at 1225 °C, 1240°C. As the amount of PAHM content increased, the weight decreased and the addition of 45vol/% of PAHM resulted in a weight drop of 39%. However, when the PAHM content increased, the strength decreases over 50%. This is caused by the presence of a large volume of surface defects (pores) and defects from the agglomeration of PAHM.

  10. Molecular mechanism of gelation upon the addition of water to a solution of poly(acrylonitrile) in dimethylsulfoxide

    Science.gov (United States)

    Vettegren, V. I.; Kulik, V. B.; Savitskii, A. V.; Fetisov, O. I.; Usov, V. V.

    2010-05-01

    The solidification of a solution of poly(acrylonitrile) (PAN) in dimethylsulfoxide (DMSO) upon introduction of water into the solution is studied by Raman spectroscopy. In the absence of water, DMSO molecules are found to produce dipole-dipole bonds with PAN molecules. Upon the introduction of water, DMSO molecules produce hydrogen bonds with it and bands at 1005 and 1015 cm-1 appear in the Raman spectrum, which are assigned to the valence vibrations of S=O bonds involved in the hydrogen bonds. Simultaneously, water molecules produce hydrogen bonds with PAN molecules: R-C≡N...H-O-H...N≡C-R, where R is the carbon skeleton of a PAN molecule. Accordingly, a band at 2250 cm-1 arises in the Raman spectrum, which is assigned to the valence vibrations of C≡N bonds producing hydrogen bonds with a water molecule. When the water content is low and the DMSO concentration is high, the length of the hydrogen bonds varies in wide limits and the band at 2250 cm-1 is wide. As the water content rises, DMSO molecules come out of PAN, the variation of the hydrogen bond length in it decreases (the band at 2250 cm-1 narrows), and a high-viscosity system (gel) arises that consists of PAN molecules bonded to water molecules via “equally strong” hydrogen bonds.

  11. Acrylonitrile-contamination induced enhancement of formic acid electro-oxidation at platinum nanoparticles modified glassy carbon electrodes

    Science.gov (United States)

    El-Nagar, Gumaa A.; Mohammad, Ahmad M.; El-Deab, Mohamed S.; Ohsaka, Takeo; El-Anadouli, Bahgat E.

    2014-11-01

    Minute amount (∼1 ppm) of acrylonitrile (AcN), a possible contaminant, shows an unexpected enhancement for the direct electro-oxidation of formic acid (FAO) at Pt nanoparticles modified GC (nano-Pt/GC) electrodes. This is reflected by a remarkable increase of the current intensity of the direct oxidation peak (Ipd, at ca. 0.3 V) in the presence of AcN, concurrently with a significant decrease of the second (indirect) oxidation current (Ipind, at ca. 0.7 V), compared to that observed in the absence of AcN (i.e., at the unpoisoned Pt electrode). The extent of enhancement depends on the surface coverage (θ) of AcN at the surface of Pt nanoparticles. AcN is thought to favor the direct FAO by disturbing the contiguity of the Pt sites, which is necessary for CO adsorption. Furthermore, XPS measurements revealed a change in the electronic structure of Pt in presence of AcN, which has a favorable positive impact on the charge transfer during the direct FAO.

  12. FT-IR and DSC studies of poly(vinylidene chloride-co-acrylonitrile) complexed with LiBF4

    Science.gov (United States)

    Shanthi, M.; Mathew, Chithra M.; Ulaganathan, M.; Rajendran, S.

    2013-05-01

    Poly(vinylidene chloride-co-acrylonitrile) (PVdC-co-AN) based solvent free electrolytes were prepared for different compositions of PVdC-co-AN and LiBF4 using solution casting technique. The ionic conductivity, thermal behavior, complexation and structure of polymer electrolytes have been investigated as a function of LiBF4 content at different weight ratios. DSC studies revealed that the glass transition temperature Tg decreases with the increase of salt concentration up to an optimum level. The change in the glass transition temperature (Tg) with respect to the LiBF4 concentration is reflected in the bulk resistance of the electrolytes and the sample containing 6 wt.% of LiBF4 exhibited minimum bulk resistance compared to other samples. FT-IR studies confirm the interaction of polymer and salt which is mainly between Li-cation and nitrogen atom of Ctbnd N group. The crystalline phase of polymer host is completely changed on the addition of Li salt.

  13. TEMPERATURE AND pH RESPONSE, AND SWELLING BEHAVIOR OF POROUS ACRYLONITRILE-ACRYLIC ACID COPOLYMER HYDROGELS

    Institute of Scientific and Technical Information of China (English)

    Jian Huang; Zhi-ming Huang; Yong-zhong Bao; Zhi-xue Weng

    2006-01-01

    Macroporous acrylonitrile-acrylic acid (AN-AA) copolymer hydrogels were synthesized by free-radical solution polymerizations, using ammonium persulfate (APS)/N,N,N',N'-tetramethylethylenediamine (TEMED) redox initiator system and alcohols porogens. The morphology, temperature and pH sensitive swelling behavior, and swelling kinetics of the resulting hydrogels were investigated. It was found that alcohol type and concentration had great influences on the pore structure and porosity of hydrogels. The pore size of hydrogel increases with the moderate increase of the length of alcohol alkyl chain. However, a further increase of alkyl length would result in the formation of cauliflower-like structure and the decrease of pore size. The porosity of hydrogels increases with the increase of porogen concentration in the polymerization medium. The hydrogels with macroporous structure swell or shrink much faster in response to the change of pH in comparison with the conventional hydrogel without macroporous structure. Furthermore, the response rate is closely related to the porosity of the hydrogels, which could be easily controlled by modulating the concentration of the porogen in the medium. The circular swelling behavior of hydrogels indicated the formation of a relaxing three-dimensional network.

  14. STUDY ON THE POLYMERIZATION OF ACRYLONITRILE INITIATED BY POLYPROPYLENE-BASED VANADYL POLYIMIDODIACETATE——THIOUREA REDOX SYSTEM

    Institute of Scientific and Technical Information of China (English)

    Yang Chaoxiong; Wu Jinyun; Liang Zhenming; Feng Zhouquan

    1989-01-01

    The present paper deals with the kinetics of polymerization of acrylonitrile ( AN ) initiated by the redox system of polypropylene-based vanadyl polyimidodiacetate (PV)-thiourea (TU)in aqueous sulfuric acid in the temperature range from 25 to 40 ℃ . The polymerization rate was measured by varying the concentrations of monomer, vanadyl polyimidodiacetate, thiourea and sulfuric acid. The overall rate of polymerization was summarized as RP =2.2 × 105e-6.860/RT[AN]1.0[PV]0.50[ TU]1.5[H2SO4]2.0 The molecular weight of polyacrylonitrile based on the experimental data was:(-M)n=k·1/T·[AN]/[PV]0.50[TU]1.5[H2SO4]2.0 These results indicated that the chain radicals are terminated by combination and/or disproportionation rather than chain transfer. The cooperation effect of carboxylic groups and the macromolecular field effect of polymer supporter are the characters of vanadyl polyimidodiacetate such as the case reported in early paper[ 1 ].

  15. Infrared reflection absorption spectroscopic study on the adsorption structures of acrylonitrile on Ag(111) and Ag(110) surfaces

    Science.gov (United States)

    Osaka, Naoki; Akita, Masato; Hiramoto, Shuji; Itoh, Koichi

    1999-06-01

    Infrared reflection-absorption spectra in CN stretching, CH 2 out-of-plane wagging and CH 2 twisting vibration regions were measured for acrylonitrile (CH 2CHCN) exposed to Ag(111) and Ag(110) in increasing amounts at 77 K. The adsorbate on Ag(111) takes on a series of discrete adsorption states; i.e., an isolated state, associated states, and ordered and amorphous multilayer states. The adsorbate on Ag(110) at lower exposures is in a state with the CN group weakly coordinated to a silver atom (or silver atoms). The adsorbate on Ag(110) takes the associated state and the amorphous multilayer at larger exposures. On raising the temperature to 96 K, the amorphous states on both Ag(111) and Ag(110) are converted to the ordered multilayer. The desorption temperature of the ordered multilayer is below 99 K for Ag(110), while the temperature is above 107 K for Ag(111); the result indicates the effect of the surface morphology on the stability of the ordered state.

  16. Correlation Between Miscibility and Rheological Characteristics of the Polystyrene (PS) and Poly(styrene-co-acrylonitrile) (PSAN) Blends

    Science.gov (United States)

    Marwat, Zafrullah Khan; Baloch, Musa Kaleem

    2016-11-01

    Rheological measurement has been an effective technique to characterize the miscibility of polymer blends. This article investigates the viscoelastic behavior of poly(styrene) (PS) and poly(styrene-co-acrylonitrile) (PSAN) binary solutions in tetrahydrofuran (THF) relative to PS/PSAN/THF ternary solutions mainly reporting the findings of the authors involving the correlation between the miscibility and rheological behavior. Rheological properties, such as shear viscosity, and shear stress as a function of shear rate were investigated for different blend compositions. Moreover, complex viscosity, loss and storage moduli were also investigated as functions of both the frequency and blend composition. The criterion of miscibility based on the rule of mixture has been discussed. The present study revealed very small window of miscibility as only composition, 50/50 showed values close to the additivity rule or intermediate to those of the neat polymers, thereby indicating very weak interactions between the blend components. On the basis of various findings during the rheological investigation, the blend under study is classified almost immiscible. Moreover, the obtained results also suggested that the miscibility depends on the blend composition and frequency.

  17. Free radical induced grafting of acrylonitrile on pre-treated rice straw for enhancing its durability and flame retardancy

    Directory of Open Access Journals (Sweden)

    Aparna Mukherjee

    2017-01-01

    Full Text Available The present investigation highlights the feasibility of a polymer grafting process to enhance the durability and flame retardancy of rice straw towards application as a low cost roofing material. The success of this grafting methodology was perceived to depend upon a bi-step pre-treatment process encompassing delignification and inorganic salts dispersion. Subsequently free radical polymer grafting of acrylonitrile onto rice straw was implemented by immersion mechanism initiated by oxalic acid-potassium permanganate initiator. The percentage of grafting, limiting oxygen index (LOI, biodegradability of the grafted rice straw and grafting yield percentage was estimated to be 57%, 27%, 0.02% and 136.67%, respectively. The weight loss of polymer grafted rice straw implied its less biodegradability over raw straw. Thus, the process of grafting contrived in the present analysis can be a promising and reliable technique for the efficient utilization of rice straw as an inexpensive roofing element through the augmentation of its durability and flame retardancy.

  18. Compatibilization of blends of low density polyethylene and poly(vinyl chloride) by segmented EB(SAN-block-EB)n block copolymers

    NARCIS (Netherlands)

    Kroeze, E.; Brinke, G. ten; Hadziioannou, G.

    1997-01-01

    Hydrogenated segmented poly[butadiene-block-((styrene-co-acrylonitrile)-block-butadiene)n] block copolymers, which were developed by use of the polymeric iniferter technique, were tested for their compatibilizing capacities for (10/90) LDPE/PVC blends. The acrylonitrile content of the SAN blocks of

  19. Compatibilization of blends of low density polyethylene and poly(vinyl chloride) by segmented EB(SAN-block-EB)(n) block copolymers

    NARCIS (Netherlands)

    Kroeze, E; ten Brinke, G.; Hadziioannou, G

    1997-01-01

    Hydrogenated segmented poly[butadiene-block-((styrene-co-acrylonitrile)-block-butadiene)(n)] block copolymers, which were developed by use of the polymeric iniferter technique, were tested for their compatibilizing capacities for (10/90) LDPE/PVC blends. The acrylonitrile content of the SAN blocks o

  20. Evaluation of DNA damage by alkaline elution technique after inhalation exposure of rats and mice to 1,3-butadiene.

    Science.gov (United States)

    Vangala, R R; Laib, R J; Bolt, H M

    1993-01-01

    The alkaline filter elution technique was used to evaluate single strand breaks (SSB), DNA-DNA (DDCL) and DNA-protein cross-links (DPCL) in liver and lung of male rats (Sprague-Dawley) and male mice (B6C3F1) after exposure to 2000 ppm 1,3-butadiene (BD) for 7 days (7 h/day and/or to 100, 250, 500, 1000) 2000 ppm BD for 7 h. SSB were detected in liver DNA of both species at 2000 ppm. Cross-links are more pronounced in mouse lung than in mouse liver. Elution rates of lung DNA from mice exposed for 7 h to different concentrations of BD revealed an increase in cross-links between 250 and 500 ppm, and a further increase in cross-links up to 2000 ppm. No such signs of genotoxicity could be observed for the lung of rats. Our data support the involvement of reactive metabolites (epoxybutene and especially diepoxybutane) in butadiene-induced carcinogenesis in the mouse but not to that extent in the rat.

  1. The gas phase reaction of ozone with 1,3-butadiene: formation yields of some toxic products

    Science.gov (United States)

    Kramp, Franz; Paulson, Suzanne E.

    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 separate experiments, small quantities of 1,3,5-trimethyl benzene were added as a tracer for OH. Formation yields of acrolein of (52±7)%, 1,2-epoxy-3-butene of (3.1±0.5)% and OH radicals of (13±3)% were observed. In addition, the rate coefficient of the gas-phase reaction of ozone with 1,2-epoxy-3-butene was measured both directly and relative to propene, finding an average of (1.6±0.4)×10 -18 cm 3 molecule -1 s -1, respectively, at 296±2 K. The results are briefly discussed in terms of the effect of atmospheric processing on the toxicity of 1,3-butadiene.

  2. Polymerase Bypass of N6-Deoxyadenosine Adducts Derived from Epoxide Metabolites of 1,3-Butadiene

    Science.gov (United States)

    Kotapati, Srikanth; Wickramaratne, Susith; Esades, Amanda; Boldry, Emily J.; Dorr, Danae Quirk; Pence, Matthew G.; Guengerich, F. Peter; Tretyakova, Natalia Y.

    2015-01-01

    N 6-(2-Hydroxy-3-buten-1-yl)-2′-deoxyadenosine (N6-HB-dA I) and N6,N6-(2,3-dihydroxybutan-1,4-diyl)-2′-deoxyadenosine (N6,N6-DHB-dA) are exocyclic DNA adducts formed upon alkylation of the N6 position of adenine in DNA by epoxide metabolites of 1,3-butadiene (BD), a common industrial and environmental chemical classified as a human and animal carcinogen. Since the N6-H atom of adenine is required for Watson-Crick hydrogen bonding with thymine, N6-alkylation can prevent adenine from normal pairing with thymine, potentially compromising the accuracy of DNA replication. To evaluate the ability of BD-derived N6-alkyladenine lesions to induce mutations, synthetic oligodeoxynucleotides containing site-specific (S)-N6-HB-dA I and (R,R)-N6,N6-DHB-dA adducts were subjected to in vitro translesion synthesis in the presence of human DNA polymerases β, η, ι, and κ. While (S)-N6-HB-dA I was readily bypassed by all four enzymes, only polymerases η and κ were able to carry out DNA synthesis past (R,R)-N6,N6-DHB-dA. Steady-state kinetic analyses indicated that all four DNA polymerases preferentially incorporated the correct base (T) opposite (S)-N6-HB-dA I. In contrast, hPol β was completely blocked by (R,R)-N6,N6-DHB-dA, while hPol η and κ inserted A, G, C, or T opposite the adduct with similar frequency. HPLC-ESI-MS/MS analysis of primer extension products confirmed that while translesion synthesis past (S)-N6-HB-dA I was mostly error-free, replication of DNA containing (R,R)-N6,N6-DHB-dA induced significant numbers of A, C, and G insertions and small deletions. These results indicate that singly substituted (S)-N6-HB-dA I lesions are not miscoding, but exocyclic (R,R)-N6,N6-DHB-dA adducts are strongly mispairing, probably due to their inability to form stable Watson-Crick pairs with dT. PMID:26098310

  3. Epigenetic mechanisms of mouse interstrain variability in genotoxicity of the environmental toxicant 1,3-butadiene.

    Science.gov (United States)

    Koturbash, Igor; Scherhag, Anne; Sorrentino, Jessica; Sexton, Kenneth; Bodnar, Wanda; Swenberg, James A; Beland, Frederick A; Pardo-Manuel Devillena, Fernando; Rusyn, Ivan; Pogribny, Igor P

    2011-08-01

    1,3-Butadiene (BD) is a common environmental contaminant classified as "carcinogenic to humans." Formation of BD-induced DNA adducts plays a major role in its carcinogenicity. BD is also an epigenotoxic agent (i.e., it affects DNA and histone methylation in the liver). We used a panel of genetically diverse inbred mice (NOD/LtJ, CAST/EiJ, A/J, WSB/EiJ, PWK/PhJ, C57BL/6J, and 129S1/SvImJ) to assess whether BD-induced genotoxic and epigenotoxic events may be subject to interstrain differences. Mice (male, 7 weeks) were exposed via inhalation to 0 or 625 ppm BD for 6 h/day and 5 days/week for 2 weeks and liver BD-DNA adducts, epigenetic alterations, and liver toxicity were assessed. N-7-(2,3,4-trihydroxybut-1-yl)-guanine adducts were detected in all strains after exposure, yet BD-induced DNA damage in CAST/EiJ mice was two to three times lower. Epigenetic effects of BD were most prominent in C57BL/6J mice where loss of global DNA methylation and loss of trimethylation of histone H3 lysine 9, histone H3 lysine 27, and histone H4 lysine 20, accompanied by dysregulation of liver gene expression indicative of hepatotoxicity, were found. Interestingly, we observed an increase in histone methylation in the absence of changes in gene expression and DNA methylation in CAST/EiJ strain. We hypothesized that mitigated genotoxicity of BD in CAST/EiJ mice may be due to chromatin condensation. Indeed, we show that in response to BD exposure, chromatin condensation occurs in CAST/EiJ, whereas the opposite effect is observed in C57BL/6J mice. These findings demonstrate that interstrain susceptibility to genotoxicity by a well-known environmental carcinogen may be due to strain-specific epigenetic events in response to the exposure.

  4. Simultaneous quantitation of urinary cotinine and acrylonitrile-derived mercapturic acids with ultraperformance liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Wu, Chia-Fang; Uang, Shi-Nian; Chiang, Su-Yin; Shih, Wei-Chung; Huang, Yu-Fang; Wu, Kuen-Yuh

    2012-02-01

    Acrylonitrile (AN), a widely used industrial chemical also found in tobacco smoke, has been classified as a possible human carcinogen (group 2B) by the International Agency for Research on Cancer. AN can be detoxified by glutathione S-transferase (GST) to form glutathione (GSH) conjugates in vivo. It can be metabolically activated by cytochrome P450 2E1 to form 2-cyanoethylene oxide, which can also be detoxified by GST to generate GSH conjugates. The GSH conjugates can be further metabolized to mercapturic acids (MAs), namely, N-acetyl-S-(2-cyanoethyl)cysteine (CEMA), N-acetyl-S-(2-hydroxyethyl)cysteine (HEMA), and N-acetyl-S-(1-cyano-2-hydroxyethyl)cysteine (CHEMA). This study developed an ultraperformance liquid chromatography coupled with tandem mass spectrometry (UPLC-MS/MS) method to quantitatively profile the major AN urinary metabolites (CEMA, HEMA, and CHEMA) to assess AN exposure, as well as analyze urinary cotinine (COT) as an indicator for tobacco smoke exposure. The limits of quantitation were 0.1, 0.1, 1.0, and 0.05 μg/L for HEMA, CEMA, CHEMA, and COT, respectively. This method was applied to analyze the three AN-derived MAs in 36 volunteers with no prior occupational AN exposure. Data analysis showed significant correlations between the level of COT and the levels of these MAs, suggesting them as biomarkers for exposure to low levels of AN. The results demonstrate that a highly specific and sensitive UPLC-MS/MS method has been successfully developed to quantitatively profile the major urinary metabolites of AN in humans to assess low AN exposure.

  5. Role of cytochrome P450 2E1 in the metabolism of acrylamide and acrylonitrile in mice.

    Science.gov (United States)

    Sumner, S C; Fennell, T R; Moore, T A; Chanas, B; Gonzalez, F; Ghanayem, B I

    1999-11-01

    Acrylonitrile (AN) and acrylamide (AM) are commonly used in the synthesis of plastics and polymers. In rodents, AM and AN are metabolized to the epoxides glycidamide and cyanoethylene oxide, respectively. The aim of this study was to determine the role of cytochrome P450 in the metabolism of AM and AN in vivo. Wild-type (WT) mice, WT mice pretreated with aminobenzotriazole (ABT, 50 mg/kg ip, 2 h pre-exposure), and mice devoid of cytochrome P450 2E1 (P450 2E1-null) were treated with 50 mg/kg [(13)C]AM po. WT mice and P450 2E1-null mice were treated with 2.5 or 10 mg/kg [(13)C]AN po. Urine was collected for 24 h, and metabolites were characterized using (13)C NMR. WT mice excreted metabolites derived from the epoxides and from direct GSH conjugation with AM or AN. Only metabolites derived from direct GSH conjugation with AM or AN were observed in the urine from ABT-pretreated WT mice and P450 2E1-null mice. On the basis of evaluation of urinary metabolites at these doses, these data suggest that P450 2E1 is possibly the only cytochrome P450 enzyme involved in the metabolism of AM and AN in mice, that inhibiting total P450 activity does not result in new pathways of non-P450 metabolism of AM, and that mice devoid of P450 2E1 do not excrete metabolites of AM or AN that would be produced by oxidation by other cytochrome P450s. P450 2E1-null mice may be an appropriate model for the investigation of the role of oxidative metabolism in the toxicity or carcinogenicity of these compounds.

  6. Development of a 4,4’-biphenyl/phosphine-based COF for the heterogeneous Pd-catalysed telomerisation of 1,3-butadiene

    NARCIS (Netherlands)

    Hausoul, P.J.C.|info:eu-repo/dai/nl/313957630; Eggenhuisen, T.M.|info:eu-repo/dai/nl/313959498; Nand, D.|info:eu-repo/dai/nl/337731403; Baldus, M.|info:eu-repo/dai/nl/314410864; Weckhuysen, B.M.|info:eu-repo/dai/nl/285484397; Klein Gebbink, R.J.M.|info:eu-repo/dai/nl/166032646; Bruijnincx, P.C.A.|info:eu-repo/dai/nl/33799529X

    2013-01-01

    The improved synthesis, characterisation and application of a microporous 4,40-biphenyl/phosphine-based covalent organic framework (COF) for the heterogeneous Pd-catalysed telomerisation of 1,3-butadiene with phenol and glycerol are presented. The solid polyphosphine is amorphous, microporous and an

  7. Mesoscopic TiO2/CH3NH3PbI3 perovskite solar cells with new hole-transporting materials containing butadiene derivatives.

    Science.gov (United States)

    Lv, Songtao; Han, Liying; Xiao, Junyan; Zhu, Lifeng; Shi, Jiangjian; Wei, Huiyun; Xu, Yuzhuan; Dong, Juan; Xu, Xin; Li, Dongmei; Wang, Shirong; Luo, Yanhong; Meng, Qingbo; Li, Xianggao

    2014-07-04

    Two new triphenylamine-based hole-transporting materials (HTMs) containing butadiene derivatives are employed in CH3NH3PbI3 perovskite solar cells. Up to 11.63% of power conversion efficiency (PCE) has been achieved. Advantages such as easy synthesis, low cost and relatively good cell performance exhibit a possibility for commercial applications in the future.

  8. Influence of Some Detoxification Enzyme Polymorphisms on Cytogenetic Biomarkers Between Individuals Exposed to Very Low Doses of 1,3-Butadiene

    NARCIS (Netherlands)

    Bukvic, Nenad; Lovreglio, Piero; Fanelli, Margherita; Susca, Francesco C.; Ballini, Andrea; Lastella, Patrizia; Foa, Vito; Fustinoni, Silvia; Soleo, Leonardo; Guanti, Ginevra

    2009-01-01

    Objective: To evaluate the variation of some biomarkers related to the level of enzymatic activity dependent on the different polymorphisms. Methods: We studied 27 butadiene-exposed workers and 37 controls using different biomarkers of the genotoxic effect. The genotypes were determined using polyme

  9. Influence of acid-base properties on the Lebedev ethanol-to-butadiene process catalyzed by SiO2-MgO materials

    NARCIS (Netherlands)

    Angelici, Carlo; Velthoen, Marjolein E. Z.; Weckhuysen, Bert M.; Bruijnincx, Pieter C. A.

