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Sample records for acrylonitrile butadiene rubber-polyvinyl

  1. Butadiene-acrylonitrile elastomers as PVC modifiers

    OpenAIRE

    M. Rojek; J. Stabik

    2007-01-01

    Purpose: The purpose of the paper is to present the results of research programme on influence of acrylonitrile-butadiene copolymers on plasticized polyvinylchloride compounds used as window gasket material.Design/methodology/approach: Short review concerning application of modified plasticized PVC compounds as gasket material was presented. In experimental part two types of acrylonitrile-butadiene copolymers were used as elastomeric plasticizers for PVC. Formulations with fifteen dif...

  2. Modification of PVC compounds with butadiene-acrylonitrile elastomers

    OpenAIRE

    J. Stabik; M. Rojek

    2006-01-01

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

  3. Modification of PVC compounds with butadiene-acrylonitrile elastomers

    Directory of Open Access Journals (Sweden)

    J. Stabik

    2006-04-01

    Full Text Available Purpose: The purpose of the paper is to present the research programme on influence of acrylonitrile-butadiene copolymers on properties of plasticized polyvinylchloride as window gaskets material.Design/methodology/approach: Short literature review concerning application of modified PVC as gasket material was presented. In experimental part two types of acrylonitrile-butadiene copolymers were used as elastomeric plasticizers. Compounds with fifteen different levels of modifiers content (up to 25% by weight were prepared and tested. Additionally three commercial compounds were tested as reference formulations. The following test were performed: Shore hardness, short-term and long-term elastic recovery, tensile strength, elongation at break and migration of plasticizers from gasket material to unplasticized PVC.Findings: Application of acrylonitrile-butadiene copolymers as PVC modifier enhanced many properties essential for window gasket materials such as long-term and short term elastic recovery, tensile strength and elongation at break. At the same time addition of these elastomers did not change migration of other plasticizers contained in gasket material. Obtained results indicated that among tested compounds best properties as gasket material exhibited plasticized PVC with 23% of acrylonitrile-butadiene copolymer Chemigum P83. Reference commercial compounds exhibited worse performance properties than compounds with this acrylonitrile-butadiene copolymer. Practical implications: Research programme allowed to elaborate plasticized PVC compounds modified with acrylonitrile-butadiene copolymer that can be industrially applied for PVC window gaskets.Originality/value: Obtained results are of scientific and practical value. Research programme allowed to investigate the influence of elastomeric modifiers on plasticized PVC properties. Research results are also of practical importance.

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

    Science.gov (United States)

    Przepiórkowska, A; Chrońska, K; Zaborski, M

    2007-03-01

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

  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. 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.

  8. 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.

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

    Science.gov (United States)

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

    2015-07-10

    The master-batch method provides a simple way to apply cellulose nanocrystal (CNC) as reinforcement in a hydrophobic matrix. The two-stage process includes making high-CNC content (70 wt%) master batch pellets, then mixing acrylonitrile-butadiene-styrene (ABS) and maleic anhydride grafted polyethylene with the master batch pellets to prepare the ABS/CNC nanocomposite in extruder. SEM image indicates that self-assembled CNC nanosheets disperse evenly throughout the polymer matrix. The improved mechanical properties shown in tensile and DMA tests reveal that the CNC combines well with the ABS. TGA results show that the thermal degradation temperature of CNC in the master batch increases because of the protection of the ABS coating. This approach not only improves the dispersion ability and the thermal stability of CNC, but it is also applicable to use with other hydrophobic thermoplastics in industrial scale production. PMID:25857992

  10. Structures and Properties Characterization of Acrylonitrile-butadiene-styrene/Organo-palygorskite Clay Composites

    Institute of Scientific and Technical Information of China (English)

    ZHANG Zhe; CHANG Ying; XU Jian; WU Zhancui; MA Hengchang; LEI Ziqiang

    2012-01-01

    Palygorskite (PGS) and vinyl tris-(2-methoxyethoxy) silane (KH-172) modified palygorskite (OPGS) were used to prepare acrylonitrile-butadiene-styrene (ABS)/clay composites.Thermal stability of the composites was evaluated by using thermogravimetric analysis (TGA).The morphology of the fractured surface and the degree of dispersion of the clay in the ABS matrix were observed by scanning electron microscopy (SEM).X-ray diffraction (XRD) analysis results showed the variation of the crystal structure.Measurements of the tensile properties of the ABS/clay composites proved that the ABS/OPGS composited material represented the most excellent tensile property,because of good compatibility and dispersion of ABS with OPGS.

  11. 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.

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

    OpenAIRE

    H. F. Xie; Wang, Y. T.; Wang, C. S.; H. Y. Yin; Wang, L.L.; R. S. Cheng

    2012-01-01

    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–COOH...

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

    Science.gov (United States)

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

    1984-01-01

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

  14. 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. Microstrueture and Properties of Fluoroelastomer/Butadiene-Acrylonitrile Rubber Interpenetrating Polymer Networks

    Institute of Scientific and Technical Information of China (English)

    CHEN Chunming; XIONG Chuanxi; YANG Jian; DONG Lijie

    2008-01-01

    Interpenetrating polymer networks(IPNs)based on fluoroelastomer/butadiene-acrylonitrile rubber(FKM/NBR)by molten blending at a high temperature and chemical cross-linking of two components were prepared.The influence of the two networks component on the mechanical properties and thermostabilities was studied.The experimental results show that the mechanical properties of the IPNs are superior to those of the individual FKM and NBR networks due to forming the case of interpenetrating and intercross-linking between the two networks,the mechanical properties and thermal resistance exhibit higher values when 80/20(w/w)FKM and NBR is blended and respectively cured simultaneously.The co-continuous morphology of the IPNs in the blends of 80/20(w/w)FKM/NBR is found by transmission electron microscopy(TEM),the differential scanning calorimetry(DSC)determination shows that the blends of 80/20(w/w)FKM/NBR have better compatibility,and the glass transition temperature of the elastomer is -21.5℃.

  16. Crack initiation and propagation on the polymeric material ABS (Acrylonitrile Butadiene Styrene, under ultrasonic fatigue testing

    Directory of Open Access Journals (Sweden)

    G. M. Domínguez Almaraz

    2015-10-01

    Full Text Available Crack initiation and propagation have been investigated on the polymeric material ABS (Acrylonitrile Butadiene Styrene, under ultrasonic fatigue testing. Three controlled actions were implemented in order to carry out fatigue tests at very high frequency on this material of low thermal conductivity, they are: a The applying load was low to limit heat dissipation at the specimen neck section, b The dimensions of testing specimen were small (but fitting the resonance condition, in order to restraint the temperature gradient at the specimen narrow section, c Temperature at the specimen neck section was restrained by immersion in water or oil during ultrasonic fatigue testing. Experimental results are discussed on the basis of thermo-mechanical behaviour: the tail phenomenon at the initial stage of fatigue, initial shear yielding deformation, crazed development on the later stage, plastic strain on the fracture surface and the transition from low to high crack growth rate. In addition, a numerical analysis is developed to evaluate the J integral of energy dissipation and the stress intensity factor K, with the crack length

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

    Science.gov (United States)

    Díez-Pascual, Ana M; Gascón, David

    2013-11-27

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

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

    Science.gov (United States)

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

    2015-09-01

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

  19. 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.

  20. 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. PMID:21313827

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

    International Nuclear Information System (INIS)

    Research highlights: → Addition of TMPTA helps to align polymer chains through crosslinking. → Improvement in fatigue life of irradiated blends due to formation of irradiation-induced crosslinks. → Excessive crosslinking caused reduction of tensile properties of irradiated SBR/NBRr blends. -- Abstract: The effects of electron beam (EB) irradiation on the thermal properties, fatigue life and natural weathering of styrene butadiene rubber/recycled acrylonitrile-butadiene rubber (SBR/NBRr) blends were investigated. The SBR/NBRr blends were prepared at 95/5, 85/15, 75/25, 65/35, or 50/50 blend ratios with and without the presence of a 3 part per hundred rubber (phr) of polyfunctional monomer, trimethylolpropane triacrylate (TMPTA). Results indicate that the crystallisation temperature (Tc) observed in polymeric blends is due to the alignment of polymer chains forming a semi-crystalline phase. Addition of TMPTA helps to align polymer chains through crosslinking. More crosslinking occurred between polymer blends with the help of TMPTA, upon irradiation. The improvement in fatigue life can also be associated with the stabilisation of SBR/NBRr blends upon irradiation and irradiation-induced crosslinking, which was accomplished with relatively low radiation-induced oxidative degradation in the presence of TMPTA. The tensile properties of both blends decreased over the periods of environmental exposure due to the effect of polymer degradation. After 6 months, the irradiated SBR/NBRr blends could not retain better retention [mainly with 25, 35 or 50 phr of recycled acrylonitrile-butadiene rubber (NBRr) particles] due to the samples becoming brittle over the long period of outdoor exposure.

  2. 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.

  3. 21 CFR 177.1020 - Acrylonitrile/butadiene/sty-rene co-polymer.

    Science.gov (United States)

    2010-04-01

    ... acrylonitrile adduct as determined by a method titled “Analysis of Cycopac Resin for Residual β-(2... copolymer is in the range of 16 to 18.5 percent as determined by Micro-Kjeldahl analysis. (2) Residual... determined by a gas chromatographic method titled “Determination of Residual Acrylonitrile and...

  4. 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...

  5. 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.

  6. 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

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

    Science.gov (United States)

    Wildes, Gregg Stephen

    1998-11-01

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

  8. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Wang, C.-C. [Department of Environmental Engineering, Hungkuang University, Shalu, Taichung 433, Taiwan (China)]. E-mail: chunchin@sunrise.hk.edu.tw; Lee, C.-M. [Department of Environmental Engineering, National Chung Hsing University, Taichung 402, Taiwan (China)

    2007-06-25

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

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

    Science.gov (United States)

    Wang, Chun-Chin; Lee, Chi-Mei

    2007-06-25

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

  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. 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.

  13. 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.

  14. 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.

  15. Effects of aminopropyltriethoxysilane (γ-APS) on tensile properties and morphology of polypropylene (PP), recycle acrylonitrile butadiene rubber (NBRr) and sugarcane bagasse (SCB) composites

    Science.gov (United States)

    Santiagoo, Ragunathan; Omar, Latifah; Zainal, Mustaffa; Ting, Sam Sung; Ismail, Hanafi

    2015-07-01

    The performance of sugarcane baggase (SCB) treated with γ-APS filled polypropylene (PP)/recycled acrylonitrile butadiene rubber (NBRr) biocomposites were investigated. The composites with different filler loading ranging from 5 to 30 wt % were prepared using heated two roll mill by melt mixing at temperature of 180 °C. Tensile properties of the PP/NBRr/SCB composites which is tensile strength, Young Modulus and elongation at break were investigated. Increasing of treated SCB filler loading in PP/NBRr/SCB composites have increased the Young modulus however decreased the tensile strength and elongation at break of the PP/NBRr/SCB composites. From the results, γ-APS treated SCB composites shown higher tensile strength and Young Modulus but lower elongation at break when compared to the untreated SCB composites. This is due to the stronger bonding between γ-APS treated SCB with PP/NBRr matrices. These findings was supported by micrograph pictures from morphological study. SCB filler treated with γ-APS has improved the adhesion as well as gave strong interfacial bonding between SCB filler and PP/NBRr matrices which results in good tensile strength of PP/NBRr/SCB composites.

  16. 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.

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

    International Nuclear Information System (INIS)

    Bisphenol A polycarbonate/acrylonitrile-butadiene-styrene (PC/ABS) with and without bisphenol A bis(diphenyl phosphate) (BDP) and 5 wt.% zinc borate (Znb) were investigated. The pyrolysis was studied by thermogravimetry (TG), TG-FTIR and NMR, the fire behaviour with a cone calorimeter applying different heat fluxes, LOI and UL 94. Fire residues were examined with NMR. BDP affects the decomposition of PC/ABS and acts as a flame retardant in the gas and condensed phases. The addition of Znb results in an additional hydrolysis of PC. The fire behaviour is similar to PC/ABS, aside from a slightly increased LOI and a reduced peak heat release rate, both caused by borates improving the barrier properties of the char. In PC/ABS + BDP + Znb, the addition of Znb yields a borate network and amorphous phosphates. Znb also reacts with BDP to form alpha-zinc phosphate and borophosphates that suppress the original flame retardancy mechanisms of BDP. The inorganic-organic residue formed provides more effective flame retardancy, in particular at low irradiation in the cone calorimeter, and a clear synergy in LOI, whereas for more developed fires BDP + Znb become less effective than BDP in PC/ABS with respect to the total heat evolved.

  18. 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.

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

    Science.gov (United States)

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

    2012-06-01

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

  20. 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)

    International Nuclear Information System (INIS)

    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

  1. 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.

  2. 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。

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

    Science.gov (United States)

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

    2014-09-01

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

  4. 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.

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

    International Nuclear Information System (INIS)

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

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

    Science.gov (United States)

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

    2014-05-01

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

  7. 21 CFR 180.22 - Acrylonitrile copolymers.

    Science.gov (United States)

    2010-04-01

    ..., preferably with animals exposed in utero to the chemical, (2) studies of multigeneration reproduction with... between acrylonitrile monomer and cyanide ion, and (6) a literature search on the effects of...

  8. 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.

  9. Power Efficient, Restart-Capable Acrylonitrile-Butadiene-Styrene Arc Ignitor for Hybrid Rockets

    OpenAIRE

    Whitmore, Stephen; Merkely, Daniel; Inkley, Nathan

    2014-01-01

    Because hybrid rocket propellant materials are individually chemically stable prior to mixing within the combustion chamber, these systems possess well-known safety advantages. Unfortunately, the relative stability of traditional hybrid propellants also makes hybrid systems difficult to ignite. Hybrid ignition has historically involved one of three means, 1) pyrotechnic charges, 2) plasma torch, and 3) electric spark plugs with bi-propellant injectors. All of these methods possess distinct di...