    2015-01-01

    The Lebedev ethanol-to-butadiene process entails a complex chain of reactions that require catalysts to possess a subtle balance in the number and strength of acidic and basic sites. SiO2-MgO materials can be excellent Lebedev catalysts if properly prepared, as catalyst performance has been found to

  10. 24-HOUR DIFFUSIVE SAMPLING OF 1,3-BUTADIENE IN AIR ONTO CARBONPAK X SOLID ADSORBENT WITH THEMAL DESORPTION/GC/MS ANALYSIS - FEASIBILITY STUDIES

    Science.gov (United States)

    Diffusive sampling of 1,3-butadiene for 24 hours onto the graphitic adsorbent Carbopack X contained in a stainless steel tube badge (6.3 mm OD, 5 mm ID, and 90 mm in length) with analysis by thermal desorption/GC/MS has been evaluated in controlled tests. A test matrix of 42 tr...

  11. 24-HOUR DIFFUSIVE SAMPLING OF 1,3-BUTADIENE IN AIR ONTO CARBOPACK X SOLID ADSORBENT FOLLOWED BY THERMAL DESORPTION/GC/MS ANALYSIS - FEASIBILITY STUDY

    Science.gov (United States)

    Diffusive sampling of 1,3-butadiene for 24 hr onto the graphitic adsorbent Carbopack X packed in a stainless steel tube badge (6.3 mm o.d., 5 mm i.d., and 90 mm in length) with analysis by thermal desorption/gas chromatography (GC)/mass spectrometry (MS) has been evaluated in con...

  12. Inner Stucture of Thin Films of Lamellar Poly(styrene-b-butadiene) Diblock Copolymers as revealed by Grazing-Incidence Small-Angle Scattering

    DEFF Research Database (Denmark)

    Busch, Peter; Posselt, Dorthe; Smilgies, Detlef-Matthias

    2007-01-01

    The lamellar orientation in supported, thin films of poly(styrene-b-butadiene) (P(S-b-B)) depends on block copolymer molar mass. We have studied films from nine block copolymer samples with molar masses between 13.9 and 183 kg/mol using grazing-incidence small-angle X-ray scattering (GISAXS) and ...

  13. Pathway and Surface Mechanism Studies of 1,3-butadiene Selective Oxidation Over Vanadium-Molybdenum-Oxygen Catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Schroeder, William David [Iowa State Univ., Ames, IA (United States)

    2001-01-01

    The partial oxidation of 1,3-butadiene has been investigated over VMoO catalysts synthesized by sol-gel techniques. Surface areas were 9-14 m2/g, and compositions were within the solid solution regime, i.e. below 15.0 mol % MoO3/(MoO3 + V2O5). Laser Raman Spectroscopy and XRD data indicated that solid solutions were formed, and pre- and post-reaction XPS data indicated that catalyst surfaces contained some V+4 and were further reduced in 1,3-butadiene oxidation. A reaction pathway for 1,3-butadiene partial oxidation to maleic anhydride was shown to involve intermediates such as 3,4-epoxy-1-butene, crotonaldehyde, furan, and 2-butene-1,4-dial. The addition of water to the reaction stream substantially increased catalyst activity and improved selectivity to crotonaldehyde and furan at specific reaction temperatures. At higher water addition concentrations, furan selectivity increased from 12% to over 25%. The catalytic effects of water addition were related to competitive adsorption with various V2O5-based surface sites, including the vanadyl V=O, corner sharing V-O-V and edge sharing V-O oxygen. Higher levels of water addition were proposed to impose acidic character by dissociative adsorption. In addition, a novel combinatorial synthesis technique for VMoO was used to investigate the phase transitions of V2O5, solid solutions of Mo in V2O5, V9Mo6O40, and other reduced VMoO compounds, characterized by laser Raman spectroscopy. The natural composition gradient imposed by the sputter deposition apparatus was used to create VMoO arrays containing 225 samples ranging from 7.0-42 mol% MoO3/(V2O5 + MoO3), determined by EDS analysis.

  14. Removal of As(V), Cr(III) and Cr(VI) from aqueous environments by poly(acrylonitril-co-acrylamidopropyl-trimethyl ammonium chloride)-based hydrogels.

    Science.gov (United States)

    Dudu, Tuba Ersen; Sahiner, Mehtap; Alpaslan, Duygu; Demirci, Sahin; Aktas, Nahit

    2015-09-15

    Cationic poly(Acrylonitril-co-Acrylamidopropyl-trimethyl Ammonium Chloride) (p(AN-co-APTMACl)) hydrogels in bulk were synthesized by using acrylonitrile (AN) and 3-acrylamidopropyl-trimethyl ammonium chloride (APTMACl) as monomers. The prepared hydrogels were exposed to amidoximation reaction to replace hydrophobic nitrile groups with hydrophilic amidoxime groups that have metal ion binding ability. Those replacements were increased the hydrogels absorption capacity for As(V) and Cr(VI). Langmuir and Freundlich isotherms equations were utilized to obtain the best-fitted isotherm model for the absorption of the ions at different metal ion concentrations. The absorption data of As(V) ion were fitted well to Freundlich isotherm while those of Cr(VI) and Cr(III) ions were fitted well to Langmuir isotherm. The maximum absorption of poly(3-acrylamidopropyl-trimethyl ammonium chloride (p(APTMACl)) and amid-p(AN-co-APTMACl) macro gels were 22.39 mg and 21.83 mg for As(V), and 30.65 mg and 18.16 mg for Cr(VI) ion per unit gram dried gel, respectively. Kinetically, the absorption behaviors of Cr(III) and Cr(VI) ions were fitted well to a pseudo 2nd-order kinetic model and those of As(V) ions were fitted well to a pseudo 1st order kinetic model.

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

    Science.gov (United States)

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

    2016-04-01

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

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

    Science.gov (United States)

    Jumpee, C.; Wongsawaeng, D.

    2015-05-01

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

  17. Studies on gel electrolyte based on nitrile-butadiene copolymers. Final report, 1 November 1991-30 November 1992

    Energy Technology Data Exchange (ETDEWEB)

    Sircar, A.K.; Kumar, B.; Linden, S.M.; Weissman, P.T.

    1993-06-01

    This study is concerned with the preparation of a hybrid electrolyte, suitable for solid-polymer batteries. Based on the study of ionic conductivity in the presence of LiBF4 of a number of nitrile-butadiene copolymers (NBR), hydrogenated NBR (HNBR) was selected as the host polymer. DC conductivity studies with three different lithium salts in different plasticizers showed the highest conductivity for LiBF4. Conductivity of LiBF4 in different plasticizers decreases in the order DMF > DMAC > Gamma butyrolactone > NMP > PC=gamma-valerolactone > glymes. NMP was chosen as the plasticizer for hybrid films based on its moderate conductivity, low vapor pressure, and low freezing point. Polymer electrolytes, Gel electrolytes, Ionic conductivity.

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

    Science.gov (United States)

    Shafieyzadeh, M.

    2015-12-01

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

  19. Conjugate addition to 1-phosphono-2-aza-1,3-butadienes: synthesis of phosphonylated gamma-lactams.

    Science.gov (United States)

    Vanderhoydonck, Bart; Stevens, Christian V

    2005-01-07

    Several 1-phosphono-2-aza-1,3-butadienes, 1 and 13-20, were evaluated in the reaction with different enolate-type nucleophiles to induce addition at the 1- or the 4-position of the azadiene. 1-Phosphono-2-azadienes 1 react with sodium malonate at the 1-position, leading to the formation of bisenamines 12 after elimination of the phosphonate moiety. On the contrary, sodium malonate adds at the 4-position of 1-aryl-1-phosphono-2-azadienes 14-19 when the azadienes bear a halogenated phenyl substituent, and the resulting addition products 21-26 are easily transformed into the corresponding phosphonylated gamma-lactams 35-40. The regioselectivity of the addition is explained by reversal of polarization of the azadiene due to the electron-withdrawing character of the halogenated phenyl substituents.

  20. Modification of asphaltic concrete with a mineral polymeric additive based on butadiene-styrene rubber and chemically precipitated calcium carbonate

    Directory of Open Access Journals (Sweden)

    S. I. Niftaliev

    2016-01-01

    Full Text Available Modification of asphaltic concrete with a mineral polymeric additive based on butadiene – styrene rubber and chemically precipitated calcium carbonate. This paper presents the results of the study of physical – mechanical and service properties of the asphaltic concrete modified with the mineral polymeric composition. Calcium carbonate is used both as a filler and a coagulant. The chalk was preliminarily ground and hydrophobizated by stearic acid. These operations contribute to even distribution of the filler and interfere with lump coagulation. As a result of the experiments, it was found that the best results were obtained by combining the operations of dispersion and hydrophobization. The optimal amount of stearic acid providing the finest grinding in a ball mill is a content from 3 to 5% by weight. The optimal grinding time of the filler was found (4–6 hours. With increasing dispersion time the particles form agglomerates. Filling the butadiene styrene latex with the hydrophobic fine-grained calcium carbonate was carried out in the laboratory mixer. As a result of the experimental works, it was found that the best distribution of the filler takes place with ratio of rubber: chalk – 100:400. The resulting modifier was subjected to the thermal analysis on the derivatograph to determine its application temperature interval. A marked reduction in weight of the mineral polymeric modifier begins at 350 °C. Thus, high temperature of the modifier destruction allows to use it at the temperature of the technological process of asphaltic concrete preparation (up to 170 °C. It was found that an increase in the amount of the carbonate filler in the rubber SKS 30АRК significantly increases its thermal resistance and connection of the polymer with the chalk in the composition.

  1. Synthesis of novel well-defined poly(vinyl acetate)-b-poly(acrylonitrile) and derivatized water-soluble poly(vinyl alcohol)-b-poly(acrylic acid) block copolymers by cobalt-mediated radical polymerization

    NARCIS (Netherlands)

    Debuigne, A.; Warnant, J.; Jerome, R.; Voets, I.K.; Keizer, de A.; Cohen Stuart, M.A.; Detrembleur, C.

    2008-01-01

    Poly(vinyl acetate)¿Co(acac)2 macroinitiators, prepared by cobalt-mediated radical polymerization of vinyl acetate (VAc), were used to synthesize well-defined poly(vinyl acetate)-b-poly(acrylonitrile) (PVAc-b-PAN) block copolymers. Different solvents and temperatures were tested for the polymerizati

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

    Science.gov (United States)

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

    2007-11-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Li Daishuang; Xia Haibing [Department of Applied Chemistry, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871 (China); Peng Jing [Department of Applied Chemistry, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871 (China)], E-mail: jpeng@pku.edu.cn; Zhai Maolin; Wei Genshuan; Li Jiuqiang [Department of Applied Chemistry, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871 (China); Qiao Jinliang [Department of Applied Chemistry, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871 (China); SINOPEC, Beijing Research Institute of Chemical Industry, Beijing 100013 (China)

    2007-11-15

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

  4. 丁二烯抽提装置防聚合措施的应用分析%Application of polymerization prevention measures in Butadiene Extraction Plant

    Institute of Scientific and Technical Information of China (English)

    张新

    2015-01-01

    分析了某丁二烯抽提装置丁二烯的聚合原理,指出控制氧的进入和减少设备死角是防止聚合发生的主要方法;对比讨论了NMP和DMF法在防聚合方面的应用情况,并提出了完善措施。%The article analyzed the butadiene polymerization mechanism of butadiene extraction plant and pointed out that the control of oxygen in system and reduction of dead area in equipment is the main method to prevent polymerization .Comparison and discussion were made to the application situation of NMP and DMF processes in polymerization prevention and perfection measures were put forward.

  5. Ab initio structures for 90 degrees -twisted s-trans-1,3-butadiene and cyclooctatetraene: the naked sp2-sp2 bond.

    Science.gov (United States)

    Feller, David; Craig, Norman C; Matlin, Albert R

    2008-03-20

    The bond length of a carbon-carbon sp2-sp2 sigma-bond without the perturbing effects of pi-interactions has been estimated by high level calculations on two prototypical systems: a 90 degrees -twisted form of butadiene and the tub conformer of cyclooctatetraene. The former system yields a value of 1.4818 A, considerably longer than previous estimates. The corresponding bond length in the latter is slightly shorter due to some pi-electron delocalization.

  6. Epigenetic Events Determine Tissue-Specific Toxicity of Inhalational Exposure to the Genotoxic Chemical 1,3-Butadiene in Male C57BL/6J Mice

    OpenAIRE

    2014-01-01

    1,3-Butadiene (BD), a widely used industrial chemical and a ubiquitous environmental pollutant, is a known human carcinogen. Although genotoxicity is an established mechanism of the tumorigenicity of BD, epigenetic effects have also been observed in livers of mice exposed to the chemical. To better characterize the diverse molecular mechanisms of BD tumorigenicity, we evaluated genotoxic and epigenotoxic effects of BD exposure in mouse tissues that are target (lung and liver) and non-target (...

  7. Susceptibility to induction of chromosomal damage by metabolites of 1,3-butadiene and its relationship to 'spontaneous' sister chromatid exchange frequencies in human lymphocytes.

    Science.gov (United States)

    Wiencke, J K; Kelsey, K T

    1993-01-01

    Occupational exposure to butadiene is associated with the occurrence of lymphohaematopoietic cancers. The mutagenicity of butadiene is thought to be mediated by its mono- and diepoxide metabolites, which are capable of binding to DNA. Diepoxybutane is the most potent genotoxic metabolite and is known to produce interstrand DNA cross-links. In order to study individual differences in response to the genotoxicity of diepoxybutane, we devised a human lymphocyte culture system that involves short-term culture of T lymphocytes and measurement of sister chromatid exchange (SCE) and chromosomal aberration frequency as genotoxic end-points. We observed that when lymphocytes from healthy individuals are exposed in vitro to 6 microM of diepoxybutane, the number of SCEs induced is distributed bimodally: about 20% of 173 healthy workers studied were twice as sensitive to the induction of SCEs as the remaining 80%. Cells from sensitive individuals also contain four times more diepoxybutane-induced chromosomal deletions and exchanges. Of particular interest is the observation that diepoxybutane-sensitive individuals have higher frequencies of baseline (i.e., uninduced) SCEs. We have now examined the sensitivity of individual lymphocytes to SCE induction by another DNA cross-linking agent (nitrogen mustard) and to monoepoxybutene. The results indicate that lymphocytes sensitive to diepoxybutane-induced SCEs have normal sensitivity to nitrogen mustard and a moderately increased response to the monofunctional agent monoepoxybutene. Measurement of diepoxybutane-induced SCEs is a potential biomarker of sensitivity to the genotoxic effects of butadiene and may be useful in occupational epidemiological studies. Such studies, in combination with measures of butadiene metabolism, could be useful in ascertaining whether the sensitivity is mediated by enzyme polymorphisms.

  8. Association between Genetic Polymorphisms of DNA Repair Genes and Chromosomal Damage for 1,3-Butadiene-Exposed Workers in a Matched Study in China

    OpenAIRE

    2015-01-01

    The aim of the study was to examine the association between polymorphisms of DNA repair genes and chromosomal damage of 1,3-butadiene- (BD-) exposed workers. The study was conducted in 45 pairs of occupationally exposed workers in a BD product workshop and matched control workers in an administrative office and a circulatory water workshop in China. Newly developed biomarkers (micronuclei, MNi; nucleoplasmic bridges, NPBs; nuclear buds, NBUDs) in the cytokinesis-blocked micronucleus (CBMN) cy...

  9. Mechanical Characterization of Hybrid Vesicles Based on Linear Poly(Dimethylsiloxane-b-Ethylene Oxide) and Poly(Butadiene-b-Ethylene Oxide) Block Copolymers

    OpenAIRE

    2016-01-01

    Poly(dimethylsiloxane-ethylene oxide) (PDMS-PEO) and poly(butadiene-b-ethylene oxide) (PBd-PEO) are two block copolymers which separately form vesicles with disparate membrane permeabilities and fluidities. Thus, hybrid vesicles formed from both PDMS-PEO and PBd-PEO may ultimately allow for systematic, application-specific tuning of vesicle membrane fluidity and permeability. However, given the relatively low strength previously noted for comb-type PDMS-PEO vesicles, the mechanical robustness...

  10. Atmospheric oxidation of 1,3-butadiene: characterization of gas and aerosol reaction products and implications for PM2.5

    OpenAIRE

    Jaoui, M.; Lewandowski, M.; K. Docherty; Offenberg, J. H.; T. E. Kleindienst

    2014-01-01

    Secondary organic aerosol (SOA) was generated by irradiating 1,3-butadiene (13BD) in the presence of H2O2 or NOx. Experiments were conducted in a smog chamber operated in either flow or batch mode. A filter/denuder sampling system was used for simultaneously collecting gas- and particle-phase products. The chemical composition of the gas phase and SOA was analyzed using derivative-based methods (BSTFA, BSTFA + PFBHA, or DNPH) followed by gas chromatography–mass spectrometry ...

  11. Synthesis of oxa-bridged derivatives from Diels–Alder bis-adducts of butadiene and 1,2,3,4-tetrahalo-5,5-dimethoxycyclopentadiene

    Directory of Open Access Journals (Sweden)

    Faiz Ahmed Khan

    2010-06-01

    Full Text Available Bis-adducts of 1,2,3,4-tetrahalo-5,5-dimethoxycyclopentadiene and 1,3-butadiene, generated in situ from 3-sulfolene, have been synthesized in excellent yield. Ruthenium catalyzed oxidation of the bis-adducts followed by a one-pot transformation of the resulting α-diketone furnished oxa-bridged compounds. Unambiguous stereochemical assignments of both diastereomeric series are reported.

  12. Cationic copper (I) complexes with bulky 1,4-diaza-1,3-butadiene ligands - Synthesis, solid state structure and catalysis

    Science.gov (United States)

    Anga, Srinivas; Kottalanka, Ravi K.; Pal, Tigmansu; Panda, Tarun K.

    2013-05-01

    We report the full characterization of two glyoxal-based ligands N,N bis(diphenylmethyl)-1,4-diaza-1,3-butadiene ligand (DADPh2, 1) and more bulky N,N bis(triphenylmethyl)-1,4-diaza-1,3-butadiene ligand (DADPh3, 2) by the condensation reaction of glyoxal and diphenylmethanamine and triphenyl-methanamine respectively. The copper (I) complex of composition [Cu(DADPh2)2]PF6 (3) having two neutral bidentate N,N bis(diphenyl-methyl)-1,4-diaza-1,3-butadiene ligand was prepared by the reaction of [Cu(CH3CN)4]PF6 and 1 in 1:2 ratio in dichloromethane. In a similar reaction with N,N bis(triphenylmethyl)-1,4-diaza-1,3-butadiene ligand (2) and [Cu(CH3CN)4]PF6 in dichloromethane yielded corresponding heteroleptic copper (I) complex [Cu(DADPh3)(CH3CN)2]PF6 (4). Another copper (I) complex [Cu(DADPh2)(PPh3)]PF6 (5) can also be obtained by the one pot reaction involving ligand 1, [Cu(CH3CN)4]PF6 and triphenylphosphine. Solid state structures of all the five compounds were established by single crystal X-ray diffraction analysis. The solid state structures of the copper complexes 3-5 reveal a distorted tetrahedral geometry around the copper (I) centers. The copper complexes 3-5 were tested as catalysts for the coupling reaction of o-iodophenol and phenyl acetylene and it was observed that complex 4 exhibits the highest catalytic activity.

  13. Combustion products of 1,3-butadiene inhibit catalase activity and induce expression of oxidative DNA damage repair enzymes in human bronchial epithelial cells.

    Science.gov (United States)

    Kennedy, Christopher H; Catallo, W James; Wilson, Vincent L; Mitchell, James B

    2009-10-01

    1,3-Butadiene, an important petrochemical, is commonly burned off when excess amounts need to be destroyed. This combustion process produces butadiene soot (BDS), which is composed of a complex mixture of polycyclic aromatic hydrocarbons in particulates ranging in size from DNA damage in NHBE cells. Thus, our aims were to determine the effect of butadiene soot ethanol extract (BSEE) on both enzyme activity and the expression of proteins involved in the repair of oxidative DNA damage. Catalase was found to be sensitive to BDS as catalase activity was potently diminished in the presence of BSEE. Using Western analysis, both the alpha isoform of human 8-oxoguanine DNA glycosylase (alpha-hOGG1) and human apurinic/apyrimidinic endonuclease (APE-1) were shown to be significantly overexpressed as compared to untreated controls after exposure of NHBE cells to BSEE. Our results indicate that BSEE is capable of effectively inactivating the antioxidant enzyme catalase, presumably via oxidation of protein amino acids. The presence of oxidized biomolecules may partially explain the extranuclear fluorescence that is detected when NHBE cells are treated with an organic extract of BDS. Overexpression of both alpha-hOGG1 and APE-1 proteins following treatment of NHBE cells with BSEE suggests that this mixture causes oxidative DNA damage.

  14. Effect of ultrasound in the free radical polymerization of acrylonitrile under a new multi-site phase-transfer catalyst - a kinetic study.

    Science.gov (United States)

    Selvaraj, Varathan; Sakthivel, Perumal; Rajendran, Venugopal

    2015-01-01

    The kinetics of polymerization of acrylonitrile (AN) was carried out under heterogeneous condition using a new multi-site phase-transfer catalyst (MPTC), viz., N,N'-dihexyl-4,4'-bipyridinium dibromide in the presence of water soluble initiator, potassium peroxydisulphate (PDS) under chlorobenzene/water two phase system assisted by ultrasound irradiation at constant temperature 60+1°C under nitrogen atmosphere. The rate of polymerization increases with an increasing the concentrations of AN, MPTC and PDS. The order with respect to [AN], [MPTC], and [PDS] were found to be 1.01, 1.03 and 0.52, respectively. Based on the observed results a suitable mechanism has been proposed to account for the experimental observations followed by a discussion on its significance.

  15. One-step Preparation and Antibacterial Property of Poly(N-iso- propyl-acrylamide) Grafted Poly(acrylonitrile/styrene) Micro- spheres Immobilized with Silver Nanoparticles

    Institute of Scientific and Technical Information of China (English)

    FENG,Jiao; FAN,Liheng; CHU,Hong; XIONG,Wanbin; JIANG,Jinqiang; CHEN,Mingqing

    2009-01-01

    Monodispersed silver nanoparticles were immobilized onto the surface of poly(N-isopropylacrylamide) grafted poly(acrylonitrile/styrene) (PNIPAAm-g-PAN/PSt) microspheres by a one-step method using AgNO3 as a silver source. This process was performed via the coordination interaction between Ag ions and amide groups on PNIPAAm-g-PAN/PSt microsphere surfaces with the reduction of the corresponding ions by ethanol taking place simultaneously. Fourier transform infrared (FTIR) spectroscopy and ultraviolet (UV)-visible spectra illustrated that the silver nanoparticles were successfully immobilized onto the PNIPAAm-g-PAN/PSt microspheres. The size and morphology of silvered microspheres were characterized by transmission electron microscopy (TEM). The weight percent of silver nanoparticles immobilized onto the microspheres was 12% based on the determination of thermogravimetric analysis (TGA). The antibacterial tests demonstrated that the as-prepared silvered microspheres showed activity against Gram-negative bacteria.

  16. Thermosensitive Poly(N-isopropylacrylamide-co-acrylonitrile) Hydrogels with Rapid Response%非离子型凝胶球在水中的溶胀行为

    Institute of Scientific and Technical Information of China (English)

    黄健; 黄志明; 包永忠; 翁志学

    2006-01-01

    Acrylonitrile (AN) was copolymerized with N-isopropylacrylamide (NIPA) to synthesize thermosensitive bydrogels, and the on-off switch behavior of poly(NIPA-co-AN) hydrogels with different fraction of hydrophobic component (AN) was investigated. It is found that the lower critical solution temperature (LCST), the swelling ratio at certain temperature and the reswelling rate of poly(NIPA-co-AN) hydrogels decreased as AN unit fraction in copolymers increased. In order to improve the responsive rate of poly(NIPA-co-AN) hydrogels, they were further treated by surface crosslinking using N, N'-methylene bisacrylamide (BIS) as a crosslinking agent. The swelling and deswelling behaviors of these copolymers were compared with those of the untreated hydrogels. The results indicated that the responsive rate of poly(NIPA-co-AN) hydrogel was improved by surface crosslinking. The resulting hydrogels bearing cyano groups with fast response have potential applications in the field of drug-controlled release and immobilization of biomolecules.