  10. 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. PMID:27060197

  11. 29 CFR 1910.1045 - Acrylonitrile.

    Science.gov (United States)

    2010-07-01

    ... addition, contact lenses should not be worn in areas where eye contact with acrylonitrile can occur. v... eye exposure. The employer shall assure that no employee is exposed to skin contact or eye contact... eye or skin contact with liquid AN may occur, the employer shall provide at no cost to the...

  12. The influence of carbon black on curing kinetics and thermal aging of acrylonitrile–butadiene rubber

    Directory of Open Access Journals (Sweden)

    Jaroslava Budinski-Simendić

    2009-10-01

    Full Text Available Elastomers based on a copolymer of butadiene and acrylonitrile (NBR have excellent oil resistance but are very sensitive for degradation at very high temperatures. The aim of this applicative contribution was to determine the effect of high abrasion furnace carbon black with primary particle size 46 nm on aging properties of elastomeric materials based on NBR as network precursor. The curing kinetics was determined using the rheometer with an oscillating disk, in which the network formation process is registered by the torque variation during time. The vulcanizates were obtained in a hydraulic press at 150 °C. The mechanical properties of elastomeric composites were determined before and after thermal aging in an air circulating oven. The reinforcing effect of the filler particles was assessed according to mechanical properties before and after aging.

  13. Surface amination of poly(acrylonitrile)

    OpenAIRE

    Hartwig, Andreas; Mulder, Marcel; Smolders, Cees A.

    1994-01-01

    The surface amination of poly (acrylonitrile) by ammonia plasma treatment has been studied. Furthermore, two other surface modification techniques have been investigated, the plasma chemical decomposition of an amino group containing chemical (tris-(2-aminoethyl)amine) onto the polymer surface and the surface reduction by lithium aluminium hydride. The three different methods are compared with respect to the adhesion improvement of the coatings onto the modified surfaces.

  14. Design and Synthesis of Transparent Poly (acrylonitrile butadiene-styrene) and Relationship Between Its Phase Construction and Transparency

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    A series of transparent ABS(T-ABS) resins were prepared by emulsion in situ suspension polymerization. The influences of the particle size and the content of rubber particles on the transparency of T-ABS resins were studied by varying the size and content of rubber particles in a single model system( rubber particles with a uniform size). The optical properties of T-ABS resins were investigated in a mixed system of SBR/PB particles and a bi-modal particle system(rubber particles with two different sizes, 70 and 400 nm in diameter) of SBR particles. It was found that when the size of the smaller particles (70 nm) in the mixed system of SBR/PB particles was in the range of 50-100 nm in diameter, the T-ABS resins showed a better transparency. These results provide a flexible and practical process for the preparation of T-ABS resins with good optical and mechanical properties.

  15. 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.

  16. Application of gamma irradiation for incorporation of rubber powder in the formulations of acrylonitrile-butadiene rubber (NBR)

    Energy Technology Data Exchange (ETDEWEB)

    Kiyan, Ludmila Y.P.; Parra, Duclerc Fernandes, E-mail: ludmilapozzo@gmail.com [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil). Centro de Quimica e Meio Ambiente (CQMA)

    2013-07-01

    Full text: Polymeric materials do not decompose easily, disposal of waste polymers is a major environmental problem of global character. Recycling is an economical alternative and environmentally recommended for polymers consumed and discarded by society. As regards the rubber in object, its natural decomposition is much slower due to their highly crosslinked, in three-dimensional networks, structures which makes it an infusible and insoluble material. Moreover, these three dimensional structures entails several problems for their recovery and reprocessing. The aim of this paper was to study the behavior of NBR rubber recycle. It was used rubber powder from industry. The powder was irradiated in master-batch composition and used directly in classical formulations for rubber vulcanization. The master-batch processed was irradiated at doses of 50, 100 and 150kGy in {sup 60}Co source at 5 kGy s{sup -1} rate, at room temperature. Gamma radiation created active sites during devulcanization that promoted further integration of the rubber powder in formulations for commercial use. The processes were compared and their products were characterized by analytical methods of the physical properties such as tensile strength and elongation. The greatest change in the properties of polymeric materials by exposure to ionizing radiation resulted mainly of two main reactions occurring in the polymer molecule: chains scission (degradation) and crosslinking. Although these two processes occur simultaneously in all the polymers, the predominance of one or other effect depends mainly of the chemical structure of each polymer, and the irradiation conditions. In the results was observed the behavior of nitrile rubber under different doses and radiation improvement of the mechanical properties. (author)

  17. 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.

  18. 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)

  19. 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%.

  20. 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 ℃.

  1. Polymerization of Acrylonitrile with(Diisopropylamido)Bis(indenyl) Lanthanides

    Institute of Scientific and Technical Information of China (English)

    李刚; 张学全; 应来强; 巴小微; 崔冬梅; 唐涛; 金鹰泰

    2002-01-01

    The polymerization of acrylonitrile was studied using (diisopropylamido)bis(indenyl) lanthanides, Ind2LnN(i-Pr)2(Ln=Y, Yb) as a single-component catalyst. The effects of the amount of catalyst, monomer concentration and polymerization temperature on catalytic activity and molecular weight of polyacrylonitrile(PAN) were studied. The results show that the catalytic activity is raised obviously with rising polymerization temperature. The monomer conversion reaches 64% under polymerization temperature, monomer concentration and catalyst concentration are 50 ℃, 5.1 mol*L-1 and 0.3%(molar ratio) sequentially. The conversion and molecular weight of the polymer increase appreciably with adding additive, PhONa. When the molar ratio of PhONa to the catalyst is three, the conversion and the molecular weight is 76% and 1.32×104, respectively. The initiation mechanism for the polymerization of acrylonitrile was proposed.

  2. 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).

  3. 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.

  4. 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...

  5. Species difference in metabolism of inhaled butadiene

    International Nuclear Information System (INIS)

    Chronic exposure of B6C3F1 mice and Sprague-Dawley rats to butadiene (BD) produced a very high incidence of cancer in mice while the incidence in rats was much lower with different tissues affected. Studies at this institute indicate that for equivalent exposures, the blood BD epoxide concentrations in mice are 5-fold higher than in rats and > 10-fold higher than in Cynomolgus monkeys. In this study, the profiles of urinary metabolites of butadiene were determined in Cynomolgus monkeys, F344/N rats, Sprague Dawley rats, B6C3F1 mice and Syrian hamsters, species containing widely divergent hepatic epoxide hydrolase (EH) activities. Animals were exposed for 2 hr to 8,000 ppm [14C]BD and 24-hr urine samples were analyzed for metabolites. Two major urinary metabolites were identified, N-acetyl-S-(-1(or 2)-3-butene-2(or 1)-ol)cysteine (1) and N-acetyl-S-(-4-butane-1,2-diol)cysteine (2). Monkeys exposed by inhalation produced primarily metabolite 2, while rodent species produced 1-4 times as much of 1 compared to 2. The ratio of 2/1 formation was related to the hepatic epoxide hydrolase activity in different species. The high 2/1 ratio in monkeys was consistent with the lower blood epoxide levels in this species. If BD metabolism by humans is similar to that in the monkey, exposure of humans to BD may result in lower tissue concentrations of reactive metabolites than an equivalent exposure of rodents. This has important implications for assessing the risk to humans of BD exposure based on rodent studies

  6. 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.

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

    Science.gov (United States)

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

  8. POLYMERIZATION OF ACRYLONITRILE WITH ORGANOLANTHANIDES AS SINGLE-COMPONENT CATALYSTS

    Institute of Scientific and Technical Information of China (English)

    Lai-qiang Ying; Xiao-wei Ba; Yu-ying Zhao; Gang Li; Tao Tang; Ying-tai Jin

    2001-01-01

    Ind2Y(μ-Et)2A1Et2 and Ind2LnN(i-Pr)2 (Ln = Y, Yb) were used as a single-component catalyst for the polymerization of acrylonitrile (AN) respectively. The regularity of polymerization of AN and stereoregularity of polyacrylonitrile (PAN) were also studied in both cases. Both catalysts can produce PAN with molecular weight from I0,000to 30,000. In addition, the catalytic activity and molecular weights were increased by the addition of PhONa.

  9. 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...

  10. 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.)

  11. 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.

  12. Radical-initiated controlled synthesis of homo- and copolymers based on acrylonitrile

    Science.gov (United States)

    Grishin, D. F.; Grishin, I. D.

    2015-07-01

    Data on the controlled synthesis of polyacrylonitrile and acrylonitrile copolymers with other (meth)acrylic and vinyl monomers upon radical initiation and metal complex catalysis are analyzed. Primary attention is given to the use of metal complexes for the synthesis of acrylonitrile-based (co)polymers with defined molecular weight and polydispersity in living mode by atom transfer radical polymerization. The prospects for using known methods of controlled synthesis of macromolecules for the preparation of acrylonitrile homo- and copolymers as carbon fibre precursors are estimated. The major array of published data analyzed in the review refers to the last decade. The bibliography includes 175 references.

  13. Application of control technology developed in the polyvinyl chloride industry to polymerization processes using acrylonitrile.

    Science.gov (United States)

    Schoultz, K S; Gideon, J A; Bochinski, J H

    1979-02-01

    Polymerization processes for PVC are sufficiently similar to acrylonitrile polymerization processes to allow a significant transfer of control technology. This transfer should be of value to manufacturers of polyacrylonitrile, ABS/SAN resins, nitrile elastomer and latex who will need to install extensive additional controls to comply with the new permanent standard for acrylonitrile scheduled to be issued by OSHA in late 1978. Control strategies and individual controls developed to limit worker exposure in the PVC industry are described and evaluated relative to applicability to acrylonitrile polymerization processes. PMID:495444

  14. 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...

  15. 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.

  16. ICAR ATRP of Acrylonitrile under Ambient and High Pressure

    Directory of Open Access Journals (Sweden)

    Zhicheng Huang

    2016-03-01

    Full Text Available It is well known that well-defined polyacrylonitrile (PAN with high molecular weight (Mw > 106 g·mol−1 is an excellent precursor for high performance carbon fiber. In this work, a strategy for initiators for a continuous activator regeneration atom transfer radical polymerization (ICAR ATRP system for acrylonitrile (AN was firstly established by using CuCl2·2H2O as the catalyst and 2,2′-azobis(2-methylpropionitrile (AIBN as the thermal initiator in the presence of ppm level catalyst under ambient and high pressure (5 kbar. The effect of catalyst concentration and polymerization temperature on the polymerization behaviors was investigated. It is important that PAN with ultrahigh viscosity and average molecular weight (Mη = 1,034,500 g·mol−1 could be synthesized within 2 h under high pressure.

  17. Determination of potentially carcinogenic compounds in food : trace analysis of vinylchloride, vinylidenechloride, acrylonitrile, epichlorohydrin and diethylpyrocarbonate

    NARCIS (Netherlands)

    Lierop, van J.B.H.

    1979-01-01

    Toxicological evidence shows that some monomers present in packaging materials may be carcinogenic. These monomers, notably vinylchloride, vinylidenechloride, acrylonitrile and epichlorohydrin, may migrate from the packaging material into the food. Therefore, severe limits are set to the contents of

  18. 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.

  19. Synthesis and Characterization of a Novel Acrylonitrile Copolymer Containing Glucose Pendants

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    In this work, a novel sugar-containing copolymer was synthesized by the copolymerization of α-allyl glucoside (AG) with acrylonitrile (AN). The copolymers were characterized by NMR spectroscopy. It was found that acrylonitrile-based copolymers containing as high as 22wt.% of α-allyl glucoside can be synthesized by the free radical solution copolymerization of the two monomers in DMSO with AIBN as initiator.

  20. 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.

  1. Biocompatibility of epoxidized styrene-butadiene-styrene block copolymer membrane

    International Nuclear Information System (INIS)

    Styrene-butadiene-styrene block copolymer (SBS) membrane was prepared by solution casting method and then was epoxidized with peroxyformic acid generated in situ to yield the epoxidized styrene-butadiene-styrene block copolymer membrane (ESBS). The structure and properties of ESBS were characterized with infrared spectroscopy, Universal Testing Machine, differential scanning calorimetry (DSC), and thermogravimetry analysis (TGA). The performances of contact angle, water content, protein adsorption, and water vapor transmission rate on ESBS membrane were determined. After epoxidation, the hydrophilicity of the membrane increased. The water vapor transmission rate of ESBS membrane is similar to human skin. The biocompatibility of ESBS membrane was evaluated with the cell culture of fibroblasts on the membrane. It revealed that the cells not only remained viable but also proliferated on the surface of the various ESBS membranes and the population doubling time for fibroblast culture decreased.

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

    OpenAIRE

    Jerry, R.; Winslow, L.(Massachusetts Institute of Technology, Cambridge, Massachusetts, 02139, U.S.A.); 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 variatio...

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

    CERN Document Server

    Pollmann, Tina; Kuźniak, Marcin

    2010-01-01

    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 ns and 275 +/-10ns.

  4. 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.

  5. 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.

  6. 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.

  7. 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

  8. 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.

  9. 40 CFR 80.55 - Measurement methods for benzene and 1,3-butadiene.

    Science.gov (United States)

    2010-07-01

    ... Measurement methods for benzene and 1,3-butadiene. (a) Sampling for benzene and 1,3-butadiene must be accomplished by bag sampling as used for total hydrocarbons determination. This procedure is detailed in 40 CFR... 40 Protection of Environment 16 2010-07-01 2010-07-01 false Measurement methods for benzene and...

  10. 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.)

  11. Carbon nanotubes as reinforcement of styrene-butadiene rubber

    International Nuclear Information System (INIS)

    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

  12. 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%.