  17. NIOSH (National Institute for Occupational Safety and Health) testimony to DOL (Department of Labor) on occupational exposure to acrylonitrile, by R. Yodaiken, M. D. , March 3, 1978

    Energy Technology Data Exchange (ETDEWEB)

    1978-03-03

    Testimony was presented concerning the establishment of an occupational exposure standard for acrylonitrile (AN) to which an estimated 125,000 workers were potentially exposed. Two-year feeding and inhalation studies with animals indicated the chemical to be carcinogenic, producing tumors of the central nervous system (CNS), cerebral tumors, squamous cell neoplasms of the Zymbal gland, adenocarcinoma of the small intestine and large intestine, along with numerous benign tumors. Other findings included papillomata in the stomach, hemangioma of the kidney, fibroadenomas of the mammary gland, benign tumors of the uterus, and tumors of the ear canal. Teratogenicity studies indicated increased incidence of fetal malformation. Cases of AN as an allergen causing contact dermatitis and ulcers have been widely documented. It was recommended that drugs essential to the treatment of acute intoxication from AN be kept in the medical facility of all facilities using AN, and that employers institute a respiratory-protection program in accordance with requirements.

  18. Modification on liquid retention property of cassava starch by radiation grafting with acrylonitrile. I. Effect of γ-irradiation on grafting parameters

    Science.gov (United States)

    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.

  19. SELECTIVE SEPARATION OF WATER-ETHANOL MIXTURES THROUGH COPOLYMERIC MEMBRANES:Ⅰ. ACRYLIC ACID AND ACRYLONITRILE COPOLYMER AND ITS IONIZED MEMBRANES

    Institute of Scientific and Technical Information of China (English)

    ZHANG Fuyao; ZHANG Yifeng; ZHAO Zhuomin; SHEN Zhiquan

    1993-01-01

    The copolymer of acrylic acid and acrylonitrile has been synthesized and pervaporation properties of the copolymeric membranes have been investigated. In order to elucidate the influence of membrane-permeate interaction on the pervaporation of water-ethanol mixtures and to prepare much improved membranes, the membranes have been treated with alkali metal, alkali earth metal and transition metal salt aqueous solutions. The treated membranes (ionized membranes)exhibited higher separation factors than the untreated membranes. The separation factors of various alkali metal cation membranes decreased in the following order: Li+>Na+>K+, and the permeation rates showed an opposite tendency. The dependence of pervaporation behavior on the copolymer composition ,feed concentration and operating temperature have been studied with both ionized and non-ionized membranes. The apparent activation energies of water and ethanol permeation were calculated.

  20. 光照射下丙烯腈活性自由基聚合的研究%Photo-induced Living Radical Polymerization of Acrylonitrile

    Institute of Scientific and Technical Information of China (English)

    何斌鸿

    2015-01-01

    Acrylonitrile as monomer, azobisisobutyronitrile as initiator, hexamethylenetetramine as ligand, copper chloride dihydrate as catalyst and Vitamin C as reducing agent, polyacrylonitrile was synthesized in N,N-dimethylformamide under the light irradiation. The effects of the amount of monomer, initiator, catalyst, hexamethylenetetramine and Vitamin C on the photo-induced polymerization of acrylonitrile have been invetigated. On the basis of experiments, it is concluded that the best polymerization conditions were that the amount of monomer is 0.2 mol and the usage of azobisisobutyronitrile, copper chloride dihydrate, hexamethylenetetramine and vitamin C was 1%, 0.75%, 1%, 4 % of the mole of monomer, respectively. The best reaction time is 11 h.%以丙烯腈作为单体,偶氮二异丁腈为引发剂,六次亚甲基四胺为配体,二水氯化铜为催化剂,维生素C为还原剂,在光的照射下,于溶剂 N,N-二甲基甲酰胺中采用自由基聚合的原理制得聚丙烯腈,并探究改变单一反应物的用量时对该聚合反应的影响,最后得出最佳的聚合条件为:在室温20℃下反应时,最佳单体用量为0.2mol,引发剂偶氮二异丁腈、催化剂二水氯化铜、配体六次亚甲基四胺、还原剂维生素C分别为单体摩尔总量的1%、0.75%、1%、4%,最佳反应时间为11 h.

  1. (32)P-postlabelling analysis of 1,3-butadiene-induced DNA adducts in vivo and in vitro.

    Science.gov (United States)

    Zhao, C; Koskinen, M; Hemminki, K

    2000-01-01

    Butadiene monoepoxide (BMO), epoxybutanediol (EBD) and diepoxybutane (DEB) are reactive metabolites of 1,3-butadiene (BD), an important industrial chemical classified as a probable human carcinogen. The covalent interactions of these metabolites with DNA lead to the formation of DNA adducts which may induce mutations or other types of DNA damage, resulting in tumour formation. In the present study, two pairs of diastereomeric N-1-BMO-adenine adducts were identified in the reaction of BMO with 2´-deoxyadenosine-5´-monophosphate (5´-dAMP). The major products formed by reacting EBD with 2´-deoxyguanosine-5´-monophosphate (5´-dGMP) were characterized as diastereomeric N-7-(2´,3´,4´-trihydroxybut-1´-yl)-5´-dGMP by UV and electrospray mass spectrometry. The formation of N-7-BMO-guanine adducts (1´-carbon, 60; 2´carbon, 54/10(4) nucleotides) in BMO-treated DNA was about four times higher than that of N-1-BMO-adenine adducts (1´-carbon, 20; 2´-carbon, 8.7/10(4) nucleotides). However, the recovery of N-1-BMO-adenine adducts in DNA (45 ± 5%) was two times higher than that of N-7-guanine adducts (20 ± 4%) by 32P-postlabelling analysis. Using the 32P-postlabelling/ HPLC assay, N-1-BMO-adenine, N-7-BMO-guanine and N-7-EBDguanine adducts were detected in BMO- or DEB-treated DNA and in liver DNA of rats exposed to BD by inhalation. The amount of N-7-EBD-guanine adducts (11/10(8) nucleotides) in rat liver was about three-fold higher than N-7-BMO-guanine adducts (4.0/10(8) nucleotides). The novel finding of N-1-BMO-adenine adducts formed in vivo may contribute to the understanding of the mechanisms of BD carcinogenic action.

  2. Vibrational quasi-degenerate perturbation theory with optimized coordinates: applications to ethylene and trans-1,3-butadiene.

    Science.gov (United States)

    Yagi, Kiyoshi; Otaki, Hiroki

    2014-02-28

    A perturbative extension to optimized coordinate vibrational self-consistent field (oc-VSCF) is proposed based on the quasi-degenerate perturbation theory (QDPT). A scheme to construct the degenerate space (P space) is developed, which incorporates degenerate configurations and alleviates the divergence of perturbative expansion due to localized coordinates in oc-VSCF (e.g., local O-H stretching modes of water). An efficient configuration selection scheme is also implemented, which screens out the Hamiltonian matrix element between the P space configuration (p) and the complementary Q space configuration (q) based on a difference in their quantum numbers (λpq = ∑s|ps - qs|). It is demonstrated that the second-order vibrational QDPT based on optimized coordinates (oc-VQDPT2) smoothly converges with respect to the order of the mode coupling, and outperforms the conventional one based on normal coordinates. Furthermore, an improved, fast algorithm is developed for optimizing the coordinates. First, the minimization of the VSCF energy is conducted in a restricted parameter space, in which only a portion of pairs of coordinates is selectively transformed. A rational index is devised for this purpose, which identifies the important coordinate pairs to mix from others that may remain unchanged based on the magnitude of harmonic coupling induced by the transformation. Second, a cubic force field (CFF) is employed in place of a quartic force field, which bypasses intensive procedures that arise due to the presence of the fourth-order force constants. It is found that oc-VSCF based on CFF together with the pair selection scheme yields the coordinates similar in character to the conventional ones such that the final vibrational energy is affected very little while gaining an order of magnitude acceleration. The proposed method is applied to ethylene and trans-1,3-butadiene. An accurate, multi-resolution potential, which combines the MP2 and coupled-cluster with singles

  3. Isolation and identification of some unknown substances in disposable nitrile-butadiene rubber gloves used for food handling.

    Science.gov (United States)

    Mutsuga, M; Wakui, C; Kawamura, Y; Maitani, T

    2002-11-01

    In Japan, disposable gloves made from nitrile-butadiene rubber (NBR) are frequently used in contact with foods. In a previous paper, we investigated substances migrating from various gloves made of polyvinyl chloride, polyethylene, natural rubber and NBR. Zinc di-n-butyldithiocarbamate (ZDBC), diethyldithiocarbamate (ZDEC) used as vulcanization accelerators, di(2-ethylhexyl)phthalate (DEHP) used as a plasticizer and many unknown compounds that migrated from NBR gloves into n-heptane were detected by GC/MS. In this paper, six unknown compounds were obtained from one kind of NBR glove by n-hexane extraction and each was isolated by silica gel chromatography. From the results of NMR and mass spectral analysis of the six unknown compounds, their structures are proposed as 1,4-dione-2,5-bis(1,1-dimethylpropyl)cyclohexadiene (1), 2-(1,1-dimethylethyl)-4-(1,1,3,3-tetra methylbutyl)phenol (2), 2,6-bis(1,1-dimethylethyl)-4-(1,1,3,3-tetramethylbutyl)phenol (3), 2,4-bis(1,1,3,3-tetramethylbutyl)phenol (4), 2-(1,1-dimethylethyl)4,6-bis(1,1,3,3-tetramethylbutyl)phenol (5) and 2,4,6-tris(1,1,3,3-tetramethylbutyl)phenol (6). Compound 1 was observed in five of the seven kinds of NBR gloves, and compounds 2-4 and 6, which are not listed in Chemical Abstract (CA), were present in four kinds of gloves.

  4. Trans-1,4 selective polymerization of 1,3-butadiene with symmetry pincer chromium complexes activated by MMAO

    KAUST Repository

    Gong, Dirong

    2014-09-01

    Tridentate chromium complexes (Cr1-Cr7) incorporated with symmetrical pincer ligand bis(arylimino)pyridine and bis(pyrzaolyl)pyridine have been synthesized and characterized by elemental analyis, FT-IR as well as ESI-MS. X-ray diffraction reveals solids-state structures of Cr2, Cr4 and Cr6 all adopt pseudo-octahedral coordination environment with respect to metal center. All complexes have been tested in stereoregulated polymerization of butadiene under various polymerization conditions. The trans-1,4 and cis-1,4 enchainment of resultant polymer are found to be dependent on the structure of ligand and amount of activator used. Under the optimized condition, free ortho-substitutes Cr catalysts Cr1, Cr3, Cr4 and Cr6 are capable of initiating high trans-1,4 selectivity (trans-1,4: 89.2%-92.0%) with good polymer yields (71.5%-78.0%), while counterparts with ortho-positioned alkyl groups Cr2, Cr5 and Cr7 display mixed selectivities with moderate polymer yields. The sterical effect of ligand and amount of MMAO on the catalytic performance, in particular, the stereoselectivity and polymer yield, has been also elucidated by conjugated diene polymerization mechanism. © 2014 Elsevier B.V. All rights reserved.

  5. Fluorescence Efficiency and Stability of Radio-Pure Tetraphenyl-butadiene Based Coatings for VUV Light Detection in Cryogenic Environments

    CERN Document Server

    Baudis, Laura; Dressler, Rugard; Piastra, Francesco; Usoltsev, Ilya; Walter, Manuel

    2015-01-01

    The detection of VUV scintillation light, e.g. in (liquid) argon detectors, commonly includes a reflector with a fluorescent coating, converting UV photons to visible light. The light yield of these detectors depends directly on the conversion efficiency. Several coating/reflector combinations were produced using VM2000, a specular reflecting multi layer polymer, and Tetratex, a diffuse reflecting PTFE fabric, as reflector foils. The efficiency of these coatings was optimised and has been measured in a dedicated liquid argon setup built at the University of Zurich. It employs a small, 1.3 kg LAr cell viewed by a 3-inch, low radioactivity PMT of type R11065-10 from Hamamatsu. The cryogenic stability of these coatings was additionally studied. The optimum reflector/coating combination was found to be Tetratex dip coated with Tetraphenyl-butadiene with a thickness of 0.9 mg/cm$^2$ resulting in a 3.6 times higher light yield compared to uncoated VM2000. Its performance was stable in long term measurements, ran up...

  6. The adsorption of 1,3-butadiene on Pd/Ni multilayers: The interplay between spin polarization and chemisorption strength

    Science.gov (United States)

    Gómez, Guillermina; Belelli, Patricia G.; Cabeza, Gabriela F.; Castellani, Norberto J.

    2010-12-01

    The adsorption of 1,3-butadiene (BD) on the Pd/Ni(1 1 1) multilayers has been studied using the VASP method in the framework of the density functional theory (DFT). The adsorption on two different configurations of the Pd n/Ni m(1 1 1) systems were considered. The most stable adsorption sites are dependent on the substrate composition and on the inclusion or not of spin polarization. On Pd 1Ni 3(1 1 1) surface, di-π-cis and 1,2,3,4-tetra-σ adsorption structures are the most stable for non-spin polarized (NSP) and spin polarized (SP) levels of calculation, respectively. Conversely, on Pd 3Ni 1(1 1 1) surface, the 1,2,3,4-tetra-σ adsorption structure is the most stable for both NSP and SP levels, respectively. The magnetization of the Pd atoms strongly modifies the adsorption energy of BD and its most stable adsorption mode. On the other hand, as a consequence of BD adsorption, the Pd magnetization decreases. The smaller adsorption energies of BD and 1-butene on the Pd 1Ni 3(1 1 1) surface than on Pd(1 1 1) can be associated to the strained Pd overlayer deposited on Ni(1 1 1).

  7. Influence of gamma irradiation on mechanical and thermal properties of waste polyethylene/nitrile butadiene rubber blend

    Directory of Open Access Journals (Sweden)

    Raouf O. Aly

    2016-11-01

    Full Text Available Gamma irradiation radical–radical interaction crosslinking of elastomers and thermoplastic is a special type of crosslinking technique that has gained importance over conventional chemical crosslinking method as process is fast, pollution free, and simple. In this work a blend polymer, based on waste polyethylene and nitrile butadiene rubber, has been irradiated with gamma-rays, mechanically and thermally investigated at varying NBR content. FTIR and SEM techniques were used in addition to the swelling behavior to emphasize the blend formation. Mechanical properties like tensile strength, elongation at break and modulus at different elongations were studied and compared with those of unirradiated ones. A relatively low-radiation dose was found effective in improving the level of mechanical properties. Differential scanning calorimeter and thermogravimetric analysis were used to study the thermal characteristics of the irradiated polymer. Enhancement in thermal stability has been observed for higher NBR containing blends and via radiation-induced crosslinking up to ≈50 kGy.

  8. Wear resistance and friction reduction in acrylo nitrile butadiene rubber through hybrid combination of graphite flakes and nano tungsten disulphide

    Energy Technology Data Exchange (ETDEWEB)

    Agrawal, Neha, E-mail: neha87bhu@gmail.com [Defence Material Store Research Development and Establishment (DMSRDE), DRDO, GT Road, Kanpur 208013, U.P (India); Indian Institute of Technology Bombay, Powai, Mumbai 400076, Maharashtra (India); Pandey, Akanksha; Parihar, A. S.; Mishra, A. K.; Mukhopadhyay, K.; Prasad, N. E. [Defence Material Store Research Development and Establishment (DMSRDE), DRDO, GT Road, Kanpur 208013, U.P (India); Gandhi, M. N.; Bhattacharyya, A. R. [Indian Institute of Technology Bombay, Powai, Mumbai 400076, Maharashtra (India)

    2016-05-06

    Friction and wear have considerable role in the life span of two interacting parts. Incorporation of nanofillers in polymers/elastomers matrix causes commendable changes in its tribologicalproperties. The main purpose of this work is to reduce the coefficient of friction and wear rate of Acrylo Nitrile Butadiene rubber (NBR). To achieve such objective traditionally well knownlubricants graphite(G), tungsten disulphide (WS{sub 2}) and there hybrid combination was incorporated in NBR matrix. Effect of applied load (force) and concentration of fillers on tribological properties of NBR had been studied. The filler incorporation enhanced the hardnessby 8%, showed resistance to hydraulic oil and aging effect also got improved significantly. A particular optimized concentration of NBR with hybrid combination of 2% WS{sub 2} and 4% Graphite showed minimum coefficient of friction as well as wear rate. A hypothesis could be attributed that similar lamellar structure of WS{sub 2} and Graphite along with formation of a stable nanoscale disulfide tribofilmcould result in lowering of friction. These substantially improved properties of nanoreinforced rubber materials would definitely pave promising path for plethora of potential technological applications.

  9. Stepwise swelling of a thin film of lamellae-forming poly(styrene-b- butadiene) in cyclohexane vapor

    KAUST Repository

    Di, Zhenyu

    2012-06-26

    We investigated the swelling of a thin film of lamellae-forming poly(styrene-b-butadiene) in cyclohexane vapor. The vapor pressure and thus the degree of swelling of the film are increased in a stepwise manner using a custom-built sample cell. The resulting structural changes during and after each step were followed in situ using time-resolved grazing-incidence small-angle X-ray scattering (GISAXS). During the first step, the lamellar thickness increases strongly, before it decreases again. At the same time, the full width at half-maximum (FWHM) of the diffuse Bragg reflection along the film normal has a sharp maximum. These observations point to the formation of new lamellae. During the subsequent swelling steps, the lamellar thickness overshoots only weakly. The behavior thus resembles qualitatively our previous results on a similar thin film during swelling in saturated vapor of cyclohexane; however, it deviates from earlier theoretical predictions. We propose a theory that is quantitatively correct for the description of the dependence of the lamellar thickness on the polymer volume fraction in the late stage of the swelling steps. © 2012 American Chemical Society.

  10. Genetic polymorphisms of DNA repair genes and chromosomal damage in workers exposed to 1,3-butadiene.

    Science.gov (United States)

    Wang, Qi; Wang, Ai-hong; Tan, Hong-shan; Feng, Nan-nan; Ye, Yun-jie; Feng, Xiao-qing; Liu, Geoffrey; Zheng, Yu-xin; Xia, Zhao-lin

    2010-05-01

    The base excision repair (BER) pathway is important in repairing DNA damage incurred from occupational exposure to 1,3-butadiene (BD). This study examines the relationship between inherited polymorphisms of the BER pathway (x-ray repair cross-complementing group 1 (XRCC1) Arg194Trp, Arg280His, Arg399Gln, T-77C, ADPRT Val762Ala, MGMT Leu84Phe and APE1 Asp148Glu) and chromosomal damage in BD-exposed workers, using the cytokinesis-blocked (CB) micronucleus (MN) assay in peripheral lymphocytes of 166 workers occupationally exposed to BD and 41 non-exposed healthy individuals. The MN frequency of exposed workers (3.39 +/- 2.42) per thousand was higher than that of the non-exposed groups (1.48 +/- 1.26) per thousand (P damage among BD-exposed workers. In workers exposed to BD, multiple BER polymorphisms and a XRCC1 haplotype were associated with differential levels of chromosome damage.

  11. Wear resistance and friction reduction in acrylo nitrile butadiene rubber through hybrid combination of graphite flakes and nano tungsten disulphide

    Science.gov (United States)

    Agrawal, Neha; Pandey, Akanksha; Parihar, A. S.; Mishra, A. K.; Gandhi, M. N.; Bhattacharyya, A. R.; Mukhopadhyay, K.; Prasad, N. E.

    2016-05-01

    Friction and wear have considerable role in the life span of two interacting parts. Incorporation of nanofillers in polymers/elastomers matrix causes commendable changes in its tribologicalproperties. The main purpose of this work is to reduce the coefficient of friction and wear rate of Acrylo Nitrile Butadiene rubber (NBR). To achieve such objective traditionally well knownlubricants graphite(G), tungsten disulphide (WS2) and there hybrid combination was incorporated in NBR matrix. Effect of applied load (force) and concentration of fillers on tribological properties of NBR had been studied. The filler incorporation enhanced the hardnessby 8%, showed resistance to hydraulic oil and aging effect also got improved significantly. A particular optimized concentration of NBR with hybrid combination of 2% WS2 and 4% Graphite showed minimum coefficient of friction as well as wear rate. A hypothesis could be attributed that similar lamellar structure of WS2 and Graphite along with formation of a stable nanoscale disulfide tribofilmcould result in lowering of friction. These substantially improved properties of nanoreinforced rubber materials would definitely pave promising path for plethora of potential technological applications.

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

    Energy Technology Data Exchange (ETDEWEB)

    Matanoski, G.M.; Santos-Burgoa, C.; Schwartz, L. (Johns Hopkins School of Hygiene and Public Health, Baltimore, MD (USA))

    1990-06-01

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

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

    Science.gov (United States)

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

    1990-01-01

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

  14. Effect of styrene-butadiene-styrene content on the adhesion properties of bitumen before and after heat aging

    Energy Technology Data Exchange (ETDEWEB)

    Zielinski, K. [Poznan Univ. of Technology, Poznan (Poland). Inst. of Structural Engineering

    2008-05-15

    Styrene-butadiene-styrene (SBS) is a common modifying polymer used in bitumen-based waterproofing building materials. SBS is used to improve the heat aging resistance of bitumen as well as to increase its resistance to temperature changes. This paper compared SBS-modified bitumen products with nonmodified bitumen products. The aim of the study was to assess the effect of heat aging and SBS content on the adhesion properties of 2 bitumen types to concrete and steel substrates. Two types of bitumen were tested: (1) paving-grade bitumen; and (2) an oxidized bitumen with a softening point at 25 degrees C. The thin film oven test was used to heat age the samples. Adhesion properties were measured before and after heat aging. The tests demonstrated that the adhesion strength of bituminous mastics to concrete and steel substrates decreased as SBS content increased. Bitumen products modified with 9 to 12 per cent of SBS showed a weaker bond with concrete and steel substrates than nonmodified equivalents. It was concluded that after heat aging, the adhesion strength of the nonmodified bitumen was higher than that of the bitumen modified with SBS. 7 refs., 4 tabs., 5 figs.

  15. Study on Secondary Pollutant Emissions from Incineration of Acrylonitrile Waste Water%丙烯腈废液焚烧二次污染物排放的特性研究

    Institute of Scientific and Technical Information of China (English)

    陈高; 李传凯

    2012-01-01

    The experiment of acrylonitrile waste water incineration are carried out to investigate the influence rule of secondary pollutant CO, NOx emissions by changing the incineration temperature, residence time of incineration, the oxygen content of furnace on acrylonitrile waste water incinerator test apparatus.%在废液焚烧炉实验台上进行丙烯腈废液焚烧实验,通过改变废液焚烧温度、焚烧停留时间、烟气中氧含量等参数,研究分析各种因素对丙烯腈废液焚烧二次污染物CO、NOx排放的影响规律.

  16. 顶空-气相色谱法测定水中乙醛、丙烯醛和丙烯腈%Determination of Acetaldehyde,Acrylaldehyde and Acrylonitrile in Water with Headspace Gas Chromatography

    Institute of Scientific and Technical Information of China (English)

    何芸菁

    2013-01-01

    A headspace gas chromatography method was developed for acetaldehyde, acrylaldehyde and acrylonitrile in water. This method shows good separating effect and high sensitivity. The lowest detection limits were 0.03mg/L for acetaldehyde, 0.07mg/L for acrylaldehyde , 0.04mg/L for acrylonitrile. The recovery rates were 86% ~115% for acetaldehyde, 81%~110%for acrylaldehyde , 80%~108%for acrylonitrile. Experiment results show that the advantages of this method are simple, rapid, accurate for determination of acetaldehyde, acrylaldehyde and acrylonitrile in surface water and wastewater.%建立了顶空-气相色谱法测定水中乙醛、丙烯醛和丙烯腈的分析方法。该方法分离度好,灵敏度高,水中乙醛、丙烯醛和丙烯腈的检出浓度为0.03mg/L、0.07mg/L、0.04mg/L,回收率分别为86%~115%、81%~110%、80%~108%。结果表明,顶空-气相色谱法测定水中乙醛、丙烯醛和丙烯腈方法简单快捷,准确,适合地表水、废水中乙醛、丙烯醛和丙烯腈的同时测定。

  17. 分壁式精馏塔精制丁二烯流程模拟%Simulation of butadiene distillation process using dividing wall column

    Institute of Scientific and Technical Information of China (English)

    贾玉霞; 李玉安; 周文勇; 叶启亮; 孙浩; 史贤林

    2015-01-01

    丁二烯是一种重要的石油化工烯烃原料,由于其生产过程能耗高,因此节能降耗成为丁二烯生产工艺的研究热点。利用Aspen Plus模拟软件对丁二烯精制工艺的两套流程进行了模拟研究,考察了分壁式精馏塔(DWC)中内部互连物流连接位置、预分离塔气液相流量和回流比对分离效果和热负荷的影响,对比了相同分离条件下DWC 分离流程和传统顺序分离流程的能耗,并根据两套分离流程中塔内液相丁二烯浓度分布情况,分析 DWC的节能原因。结果表明,当主塔理论板数105,预分离塔理论板数56,进入预分离塔气相流量1020kmol/h,液相流量890kmol/h,回流比7800时,DWC分离效果最好,丁二烯质量分数可达99.7%,这为DWC精制丁二烯工艺的工业化提供了理论依据。由于DWC有效减少了精馏过程中的返混效应,提高了能量利用率,使其冷凝器可节能29.36%,再沸器可节能29.19%,存在明显的节能优势。%Butadiene is an important petrochemical olefin raw material. Due to the high energy consumption,energy saving has become the focus in the butadiene production process research. This research simulated the two butadiene distillation processes using Aspen Plus software,and investigated the influences of intraconnection stage,vapor and liquid flow of side column and reflex ratio on the separation effect and reboiler duty in dividing wall column(DWC). This research also compared the energy consumption of the DWC process and the conventional process under the same separation conditions and analyzed the reason why DWC can save energy according to the butadiene concentration distribution in the liquid of columns. The results showed that the separation effect of DWC was the best and the butadiene concentration was up to 99.7% when the number of theoretical plates in main column was 105,the number of theoretical plates in side column was 56,vapor flow was 1020

  18. COPOLYMERIZATION OF BUTADIENE AND ISOPRENE CATALYZED BY V(acac)3 -Al(i-Bu)2 Cl-Al2Et3Cl3 CATALYST AND CHARACTERIZATION OF THE PRODUCTS

    Institute of Scientific and Technical Information of China (English)

    HU Zhenya; WEI Jinzhu; YANG Jipo; LI Xiaoyan

    1984-01-01

    Copolymerization of butadiene and isoprene catalyzed by the catalyst system V(acac)3-Al(i-Bu)2Cl-Al2Et3Cl3 has been studied. Composition, microstructure, crystallinity and melting point of the copolymer obtained were determined by PGC, IR, X-ray diffraction and DSC methods respectively. The results revealed that the product was a copolymer and not a blend. The butadiene units presented in the copolymer were of trans-1,4-configuration, while the isoprene units were of both trans-1,4- and 3,4- forms. The melting point and crystallinity of the copolymer decreased with increase of molar ratio of isoprene to butadiene.

  19. Effect of magnetic and thermal properties of iron oxide nanoparticles (IONs) in nitrile butadiene rubber (NBR) latex

    Science.gov (United States)

    Ong, Hun Tiar; Julkapli, Nurhidayatullaili Muhd; Hamid, Sharifah Bee Abd; Boondamnoen, O.; Tai, Mun Foong

    2015-12-01

    Nitrile butadiene rubber (NBR) gloves are one of the most important personal protective equipments but they are possible to tear off and contaminate food or pharmaceutical and healthcare products during manufacturing and packaging process. High tendency of torn glove remaining in food or products due to white or light flesh-coloured glove is not easy to be detected by naked eyes. In this paper, iron oxide nanoparticles (IONs) selected as additive for NBR to improve its detectability by mean of magnetic properties. IONs synthesized via precipitation method and compounded with NBR latex before casting on petri dish. The properties of IONs were investigated by X-ray Diffractometry (XRD), Transmission Electron Microscope (TEM), Raman Spectroscopy and Vibrating Sample Magnetometer (VSM). Meanwhile NBR/IONs composites were studied by Thermogravimetry Analysis (TGA), Differential Scanning Calorimetry (DSC) and Vibrating Sample Magnetometer (VSM). It observed that, synthesized IONs shows of 25.28 nm crystallite with 25.86 nm semipherical (changed as) shape. Meanwhile, Magnetite and maghemite phase are found in range of 670 cm-1 and 700 cm-1 respectively, which it contributes magnetization saturation of 73.96 emu/g at 10,000 G by VSM. Thermal stability and magnetic properties were increased with incorporating IONs into NBR latex up to 20 phr. NBR/IONs 5 phr has the optimum thermal stability, lowest glass transition temperature (-14.83 °C) and acceptable range of magnetization saturation (3.83 emu/g at 10,000 G) to form NBR gloves with magnetic detectability.

  20. A theoretical view of 1,3-butadiene selective hydrogenation toward cis-2-butene on Pdsbnd Ni layered catalyst

    Science.gov (United States)

    Gómez, Guillermina; Belelli, Patricia G.; Cabeza, Gabriela F.; Castellani, Norberto J.

    2015-10-01

    The production of cis-2-butene (cis-2B) on Pd/Ni(1 1 1) bimetallic model was evaluated considering two possible reactions: through the hydrogenation of 1,3-butadiene (13BD) adsorbed on a cis-geometry site and through the isomerization of trans-2-butene (trans-2B). For that purpose, density functional theory (DFT) calculations were performed following the corresponding Horiuti-Polanyi mechanisms. In the hydrogenation, two competitive pathways produce cis-2B and trans-2B from 13BD species adsorbed on di-π-cis and 1,2,3,4-tetra-σ sites, respectively. The cis-2B is obtained with smaller energy requirements than the trans-2B isomer in spite of the adsorption of 13BD on the di-π-cis site is 0.10 eV less stable than on the 1,2,3,4-tetra-σ site. On the other hand, the trans-2B previously formed could be isomerized to cis-2B, and vice versa, trough the 2-butyl intermediates, but the elevated energetic barriers to hydrogenate/dehydrogenate both 2B isomers would avoid these processes. In fact, the dehydrogenation reaction is the limiting step of the isomerization reaction. From these results, we infer that on the Pd/Ni(1 1 1) surface the cis-2B isomer is easier to be formed via the 13BD hydrogenation on the di-π-cis site than via the trans/cis isomerization of 2B.

  1. Synthesis of mixed-ligand cobalt complexes and their applications in high cis-1,4-selective butadiene polymerization

    KAUST Repository

    Liu, Wen

    2015-08-03

    Incomplete oxidation of (N-di-tert-butylphosphino)-6-(2-methyl-2’H-benzoimidazole)-2-aminepyridine dichlorocobalt (PN3CoCl2) in DMF results in a unique co-crystal I formed with three parts including DMF, unit A and unit B complex with Co1 and Co2, respectively, (PN3 ligand in unit A: (N-di-tert-butylphosphino)-6-(2’-methyl-2’H-benzoimidazole)-2-aminepyridine, and O=PN3 ligand in unit B: (N-di-tert-butylphosphinoxide)-6-(2’-methyl-2’H-benzoimidazole)-2-aminepyridine) with 1:1:1 molar ratio. Co1 and Co2 complexes both display a five-coordinated distorted-square-pyramidal geometry around the metal center. The Co1 center is coordinated with PN3 ligand via two N atoms from pyridine, benzoimidazole moiety as well as one P atom, and the Co2 center is coordinated with the oxidized ligandO=PN3 via two N atoms from pyridine, benzoimidazole moiety as well as one O atom from DMF molecule, while the oxidized phosphine moiety (O=P) being excluded from the coordination sphere. Activated with AlEt2Cl, the co-crystallized complexes I are able to actively convert butadiene to polybutadiene, affording cis-1,4 polybutadiene with cis-1,4 unit up to 95.5-97.8% and number average molecular weight of cal. 105g/mol. The high cis-1,4 selectivity and monomodal GPC curve of resultant polymer imply that the identical active species generated from two distinctive cobalt centers.

  2. Blends of nitrile butadiene rubber/poly (vinyl chloride: The use of maleated anhydride castor oil based plasticizer

    Directory of Open Access Journals (Sweden)

    Indiah Ratna Dewi

    2016-06-01

    Full Text Available Recently, much attention has been focused on research to replace petroleum-based plasticizers, with biodegradable materials, such as biopolymer which offers competitive mechanical properties. In this study, castor oil was modified with maleic anhydride (MAH to produce bioplasticizer named maleated anhydride castor oil (MACO, and used in nitrile butadiene rubber (NBR/poly vinyl chloride (PVC blend. The effect of MACO on its cure characteristics and mechanical properties of NBR/PVC blend has been determined. The reactions were carried out at different castor oil (CO/xylene ratios, i.e. 1:0 and 1:1 by weight, and fixed CO/MAH ratio, 1:3 by mole. DOP, CO, and MACO were added into each NBR/PVC blend according to the formula. It was found that the viscosity and safe process level of NBR/PVC blend is similar from all plasticizer, however, MACO (1:0 showed the highest cure rate index (CRI. MACO-based plasticizer gave a higher value of the mechanical properties of the NBR/PVC blend as compared to DOP based plasticizer. MACO (1:1 based plasticizer showed a rather significance performance compared to another type of plasticizers both before and after aging. The value of hardness, elongation at break, tensile strength, and tear strength were 96 Shore A, 155.91 %, 19.15 MPa, and 74.47 MPa, respectively. From this result, NBR/PVC blends based on MACO plasticizer can potentially replace the DOP, and therefore, making the rubber blends eco-friendly.

  3. Structure Sensitivity in Pt Nanoparticle Catalysts for Hydrogenation of 1,3-Butadiene: In Situ Study of Reaction Intermediates Using SFG Vibrational Spectroscopy

    KAUST Repository

    Michalak, William D.

    2013-01-31

    The product selectivity during 1,3-butadiene hydrogenation on monodisperse, colloidally synthesized, Pt nanoparticles was studied under reaction conditions with kinetic measurements and in situ sum frequency generation (SFG) vibrational spectroscopy. SFG was performed with the capping ligands intact in order to maintain nanoparticle size by reduced sintering. Four products are formed at 75 C: 1-butene, cis-2-butene, trans-2-butene, and n-butane. Ensembles of Pt nanoparticles with average diameters of 0.9 and 1.8 nm exhibit a ∼30% and ∼20% increase in the full hydrogenation products, respectively, as compared to Pt nanoparticles with average diameters of 4.6 and 6.7 nm. Methyl and methylene vibrational stretches of reaction intermediates observed under working conditions using SFG were used to correlate the stable reaction intermediates with the product distribution. Kinetic and SFG results correlate with previous DFT predictions for two parallel reaction pathways of 1,3-butadiene hydrogenation. Hydrogenation of 1,3-butadiene can initiate with H-addition at internal or terminal carbons leading to the formation of 1-buten-4-yl radical (metallocycle) and 2-buten-1-yl radical intermediates, respectively. Small (0.9 and 1.8 nm) nanoparticles exhibited vibrational resonances originating from both intermediates, while the large (4.6 and 6.7 nm) particles exhibited vibrational resonances originating predominately from the 2-buten-1-yl radical. This suggests each reaction pathway competes for partial and full hydrogenation and the nanoparticle size affects the kinetic preference for the two pathways. The reaction pathway through the metallocycle intermediate on the small nanoparticles is likely due to the presence of low-coordinated sites. © 2012 American Chemical Society.

  4. A model of sensitivity: 1,3-butadiene increases mutant frequencies and genomic damage in mice lacking a functional microsomal epoxide hydrolase gene.

    Science.gov (United States)

    Wickliffe, Jeffrey K; Ammenheuser, Marinel M; Salazar, James J; Abdel-Rahman, Sherif Z; Hastings-Smith, Darlene A; Postlethwait, Edward M; Lloyd, R Stephen; Ward, Jonathan B

    2003-01-01

    The specific role that polymorphisms in xenobiotic metabolizing enzymes play in modulating sensitivity to 1,3-butadiene (BD) genotoxicity has been relatively unexplored. The enzyme microsomal epoxide hydrolase (mEH) is important in detoxifying the mutagenic epoxides of BD (butadiene monoepoxide [BDO], butadiene diepoxide [BDO(2)]). Polymorphisms in the human mEH gene appear to affect the function of the enzyme. We exposed mice with normal mEH activity (WT) and knockout mice without mEH activity (KO) to 20 ppm BD (inhalation) or 30 mg/kg BDO(2) (intraperitoneal [IP] injection). We then compared Hprt mutant frequencies (MFs) among these groups. KO mice exposed to BD exhibited a significant (P damage in WT and KO mice (comet tail moment) following IP exposure to 3 mg/kg and 30 mg/kg BDO(2). KO mice exposed to 3 mg/kg exhibited significantly more DNA damage than controls (7.5-12.1-fold increase) and exposed WT mice (3 mg/kg; 4.8-fold increase). KO mice exposed to 30 mg/kg BDO(2) exhibited significantly more DNA damage than all other groups (2.3-27.9-fold increase). Correlation analysis indicated that a significant, positive relationship (r(2) = 0.92) exists between comet-measured damage and Hprt MFs. The lack of mEH activity increases the genetic sensitivity of mice exposed to BD and BDO(2). This model should facilitate a mechanistic understanding of the observed variation in human genetic sensitivity following exposure to BD.

  5. Preparation and Properties of Epoxidized Acrylonitrile-butadiene rubber/Carboxylic Carbon Nanotubes Composites%环氧化丁腈橡胶/羧基化碳纳米管复合材料的制备与性能研究

    Institute of Scientific and Technical Information of China (English)

    徐绍彬; 任文坛; 张勇; 张隐西

    2010-01-01

    采用无溶剂反应性加工技术,以叔丁基过氧化氢为氧化剂、三氧化钼为催化剂,在哈克转矩流变仪中实施了原位催化环氧化反应.产物的全反射红外光谱证实了环氧化丁腈橡胶的生成,用化学滴定法测定了其环氧化度为3.6%;将环氧化丁腈橡胶与羧基化多壁碳纳米管(MWNT-COOH)直接共混制备复合材料,研究了MWNT-COOH对复合材料的硫化性能、动态力学性能、热性能的影响.结果表明,复合材料在150℃~190℃范围内表现出较好的硫化性能,MWNT-COOH含量提高可促进橡胶的交联;复合材料在温度低于Tg时,MWNT-COOH可显著提高材料的储能模量;复合材料的热稳定性能随MWNT-COOH用量的增加而提高,其中4份用量的MWNT-COOH可使环氧化丁腈橡胶的最大热失重速率温度由465℃提高到471℃.

  6. 顶空气相色谱法同时测定水中乙醛、丙烯醛和丙烯腈%Determination of Acetaldehyde, Acrylaldehyde and Acrylonitrile in Water with Headspace Gas Chromatography

    Institute of Scientific and Technical Information of China (English)

    於香湘; 缪建军; 吴鹏; 项徐伟

    2011-01-01

    A headspace gas chromatography method was developed for the simultaneous determination of acetaldehyde,acrylaldehyde and acrylonitrile in water. Acetaldehyde, acrylaldehyde and acrylonitrile in water samples were extracted by headspace technology,then seperated with HP-innowax capillary column and detected by FID. Retention time of the peaks was used for qualitative analysis,while external standard method was used for quantitative analysis. The lowest detection limits were 0.04 mg/L for acetaldehyde, 0.02 mg/L for acrylaldehyde and 0.01 mg/L for acrylonitrile. The recovery rates were 95.2% ~ 98.7% for acetaldehyde, 95.8% ~ 97.9% for acrylaldehyde and 96.7% ~ 99.6% for acrylonitrile. And RSD (n = 6)were lower than 5.2%. This method is simple, rapid, accurate and applicable for determination of acetaldehyde,acrylaldehyde and acrylonitrile in various water samples.%建立水中微量乙醛、丙烯醛和丙烯腈的顶空气相色谱(HS-GC)测定方法,经项空进样,用HP-INNOWAX毛细管色谱柱程序升温分离,FID检测,以保留时间定性,外标法定量.水中乙醛、丙烯醛和丙烯腈的检出质量浓度分别为0.04,0.02和0.01 mg/L.样品加标回收率乙醛为952%~98.7%,丙烯醛为95.8%~97.9%,丙烯腈为96.7%~99.6%,6次平行测定结果的相对标准差不大于5.2%.该方法简便、快速、准确、重现性好,适合各种水中乙醛、丙烯醛和丙烯腈的同时测定.

  7. Ultrasonic pretreatment of liquid NaK metal catalyst for side-chain alkenylation of o-xylene with 1,3-butadiene.

    Science.gov (United States)

    Wang, Leizheng; Zheng, Jiaming

    2006-04-01

    The effects of sonochemical treatment of a NaK eutectic mixture as catalyst on the side-chain alkenylation of o-xylene with 1,3-butadiene were studied. The parameters studied include ultrasound frequency, insonation time, sonication power as well as the reaction temperature. In addition, the effect of N,N,N',N'-tetramethylethylenediamine (TMEDA) on the reaction was also studied. The results showed that sonochemical treatment of this NaK eutectic mixture catalyst resulted in excellent conversion (up to 83.16%) under mild conditions. The introduction of TMEDA further increased the conversion to 89.4%.

  8. STUDY ON THE SEQUENCE STRUCTURE OF BUTADIENE-STYRENE RUBBER BY 13C-NMR METHOD Ⅲ. QUANTITATIVE CHARACTERIZATION OF SEQUENCE STRUCTURE

    Institute of Scientific and Technical Information of China (English)

    CHEN Xiaonong; HU Liping; YAN Baozhen; JIAO Shuke

    1990-01-01

    The quantitative description of the sequence structure of emulsion-processed SBR and solution-processed SBR (by lithium catalyst)was carried out based on their spectral data of 13C-NMR.The calculating formulae which could be used to obtain diad concentration from the peak intensities of carbon spectra, average block length, average number of block, and the microstructure composition of the molecular chain were derived. The quantitative result showed that on the molecular chain styrene unit had the tendency to attach to trans-1,4 butadiene unit. The calculated result of the microstructure was in good agreement with that obtained through IR measurement.

  9. Enhancement of Compatibility between Ultrahigh-Molecular-Weight Polyethylene Particles and Butadiene.Nitrile Rubber Matrix with Nanoscale Ceramic Particles and Characterization of Evolving Layer

    Energy Technology Data Exchange (ETDEWEB)

    Shadrinov, Nikolay V.; Sokolova, Marina D.; Cho, Jinho [Institute of Oil and Gas Issues, Yakutsk (Russian Federation); Okhlopkova, A. A. [North-Eastern Federal Univ., Yakutsk (Russian Federation); Lee, Jungkeun; Jeong, Daeyong [Myongji Univ., Seoul (Korea, Republic of)

    2013-12-15

    This article examines the modification of surface properties of ultrahigh-molecular-weight polyethylene (UHMWPE) with nanoscale ceramic particles to fabricate an improved composite with butadiene.nitrile rubber (BNR). Adhesion force data showed that ceramic zeolite particles on the surface of UHMWPE modulated the surface state of the polymer and increased its compatibility with BNR. Atomic force microscopy phase images showed that UHMWPE made up the microphase around the zeolite particles and formed the evolving layer with a complex interface. The complex interface resulted in improvements in the mechanical properties of the composite, especially its low-temperature resistance coefficients, thereby improving its performance in low-temperature applications.

  10. 二甲基甲酰胺法萃取精馏生产1,3-丁二烯的模拟计算%Simulation of 1,3-Butadiene Production Process by Dimethylfomamide Extractive Distillation

    Institute of Scientific and Technical Information of China (English)

    杨小健; 殷绚; 欧阳平凯

    2009-01-01

    Nowadays, extractive distillation is the main technique to produce 1,3-butadiene. This study simulated the 1,3-butadiene production process with DMF extractive distillation by Aspen Plus. The solvent ratio is the most important parameter to the extractive distillation process. The article has given out the proper solvent ratios, reflux ratios, distillate ratios, and bottom product ratios of the columns. It also discusses the thermal loads of several columns. The results of simulation are consequently compared with the plant data, which shows good accordance with each other.

  11. Mechanistic insight into selective catalytic combustion of acrylonitrile (C2H3CN): NCO formation and its further transformation towards N2.

    Science.gov (United States)

    Liu, Ning; Yuan, Xiaoning; Zhang, Runduo; Xu, Rongrong; Li, Yingxia

    2017-03-15

    A series of zeolite catalysts, M(Cu, Fe, Co)-ZSM-5, was prepared by an impregnation method and evaluated for the selective catalytic combustion of acrylonitrile (AN-SCC). Cu-ZSM-5, exhibiting the highest AN conversion activity and best N2 yield, was further selected for an AN-SCC mechanism investigation, wherein both experimental [in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS)] and theoretical [density functional theory (DFT)] approaches were employed. The in situ DRIFTS revealed that AN-SCC followed a hydrolysis mechanism at T 300 °C via an intermediate of NCO. The DFT simulations gave much deeper insights suggesting that: (i) the NCO could be generated by oxidation of AN over [Cu](+) active sites, with an assistance of dissociated atomic O from gaseous O2; (ii) three types of reaction routes could be proposed for the further reaction of NCO to produce N2, namely NCO direct dissociation, NCO coupling, and NO + NCO reaction; and (iii) the last route (NO + NCO), possessing the lowest energy barrier, was the most probable reaction pathway, wherein the NO could be produced by oxidation of NCO. The DFT energy calculation results and microkinetic analyses revealed that the NCO generation step, possessing an energy barrier of 17.0 kcal mol(-1) and a forward reaction rate constant of 2.20 × 10(7) s(-1), was the rate-determining step of the whole catalytic cycle.

  12. Study on ion conductivity and crystallinity of composite polymer electrolytes based on poly(ethylene oxide)/poly(acrylonitrile) containing nano-sized Al2O3 fillers.

    Science.gov (United States)

    Kim, Mingyeong; Lee, Lyungyu; Jung, Yongju; Kim, Seok

    2013-12-01

    In this paper, composite polymer electrolytes were prepared by a blend of poly(ethylene oxide) (PEO) and poly(acrylonitrile) (PAN) as a polymer matrix, ethylene carbonate as a plasticizer, LiClO4 as a salt, and by containing a different content of nano-sized Al2O3. The composite films were prepared by using the solution casting method. The crystallinity and ionic conductivity of the polymer electrolytes was investigated using X-ray diffraction (XRD) and AC impedance method, respectively. The morphology of composite polymer electrolyte film was analyzed by SEM method. From the experimental results, by increasing the Al2O3 content, the crystallinity of PEO was reduced, and the ionic conductivity was increased. In particular, by a doping of 15 wt.% Al2O3 in PEO/PAN polymer blend, the CPEs showed the superior ionic conductivity. However, when Al2O3 content exceeds 15 wt.%, the ionic conductivity was decreased. From the surface morphology, it was concluded that the ionic conductivity was decreased because the CPEs showed a heterogenous morphology due to immiscibility or aggregation of the ceramic filler within the polymer matrix.

  13. Successful startup of a full-scale acrylonitrile wastewater biological treatment plant (ACN-WWTP) by eliminating the inhibitory effects of toxic compounds on nitrification.