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

    International Nuclear Information System (INIS)

    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.)

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

    OpenAIRE

    Siti Nurul Ain Md Jamil; Rusli Daik; Ishak Ahmad

    2014-01-01

    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 Thermog...

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

    Science.gov (United States)

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

  16. New Star-Branched Poly(acrylonitrile) Architectures : ATRP Synthesis and Solution Properties

    NARCIS (Netherlands)

    Pitto, Valentina; Voit, Brigitte I.; Loontjens, Ton J.A.; Benthem, Rolf A.T.M. van

    2004-01-01

    Atom transfer radical polymerization (ATRP) has been chosen as ‘‘living’’/controlled free radical polymerization system to synthesize a number of novel poly(acrylonitrile) (PAN) architectures. The reaction conditions for the synthesis of linear samples with control over molar mass and molar mass dis

  17. 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.

  18. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1994-09-12

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

  20. 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.

  1. Heck Arylation of Acrylonitrile with Aryl Iodides Catalyzed by a Silica-bound Arsine Palladium(0) Complex

    Institute of Scientific and Technical Information of China (English)

    Ming Zhong CAI; Hong ZHAO; Rong Li ZHANG

    2005-01-01

    Acrylonitrile reacts with aryl iodides in the presence of tri-n-butylamine and a catalytic amount of a silica-bound arsine palladium(0) complex to afford stereoselectively (E)-cinnamonitriles in high yields.

  2. 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.

  3. 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.

  4. Aging studies on thin tetra-phenyl butadiene films

    Science.gov (United States)

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

    2013-10-01

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

  5. Photodegradation mechanisms of tetraphenyl butadiene coatings for liquid argon detectors

    Science.gov (United States)

    Jones, B. J. P.; VanGemert, J. K.; 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. 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.

  6. 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.

  7. 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.

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

    Science.gov (United States)

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

    2014-11-21

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

  9. Copolymerization of Indene with Acrylic Acid, Itaconic Acid and Acrylonitrile: Characterization and Reactivity Ratios

    International Nuclear Information System (INIS)

    Random copolymers of indene (In) with acrylic acid (AA), itaconic acid (IA) and acrylonitrile (AN) were synthesized by free radical polymerization in dioxane in the presence of azobisisobutyronitrile as an initiator at 60 degree C. The homopolymer of indene and acrylonitrile was prepared using K2MnO4 and sulphuric acid as an initiator, while acrylic acid and itaconic acid were prepared using K2S2O8 solution. The reactivity ratios of the monomers were calculated by different methods. X-ray diffraction as well as thermal analyses were studied. The latter was studied via thermogravimetric analysis and differential thermal analysis. The complexation with metal ions such as Cu+2 and Fe+2 was investigated. The copolymerization and the complexation processes were confirmed by FTIR spectroscopy. Also the activation energy of the prepared copolymers was determined

  10. 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.

  11. 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).

  12. Acrylonitrile polymerization by Cy3PCuMe and (Bipy)2FeEt2.

    Science.gov (United States)

    Schaper, Frank; Foley, Stephen R; Jordan, Richard F

    2004-02-25

    Cy(3)PCuMe (1) undergoes reversible ligand redistribution at low temperature in solution to form the tight ion pair [Cu(PCy(3))(2)][CuMe(2)] (3). The structure of 3 was assigned on the basis of (i) the stoichiometry of the 1 = 3 equilibrium, (ii) the observation of a triplet for the PCy(3) C1 (13)C NMR resonance due to virtual coupling to two (31)P nuclei, and (iii) reverse synthesis of 1 by combining separately generated Cu(PCy(3))(2)(+) and CuMe(2)(-) ions. Complex 1 and [Cu(PCy(3))(2)][PF(6)] (5) coordinate additional PCy(3) to form (Cy(3)P)(2)CuMe and [Cu(PCy(3))(3)][PF(6)], respectively, while 3 does not. Complex 1, free PCy(3), and (bipy)(2)FeEt(2) (2) each initiate the polymerization of acrylonitrile. In each case, the polyacrylonitrile contains branches that are characteristic of an anionic polymerization mechanism. The major initiator in acrylonitrile polymerization by 1 is PCy(3), which is liberated from 1. A transient iron hydride complex is proposed to initiate acrylonitrile polymerization by 2. PMID:14971946

  13. An estimation of photon scattering length in tetraphenyl-butadiene

    Science.gov (United States)

    Stolp, D.; Dalager, O.; Dhaliwal, N.; Godfrey, B.; Irving, M.; Kazkaz, K.; Manalaysay, A.; Neher, C.; Stephenson, S.; Tripathi, M.

    2016-03-01

    Tetraphenyl-butadiene (TPB) is a wavelength shifting material that can absorb ultraviolet photons and emit blue photons. It is used in the detection of vacuum ultraviolet (VUV) photons, for which typical photo-sensors, such as most photomultiplier tubes (PMT) and silicon photomultipliers (SiPM), do not have any quantum efficiency. The secondary blue light is emitted isotropically, however, due to scattering within the material, its angular distribution upon exiting the material can not be easily predicted. Here we describe a procedure for estimating the scattering length of blue light in TPB, by measuring and modeling the angular distribution as a function of layer thickness. The experiment consists of shining 254nm light at various thicknesses of TPB deposited on fused silica, and measuring the intensity of blue light using SiPMs on either side of the sample. We simulate light propagation within the sample to estimate the light yield and compare that to the data, which allows us to estimate mean scattering length for photons in TPB to be in the range 2-3 μm, with some preference for a central value of 2.75 μm.

  14. High performance light-colored nitrile-butadiene rubber nanocomposites.

    Science.gov (United States)

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

    2011-12-01

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

  15. 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.

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

    CERN Document Server

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

    2007-01-01

    In line with the study presented in the part I of this paper, the structure of a laminar rich premixed methane flame doped with 1,3-butadiene has been investigated. The flame contains 20.7% (molar) of methane, 31.4% of oxygen and 3.3% of 1,3-butadiene, corresponding to an equivalence ratio of 1.8, and a ratio C4H6 / CH4 of 16 %. The flame has been stabilized on a burner at a pressure of 6.7 kPa using argon as dilutant, with a gas velocity at the burner of 36 cm/s at 333 K. The temperature ranged from 600 K close to the burner up to 2150 K. Quantified species included usual methane C0-C2 combustion products and 1,3-butadiene, but also propyne, allene, propene, propane, 1,2-butadiene, butynes, vinylacetylene, diacetylene, 1,3-pentadiene, 2-methyl-1,3-butadiene (isoprene), 1-pentene, 3-methyl-1-butene, benzene and toluene. In order to model these new results, some improvements have been made to a mechanism previously developed in our laboratory for the reactions of C3-C4 unsaturated hydrocarbons. The main reacti...