    Science.gov (United States)

    Han, Yuanyuan; Jin, Xibiao; Wang, Feng; Liu, Yongdi; Chen, Xiurong

    2014-01-01

    During the startup of a full-scale anoxic/aerobic (A/O) biological treatment plant for acrylonitrile wastewater, the removal efficiencies of NH(3)-N and total Kjeldahl nitrogen (TKN) were 1.29 and 0.83% on day 30, respectively. The nitrification process was almost totally inhibited, which was mainly caused by the inhibitory effects of toxic compounds. To eliminate the inhibition, cultivating the bacteria that degrade toxic compounds with patience was applied into the second startup of the biological treatment plant. After 75 days of startup, the inhibitory effects of the toxic compounds on nitrification were eliminated. The treatment plant has been operated stably for more than 3 years. During the last 100 days, the influent concentrations of chemical oxygen demand (COD), NH(3)-N, TKN and total cyanide (TCN) were 831-2,164, 188-516, 306-542 and 1.17-9.57 mg L(-1) respectively, and the effluent concentrations were 257 ± 30.9, 3.30 ± 1.10, 31.6 ± 4.49 and 0.40 ± 0.10 mg L(-1) (n = 100), respectively. Four strains of cyanide-degrading bacteria which were able to grow with cyanide as the sole carbon and nitrogen source were isolated from the full-scale biological treatment plant. They were short and rod-shaped under scanning electron microscopy (SEM) and were identified as Brevundimonas sp., Rhizobium sp., Dietzia natronolimnaea and Microbacterium sp., respectively.

  14. Microwave absorption properties of lightweight absorber based on Fe50Ni50-coated poly(acrylonitrile) microspheres and reduced graphene oxide composites

    Science.gov (United States)

    Zhang, Bin; Wang, Jun; Wang, Junpeng; Huo, Siqi; Zhang, Bin; Tang, Yushan

    2016-09-01

    In this paper, we proposed a facile method to obtain the lightweight composites consisting of surface modified Fe50Ni50-coated poly(acrylonitrile) microspheres (PANS@SMF), reduced graphene oxide (RGO) and epoxy resin. The as-prepared samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), vibrating sample magnetometry (VSM) and vector network analyzer (VNA). Impedance matching condition and electromagnetic wave attenuation characteristic were used for the reflection loss (RL) performance of the composites. Compared with pure PANS@SMF and RGO composites, the -10 dB absorption bandwidth and the minimum RL of the hybrid composites were enhanced. The bandwidth less than -10 dB was almost 4.5 GHz in the range of 10 GHz to 14.5 GHz, with a matching thickness of 2.5 mm. The density of the hybrid composites was in the range of 0.25-0.34 g/cm3. Therefore, the hybrid composite can be considered as a potential lightweight microwave absorber.

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

    Science.gov (United States)

    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.

  16. Road asphalt modifiers based on oil-resistant rubbers and products of thermal transformations of coals

    Energy Technology Data Exchange (ETDEWEB)

    Sharypov, V.I.; Kiselev, V.P.; Beregovtsova, N.G.; Bugaenko, M.B.; Kuznetsov, B.N. [Russian Academy of Sciences, Moscow (Russian Federation)

    2008-07-15

    The properties of asphalt binder modifiers prepared by dissolving butadiene-acrylonitrile rubbers and their production waste in liquid products of heat treatment of various brands of coal were studied.

  17. The Diels-Alder Cycloaddition Reaction of Substituted Hemifullerenes with 1,3-Butadiene: Effect of Electron-Donating and Electron-Withdrawing Substituents

    Directory of Open Access Journals (Sweden)

    Martha Mojica

    2016-02-01

    Full Text Available The Diels-Alder (DA reaction provides an attractive route to increase the number of six member rings in substituted Polycyclic Aromatic Hydrocarbons (PAHs. The density functional theory (DFT B3LYP method has been used in this work to inquire if the substitution of H over the edge of triindenetriphenylene (pristine hemifullerene 1 and pentacyclopentacorannulene (pristine hemifullerene 2, could improve the DA cycloaddition reaction with 1,3-butadiene. The substituents tested include electron-donating (NH2, OMe, OH, Me, i-Pr and electron-withdrawing groups (F, COOH, CF3, CHO, CN, NO2. The electronic, kinetic and thermodynamic parameters of the DA reactions of the substituted hemifullerenes with 1,3-butadiene have been analyzed. The most promising results were obtained for the NO2 substituent; the activation energy barriers for reactions using this substituent were lower than the barriers for the pristine hemifullerenes. This leads us to expect that the cycloadditions to a starting fullerene fragment will be possible.

  18. Synthesis and characterization of butadiene-1,3 and octene-1 copolymer prepared by a Ziegler-Natta catalyst based on neodymium

    Directory of Open Access Journals (Sweden)

    Gustavo M. Silva

    2011-01-01

    Full Text Available The aim of this work is to evaluate the influence of octene-1 incorporation in the polybutadiene chain on the polymerization reaction and polymer characteristics. Thus, copolymerization of butadiene-1,3 with octene-1 using a Ziegler-Natta ternary catalyst based on neodymium was performed. The weight ratios of butadiene-1,3/α-olefin 100/0, 99/1, 97/3, 95/5, 90/10, 80/20 and 70/30 were evaluated. The copolymers were characterized by size exclusion chromatography (SEC, infrared spectroscopy (FTIR and thermogravimetric analysis (TG. The results showed that the degradation temperature (Tmax was not affected by the addition of alpha-olefin, while the thermal behavior has undergone significant changes. The polymer microstructure was not influenced by the increasing of octene-1 content. However, a tendency to molecular mass increase was observed with the increasing of octene-1 content. It was also observed a trend in reduction of the polymerization conversion as the octene-1 content increased.

  19. Poly(styrene-co-butadiene) random copolymer thin films and nanostructures on a mica surface: morphology and contact angles of nanodroplets.

    Science.gov (United States)

    McClements, Jake; Buffone, Cosimo; Shaver, Michael P; Sefiane, Khellil; Koutsos, Vasileios

    2017-09-20

    The self-assembly of poly(styrene-co-butadiene) random copolymers on mica surfaces was studied by varying solution concentrations and polymer molecular weights. Toluene solutions of the poly(styrene-co-butadiene) samples were spin coated onto a mica surface and the resulting polymer morphology was investigated by atomic force microscopy. At higher concentrations, thin films formed with varying thicknesses; some dewetting was observed which depended on the molecular weight. Total dewetting did not occur despite the polymer's low glass transition temperature. Instead, partial dewetting was observed suggesting that the polymer was in a metastable equilibrium state. At lower concentrations, spherical cap shaped nanodroplets formed with varying sizes from single polymer chains to aggregates containing millions of chains. As the molecular weight was increased, fewer aggregates were observed on the surface, albeit with larger sizes resulting from increased solution viscosities and more chain entanglements at higher molecular weights. The contact angles of the nanodroplets were shown to be size dependent. A minimum contact angle occurs for droplets with radii of 100-250 nm at each molecular weight. Droplets smaller than 100 nm showed a sharp increase in contact angle; attributed to an increase in the elastic modulus of the droplets, in addition, to a positive line tension value. Droplets larger than 250 nm also showed an increased contact angle due to surface heterogeneities which cannot be avoided for larger droplets. This increase in contact angle plateaus as the droplet size reaches the macroscopic scale.

  20. Rotational Analysis of Several Bands in the High-Resolution Infrared Spectrum of Butadiene-1- 13C1: Assignment of Vibrational Fundamentals

    Energy Technology Data Exchange (ETDEWEB)

    Craig, Norman C.; Hanson, Keith A.; Moore, M C.; Sams, Robert L.

    2005-02-10

    Butadiene-113C1 was synthesized, and its high-resolution (0.002 cm-1) infrared spectrum was recorded for several bands in the mid-infrared region. A complete analysis of the rotational structure in the C-type bands at 900.0 and 909 cm-1 were performed. Of these latter two bands, which are of comparable intensity, the higher frequency one is largely CH2 out-of-plane wagging and the lower frequency one is largely 13CH2 out-of-plane wagging. Taken together these bands correlate with one infrared-active au fundamental and one Raman-active bg fundamental of butadiene. The ground state rotational constants are A=1.3887919(6), B=0.1436683(3), and C=0.1302251(3) cm-1, and upper state rotational constants are reported for the bands at 524.485 and 900.0 cm-1. Medium resolution infrared and Raman spectra gave a complete assignment of the vibrational fundamentals, including 11 fundamentals observed directly for the first time.

  1. Rotational analysis of several bands in the high-resolution infrared spectrum of butadiene-1- 13C 1: assignment of vibrational fundamentals

    Science.gov (United States)

    Craig, Norman C.; Hanson, Keith A.; Moore, Michael C.; Sams, Robert L.

    2005-05-01

    Butadiene-1- 13C 1 was synthesized, and its high-resolution (0.002 cm -1) infrared spectrum was recorded for several bands in the mid-infrared region. A complete analysis of the rotational structure in the C-type band at 524.485 cm -1 for CH 2 twisting and a partial analysis of the rotational structure in the C-type bands at 900.0 and 909 cm -1 were performed. Of these latter two bands, which are of comparable intensity, the higher frequency one is largely CH 2 out-of-plane wagging and the lower frequency one is largely 13CH 2 out-of-plane wagging. Taken together these bands correlate with one infrared-active au fundamental and one Raman-active bg fundamental of butadiene. The ground state rotational constants are A=1.3887919 (6), B=0.1436683 (3), and C=0.1302251 (3) cm -1, and upper state rotational constants are reported for the bands at 524.485 and 900.0 cm -1. Medium resolution infrared and Raman spectra gave a complete assignment of the vibrational fundamentals, including 11 fundamentals observed directly for the first time.

  2. Selective hydrogenation of 1,3-butadiene from crude C{sub 4} cracker stream with a solid catalyst with ionic liquid layer (SCILL). DSC and solubility study

    Energy Technology Data Exchange (ETDEWEB)

    Mangartz, T.; Korth, W.; Kern, C.; Jess, A. [Bayreuth Univ. (Germany). Dept. of Chemical Engineering

    2013-11-01

    In petroleum as well as in fine chemical industry, selective catalytic hydrogenation is an important reaction. The selective hydrogenation of 1,3-butadiene (BD) to butene (trans-,1- and cis-butene) from the crude C4 steam cracker fraction represents one example, but under today's technical conditions undesired butane forms inevitably in relevant amounts. To increase the butene yield, the concept of Solid Catalyst with Ionic Liquid Layer (SCILL) was employed. The SCILL catalyst, in contrast to the uncoated catalyst, yielded a remarkably high selectivity to butenes (S{sub butenes} > 99 %) even at high residence times or at high hydrogen partial pressure. Nearly no butane (S{sub butane} {approx} 0 %) was analytically detected. We expected that due to different solubility, the poorer soluble compounds discharged from the ionic liquid and, thus, caused the shift in selectivity to a great extent. Temperature dependent solubility measurements in the used ionic liquid ([DMIM][DMP]) revealed that the order of increasing solubility is 1,3-butadiene > butenes > butane which matches the assumption. However, since differences in solubility cannot explain this SCILL effect satisfyingly, ionic liquids are expected to affect the surface of the catalyst (side-specific ligand-type effect). Investigations using spectroscopic methods (e.g. FTIR) confirmed this suggestion. (orig.)

  3. Interception and characterization of catalyst species in rhodium bis(diazaphospholane)-catalyzed hydroformylation of octene, vinyl acetate, allyl cyanide, and 1-phenyl-1,3-butadiene.

    Science.gov (United States)

    Nelsen, Eleanor R; Brezny, Anna C; Landis, Clark R

    2015-11-11

    In the absence of H2, reaction of [Rh(H) (CO)2(BDP)] [BDP = bis(diazaphospholane)] with hydroformylation substrates vinyl acetate, allyl cyanide, 1-octene, and trans-1-phenyl-1,3-butadiene at low temperatures and pressures with passive mixing enables detailed NMR spectroscopic characterization of rhodium acyl and, in some cases, alkyl complexes of these substrates. For trans-1-phenyl-1,3-butadiene, the stable alkyl complex is an η(3)-allyl complex. Five-coordinate acyl dicarbonyl complexes appear to be thermodynamically preferred over the four-coordinate acyl monocarbonyls at low temperatures and one atmosphere of CO. Under noncatalytic (i.e., no H2 present) reaction conditions, NMR spectroscopy reveals the kinetic and thermodynamic selectivity of linear and branched acyl dicarbonyl formation. Over the range of substrates investigated, the kinetic regioselectivity observed at low temperatures under noncatalytic conditions roughly predicts the regioselectivity observed for catalytic transformations at higher temperatures and pressures. Thus, kinetic distributions of off-cycle acyl dicarbonyls constitute reasonable models for catalytic selectivity. The Wisconsin high-pressure NMR reactor (WiHP-NMRR) enables single-turnover experiments with active mixing; such experiments constitute a powerful strategy for elucidating the inherent selectivity of acyl formation and acyl hydrogenolysis in hydroformylation reactions.

  4. DNA damage induced by three major metabolites of 1,3-butadiene in human hepatocyte L02 cells.

    Science.gov (United States)

    Zhang, Pan-Pan; Wen, Ying; An, Jing; Yu, Ying-Xin; Wu, Ming-Hong; Zhang, Xin-Yu

    2012-09-18

    1,3-Butadiene (BD) is a carcinogenic air pollutant. Its bioactivation produces four major metabolites, i.e., 3,4-epoxy-1-butene (EB), 3,4-epoxy-1,2-butanediol (EBD), 1,2,3,4-diepoxybutane (DEB), and 3-butene-1,2-diol (BDD). Studies have been mostly focused on DEB due to its strong mutagenicity/carcinogenicity. In contrast, studies of genotoxicity of EB, EBD, and BDD have been limited. In particular, genotoxicity of EBD and BDD using strand breaks as the endpoint has not been investigated. To obtain a more complete understanding of BD toxicity, in the present study, we used comet assay to investigate DNA damage induced by EB, EBD, and BDD in human hepatocyte L02 cells, with the aim to determine their relative potencies, the types of DNA damage, and the possible pathway to form strand breaks. Using alkaline comet assay (pH>13), it was observed that EB and EBD caused similar concentration-dependent increases in DNA migration from 50 to 1000μM. However, BDD induced a statistically significant increase only at 1000μM, and the increase itself was very small. EBD was as potent as EB at lower concentrations (≤200μM), and was slightly less potent than EB at higher concentrations. The results indicated that these metabolites could generate strand breaks in cells with the rank order of the potencies being EB>≈EBD≫BDD. All three compounds failed to cause statistically significant increases in DNA migration in pre-lysed cells, suggesting that they did not produce strand breaks through chemical pathways under our experimental conditions. By using comet assays at pH 11.9 and pH 9, it was demonstrated that EB and EBD generated both single-strand breaks (SSB) and alkali-labile sites, but BDD produced only SSB. To our knowledge, this is the first report to investigate EBD- and BDD-induced strand breaks in cells. The results implied that EBD could play an important role in toxicity of BD.

  5. Effect of magnetic and thermal properties of iron oxide nanoparticles (IONs) in nitrile butadiene rubber (NBR) latex

    Energy Technology Data Exchange (ETDEWEB)

    Ong, Hun Tiar; Julkapli, Nurhidayatullaili Muhd; Hamid, Sharifah Bee Abd, E-mail: sharifahbee@um.edu.my; Boondamnoen, O.; Tai, Mun Foong

    2015-12-01

    Nitrile butadiene rubber (NBR) gloves are one of the most important personal protective equipments but they are possible to tear off and contaminate food or pharmaceutical and healthcare products during manufacturing and packaging process. High tendency of torn glove remaining in food or products due to white or light flesh-coloured glove is not easy to be detected by naked eyes. In this paper, iron oxide nanoparticles (IONs) selected as additive for NBR to improve its detectability by mean of magnetic properties. IONs synthesized via precipitation method and compounded with NBR latex before casting on petri dish. The properties of IONs were investigated by X-ray Diffractometry (XRD), Transmission Electron Microscope (TEM), Raman Spectroscopy and Vibrating Sample Magnetometer (VSM). Meanwhile NBR/IONs composites were studied by Thermogravimetry Analysis (TGA), Differential Scanning Calorimetry (DSC) and Vibrating Sample Magnetometer (VSM). It observed that, synthesized IONs shows of 25.28 nm crystallite with 25.86 nm semipherical (changed as) shape. Meanwhile, Magnetite and maghemite phase are found in range of 670 cm{sup −1} and 700 cm{sup −1} respectively, which it contributes magnetization saturation of 73.96 emu/g at 10,000 G by VSM. Thermal stability and magnetic properties were increased with incorporating IONs into NBR latex up to 20 phr. NBR/IONs 5 phr has the optimum thermal stability, lowest glass transition temperature (−14.83 °C) and acceptable range of magnetization saturation (3.83 emu/g at 10,000 G) to form NBR gloves with magnetic detectability. - Highlights: • We synthesized IONs with high magnetization saturation (M{sub s}). • High M{sub s} of IONs were incorporated into NBR latex in order to induce magnetic properties in the NBR composite. • Introduction of IONs into NBR latex would improve thermal properties. • The produced NBR/IONs 5 phr composite exceeded the minimum magnetic moment sensor of the detector. • They have high

  6. 丙烯腈吸收过程模拟优化%Simulation and Optimization of the Absorption Process to a Acrylonitrile Plant

    Institute of Scientific and Technical Information of China (English)

    杨家军; 霍凤华; 崔吉成

    2015-01-01

    Throughout its history,chemical process simulation software has been widely used in chemical process design,operational evaluation and optimization.As well known by chemical technicans,the PROII software was used for the simulation of the absorption process of acrylonitrile production plant in the study.Firstly,the operating parameters of the absorption process were analyzed to determine the optimization variables.After that, the absorption tower was simulated with PROII software.By comparing the simulation results of different conditions,the process parameters related to the sbsorption process were analyzed,such as the comsuption of absorption water and side withdrawing,and the operating pressure. The optimum values in the corresponding conditions were obtained.%化工过程模拟软件发展至今已被广泛地应用于化工过程的设计计算、操作评估和优化中。该文应用化工技术人员熟知的PROII软件对丙烯腈的吸收过程进行模拟研究。首先对年产20万吨的丙烯腈生产过程吸收塔单元中的操作参数进行分析,确定要优化的参数。然后应用PROII软件对丙烯腈吸收塔进行模拟,通过改变操作参数后模拟结果的比较对操作参数中的吸收水用量、侧线采出量和吸收塔的操作压力进行了模拟分析,并得到相应条件下的最佳值。

  7. Microwave absorption properties of lightweight absorber based on Fe{sub 50}Ni{sub 50}-coated poly(acrylonitrile) microspheres and reduced graphene oxide composites

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Bin [School of Material Science And Engineering, Wuhan University of Technology, Wuhan 430070 (China); Wang, Jun, E-mail: wgdfrp@whut.edu.cn [School of Material Science And Engineering, Wuhan University of Technology, Wuhan 430070 (China); Wang, Junpeng; Huo, Siqi [School of Material Science And Engineering, Wuhan University of Technology, Wuhan 430070 (China); Zhang, Bin [School of Science, Wuhan University of Technology, Wuhan 430070 (China); Tang, Yushan [School of Material Science And Engineering, Wuhan University of Technology, Wuhan 430070 (China)

    2016-09-01

    In this paper, we proposed a facile method to obtain the lightweight composites consisting of surface modified Fe{sub 50}Ni{sub 50}-coated poly(acrylonitrile) microspheres (PANS@SMF), reduced graphene oxide (RGO) and epoxy resin. The as-prepared samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), vibrating sample magnetometry (VSM) and vector network analyzer (VNA). Impedance matching condition and electromagnetic wave attenuation characteristic were used for the reflection loss (RL) performance of the composites. Compared with pure PANS@SMF and RGO composites, the −10 dB absorption bandwidth and the minimum RL of the hybrid composites were enhanced. The bandwidth less than −10 dB was almost 4.5 GHz in the range of 10 GHz to 14.5 GHz, with a matching thickness of 2.5 mm. The density of the hybrid composites was in the range of 0.25–0.34 g/cm{sup 3}. Therefore, the hybrid composite can be considered as a potential lightweight microwave absorber. - Highlights: • PANS@SMF – RGO epoxy composite was fabricated by a facile method. • The absorption bandwidth less than −10 dB can reach up to 4.5 GHz with layer thickness of 2.5 mm. • The density of the composites is in the range of 0.25–0.34 g/cm{sup 3} and can be considered as a lightweight microwave absorber.

  8. Molecular Structure and Crystal Packing of n-Type Semiconducting Material 3′,3′-(1,4-Phenylene)bis{2′-(4′′-trifluoromethyl)phenyl}acrylonitrile

    OpenAIRE

    Tetsuji Moriguchi; Shuichi Nagamatsu; Tatsuo Okauchi; Akihiko Tsuge; Wataru Takashima; Shuji Hayase

    2014-01-01

    The exact molecular structure and the crystal packing of the n-type semiconducting material 3′,3′-(1,4-phenylene)bis{2′-(4′′-trifluoromethyl)phenyl}acrylonitrile was determined by a single crystal X-ray diffraction with twin treatment technique. The air-stable product was crystallized from dichloromethane-hexane mixed solution. The solid-state structure is the example of a typical π-π stacking with side intermolecular CN–H short contact networks.

  9. Simultaneous determination of acrylonitrile and trichloroethylene in the air of workplace by gas chromatography%气相色谱法同时测定工作场所空气中的丙烯腈和三氯乙烯

    Institute of Scientific and Technical Information of China (English)

    刘云富; 谭广辉

    2013-01-01

    Objective: To establish a method for the simultaneous determination of acrylonitrile and trichloroethyl-ene in the air of workplace by gas chromatography. Methods: Acrylonitrile and trichloroethylene in the air of workplace were collected with charcoal tube, then desorbed with carbon disulfide, and finally separated with a Rtx(R) -Wax capillary column (30 m ×0. 25 mm ×0. 25 μm) and detected with flame ionization detector. Results: The linearity ranges were 0.5 μg/ml ~200 μg/ml,2.6 μg/ml ~250 μg/ml for acrylonitrile and trichloroethylene, respectively. The coefficients of correlation were 0. 9999, 0. 9992 and the limits of detection were 0. 5 μg/ml and 2. 6 μg/ml. Conclusion: Separation effect of the two organic compounds was good, the method is suitable for determining acrylonitrile and trichloroethylene in the air of workplace simultaneously.%目的:建立工作场所空气中丙烯腈和三氯乙烯的气相色谱同时测定方法.方法:采用活性炭管吸附工作场所空气中丙烯腈和三氯乙烯,经二硫化碳解吸后进样,使用Rtx@-Wax毛细管柱(30 m×0.25 mm×0.25μm)分离和火焰离子化检测器检测.结果:丙烯腈、三氯乙烯的线性范围分别为0.5μg/ml ~200μg/ml和2.6 μg/ml ~ 250 μg/ml;相关系数分别为0.9999和0.9992;检出限分别为0.5 μg/ml和2.6 μg/ml,解吸效率分别为89%和95%,相对标准偏差为1.2% ~6.4%、0.9% ~4.7%.结论:该方法对两种物质的分离效果好,适合工作场所空气中丙烯腈和三氯乙烯的同时测定.

  10. Micronuclei and gene mutations in transgenic big Blue((R)) mouse and rat fibroblasts after exposure to the epoxide metabolites of 1, 3-butadiene.

    Science.gov (United States)

    Erexson, G L; Tindall, K R

    2000-12-20

    1,3-Butadiene (BD) is a commodity compound and by-product in the manufacture of synthetic rubber that elicits a differential carcinogenic response in rodents after chronic exposure. Mice are up to approximately 1000-fold more sensitive to the tumorigenicity of inhaled BD than rats, thereby confounding human risk assessment analyses. Rodent transgenic in vivo and in vitro models have been recently utilized for generating genetic toxicology data in support of risk assessment studies. However, studies have not been extended to investigate multiple endpoints of genetic damage using in vitro transgenic models. The goal of this study was to evaluate possible differences in the production of genetic damage in transgenic Big Blue((R)) mouse (BBM1) and rat (BBR1) fibroblasts exposed to three predominant epoxide metabolites of BD. Analyses of cytotoxicity, micronucleus (MN) formation, cII mutant frequency (MF) and apoptosis were assessed after in vitro exposure of BBM1 and BBR1 cells exposed to various concentrations of butadiene monoepoxide (BMO), diepoxybutane (DEB) and butadiene diolepoxide (BDE). Both BMO and DEB reduced cell survival in BBM1 and BBR1 cells. However, BDE decreased cell survival only in BBM1 cells at the concentrations evaluated. Concentration-dependent increases in the formation of MN was observed in both BBM1 and BBR1 cells, with DEB being the most potent followed by BDE and then BMO. The dose-response for mutations induced at the cII locus was essentially equal after DEB exposure of BBM1 and BBR1 fibroblasts. In contrast, the cII MF was significantly increased only in BBM1 cells after exposure to either BMO or BDE. These data demonstrate a differential genetic response for gene mutations but not for MN formation in transgenic BBM1 and BBR1 fibroblasts and suggest a rodent species-specific difference in the persistence of DNA damage that results in gene mutations. In addition, apoptosis was observed in BBR1 cells but not in BBM1 cells when treated with

  11. Theoretical Kinetics Analysis for Ḣ Atom Addition to 1,3-Butadiene and Related Reactions on the Ċ4H7 Potential Energy Surface.

    Science.gov (United States)

    Li, Yang; Klippenstein, Stephen J; Zhou, Chong-Wen; Curran, Henry J

    2017-09-08

    As the simplest conjugated hydrocarbon, 1,3-butadiene oxidation chemistry can provide a first step in understanding the role of poly-unsaturated hydrocarbons in combustion and, in particular, an understanding of their contribution towards soot formation. Based on our previous work on propene and the butene isomers (1-, 2- and isobutene), it was found that the reaction kinetics of H-atom addition to the C=C double bond plays a significant role in fuel consumption kinetics and influences the predictions of high-temperature ignition delay times, product species concentrations and flame speed measurements. In this study, the rate constants and thermodynamic properties for Ḣ-atom addition to 1,3-butadiene and related reactions on the Ċ4H7 potential energy surface (PES) have been calculated using two different series of quantum chemical methods and two different kinetic solvers. The calculated results including Zero Point Energies (ZPEs), Single Point Energies (SPEs), rate constants, barrier heights and thermochemistry are systematically compared among the two methods. 1-methylallyl (Ċ4H71-3) and 3-buten-1-yl (Ċ4H71-4) radicals and C2H4 + Ċ2H3 are found to be the most important channels and reactivity promoting products, respectively. We calculated that terminal addition is dominant (> 80%) compared to internal Ḣ-atom addition at all temperatures in the range 298 - 2000 K. However, this dominance decreases with increasing temperature. Particularly, for the bimolecular reaction C4H6 + Ḣ ↔ products and C2H4 +Ċ2H3 ↔ products, the calculated rate constants are in excellent agreement with both experimental and theoretical results from the literature. For selected C4 species, the calculated thermochemical values are also in good agreement with literature data. In addition, the rate constants for H-atom abstraction by Ḣ atoms have also been calculated, and it is found that abstraction from the central carbon atoms is the dominant channel (> 70%) at temperatures

  12. Cytotoxicity, genotoxicity, and mutagenicity of 1-chloro-2-hydroxy-3-butene and 1-chloro-3-buten-2-one, two alternative metabolites of 1,3-butadiene

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Xin-Jie; Zeng, Fang-Mao; An, Jing; Yu, Ying-Xin [Institute of Environmental Pollution and Health, School of Environmental and Chemical Engineering, Shanghai University, Shanghai 200444 (China); Zhang, Xin-Yu, E-mail: xyzhang999@shu.edu.cn [Institute of Environmental Pollution and Health, School of Environmental and Chemical Engineering, Shanghai University, Shanghai 200444 (China); Elfarra, Adnan A., E-mail: elfarra@svm.vetmed.wisc.edu [Department of Comparative Biosciences, University of Wisconsin-Madison, Madison, WI 53706 (United States); Molecular and Environmental Toxicology Center, University of Wisconsin-Madison, Madison, WI 53706 (United States)

    2013-08-15

    The cytotoxicity, genotoxicity, and mutagenicity of 1-chloro-2-hydroxy-3-butene (CHB), a known in vitro metabolite of the human carcinogen 1,3-butadiene, have not previously been investigated. Because CHB can be bioactivated by alcohol dehydrogenases to yield 1-chloro-3-buten-2-one (CBO), a bifunctional alkylating agent that caused globin-chain cross-links in erythrocytes, in the present study we investigated the cytotoxic and genotoxic potential of CHB and CBO in human normal hepatocyte L02 cells using the MTT assay, the relative cloning efficiency assay and the comet assay. We also investigated the mutagenic potential of these compounds with the Ames test using Salmonella strains TA1535 and TA1537. The results provide clear evidence for CHB and CBO being both cytotoxic and genotoxic with CBO being approximately 100-fold more potent than CHB. Interestingly, CHB generated both single-strand breaks and alkali-labile sites on DNA, whereas CBO produced only alkali-labile sites. CHB did not directly result in DNA breaks, whereas CBO was capable of directly generating breaks on DNA. Interestingly, both compounds did not induce DNA cross-links as examined by the comet assay. The Ames test results showed that CHB induced point mutation but not frameshift mutation, whereas the toxic effects of CBO made it difficult to reliably assess the mutagenic potential of CBO in the two strains. Collectively, the results suggest that CHB and CBO may play a role in the mutagenicity and carcinogenicity of 1,3-butadiene. - Highlights: • 1-Chloro-2-hydroxy-3-butene (CHB) is cytotoxic and genotoxic in human liver cells. • The CHB metabolite, 1-chloro-3-buten-2-one (CBO) is ∼ 100-fold more toxic than CHB. • CHB and CBO cause DNA alkali-labile sites, but only CBO directly causes DNA breaks. • CHB is mutagenic in the Ames test, but CBO is too toxic in the assay. • The results suggest a role for CHB in 1,3-butadiene genotoxicity and mutagenicity.

  13. Synthesis of SAN-PB-SAN triblock copolymers via a ''living'' copolymerization with macro-photoiniferters

    NARCIS (Netherlands)

    Kroeze, E; de Boer, B.; ten Brinke, G.; Hadziioannou, G

    1996-01-01

    A technique is described for the synthesis of poly((styrene-co-acrylonitrile)-block-butadiene-block-(styrene-co-acrylonitrile)) (SAN-PB-SAN) triblock copolymers through polybutadiene-based photo-iniferters. Dihydroxy- and dicarboxy-terminated polybutadienes were transformed into the chloro-terminate

  14. 21 CFR 177.2600 - Rubber articles intended for repeated use.

    Science.gov (United States)

    2010-04-01

    ...-acrylonitrile-ethylene glycol dimethacrylate copolymers containing not more than 5 weight percent of polymer units derived from ethylene glycol dimethacrylate. Butadiene-acrylonitrile-methacrylic acid copolymer... production of rubber articles intended for repeated use shall not exceed the amount reasonably required to...

  15. Temperature dependence of alpha-induced scintillation in the 1,1,4,4-tetraphenyl-1,3-butadiene wavelength shifter

    CERN Document Server

    Veloce, L M; Di Stefano, P C F; Noble, A J; Boulay, M G; Nadeau, P; Pollmann, T; Clark, M; Piquemal, M; Schreiner, K

    2015-01-01

    Liquid noble gas based particle detectors often use the organic wavelength shifter 1,1,4,4-tetraphenyl-1,3-butadiene (TPB) which shifts UV scintillation light to the visible regime, facilitating its detection, but which also can scintillate on its own. Dark matter searches based on this type of detector commonly rely on pulse-shape discrimination (PSD) for background mitigation. Alpha-induced scintillation therefore represents a possible background source in dark matter searches. The timing characteristics of this scintillation determine whether this background can be mitigated through PSD. We have therefore characterized the pulse shape and light yield of alpha induced TPB scintillation at temperatures ranging from 300 K down to 4 K, with special attention given to liquid noble temperatures. We find that the pulse shapes and light yield depend strongly on temperature. In addition, the significant contribution of long time constants above ~50 K provides an avenue for discrimination between alpha decay events ...

  16. VUV-VIS optical characterization of Tetraphenyl-butadiene films on glass and specular reflector substrates from room to liquid Argon temperature

    CERN Document Server

    Francini, R; Nichelatti, E; Vincenti, M A; Canci, N; Segreto, E; Cavanna, F; Di Pompeo, F; Carbonara, F; Fiorillo, G; Perfetto, F

    2013-01-01

    The use of efficient wavelength-shifters from the vacuum-ultraviolet to the photosensor's range of sensitivity is a key feature in detectors for Dark Matter search and neutrino physics based on liquid argon scintillation detection. Thin film of Tetraphenyl-butadiene (TPB) deposited onto the surface delimiting the active volume of the detector and/or onto the photosensor optical window is the most common solution in current and planned experiments. Detector design and response can be evaluated and correctly simulated only when the properties of the optical system in use (TPB film + substrate) are fully understood. Characterization of the optical system requires specific, sometimes sophisticated optical methodologies. In this paper the main features of TPB coatings on different, commonly used substrates is reported, as a result of two independent campaigns of measurements at the specialized optical metrology labs of ENEA and University of Tor Vergata. Measured features include TPB emission spectra with lineshap...

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

    Science.gov (United States)

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

    2007-11-01

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

  18. DNA damage induced by the environmental carcinogen butadiene: identification of a diepoxybutane-adenine adduct and its detection by 32P-postlabelling.

    Science.gov (United States)

    Leuratti, C; Jones, N J; Marafante, E; Kostiainen, R; Peltonen, K; Waters, R

    1994-09-01

    To date only a few studies have been undertaken on DNA adducts formed by epoxybutene (EB) and diepoxybutane (DEB), the two active metabolites of 1,3-butadiene. Our interests have focused on further investigating DNA alkylation by the two epoxides, especially in relation to the development of a method for human biomonitoring. Here, following the reaction of deoxyadenosine monophosphate and poly(dA-dT)(dA-dT) with DEB and subsequent HPLC, we have identified an adenine adduct. MS analyses indicate the structure of an adenine adducted by DEB at the N6 position. A HPLC/32P-postlabelling method was developed for its measurement in DNA samples and the adduct was detected in calf thymus DNA and DNA from Chinese hamster ovary cells exposed to DEB. The 100% labelling efficiency during postlabelling, the amount of the adduct and its elution before the normal nucleotides during HPLC suggest it could be a suitable indicator of BUT exposure.

  19. Copolymerization of 1-hexene and 1-dodecene with 1,3-butadiene by a versatate/diisobutylaluminum hydride/t-butyl chloride catalyst system

    Directory of Open Access Journals (Sweden)

    Gustavo Monteiro da Silva

    2014-01-01

    Full Text Available The aim of this study was to incorporate an alpha-olefin (1-hexene or 1-dodecene in a high cis polybutadiene chain, using a neodymium versatate/diisobutylaluminum hydride/t-butyl chloride catalyst system. The influence of alpha-olefin on polymerization reaction and polymer characteristics, using different weight ratios of butadiene/α-olefin, was evaluated. The copolymers were characterized by SEC, FTIR, NMR, TGA and viscosimetric analysis. The thermal stability of the polymer tended to increase with incorporation of alpha-olefins, while its microstructure was not affected. The weight average molecular mass (Mw tended to increase and the polymerization conversion tended to decrease with increasing alpha-olefins content. The copolymers showed a lower intrinsic viscosity than for the homopolymer. The results indicated that the alpha-olefins were incorporated in the polybutadiene chain.

  20. Sub-Doppler RQ-branch spectra and ab initio dipole derivative calculation for the ν11 ( au) CH 2-wagging mode of 1,3-butadiene

    Science.gov (United States)

    Sun, Zhen-Dong; Xu, Li-Hong; Lees, R. M.; Jiang, Xing-Jie; Perry, Sean; Craig, Norman C.

    2005-05-01

    The infrared spectrum of the ν11 ( au) out-of-plane CH 2-wagging vibrational mode of the environmentally important 1,3-butadiene molecule has been investigated at sub-Doppler resolution with a CO 2-laser/microwave-sideband spectrometer in order to fully resolve the rotational structure in a number of compact RQ-branch heads. The center frequencies of over 90 saturation Lamb dips in the 11 μm region have been measured with an estimated absolute accuracy of 200 kHz. The new data have been combined with previous Fourier transform results to refine the parameters in the molecular Hamiltonian. A value of |d μc/d Q11|=0.3135 debye has been obtained for the transition dipole derivative for the ν11 mode on the basis of ab initio calculations.

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

    Indian Academy of Sciences (India)

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

    2007-09-01

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

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

    Science.gov (United States)

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

    2015-11-05

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

  3. Comparison of two-body and three-body decomposition of ethanedial, propanal, propenal, n-butane, 1-butene, and 1,3-butadiene

    Science.gov (United States)

    Chin, Chih-Hao; Lee, Shih-Huang

    2012-01-01

    We investigated two-body (binary) and three-body (triple) dissociations of ethanedial, propanal, propenal, n-butane, 1-butene, and 1,3-butadiene on the ground potential-energy surfaces using quantum-chemical and Rice-Ramsperger-Kassel-Marcus calculations; most attention is paid on the triple dissociation mechanisms. The triple dissociation includes elimination of a hydrogen molecule from a combination of two separate terminal hydrogen atoms; meanwhile, the rest part simultaneously decomposes to two stable fragments, e.g., C2H4, C2H2, or CO. Transition structures corresponding to the concerted triple dissociation were identified using the B3LYP/6-311G(d,p) level of theory and total energies were computed using the method CCSD(T)/6-311+G(3df, 2p). The forward barrier height of triple dissociation has a trend of ethanedial reaction enthalpy. Ratios of translational energies of three separate fragments could be estimated from the transition structure of triple dissociation. The synchronous concerted dissociation of propanal, propenal, and 1-butene leading to three different types of molecular fragments by breaking nonequivalent chemical bonds is rare. The triple dissociation of propanal, n-butane, 1-butene, and 1,3-butadiene were investigated for the first time. To outline a whole picture of dissociation mechanisms, some significant two-body dissociation channels were investigated for the calculations of product branching ratios. The triple dissociation plays an important role in the three carbonyl compounds, but plays a minor or negligible role in the three hydrocarbons.

  4. Study of the molecular structure, ionization spectrum, and electronic wave function of 1,3-butadiene using electron momentum spectroscopy and benchmark Dyson orbital theories

    Science.gov (United States)

    Deleuze, M. S.; Knippenberg, S.

    2006-09-01

    The scope of the present work is to reconcile electron momentum spectroscopy with elementary thermodynamics, and refute conclusions drawn by Saha et al. in J. Chem. Phys. 123, 124315 (2005) regarding fingerprints of the gauche conformational isomer of 1,3-butadiene in electron momentum distributions that were experimentally inferred from gas phase (e,2e) measurements on this compound [M. J. Brunger et al., J. Chem. Phys. 108, 1859 (1998)]. Our analysis is based on thorough calculations of one-electron and shake-up ionization spectra employing one-particle Green's function theory along with the benchmark third-order algebraic diagrammatic construction [ADC(3)] scheme. Accurate spherically averaged electron momentum distributions are correspondingly computed from the related Dyson orbitals. The ionization spectra and Dyson orbital momentum distributions that were computed for the trans-conformer of 1,3-butadiene alone are amply sufficient to quantitatively unravel the shape of all available experimental (e,2e) electron momentum distributions. A comparison of theoretical ADC(3) spectra for the s-trans and gauche energy minima with inner- and outer-valence high-resolution photoelectron measurements employing a synchrotron radiation beam [D. M. P. Holland et al., J. Phys. B 29, 3091 (1996)] demonstrates that the gauche structure is incompatible with ionization experiments in high-vacuum conditions and at standard temperatures. On the other hand, outer-valence Green's function calculations on the s-trans energy minimum form and approaching basis set completeness provide highly quantitative insights, within ˜0.2eV accuracy, into the available experimental one-electron ionization energies. At last, analysis of the angular dependence of relative (e,2e) ionization intensities nicely confirms the presence of one rather intense π-2 π*+1 satellite at ˜13.1eV in the ionization spectrum of the s-trans conformer.

  5. Synthesis of segmented (pb(ps-block-pb)(n)) and (pb(san-block- pb)(n)) block-copolymers via polymeric thermal iniferters

    NARCIS (Netherlands)

    Kroeze, E; ten Brinke, G.; Hadziioannou, G

    1995-01-01

    A technique is described for the synthesis of segmented poly(butadiene-block-styrene) block copolymers and segmented poly(butadiene-block-(styrene-co-acrylonitrile)) block copolymers through polybutadiene-based thermal iniferters. Dihydroxy- and dicarboxy-terminated polybutadienes were transformed i

  6. Simultaneous quantification of haemoglobin adducts of ethylene oxide, propylene oxide, acrylonitrile, acrylamide and glycidamide in human blood by isotope-dilution GC/NCI-MS/MS.

    Science.gov (United States)

    Schettgen, T; Müller, J; Fromme, H; Angerer, J

    2010-10-01

    Haemoglobin adducts are highly valuable biomarkers of cumulative exposure to carcinogenic substances. We have developed and applied an analytical method for the simultaneous quantification of five haemoglobin adducts of important occupational and environmental carcinogens. The N-terminal adducts were determined with gas chromatography as pentafluorophenylthiohydantoine derivatives according to the modified Edman-procedure and subsequent acetonization of the glycidamide adduct N-(R,S)-2-hydroxy-2-carbamoylethylvaline (GAVal). The use of self-synthesized labelled internal standards in combination with tandem mass spectrometry using negative chemical ionisation guarantees both high accuracy and sensitivity of our determination. The limit of detection for N-2-hydroxyethylvaline (HEVal), N-(R,S)-2-hydroxypropylvaline (HPVal), N-2-carbamoylethylvaline (AAVal) and N-(R,S)-2-hydroxy-2-carbamoylethylvaline (GAVal) was 2 pmol/g globin, for N-2-cyanoethylvaline (CEVal) it was determined as 0.5 pmol/g globin, which was sufficient to determine the background levels of these adducts in the non-smoking general population. The between-day-precision for all analytes using a human blood sample as quality control material ranged from 4.7 to 12.3%. We investigated blood samples of a small group (n=104) of non-smoking persons of the general population for the background levels of these haemoglobin adducts. The median values for HEVal, HPVal, CEVal, AAVal and GAVal in a group of 92 non-smoking persons were 18.1, 4.1, <0.5, 29.9 and 35.2 pmol/g globin, respectively. The adduct levels in 12 persons reporting exposure to passive smoke at home were similar for most adducts with median values of 17.2, 4.1, 1.0, 24.9 and 29.7 pmol/g globin for HEVal, HPVal, CEVal, AAVal and GAVal, respectively. Our results point to an elevated uptake of acrylonitrile caused by passive smoking as indicated by higher levels of the corresponding haemoglobin adduct CEVal.

  7. Fabrication of conducting composite sheets using cost-effective graphite flakes and amorphous styrene acrylonitrile for enhanced thermistor, dielectric, and electromagnetic interference shielding properties

    Energy Technology Data Exchange (ETDEWEB)

    Panwar, Varij, E-mail: varijpanwarcertain@gmail.com [Electronics and Communication Engineering, Graphic Era University, Dehradun, Uttarakhand (India); Gill, Fateh Singh; Rathi, Vikas; Tewari, V.K. [Electronics and Communication Engineering, Graphic Era University, Dehradun, Uttarakhand (India); Mehra, R.M. [Sharda University, Greater Noida (India); Park, Jong-Oh, E-mail: jop@jnu.ac.kr [School of Mechanical Engineering, Chonnam National University, Gwangju (Korea, Republic of); Park, Sukho, E-mail: shpark12@dgist.ac.kr [Department of Robotics Engineering, Daegu Gyeongbuk Institute of Science and Technology, Daegu (Korea, Republic of)

    2017-06-01

    The fabrication of strong conducting composite sheets (CCSs) using a simple technique with cost-effective materials is desirable for capacitor, decoupling capacitor, and electromagnetic interference (EMI) shielding applications. Here, we used cost-effective graphite flakes (GFs) as a conducting filler and amorphous poly (styrene-co-acrylonitrile) (PSAN) as an insulating polymer to fabricate a CCS via a simple mechanical mixing and hot compression molding process in 2.5 h, with the aim to save time and avoid the use of toxic reagents, which are generally used in chemical methods. In the present method, the GFs are connected in diffusively adhere polymer matrix, controlled by temperature and pressure that generate the conduction in the CCSs. The resulting PSAN/GF CCSs were characterized by using scanning electron microscopy (SEM), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and hardness tests. The GFs penetrated the interfacial region of PSAN, thus improving the thermistor and dielectric properties (dielectric constant, AC conductivity, and dissipation factor) of the PSAN/GF CCSs. Furthermore, the PSAN/GF CCSs showed enhanced hardness and EMI shielding effectiveness (SE) properties in the X-band frequency range (8.5–12.5 GHz). The percolation theory was implemented to DC and AC conductivity. To detect the transition of the dielectric properties, the dielectric constant of the CCSs was analyzed with increasing volume fraction of GFs in the radio frequency region. The improved dielectric constant, AC conductivity, and dissipation factor of the PSAN/GF CCS, indicated a significant improvement in their EMI shielding properties in the X-band frequency range, which were measured using the waveguide method. The ac conductivity of PSAN/GF CCS shows stable behavior in the higher frequency ranges. The EMISE of PSAN/GF CCS were found to increase with increasing GF content due to the absorbance mechanism. - Highlights: • Enhanced hardness and

  8. 纤维素纳米纤维-丁苯胶乳复合材料的制备与表征%Preparation and characterization of cellulose-nanoifbers/styrene-butadiene latex (NFs/SBL) composites

    Institute of Scientific and Technical Information of China (English)

    宋冰; 石勇; 陆海龙; 马金霞; 周小凡

    2016-01-01

    采用共混法制备不同纤维素纳米纤维含量的纤维素纳米纤维-丁苯胶乳复合材料,并通过拉伸性能、扫描电镜、热重分析以及红外光谱检测该复合材料的相关性能。分析结果表明:纤维素纳米纤维能均匀分散在丁苯胶乳溶液中,对丁苯胶乳有较好的补强效果;和丁苯胶乳相比,制得复合材料的裂断伸长率增大,弹性变好;但纤维素纳米纤维的加入对丁苯胶乳热稳定性的影响不明显。%Cellulose-nanofibers/styrene-butadiene latex(NFs-SBL) composites were prepared by blending different amount of cellulose nanofibers with styrene-butadiene latex(SBL), through the tensile properties testing, scanning electron microscopy (SEM), thermo-gravimetric analysis and infrared spectrometric analysis(FT-IR). The result showed that NFs are dispersed uniformly in styrene-butadiene latex and showed a good reinforcing effect on SBL, composite material breaking elongation increased and elastic becoming good. However, the addition of NFs had a less impact on thermal stability of styrene-butadiene latex.

  9. Dynamic Mechanical Property of Styrene-Butadiene Rubber/Natural Rubber Composite%丁苯橡胶/天然橡胶复合体系动态力学性能

    Institute of Scientific and Technical Information of China (English)

    徐文总; 郝文涛; 马德柱; 梁俐

    2001-01-01

    The dynamic mechanical properties of blends of natural rubberrespectively with three kinds of styrene-butadiene rubbers, two solution polymerized styrene-butadiene rubbers: SSBR(B), SSBR(C) and an emulsion polymerized styrene-butadiene rubber:ESSA have been investigated. The results showed that SSBR(B) had characteristic chain structure and the SSBR/NR composite showed a good compatibility and low heat generation under pressure.%选取乳聚丁苯橡胶、溶聚丁苯橡胶(C)和溶聚丁苯橡胶(B)3种典型的丁苯橡胶,研究了它们与天然橡胶复合体系的动态力学性能.结果表明,溶聚丁苯橡胶SSBR(B)具有特征的链化学结构,与天然橡胶有良好的混容性.溶聚丁苯橡胶/天然橡胶复合体系生热低,而且具有比较均匀的交联网状结构.