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

    Energy Technology Data Exchange (ETDEWEB)

    Gueniche, H.A.; Glaude, P.A.; Fournet, R.; Battin-Leclerc, F. [Departement de Chimie-Physique des Reactions, UMR 7630 CNRS, INPL-ENSIC, 1 rue Grandville, BP 20451, 54001 Nancy Cedex (France)

    2007-10-15

    In line with the study presented in Part I of this paper, the structure of a rich premixed laminar methane flame doped with 1,3-butadiene has been investigated. The flame contains 20.7% (molar) of methane, 31.4% of oxygen, and 3.3% of 1,3-butadiene, corresponding to an equivalence ratio of 1.8, and a C{sub 4}H{sub 6}/CH{sub 4} ratio of 16%. The flame has been stabilized on a burner at a pressure of 6.7 kPa using argon as dilutant, with a gas velocity at the burner of 36 cm/s at 333 K. The temperature ranged from 600 K close to the burner up to 2150 K. Quantified species included the usual methane C{sub 0}-C{sub 2} combustion products and 1,3-butadiene, but also propyne, allene, propene, propane, 1,2-butadiene, butynes, vinylacetylene, diacetylene, 1,3-pentadiene, 2-methyl-1,3-butadiene (isoprene), 1-pentene, 3-methyl-1-butene, benzene, and toluene. To model these new results, some improvements have been made to a mechanism previously developed in our laboratory for the reactions of C{sub 3}-C{sub 4} unsaturated hydrocarbons. The main reaction pathways of consumption of 1,3-butadiene and of formation of C{sub 6} aromatic species have been derived from flow rate analyses. In this case, the C{sub 4} route to benzene formation plays an important role in comparison to the C{sub 3} pathway. (author)

  18. 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.

  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. Modification of fiber properties through grafting of acrylonitrile to rayon by chemical and radiation methods

    OpenAIRE

    Inderjeet Kaur; Neelam Sharma; Vandna Kumari

    2013-01-01

    Fibrous properties of rayon has been modified through synthesis of graft copolymers of rayon with acrylonitrile (AN) by chemical method using ceric ammonium nitrate (CAN/HNO3) as a redox initiator and gamma radiation mutual method. Percentage of grafting (Pg) was determined as a function of initiator concentration, monomer concentration, irradiation dose, temperature, time of reaction and the amount of water. Maximum percentage of grafting (160.01%) using CAN/HNO3 was obtained at [CAN] = 22.8...

  1. Deposition of acrylonitrile cluster ions on solid substrates: thin film formation by intracluster polymerization products.

    Science.gov (United States)

    Yoshida, Hiroyuki; Sato, Naoki

    2006-03-01

    Cluster anions of acrylonitrile (AN), known to give intracluster anionic polymerization products, were deposited on solid substrates. The obtained films were examined by using infrared absorption spectroscopy, X-ray photoemission spectroscopy, and gel permeation chromatography with the aid of quantum chemical calculations. The acquired spectroscopic data are similar to those of polyacrylonitrile (PAN), while the normal polymerization of AN or reactions related to PAN seemed not to occur noticeably. On the contrary, the product analysis shows that most of the constituent molecules of the films are formed via cyclohexane-1,3,5-tricarbonitrile (CHTCN), a dominant product of the intracluster polymerization of AN, accompanied by fragmentation and dimerization. PMID:16509718

  2. 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

  3. 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.

  4. 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.

  5. 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).

  6. 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

  7. Ternary Ag/MgO-SiO2 catalysts for the conversion of ethanol into butadiene.

    Science.gov (United States)

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

    2015-03-01

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

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

    Science.gov (United States)

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

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

    Science.gov (United States)

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

    2012-12-01

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

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

    International Nuclear Information System (INIS)

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

  11. 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

    2011-07-01

    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 that the signals of oligoesters comprise a major fraction (0.10–0.33 of the signals of the SOA products observed from all dienes investigated. The oligoesters originate from the unsaturated aldehyde gas phase diene reaction products; namely, semi-volatile compounds produced by the oxidation of the unsaturated aldehyde undergo particle-phase oligoester formation. Oligoesters produced by the dehydration reaction between nitrooxypolyol and 2-methylglyceric acid monomer or its oligomer were also characterized 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

  12. 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.

  13. Production and market analysis of styrene butadiene rubber%丁苯橡胶生产及市场分析

    Institute of Scientific and Technical Information of China (English)

    晓战东; 孙雅斌; 白延军; 苏波; 郭滨诗

    2013-01-01

    The paper summarizes the production and market of styrene butadiene rubber both at home and abroad,analyzes the domestic styrene butadiene rubber development trend,and puts forward some advices on the problems in the domestic styrene butadiene rubber industry.%综述了国内外丁苯橡胶的生产及市场情况,对国内丁苯橡胶的市场发展趋势进行了分析.此外,还对国内丁苯橡胶行业存在的不足提出了几点建议.

  14. 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.

  15. 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.

  16. 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.

  17. Studies of plastic crystal gel polymer electrolytes based on poly(vinylidene chloride-co-acrylonitrile)

    Science.gov (United States)

    Hambali, D.; Zainuddin, Z.; Supa'at, I.; Osman, Z.

    2016-02-01

    In this work, we have prepared systems of poly(vinylidene chloride-co-acrylonitrile) (PVdC-co-AN) based gel polymer electrolytes (GPEs) which are single plasticized-GPEs and double plasticized-GPEs. Both systems comprised plastic crystal succinonitrile SN to form plastic crystal gel polymer electrolyte (PGPE) films. The ionic conductivity of the PGPE films were analysed by means of a.c. impedance spectroscopy at room temperature as well as at the temperature range of 303 K to 353 K. The temperature dependence ionic conductivity was found to obey the VTF rule. To study the interactions among the constituents in the PGPEs, Fourier Transform Infrared Spectroscopy (FTIR) was carried out and hence, the complexation between them has also been confirmed.

  18. 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

  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. Acrylonitrile-14C metabolism in rats: effect of the route of administration on the elimination of thiocyanate and other radioactive metabolites in urine and feces

    International Nuclear Information System (INIS)

    In Wistar rats, the elimination of the sum of radioactive metabolites of acrylonitrile-14C was not markedly influenced by the route of acrylonitrile administration. The elimination of thiocyanate, however, was significantly higher after oral (23% of the dose) than after intraperitoneal (4%), subcutaneous (4.6%), or intravenous (1.2%) administrations. The elimination of the sum of radioactive metabolites was highest in the first 4 hours after acrylonitrile administration and rapidly decreased whereas the excretion of thiocyanate reached the maximum between hours 8 and 14 after oral or intraperitoneal administration. Less than 1% of the radioactivity of the acrylonitrile-14C dose was eliminated in feces irrespective of the route of administration. (author)

  1. Covalent immobilization of glucose oxidase onto new modified acrylonitrile copolymer/silica gel hybrid supports.

    Science.gov (United States)