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

    Science.gov (United States)

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

    2015-05-21

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

  11. Study on Teratogenicity of Acrylonitrile in Rats by Subcutaneous Injection%皮下注射丙烯腈对大鼠致畸作用研究

    Institute of Scientific and Technical Information of China (English)

    崔金山; 杨衍凯; 付守林; 张玉敏; 段志文; 李海山; 王瀛; 张岸舸

    2001-01-01

    目的评价丙烯腈对雌性大鼠有无致畸作用。方法于雌性大鼠妊娠第7~16天皮下注射丙烯腈(AN)15,25,35 mg·kg-1,常规方法检测AN的胚胎毒性和致畸作用。结果 25 mg·kg-1组死胎率、吸收胎率升高,胎鼠平均体重、体长、尾长减小,与阴性对照组比较差异有显著性(P<0.05);35 mg·kg-1组除窝平均活胎数减少,差异有显著性( P<0.05),其余各指标与阴性对照组比较差异有非常显著性(P <0.01);25,35 mg·kg-1组畸胎率、母体畸胎率、活胎畸形率升高,与对照组相比差异有显著性和/或非常显著性(P<0.05或P <0.01),且有明确的剂量效应或剂量反应关系。本实验皮下注射AN染毒的致畸最低剂量为 15 mg·kg-1,致畸指数为6.3,以骨骼畸形为主,外观畸形主要为无尾、短尾等。结论丙烯腈皮下注射染毒有明显的胚胎毒性,致畸剂量小于经口染毒阈剂量,是一种弱致畸物。%Objective The teratogenicity of acrylonitrile(AN)on fe male rats was evaluated.Methods 15,25 and 35 mg/kg AN were administ ered by subcutaneous injection to rats on the time 7~16 d of gestation.Embryoto x icity and teratogenicity of AN were examined by a traditional teratogenic method .Results At the dosage of 25 mg/kg,AN could induce higher incidence of fetal resorption and death,and decrease the average fetal body weight and le ngth with significant difference(P<0.05)when compared with neg ative controls.At the dosage of 35 mg/kg,AN could decrease average vital fet us p er litter with significant difference(P<0.05),and induce chang es of other indexes with highly significant difference(P<0.0 1).At the dosage of 25 and 35 mg/kg,AN could induce higher teras rate,maternal t eras rate and malformation rate of vital fetus with significant and/or highly s ignificant difference(P<0.05 or P<0.01),resp ectively.There existed a dose-effect or dose-response relationship between abo ve

  12. GC Determination of Acetaldehyde, Acrolein and Acrylonitrile in Water with Purge and Trap Technique%吹扫捕集-气相色谱法测定水中乙醛、丙烯醛、丙烯腈

    Institute of Scientific and Technical Information of China (English)

    陆文娟; 王晋宇; 陈玲瑚; 赵辰

    2011-01-01

    Purge and trap technique was applied in the GC determination of acetaldehyde, acrolein and acrylonitrile in water. The analytes were purged, trapped and thermodesorbed using the Trap Vocarb 3000, and determined by CR2 with flame ionization detector (FID). Linear relationships between values of peak area and mass concentration of acetaldehyde, acrolein and acrylonitrile obtained were same in the range of 0. 020--0.20 mg·L^-1 , with detection limits (3S/N) of 0. 005, 0. 010, 0. 001mg·L^-1 respectively. Tests for recovery and precision were made by standard addition method, values of recovery found were in the range of 90. 0%-110.0% and values of RSD's (n=7) were less than 50%.%提出了吹扫捕集-气相色谱法测定水中乙醛、丙烯醛和丙烯腈的分析方法。样品用Trap Vocarb 3000捕集阱吹扫、捕集及热解析后,用气相色谱法氢火焰离子化检测器分析。3种化合物的质量浓度在0.020~0.20mg·L^-1的相同范围内与其峰面积呈线性关系,方法的检出限(3S/N)分别为0.005,0.010,0.001mg·L^-。标准加入回收率在90.0%~110.0%之间,相对标准偏差(n=7)均小于5%。

  13. Fast Determination of Acrolein and Acrylonitrile in Water by the Portable GC-MS and Selected Ion Monitoring%便携式GC-MS选择离子快速测定水中丙烯醛和丙烯腈

    Institute of Scientific and Technical Information of China (English)

    邓敏军; 罗艳; 黄小佳; 邓超冰; 梁柳玲; 杨安平

    2012-01-01

    Portable gas chromatography mass spectrometry (GC-MS) can simultaneously carry out qualitative and quantitative analysis of multi-component complex organic compounds and plays an increasingly important role in environmental monitoring, especially in the spot emergent monitoring. The Method of Fast Determination of Acrolein and Acrylonitrile in Water was established by the portable headspace gas chromatography and mass spectrometry (GC-MS) in this paper. It is suitable for environmental emergency monitoring and laboratory for analysis of acrolein and acrylonitrile in water because this method possessed relativity r >0. 997 , detection limits 5-10 μg/L and the average recoveries 93. 3% -99. 5% .%便携式气相色谱-质谱仪(GC-MS)能同时对多组分复杂有机物进行定性、定量分析,在环境监测尤其是事故现场应急监测中发挥越来越重要的作用.文章建立了便携式顶空-GC-MS选择离子测定水中丙烯醛、丙烯腈的分析方法,其相关性大于0.997,检测限为5~ 10μg/L,回收率为93.3%~99.5%,该方法适用于水中丙烯腈、丙烯醛的应急现场及日常实验室分析工作.

  14. Thermal oxidative and ozone oxidative stabilization effect of hybridized functional graphene oxide in a silica-filled solution styrene butadiene elastomer.

    Science.gov (United States)

    Su, Juqiao; Zhao, Zhongguo; Huang, Yajiang; Liao, Xia; Yang, Qi

    2016-10-26

    Hybridization of modified functional graphene oxide (fGO) in silica-filled solution styrene butadiene rubber (SSBR) endows preferable tensile and dynamic properties before and after thermal oxidative aging, and similar mechanical hysteresis performance compared with the composites without fGO. The preventing mechanism of fGO is attributed to its intrinsic peroxy radical scavenging and gas barrier abilities, which significantly reduces the peroxy radical concentration and oxygen permeability of nanocomposites and then prolongs oxidative induction time (OIT), characterized by differential scanning calorimetry (DSC). The ozone resisting effect of different loadings of fGO on nanocomposites have also been investigated by Fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM) after ozonization under 50 ppm ozone concentration. As a result, incorporation of fGO apparently suppresses both the formation of oxygenic groups of the olefinic elastomer and crack morphology extension upon ozonization. We propose that fGO protects the SSBR elastomer from ozone attack through the conjugated delocalized π-bonds of the fGO instead of the C[double bond, length as m-dash]C bonds of the elastomer matrix being attacked, and the compared experiments, characterized by X-ray photoelectron spectroscopy (XPS), confirm that this presumption is perhaps reasonable. Moreover, more than 3 phr incorporation of fGO in nanocomposites deteriorates the chemical and mechanical properties of the elastomer during the thermal oxidation and ozonization because of the cleavage influence of oxygenic groups on peroxy radicals.

  15. The use of styrene-butadiene rubber waste as a potential filler in nitrile rubber: order of addition and size of waste particles

    Directory of Open Access Journals (Sweden)

    D. A. Baeta

    2009-03-01

    Full Text Available Styrene-butadiene rubber (SBR has large applications in the shoe industry, especially as expanded sheets used to produce insoles and inner soles. According to TG analysis, the rubber content in SBR residues (SBR-r was found to be around 26-wt%. Based on that data, a cost-effective technique for the reuse of SBR-r in Nitrile rubber (NBR was developed. Later, the effect of SBR-r on the cure behavior, mechanical performance, swelling, and crosslink density of reused rubber was investigated, with more emphasis placed on the effect of both particle size and loading of waste filler. Cure characteristics such as optimum cure time and scorch time were then reduced by the increasing amount of SBR-r filler. Owing to the reinforced nature of the largest particle size SBR-r, the best results for the mechanical properties of NBR were those in which SBR-r was added at the end of the cure process. The study has thus shown that SBR residue (SBR-r can be used as an economical alternative filler in NBR.

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

    Science.gov (United States)

    Wu, Jinping; Soucek, Mark D.

    2016-02-01

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

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

    Science.gov (United States)

    Kwon, Eilhann; Castaldi, Marco J

    2008-03-15

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

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

    Science.gov (United States)

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

    2012-10-02

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

  19. Detoxification of olefinic epoxides and nucleotide excision repair of epoxide-mediated DNA damage: Insights from animal models examining human sensitivity to 1,3-butadiene.

    Science.gov (United States)

    Wickliffe, Jeffrey K; Herring, Stacy M; Hallberg, Lance M; Galbert, Lori A; Masters, Oscar E; Ammenheuser, Marinel M; Xie, Jingwu; Friedberg, Errol C; Lloyd, R Stephen; Abdel-Rahman, Sherif Z; Ward, Jonathan B

    2007-03-20

    1,3-Butadiene (BD) is a well-documented mutagen and carcinogen in rodents and is currently classified as a probable carcinogen in humans. Studies investigating workers exposed to BD indicate that, in some plants, there may be an increased genetic risk, and that polymorphisms in biotransformation and DNA repair proteins may modulate genetic susceptibility. To investigate the role of genetic polymorphisms in microsomal epoxide hydrolase (mEH) or nucleotide excision repair (NER) in contributing to the mutagenicity of BD, we conducted a series of experiments in which mice lacking mEH or NER activity were exposed to BD by inhalation or to the reactive epoxide metabolites of BD (epoxybutene-EB or diepoxybutane-DEB) by i.p. injection. Genetic susceptibility was measured using the Hprt cloning assay. Both deficient strains of mouse were significantly more sensitive to the mutagenic effects of BD and the injected epoxides. These studies provide support for the critical role that mEH plays in the biotransformation of BD, and the role that NER plays in maintaining genomic integrity following exposure to BD. Additional studies are needed to examine the importance of base excision repair (BER) in maintaining genomic integrity, the differential formation of DNA and protein adducts in deficient strains, and the potential for enhanced sensitivity to BD genotoxicity in mice either lacking or deficient in both biotransformation and DNA repair activity.

  20. Chromosomal aberrations, sister-chromatid exchanges, cells with high frequency of SCE, micronuclei and comet assay parameters in 1, 3-butadiene-exposed workers.

    Science.gov (United States)

    Srám, R J; Rössner, P; Peltonen, K; Podrazilová, K; Mracková, G; Demopoulos, N A; Stephanou, G; Vlachodimitropoulos, D; Darroudi, F; Tates, A D

    1998-11-09

    The association of occupational exposure to 1,3-butadiene (BD) and induction of cytogenetic damage in peripheral lymphocytes was studied in 19 male workers from a monomer production unit and 19 control subjects from a heat production unit. The exposure to BD was measured by passive personal monitors. The following biomarkers were used: chromosomal aberrations (CA), sister chromatid exchanges (SCE), cells with a high frequency of SCE (HFC), micronuclei, comet assay parameters like tail length (TL) and percentage of DNA in tail [T (%)] and polymorphisms of GSTM1 and GSTT1 genotypes. BD exposure with a median value of 0.53 mg/m3 (range: 0.024-23.0) significantly increased (a) the percentage of cells with chromosomal aberrations in exposed vs. control groups (3.11% vs. 2.03%, P<0.01), (b) the frequency of SCE per cell (6.96 vs. 4.87, P<0.001), and (c) the percentage of HFC (19.9% vs. 4.1%, P<0.001). BD exposure had no significant effects on formation of micronuclei and on comet assay parameters. Effect of smoking was observed only for HFC in BD-exposed group. GSTM1 genotype affected chromosomal aberrations in exposed group, while GSTT1 genotype affected chromosomal aberrations in controls. No effect of GSTM1 or GSTT1 genotypes was observed on any other biomarkers used.

  1. Association between Genetic Polymorphisms of DNA Repair Genes and Chromosomal Damage for 1,3-Butadiene-Exposed Workers in a Matched Study in China.

    Science.gov (United States)

    Xiang, Menglong; Sun, Lei; Dong, Xiaomei; Yang, Huan; Liu, Wen-bin; Zhou, Niya; Han, Xue; Zhou, Ziyuan; Cui, Zhihong; Liu, Jing-yi; Cao, Jia; Ao, Lin

    2015-01-01

    The aim of the study was to examine the association between polymorphisms of DNA repair genes and chromosomal damage of 1,3-butadiene- (BD-) exposed workers. The study was conducted in 45 pairs of occupationally exposed workers in a BD product workshop and matched control workers in an administrative office and a circulatory water workshop in China. Newly developed biomarkers (micronuclei, MNi; nucleoplasmic bridges, NPBs; nuclear buds, NBUDs) in the cytokinesis-blocked micronucleus (CBMN) cytome assay were adopted to detect chromosomal damage. PCR and PCR-restriction fragment length polymorphism (RFLP) are adopted to analyze polymorphisms of DNA repair genes, such as X-ray repair cross-complementing Group 1 (XRCC1), O6-methylguanine-DNA methyltransferase (MGMT), poly (adenosine diphosphate-ribose) polymerases (ADPRT), and apurinic/apyrimidinic endonucleases (APE1). The BD-exposed workers exhibited increased frequencies of MNi and NPBs when compared to subjects in the control group. The results also show that the BD-exposed workers carrying XRCC1 diplotypes TCGA-CCGG (4.25 ± 2.06 ‰) (FR = 2.10, 95% CI: 1.03-4.28) and TCGG-TCGA (5.80 ± 3.56 ‰) (FR = 2.75, 95% CI: 0.76-2.65) had statistically higher NBUD frequencies than those who carried diplotype TCGG-TCGG (1.89 ± 1.27 ‰). Our study suggests that polymorphisms of XRCC1 gene may influence chromosomal damage in BD-exposed workers.

  2. 3,4-Epoxy-1-butene, a reactive metabolite of 1,3-butadiene, induces somatic mutations in Xpc-null mice.

    Science.gov (United States)

    Wickliffe, J K; Galbert, L A; Ammenheuser, M M; Herring, S M; Xie, J; Masters, O E; Friedberg, E C; Lloyd, R S; Ward, J B

    2006-01-01

    Xpc-null (Xpc-/-) mice, deficient in the global genome repair subpathway of nucleotide excision repair (NER-GGR), were exposed by intraperitoneal (i.p.) injection to a 300 mg/kg mutagenic dose of 3,4-epoxy-1-butene (EB), to investigate NER's potential role in repairing butadiene (BD) epoxide DNA lesions. Mutagenic sensitivity was assessed using the Hprt assay. Xpc-/- mice were significantly more sensitive to EB exposure, exhibiting an average 2.8-fold increase in Hprt mutant frequency (MF) relative to those of exposed Xpc+/+ (wild-type) mice. As a positive control for NER-GGR, additional mice were exposed by i.p. injection to a 150 mg/kg mutagenic dose of benzo[a]pyrene (B[a]P). The Xpc-/- mice had MFs 2.9-fold higher than those of exposed Xpc+/+ mice. These results suggest that NER-GGR plays a role in recognizing and repairing some of the DNA adducts formed following in vivo exposure to EB. Additional research is needed to examine the response of Xpc-/- mice, as well as other NER-deficient strains, to inhaled BD. Furthermore, it is likely that alternative DNA repair pathways also are involved in restoring genomic integrity compromised by BD-epoxide DNA damage. Collaborative studies are currently underway to address these critical issues.

  3. Adhesion properties of styrene-butadiene rubber (SBR/Standard Malaysian Rubber (SMR L-based adhesives in the presence of phenol formaldehyde resin

    Directory of Open Access Journals (Sweden)

    2007-10-01

    Full Text Available The adhesion properties, i. e. viscosity, tack and peel strength of styrene-butadiene rubber (SBR/Standard Malaysian Rubber (SMR L-based pressure-sensitive adhesive was studied using phenol formaldehyde resin as the tackifying resin. Toluene was used as the solvent throughout the experiment. SBR composition in SBR/SMR L blend used was 0, 20, 40, 60, 80, 100%. Three different resin loadings, i. e. 40, 80 and 120 parts per hundred parts of rubber (phr were used in the adhesive formulation. The viscosity of adhesive was determined by a HAAKE Rotary Viscometer whereas loop tack and peel strength of paper/polyethylene terephthalate (PET film were measured using a Lloyd Adhesion Tester operating at 30 cm/min. Results indicate that the viscosity of adhesive decreases with increasing % SBR whereas loop tack passes through a maximum value at 20% SBR for all resin loadings. Except for the control sample (without resin, the peel strength shows a maximum value at 60% SBR for the three modes of peel tests. For a fixed % SBR, adhesive sample containing 40 phr phenol formaldehyde resin always exhibits the highest loop tack and peel strength, an observation which is associated to the optimum wettability of adhesive on the substrate.

  4. Mechanical Characterization of Hybrid Vesicles Based on Linear Poly(Dimethylsiloxane-b-Ethylene Oxide) and Poly(Butadiene-b-Ethylene Oxide) Block Copolymers.

    Science.gov (United States)

    Gaspard, Jeffery; Casey, Liam M; Rozin, Matt; Munoz-Pinto, Dany J; Silas, James A; Hahn, Mariah S

    2016-03-18

    Poly(dimethylsiloxane-ethylene oxide) (PDMS-PEO) and poly(butadiene-b-ethylene oxide) (PBd-PEO) are two block copolymers which separately form vesicles with disparate membrane permeabilities and fluidities. Thus, hybrid vesicles formed from both PDMS-PEO and PBd-PEO may ultimately allow for systematic, application-specific tuning of vesicle membrane fluidity and permeability. However, given the relatively low strength previously noted for comb-type PDMS-PEO vesicles, the mechanical robustness of the resulting hybrid vesicles must first be confirmed. Toward this end, we have characterized the mechanical behavior of vesicles formed from mixtures of linear PDMS-PEO and linear PBd-PEO using micropipette aspiration. Tension versus strain plots of pure PDMS12-PEO46 vesicles revealed a non-linear response in the high tension regime, in contrast to the approximately linear response of pure PBd33-PEO20 vesicles. Remarkably, the area expansion modulus, critical tension, and cohesive energy density of PDMS12-PEO46 vesicles were each significantly greater than for PBd33-PEO20 vesicles, although critical strain was not significantly different between these vesicle types. PDMS12-PEO46/PBd33-PEO20 hybrid vesicles generally displayed graded responses in between that of the pure component vesicles. Thus, the PDMS12-PEO46/PBd33-PEO20 hybrid vesicles retained or exceeded the strength and toughness characteristic of pure PBd-PEO vesicles, indicating that future assessment of the membrane permeability and fluidity of these hybrid vesicles may be warranted.

  5. Shape Memory Polymer Composites of Poly(styrene-b-butadiene-b-styrene Copolymer/Liner Low Density Polyethylene/Fe3O4 Nanoparticles for Remote Activation

    Directory of Open Access Journals (Sweden)

    Yongkun Wang

    2016-11-01

    Full Text Available Magnetically sensitive shape memory poly(styrene-b-butadiene-b-styrene copolymer (SBS/liner low density polyethylene (LLDPE composites filled with various contents of Fe3O4 nanoparticles were prepared. The influence of the Fe3O4 nanoparticles content on the thermal properties, mechanical properties, fracture morphology, magnetic behavior, and shape memory effect of SBS/LLDPE/Fe3O4 composites was systematically studied in this paper. The results indicated that homogeneously dispersed Fe3O4 nanoparticles ensured the uniform heat generation and transfer in the alternating magnetic field, and endowed the SBS/LLDPE/Fe3O4 composites with an excellent magnetically responsive shape memory effect. When the shape memory composites were in the alternating magnetic field (f = 60 kHz, H = 21.21 kA·m−1, the best shape recovery ratio reached 99%, the shape retention ratio reached 99.4%, and the shape recovery speed increased significantly with the increment of Fe3O4 nanoparticles. It is anticipated that tagging products with this novel shape memory composite is helpful for the purpose of an intravascular delivery system in Micro-Electro-Mechanical System (MEMS devices.

  6. Synthesis and Molecular Structures of Two [1,4-bis(3-pyridyl-2,3-diazo-1,3-butadiene]-dichloro-Zn(II Coordination Polymers

    Directory of Open Access Journals (Sweden)

    Hsin-Ta Wang

    2006-08-01

    Full Text Available Two novel coordination polymers with 3D metal-organic frameworks (MOFs have been synthesized by reacting 1,4-bis(3-pyridyl-2,3-diazo-1,3-butadiene (L with zinc dichloride. Both compounds have the same repeating unit consisting of a distorted tetrahedral Zn(II center coordinated by two chlorides and two pyridyl nitrogen atoms of two bridging bismonodentate L ligands, however, different structural conformations have been found, one forming a helical chain and the other producing a square-wave chain. The intermolecular C−H···Cl hydrogen bonds in 1 and 2 play important roles in the formation of three-dimensional coordination polymers. Compound 1 crystallized in an orthorhombic space group Pna21 with a = 7.9652(3, b = 21.4716(7, c = 8.2491(3Å, V = 1410.81(9 Å 3 and Z = 4. Compound 2 crystallized in a monoclinic space group P21/n with a = 9.1752(3, b = 14.5976(4, c = 10.3666(3 Å , β = 98.231(2°, V = 1374.16(7 Å 3 and Z = 4.

  7. Uterotrophic and Hershberber Assays for Acrylonitrile in Rats%丙烯腈类性激素作用的整体动物筛检试验

    Institute of Scientific and Technical Information of China (English)

    王宁; 荣顺兴; 朱菊一; 黄简抒; 周元陵; 金泰廙

    2005-01-01

    [目的]研究丙烯腈(AN)的类性激素样作用.[方法]①采用经典大鼠子宫增重方法测试丙烯腈的类雌激素样作用,对去卵巢SD大鼠皮下注射剂量分别为0、10、15、25、40、60 mg/kg受试物丙烯腈,每天一次、连续3天;同时皮下注射剂量为0.001 mg/kg雌二醇玉米油溶液为阳性对照组.最后一次给药24 h后,将大鼠麻醉后取血并处死,观察受试动物子宫湿重、干重、肝重、肾重等指标.②研究丙烯腈的抗雄激素作用.采用OECD推荐的内分泌干扰体内筛检实验方法(Hershberger试验),对雄性去势大鼠皮下注射剂量为0.4mg/kg体重丙酸睾酮,同时经口灌胃剂量分别为0,10,20,30,40,50 mg/kg体重的受试物丙烯腈以及25 mg/kg体重的阳性参照物氟他胺(flutamide,FLU),每天一次,连续10天.最后一次给药24 h后,将大鼠麻醉后取血并处死,观察受试动物前列腺、精囊腺、阴茎、肛提肌/球体海绵体肌、尿道球腺等附性腺组织(sex accessorytissue,SAT)重量和肝重、肾重等指标.[结果]①子宫增重实验:丙烯腈各剂量组大鼠子宫干重、湿重与溶剂对照组无显著差异(P>0.05),阳性对照组与溶剂对照组及丙烯腈各剂量组比较,子宫干重、湿重差异存在显著性(P<0.05).②Hershberger试验:丙烯腈各剂量组与阴性对照组相比,SAT重量差异无显著性(P>0.05),阳性对照组(FLU)与阴性对照组相比,SAT重量差别具有显著性(P<0.05).丙烯腈各剂量组肝、肾重量与阴性对照组差别无显著性(P>0.05),提示受试动物无明显系统毒性.[结论]采用子宫增重测试和Hershberger体内筛检试验未发现丙烯腈具有类性激素作用.%[ Objective ] To assess the estrogenic and anti-androgenic effects of acrylonitrile (AN) by in-vivo uterotrophic and Hershberger assays proposed by the OECD. [ Methods ] For the uterotrophic assay, AN was injected subcutaneously at the doses of 0, 10, 15, 25, 40 and 60mg/kg to

  8. Application of solution polymerized styrene-butadiene rubber 2557-A in tire%溶聚丁苯橡胶2557-A在轮胎中的应用

    Institute of Scientific and Technical Information of China (English)

    徐燕; 孙举涛; 徐文清; 张萍; 孙学红

    2012-01-01

    In accordance with the pure carbon black formula, solution polymerized styrene-butadiene rubber ( SSBR, grade 2557-A) and emulsion styrene-butadiene rubber(ESBR, grade 1712) were applied to crown rubbers of all-steel and semi-steel radial tires seperately, their application results were compared, and the acceptable crown rubber formula of SSBR 2557-A was achieved. The all-steel and semi-steel radial tires were trial-produced, and their performances were tested. The results showed that compared to ESBR 1712 all-ateel crown vulcanizate. The tensile strength, modulus at 100% and 300% , abrasion resistance ( Akron) , compression heat built-up as well as the balance between wet skid resistance and rolling resistance of the equivalent SSBR 2557-A crown vulcani- zate increased, but abrasion resistance ( DIN ) decreased- And compared to ESBR 1712 semi-stell crown vulcanizate, the equivalent SSBR 2557-A also improved semi-steel crown vulcanizate in skid resistance without changing any other performances. The trial tire based on SSBR 2557-A all-steel crown rubber formula passed endurance test, and the tire based on SSBR 2557-A semi-steel crown rubber formula met the national standard in outer dia, strength, unseating resistance, highspeed performance and durability, in addition, it had substantial high wet skid resistance and noise performance.%按照纯炭黑配方,将溶聚丁苯橡胶(SSBR,牌号为2557 -A)同乳聚丁苯橡胶(ESBR,牌号为1712)对比应用于全钢和半钢子午线轮胎胎冠胶配方中,确定了合适的胎冠胶配方,且进行了轮胎的试制和性能检测.结果表明,与ESBR 1712全钢胎冠胶相比,同等用量SSBR 2557 -A的胎冠胶拉伸强度、定伸应力、Akron磨耗性能和压缩生热等性能均得到提高,但DIN磨耗性能有所下降,且具有更优的抗湿滑性和更低的滚动阻力;与ESBR 1712半钢胎冠胶相比,SSBR 2557 -A胎冠胶具有优异的抗湿滑性能,而其他性能相差不大;采用SSBR 2557 -A

  9. Atmospheric oxidation of 1,3-butadiene: characterization of gas and aerosol reaction products and implication for PM2.5

    Science.gov (United States)

    Jaoui, M.; Lewandowski, M.; Docherty, K.; Offenberg, J. H.; Kleindienst, T. E.