    Godjevargova, Tzonka; Nenkova, Ruska; Dimova, Nedyalka

    2005-08-12

    New polymer/silica gel hybrid supports were prepared by coating high surface area of silica gel with modified acrylonitrile copolymer. The concentrations of the modifying agent (NaOH) and the modified polymer were varied. GOD was covalently immobilized on these hybrid supports and the relative activity and the amount of bound protein were determined. The highest relative activity and sufficient amount of bound protein of the immobilized GOD were achieved in 10% NaOH and 2% solution of modified acrylonitrile copolymer. The influence of glutaraldehyde concentration and the storage time on enzyme efficiency were examined. Glutaraldehyde concentration of 0.5% is optimal for the immobilized GOD. It was shown that the covalently bound enzyme (using 0.5% glutaraldehyde) had higher relative activity than the activity of the adsorbed enzyme. Covalently immobilized GOD with 0.5% glutaraldehyde was more stable for four months in comparison with the one immobilized on pure silica gel, hybrid support with 10% glutaraldehyde and the free enzyme. The effect of the pore size on the enzyme efficiency was studied on four types of silica gel with different pore size. Silica with large pores (CPC-Silica carrier, 375 A) presented higher relative activity than those with smaller pore size (Silica gel with 4, 40 and 100 A). The amount of bound protein was also reduced with decreasing the pore size. The effect of particle size was studied and it was found out that the smaller the particle size was, the greater the activity and the amount of immobilized enzyme were. The obtained results proved that these new polymer/silica gel hybrid supports were suitable for GOD immobilization. PMID:16080168

  2. 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.

  3. 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.

  4. 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%.

  5. 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%.

  6. Genotoxicity of 1,3-butadiene and its epoxy intermediates.

    Science.gov (United States)

    Walker, Vernon E; Walker, Dale M; Meng, Quanxin; McDonald, Jacob D; Scott, Bobby R; Seilkop, Steven K; Claffey, David J; Upton, Patricia B; Powley, Mark W; Swenberg, James A; Henderson, Rogene F

    2009-08-01

    Current risk assessments of 1,3-butadiene (BD*) are complicated by limited evidence of its carcinogenicity in humans. Hence, there is a critical need to identify early events and factors that account for the heightened sensitivity of mice to BD-induced carcinogenesis and to deter-mine which animal model, mouse or rat, is the more useful surrogate of potency for predicting health effects in BD-exposed humans. HEI sponsored an earlier investigation of mutagenic responses in mice and rats exposed to BD, or to the racemic mixture of 1,2-epoxy-3-butene (BDO) or of 1,2,3,4-diepoxybutane (BDO2; Walker and Meng 2000). In that study, our research team demonstrated (1) that the frequency of mutations in the hypoxanthine-guanine phosphoribosyl transferase (Hprt) gene of splenic T cells from BD-exposed mice and rats could be correlated with the species-related differences in cancer susceptibility; (2) that mutagenic-potency and mutagenic-specificity data from mice and rats exposed to BD or its individual epoxy intermediates could provide useful information about the BD metabolites responsible for mutations in each species; and (3) that our novel approach to measuring the mutagenic potency of a given chemical exposure as the change in Hprt mutant frequencies (Mfs) over time was valuable for estimating species-specific differences in mutagenic responses to BD exposure and for predicting the effect of BD metabolites in each species. To gain additional mode-of-action information that can be used to inform studies of human responses to BD exposure, experiments in the current investigation tested a new set of five hypotheses about species-specific patterns in the mutagenic effects in rodents of exposure to BD and BD metabolites: 1. Repeated BD exposures at low levels that approach the occupational exposure limit for BD workers (set by the U.S. Occupational Safety and Health Administration) are mutagenic in female mice. 2. The differences in mutagenic responses of the Hprt gene to BD

  7. Oxidative Dehydrogenation of Butane to Butadiene and Butene Using a Novel Inert Membrane Reactor

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The oxidative dehydrogenation of butane to butadiene and butene was studied using a conventional fixed-bed ractor (FBR), inert membrane reactor (IMR) and mixed inert membrane reactor (MIMR). When IMR and MIMR were employed, a ceramic membrane modified by partially coating with glaze was used to distribute oxygen to a fixed-bed of 24-V-Mg-O catalyst. The oxygen partial pressure in the catalyst bed could be decreased. The effect of feeding modes and operation conditions were investigated. The selectivity of C4 dehydrogenation products (butene and butadiene) was found to be higher in IMR than in FBR. The feeding mode with 20% of air mixing with butane in MIMR was found to be more efficient than the feeding mode with all air permeating through ceramic membrane. The MIMR gave the most smooth temperature profile along the bed.

  8. Gamma Radiation Shielding Properties of Styrene- Butadiene Rubber/Lead Oxide Composites

    International Nuclear Information System (INIS)

    Styrene-butadiene rubber/lead oxide composites were prepared as gamma-radiation shields. The composites were prepared with different concentrations of red lead oxide (Pb3O4). The assessment of the linear attenuation coefficient of the SBR/lead oxide composites for gamma -rays from 137Cs gamma -radiation point source was studied. The styrene-butadiene rubber/lead oxide composites can attain up to about 43% of the shielding capacity of pure lead. The incorporation of high concentrations of lead oxide and the effect of accumulative irradiation doses up to 3000 kGy on the physico-mechanical properties of the composites were studied. These led to hardening of the SBR rubber/lead oxide composites

  9. 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...

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

    OpenAIRE

    S. Goksin Aydinli; Cemil Ibis

    2010-01-01

    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 compou...

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

    OpenAIRE

    Er. Kapil Soni; Dr. Y. P Joshi

    2014-01-01

    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 t...

  12. 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 ...

  13. 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.

  14. 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.

  15. 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.

  16. 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+.

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

    Science.gov (United States)

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

    2014-09-15

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

  18. Preparation and evaluation of some investigated natural and acrylonitrile rubber vulcanizations for physiotherapeutic purposes

    International Nuclear Information System (INIS)

    A trial was made to design and prepare rubber article that can be used to reactivate, strengthen and reinforce the hand muscles and fingers which had suffered from trouble movement.The investigated rubber article was prepared from natural and acrylonitrile rubber formulations. These formulations were processed in the form of compounds which contain significant quantities of fillers as Hisil, CaCO3 and TiO2.The rheological characteristics and physicochemical properties of the vulcanizations were determined according to standard tests. It was found that it is possible to prepare the designated rubber article for the desired purpose. The test results show that the prepared rubber article has a good chemical resistant against acid, alkali, and salt. Also it possesses high resistance to deterioration and deformation. The prepared article has an ability to retain its elastic property after the action of compressive forces at 70 degree C for 24 hours.This was conformed with applied commercial hand exercise therapeutic article

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. AGET ATRP of acrylonitrile with ionic liquids as reaction medium without any additional ligand

    Energy Technology Data Exchange (ETDEWEB)

    Chen Hou, E-mail: lduchenhou@hotmail.com [School of Chemistry and Materials Science, Ludong University, Yantai 264025 (China); Liang Ying; Liu Delong; Tan Zhi; Zhang Shaohong; Zheng Meiling; Qu Rongjun [School of Chemistry and Materials Science, Ludong University, Yantai 264025 (China)