    2014-06-01

    Secondary organic aerosol (SOA) was generated by irradiating 1,3-butadiene (13BD) in the presence of H2O2 or NOx. Experiments were conducted in a smog chamber operated in either flow or batch mode. A filter/denuder sampling system was used for simultaneously collecting gas- and particle-phase products. The chemical composition of the gas phase and SOA was analyzed using derivative-based methods (BSTFA, BSTFA + PFBHA, or DNPH) followed by gas chromatography-mass spectrometry (GC-MS) or high-performance liquid chromatography (HPLC) analysis of the derivative compounds. The analysis showed the occurrence of more than 60 oxygenated organic compounds in the gas and particle phases, of which 31 organic monomers were tentatively identified. The major identified products include glyceric acid, d-threitol, erythritol, d-threonic acid, meso-threonic acid, erythrose, malic acid, tartaric acid, and carbonyls including glycolaldehyde, glyoxal, acrolein, malonaldehyde, glyceraldehyde, and peroxyacryloyl nitrate (APAN). Some of these were detected in ambient PM2.5 samples and could potentially serve as organic markers of 1,3-butadiene (13BD). Furthermore, a series of oligoesters were detected and found to be produced from esterification reactions among compounds bearing alcoholic groups and compounds bearing acidic groups. Time profiles are provided for selected compounds. SOA was analyzed for organic mass to organic carbon (OM / OC) ratio, effective enthalpy of vaporization (ΔHvapeff), and aerosol yield. The average OM / OC ratio and SOA density were 2.7 ± 0.09 and 1.2 ± 0.05, respectively. The average ΔHvapeff was 26.1 ± 1.5 kJ mol-1, a value lower than that of isoprene SOA. The average laboratory SOA yield measured in this study at aerosol mass concentrations between 22.5 and 140.2 μg m-3 was 0.025 ± 0.011, a value consistent with the literature (0.021-0.178). While the focus of this study has been examination of the particle-phase measurements, the gas

  10. Anharmonic Vibrational Analysis of the Infrared and Raman Gas-Phase Spectra of s-trans- and s-gauche-1,3-Butadiene.

    Science.gov (United States)

    Krasnoshchekov, Sergey V; Craig, Norman C; Boopalachandran, Praveenkumar; Laane, Jaan; Stepanov, Nikolay F

    2015-10-29

    A quantum-mechanical (hybrid MP2/cc-pVTZ and CCSD(T)/cc-pVTZ) full quartic potential energy surface (PES) in rectilinear normal coordinates and the second-order operator canonical Van Vleck perturbation theory (CVPT2) are employed to predict the anharmonic vibrational spectra of s-trans- and s-gauche-butadiene (BDE). These predictions are used to interpret their infrared and Raman scattering spectra. New high-temperature Raman spectra in the gas phase are presented in support of assignments for the gauche conformer. The CVPT2 solution is based on a PES and electro-optical properties (EOP; dipole moment and polarizability) expanded in Taylor series. Higher terms than those routinely available from Gaussian09 software were calculated by numerical differentiation of quadratic force fields and EOP using the MP2/cc-pVTZ model. The integer coefficients of the polyad quantum numbers were derived for both conformers of BDE. Replacement of harmonic frequencies by their counterparts from the CCSD(T)/cc-pVTZ model significantly improved the agreement with experimental data for s-trans-BDE (root-mean-square deviation ≈ 5.5 cm(-1)). The accuracy in predicting the rather well-studied spectrum of fundamentals of s-trans-BDE assures good predictions of the spectrum of s-gauche-BDE. A nearly complete assignment of fundamentals was obtained for the gauche conformer. Many nonfundamental transitions of the BDE conformers were interpreted as well. The predictions of multiple Fermi resonances in the complex CH-stretching region correlate well with experiment. It is shown that solving a vibrational anharmonic problem through a numerical-analytic implementation of CVPT2 is a straightforward and computationally advantageous approach for medium-size molecules in comparison with the standard second-order vibrational perturbation theory (VPT2) based on analytic expressions.

  11. Mechanical Characterization of Hybrid Vesicles Based on Linear Poly(Dimethylsiloxane-b-Ethylene Oxide and Poly(Butadiene-b-Ethylene Oxide Block Copolymers

    Directory of Open Access Journals (Sweden)

    Jeffery Gaspard

    2016-03-01

    Full Text Available Poly(dimethylsiloxane-ethylene oxide (PDMS-PEO and poly(butadiene-b-ethylene oxide (PBd-PEO are two block copolymers which separately form vesicles with disparate membrane permeabilities and fluidities. Thus, hybrid vesicles formed from both PDMS-PEO and PBd-PEO may ultimately allow for systematic, application-specific tuning of vesicle membrane fluidity and permeability. However, given the relatively low strength previously noted for comb-type PDMS-PEO vesicles, the mechanical robustness of the resulting hybrid vesicles must first be confirmed. Toward this end, we have characterized the mechanical behavior of vesicles formed from mixtures of linear PDMS-PEO and linear PBd-PEO using micropipette aspiration. Tension versus strain plots of pure PDMS12-PEO46 vesicles revealed a non-linear response in the high tension regime, in contrast to the approximately linear response of pure PBd33-PEO20 vesicles. Remarkably, the area expansion modulus, critical tension, and cohesive energy density of PDMS12-PEO46 vesicles were each significantly greater than for PBd33-PEO20 vesicles, although critical strain was not significantly different between these vesicle types. PDMS12-PEO46/PBd33-PEO20 hybrid vesicles generally displayed graded responses in between that of the pure component vesicles. Thus, the PDMS12-PEO46/PBd33-PEO20 hybrid vesicles retained or exceeded the strength and toughness characteristic of pure PBd-PEO vesicles, indicating that future assessment of the membrane permeability and fluidity of these hybrid vesicles may be warranted.

  12. Bis-butanediol-mercapturic acid (bis-BDMA) as a urinary biomarker of metabolic activation of butadiene to its ultimate carcinogenic species.

    Science.gov (United States)

    Kotapati, Srikanth; Sangaraju, Dewakar; Esades, Amanda; Hallberg, Lance; Walker, Vernon E; Swenberg, James A; Tretyakova, Natalia Y

    2014-06-01

    Human carcinogen 1,3-butadiene (BD) undergoes metabolic activation to 3,4-epoxy-1-butene (EB), hydroxymethylvinyl ketone (HMVK), 3,4-epoxy-1,2-butanediol (EBD) and 1,2,3,4-diepoxybutane (DEB). Among these, DEB is by far the most genotoxic metabolite and is considered the ultimate carcinogenic species of BD. We have shown previously that BD-exposed laboratory mice form 8- to 10-fold more DEB-DNA adducts than rats exposed at the same conditions, which may be responsible for the enhanced sensitivity of mice to BD-mediated cancer. In the present study, we have identified 1,4-bis-(N-acetyl-L-cystein-S-yl)butane-2,3-diol (bis-BDMA) as a novel DEB-specific urinary biomarker. Isotope dilution high-performance liquid chromatography-electrospray ionization-tandem mass spectrometry was employed to quantify bis-BDMA and three other BD-mercapturic acids, 2-(N-acetyl-L-cystein-S-yl)-1-hydroxybut-3-ene/1-(N-acetyl-L-cystein-S-yl)-2-hydroxy-but-3-ene (MHBMA, from EB), 4-(N-acetyl-L-cystein-S-yl)-1,2-dihydroxybutane (DHBMA, from HMVK) and 4-(N-acetyl-L-cystein-S-yl)-1,2,3-trihydroxybutane (THBMA, from EBD), in urine of confirmed smokers, occupationally exposed workers and BD-exposed laboratory rats. Bis-BDMA was formed in a dose-dependent manner in urine of rats exposed to 0-200 p.p.m. BD by inhalation, although it was a minor metabolite (1%) as compared with DHBMA (47%) and THBMA (37%). In humans, DHBMA was the most abundant BD-mercapturic acid excreted (93%), followed by THBMA (5%) and MHBMA (2%), whereas no bis-BDMA was detected. These results reveal significant differences in metabolism of BD between rats and humans.

  13. Polymerization of 1,3-butadiene catalyzed by pincer cobalt(II) complexes derived from 2-(1-arylimino)-6-(pyrazol-1-yl)pyridine ligands

    KAUST Repository

    Gong, Dirong

    2013-08-01

    A new class of air stable and structurally well-defined cobalt complexes with unsymmetrical pincer type ligands ([2-(ArNCMe)-6-(Py)C5H 3N]CoCl2) (Ar = C6H5, Py = pyrazol-1-yl, 5a; Ar = 2,4,6-Me3C6H2, Py = pyrazol-1-yl, 5b; Ar = 2,6-iPr2C6H3, Py = pyrazol-1-yl, 5c; Ar = C6H5, Py = 3,5-Me 2pyrazol-1-yl, 5d; Ar = 2,4,6-Me3C6H 2, Py = 3,5-Me2pyrazol-1-yl, 5e; Ar = 2,6- iPr2C6H3, Py = 3,5-Me 2pyrazol-1-yl, 5f; Ar = 2,6-iPr2C 6H3, Py = 3,5-iPr2pyrazol-1-yl, 5g and [2-(OCMe)-6-(3,5-diphenylpyrazol-1-yl)C5H3N]CoCl 2 5h) were prepared and the molecular structures of 5a, 5c and 5f were determined by single crystal X-ray crystallography. Upon activation by methylaluminoxane (MAO) in toluene at room temperature, all complexes initiate polymerization of 1,3-butadiene (polymer yields: 65-99%), affording polybutadiene with excellent cis-1,4 regularity (97.5-98.7%). The polymer yields and properties in terms of molecular weight and distribution are well controlled by the substituents on iminoaryl rings and pyrazole rings. Selectivity switch from cis-1,4 to syndio-1,2 was also achievable by adding phosphine as microstructure regulator. © 2013 Elsevier B.V. All rights reserved.

  14. Hyaline droplet accumulation in kidney of rats treated with hexachloro-1:3-butadiene: influence of age, dose and time-course.

    Science.gov (United States)

    Cristofori, Patrizia; Defazio, Rossella; Chiusolo, Arianna; Mongillo, Michele; Bartolucci, Giovanni Battista; Chiara, Federica; Trevisan, Andrea

    2013-03-01

    The present research investigates the occurrence of hyaline droplet (HD) accumulation related to age, dose and time after treatment in male Wistar rats given a single i.p. injection of hexachloro-1:3-butadiene (HCBD). In the study on age, rats from 1 to 12 months of age were treated with 100 mg kg(-1) body weight (b.w.) HCBD dose. Rats treated at 2 months of age showed a greater accumulation of HD than the other age groups; HD accumulation was not observed in 1-month-old rats. In the dose-response study, the treatment with 25, 50 and 100 mg kg(-1) b.w. at 2 months of age caused HD accumulation in the proximal convoluted tubule at all doses, with the 100 mg kg(-1) b.w. group slightly more affected. Finally, in the time-course study, rats treated with a 100 mg kg(-1) b.w. dose at 2 months of age and sacrificed at 6, 12, 24, 48, 72 and 96 h post-dosing showed a time-related HD accumulation in terms of incidence and severity, after 6 h, with a peak at 24 and 48 h and decreasing at 72 and 96 h. The present results show that HD accumulation is an early finding, and is unrelated to dose level and particularly evident in rats of 2 month of age. These findings in male rats treated with HCBD emphasize the importance of considering the age of rats at the start of a study. The more sensitive model was used in the detection of nephrotoxic effects of chemicals.

  15. Association between Genetic Polymorphisms of DNA Repair Genes and Chromosomal Damage for 1,3-Butadiene-Exposed Workers in a Matched Study in China

    Directory of Open Access Journals (Sweden)

    Menglong Xiang

    2015-01-01

    Full Text Available The aim of the study was to examine the association between polymorphisms of DNA repair genes and chromosomal damage of 1,3-butadiene- (BD- exposed workers. The study was conducted in 45 pairs of occupationally exposed workers in a BD product workshop and matched control workers in an administrative office and a circulatory water workshop in China. Newly developed biomarkers (micronuclei, MNi; nucleoplasmic bridges, NPBs; nuclear buds, NBUDs in the cytokinesis-blocked micronucleus (CBMN cytome assay were adopted to detect chromosomal damage. PCR and PCR-restriction fragment length polymorphism (RFLP are adopted to analyze polymorphisms of DNA repair genes, such as X-ray repair cross-complementing Group 1 (XRCC1, O6-methylguanine-DNA methyltransferase (MGMT, poly (adenosine diphosphate-ribose polymerases (ADPRT, and apurinic/apyrimidinic endonucleases (APE1. The BD-exposed workers exhibited increased frequencies of MNi and NPBs when compared to subjects in the control group. The results also show that the BD-exposed workers carrying XRCC1 diplotypes TCGA-CCGG (4.25±2.06‰ (FR=2.10, 95% CI: 1.03–4.28 and TCGG-TCGA (5.80±3.56‰ (FR=2.75, 95% CI: 0.76–2.65 had statistically higher NBUD frequencies than those who carried diplotype TCGG-TCGG (1.89±1.27‰. Our study suggests that polymorphisms of XRCC1 gene may influence chromosomal damage in BD-exposed workers.

  16. Epigenetic events determine tissue-specific toxicity of inhalational exposure to the genotoxic chemical 1,3-butadiene in male C57BL/6J mice.

    Science.gov (United States)

    Chappell, Grace; Kobets, Tetyana; O'Brien, Bridget; Tretyakova, Natalia; Sangaraju, Dewakar; Kosyk, Oksana; Sexton, Kenneth G; Bodnar, Wanda; Pogribny, Igor P; Rusyn, Ivan

    2014-12-01

    1,3-Butadiene (BD), a widely used industrial chemical and a ubiquitous environmental pollutant, is a known human carcinogen. Although genotoxicity is an established mechanism of the tumorigenicity of BD, epigenetic effects have also been observed in livers of mice exposed to the chemical. To better characterize the diverse molecular mechanisms of BD tumorigenicity, we evaluated genotoxic and epigenotoxic effects of BD exposure in mouse tissues that are target (lung and liver) and non-target (kidney) for BD-induced tumors. We hypothesized that epigenetic alterations may explain, at least in part, the tissue-specific differences in BD tumorigenicity in mice. We evaluated the level of N-7-(2,3,4-trihydroxybut-1-yl)guanine adducts and 1,4-bis-(guan-7-yl)-2,3-butanediol crosslinks, DNA methylation, and histone modifications in male C57BL/6 mice exposed to filtered air or 425 ppm of BD by inhalation (6 h/day, 5 days/week) for 2 weeks. Although DNA damage was observed in all three tissues of BD-exposed mice, variation in epigenetic effects clearly existed between the kidneys, liver, and lungs. Epigenetic alterations indicative of genomic instability, including demethylation of repetitive DNA sequences and alterations in histone-lysine acetylation, were evident in the liver and lung tissues of BD-exposed mice. Changes in DNA methylation were insignificant in the kidneys of treated mice, whereas marks of condensed heterochromatin and transcriptional silencing (histone-lysine trimethylation) were increased. These modifications may represent a potential mechanistic explanation for the lack of tumorigenesis in the kidney. Our results indicate that differential tissue susceptibility to chemical-induced tumorigenesis may be attributed to tissue-specific epigenetic alterations.

  17. Positron annihilation and relaxation dynamics from dielectric spectroscopy and nuclear magnetic resonance: Cis-trans-1,4-poly(butadiene)

    Science.gov (United States)

    Bartoš, J.; Šauša, O.; Schwartz, G. A.; Alegría, A.; Alberdi, J. M.; Arbe, A.; Krištiak, J.; Colmenero, J.

    2011-04-01

    We report a joint analysis of positron annihilation lifetime spectroscopy (PALS), dielectric spectroscopy (BDS), and nuclear magnetic resonance (NMR) on cis-trans-1,4-poly(butadiene) (c-t-1,4-PBD). Phenomenological analysis of the orthopositronium lifetime τ3 - T dependence by linear fitting reveals four characteristic PALS temperatures: T_{b1} ^G = 0{.63}T_g^{PALS}, T_g^{PALS}, T_{b1} ^L = 1.22T_g^{PALS}, and T_{b2} ^L = 1.52T_g^{PALS}. Slight bend effects in the glassy and supercooled liquid states are related to the fast or slow secondary β process, from neutron scattering, respectively, the latter being connected with the trans-isomers. In addition, the first bend effect in the supercooled liquid coincides with a deviation of the slow effective secondary βeff relaxation related to the cis-isomers from low-T Arrhenius behavior to non-Arrhenius one and correlates with the onset of the primary α process from BDS. The second plateau effect in the liquid state occurs when τ3 becomes commensurable with the structural relaxation time τα(Tb2). It is also approximately related to its crossover from non-Arrhenius to Arrhenius regime in the combined BDS and NMR data. Finally, the combined BDS and NMR structural relaxation data, when analyzed in terms of the two-order parameter (TOP) model, suggest the influence of solidlike domains on both the annihilation behavior and the local and segmental chain mobility in the supercooled liquid. All these findings indicate the influence of the dynamic heterogeneity in both the primary and secondary relaxations due to the cis-trans isomerism in c-t-1,4-PBD and their impact into the PALS response.

  18. Synthesis of vanadium complexes and butadiene polymerization catalyzed by the complexes%钒配合物的合成及其催化丁二烯聚合

    Institute of Scientific and Technical Information of China (English)

    黄贵秋; 陈敏娥; 熊拯

    2012-01-01

    采用N-亚硝基苯胲铵、二乙基二硫代氨基甲酸钠合三水和8-羟基喹啉三种萃取剂,萃取合成了三个双配位基配体钒配合物,将其用于催化丁二烯聚合获得聚丁二烯产品.用元素分析及红外光谱分析测定了钒配合物的结构,用凝胶渗透色谱、红外光谱及核磁共振波谱分析了聚合产物结构.所得聚丁二烯的数均分子量为(0.96~1.36)×104,相对分子质量分布为3.5~4.3,1,2-结构单元的摩尔分数高于60%,且构型为间同立构和无规结构.%Three vanadium complexes were synthesized via extraction with cupferron, sodium diethyl dithiocarbamate and 8-hydroxyquinoline as extraction reagents. The resultant vanadium complex with bifunctional ligand was successfully applied in catalyzing butadiene polymerization through which the corresponding polymer was acquired. The structure of the vanadium complexes was tested by elemental analyses and infrared spectroscopy (IR). The structure of the resultant polybutadiene was analysized with gel permeation chromatography (GPC), IR, nuclear magnetic resonance spectroscopy (1H-NMR and 13C-NMR). The polybutadiene possessed number average molecular mass of (0.96-1.36)xl04 and relative molecular mass distribution of 3.5-4.3. The molar content of 1,2-configuration unit, in either syndiotactie or atactic microstructure, was higher than 60% of the polybutadiene.

  19. 丙烯腈-苯乙烯磺酸共聚物/层状双金属氢氧化物纳米复合质子传导聚合物电解质的制备与表征%Synthesis and characterization of proton-conducting polymer electrolytes based on acrylonitrile-styrene sulfonic acid copolymer/layered double hydroxides nanocomposites

    Institute of Scientific and Technical Information of China (English)

    王盎然; 包永忠; 翁志学; 黄志明

    2008-01-01

    Acrylonitrile-sodium styrene sulfonate copolymer/layered double hydroxides nanocomposites were prepared by in situ aqueous precipitation copolymerization of acrylonitrile (AN) and sodium styrene sulfonate (SSS) in the presence of 4-vinylbenzene sulfonate intercalated layered double hydroxides (MgAl-VBS LDHs) and transferred to acrylonitrile-styrene sulfonic acid (AN-SSA) copolymer/LDHs nanocomposites as a proton-conducting polymer electrolyte. MgAl-VBS LDHs were prepared by a coprecipitation method, and the structure and composition of MgAl-VBS LDHs were determined by X-ray diffraction (XRD), infrared spectroscopy, and elemental analysis. X-ray diffraction result of AN-SSS copolymer/LDHs nanocomposites indicated that the LDHs layers were well dispersed in the AN-SSS copolymer matrix. All the AN-SSS copolymer/LDHs nanocomposites showed significant enhancement of the decomposition temperatures compared with the pristine AN-SSS copolymer, as identified by the thermogravimetric analysis. The methanol crossover was decreased and the proton conductivity was highly enhanced for the AN-SSA copolymer/LDHs nanocomposite electrolyte systems In the case of the nanocomposite electrolyte containing 2% (by mass) LDHs, the proton conductivity of 2.60×10-3 S·m-1 was achieved for the polymer electrolyte.

  20. Principais copolímeros elastoméricos à base de butadieno utilizados na indústria automobilística The most important butadiene based elastomers employed in the automotive industry

    Directory of Open Access Journals (Sweden)

    Tereza C. J. Rocha

    2007-12-01

    Full Text Available Copolímeros elastoméricos à base de butadieno são amplamente utilizados na indústria automobilística. Dentre esses destacam-se os copolímeros de butadieno-estireno (SBR e butadieno-acrilonitrila (NBR. O SBR apresenta maior importância comercial, devido a sua aplicação na produção de pneus. Quando SBR é utilizado juntamente com o homopolímero de butadieno BR-alto cis, excelentes propriedades são obtidas para sua aplicação na banda de rodagem de pneus. O copolímero elastomérico NBR é empregado em artefatos em que é necessária boa resistência a solventes orgânicos e a óleos. Nos últimos anos, as empresas automobilísticas e produtoras de pneumáticos vêm se preocupando com o meio-ambiente e, conseqüentemente, têm investido em novos processos de síntese, mais limpos, para a produção desses elastômeros. Assim, o objetivo deste artigo é apresentar uma revisão sobre dois importantes copolímeros elastoméricos à base de butadieno, SBR e NBR, abordando os processos de síntese, características principais, processamento e aplicações.Elastomer copolymers based on butadiene are widely applied in the automotive industry. Among those copolymers the most important ones are styrene-butadiene (SBR and nitrile-butadiene (NBR. SBR presents higher commercial interest, due to its application in the tire production. When SBR is mixed with high cis-1,4 polybutadiene, excellent properties are attained for application on the pneumatics treads. NBR can be used in a wide variety of application areas requiring oil, fuel, and chemical resistance. In the last years, the automotive and pneumatic industries have been increasingly concerned with environmental issues, and have invested in synthesis processes for elastomers that are less aggressive to the environment. Thus, the purpose of this article is to present a review on two important butadiene elastomer copolymers, SBR and NBR, with emphasis on the polymerization processes. The main