    2010-05-10

    Atom transfer radical polymerization using activators generated by electron transfer (AGET ATRP) of acrylonitrile (AN) was carried out for the first time in 1-methylimidazolium acetate ([mim][AT]), 1-methylimidazolium propionate([mim][PT]), and 1-methylimidazolium butyrate ([mim][BT]), respectively. The polymerization was approached by using ascorbic acid (VC) as a reducing agent, ethyl 2-bromoisobutyrate (EBiB) as initiator, only FeBr{sub 3} as catalyst without any additional ligand. Kinetic studies showed that both AGET ATRP of AN in the absence of oxygen and in the presence of air proceeded in a well-controlled manner. Under the same conditions, the polymerization in the presence of air provided rather slower reaction rate and showed better control of molecular weight and its distribution than in the absence of oxygen. The sequence of the apparent polymerization rate constants of AGET ATRP of AN in three ionic liquids was k{sub app}([mim][AT]) > k{sub app}([mim][PT]) > k{sub app}([mim][BT]). The living nature of the polymerization was confirmed by chain end analysis and block copolymerization of methyl methacrylate with polyacrylonitrile as macroinitiator. All the three ionic liquids and FeBr{sub 3} could be recycled and reused and had no effect on the living nature of polymerization.

  4. "CAGE" VANADYL POLYCARBOXYLATE-THIOUREA COMPLEX FOR THE POLYMERIZATION OF ACRYLONITRILE

    Institute of Scientific and Technical Information of China (English)

    WU Jinyuan; YANG Chaoxiong

    1993-01-01

    The polymerization of acrylonitrile (AN) in aqueous nitric acid initiated by " cage" vanadyl polycarboxylate (P=VO)- thiourea (TU) complex was investigated. The overall rate of polymerization is Rp=9.7×105e-10,500/RT[AN][HNO3]1.5[P =VO]0.50[TU]0.76 The relationship between the induction period (τ) and the temperature of polymerization as well as the concentrations of reactants can be expressed as follows: 1/τ=4.6× 1012e-13,500/RT[HNO3]3[p=VO][TU]3/2=KτRiThe molecular weight of polyacrylonitrile(-Mn)increases with increasing monomer concentrationand decreases with increasing temperature of polymerization and concentrations of vanadyl polycarboxylate and thiourea (-M)n=KM1/τ.[AN]/[HNO3]3/2[P=VO1/2[TU]3/4=KM·1/τ·Rp/R1] The polymerization mechanism was proposed and discussed.

  5. 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.

  6. 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.

  7. Mutations induced by 1,3-butadiene metabolites, butadiene diolepoxide, and 1,2,3,4-diepoxybutane at the Hprt locus in CHO-K1 cells.

    Science.gov (United States)

    Lee, Dong-Hyun; Kim, Tae-Ho; Lee, Sun-Young; Kim, Hyun-Jo; Rhee, Seung Keun; Yoon, ByoungSu; Pfeifer, Gerd P; Lee, Chong-Soon

    2002-12-31

    Butadiene (BD) is an important industrial chemical that is classified as a probable human carcinogen. Butadiene diolepoxide (BDE) and 1,2,3,4-diepoxybutane (DEB) are metabolites of carcinogenic BD and contain the DNA-reactive one and two epoxides, respectively. In this study, the mutation frequencies and mutation spectra that are induced by BDE and DEB have been investigated at the hprt locus in CHO-K1 cells. The BDE- and DEB-treated CHO-K1 cells were allowed to grow for several days, then seeded in a medium that contained 6-thioguanine in order to select the hprt mutants. BDE exhibited the mutagenic activity at concentrations that were approximately 100-times higher than DEB. The mutation spectra for BDE and DEB were determined by a reverse transcription-polymerase chain reaction of hprt mRNA, which was followed by automatic DNA sequencing of the PCR products. The mutational spectrum for BDE was exon deletions (16/41), G x C --> A x T transitions (11/41), and A x T --> G x C transitions (5/41). The mutational spectrum for DEB was exon deletions (15/39), G x C --> A x T transitions (11/39), and A x T --> T x A transversions (5/39). The most common base substitution that was induced by both BDE and DEB was G x C --> A x T transitions. The sites of the single base substitutions that were induced by BDE and DEB were guanine and adenine, which was consistent with the DNA adduct profiles. The high frequencies of the exon deletions by each metabolite occurred in the regions of exons 2, 3, or 4. These data indicate that BDE and DEB are mutagenic carcinogens by forming DNA adducts at the site of adenine and guanine, and inducing large exon deletions and single base substitutions. PMID:12521305

  8. 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.

  9. STUDY ON STYRENE-BUTADIENE BLOCK COPOLYMER FOR THE MODIFICATION OF TIRE TREAD

    Institute of Scientific and Technical Information of China (English)

    WANG Yan; CHEN Weijie; MU Ruifeng; WANG Yongwei; YU Fengnian; LIU Qing

    1996-01-01

    This paper mainly deals with the design and synthesis of a novel styrene-butadiene block copolymer. When this copolymer is used in the tread portion of tyres, it can improve wet skid resistance and reduce rolling resistance without sacrificing its general physicalmechanical properties. The visco-elastic curve of tire tread using the novel copolymer as its rubber portion was showed. Reactivity ratios for two monomers in the polymerizing system were calculated. The diagrams of differential, integral and finite difference calculi throughout the whole molecular chain were presented. The influence of the micro- and macro-structure of the copolymer chain on wet skid resistance and rolling resistance was discussed.

  10. Reinforcing styrene butadiene rubber with lignin-novolac epoxy resin networks

    OpenAIRE

    Yu, P.; He, H; Jiang, C; Wang, D; Jia, Y.; Zhou, L.; D. M. Jia

    2015-01-01

    In this study, lignin-novolac epoxy resin networks were fabricated in the styrene butadiene rubber (SBR) matrix by combination of latex compounding and melt mixing. Firstly, SBR/lignin compounds were co-coagulated by SBR latex and lignin aqueous solution. Then the novolac epoxy resin (F51) was added in the SBR/lignin compounds by melt compounding method. F51 was directly cured by lignin via the ring-opening reaction of epoxy groups of F51 and OH groups (or COOH groups) of lignin during the cu...

  11. Analysis and optimization of nitrile butadiene rubber sealing mechanism of ball valve

    Institute of Scientific and Technical Information of China (English)

    Xue-Guan SONG; Lin WANG; Young-Chul PARK

    2009-01-01

    An approach for analyzing and optimizing sealing mechanism of ball valve made of nitrile butadiene mbber(NBR) with finite element method was presented. The Mooney-Rivlin hyperelastic material model was chosen to characterize NBR sealing, as it has been recommended in the similar applications. That is, NBR sealing was modeled as incompressible hyperelasticity, as well as the assumption of isotropic flow. The results illustrate the structural pressure and contact pressure on the contact surface, which shows that the NBR sealing mechanism is very suitable for sealing after dimension optimization.

  12. 1,3-Butadiene hydrogenation on pd-supported systems: geometric effects

    Directory of Open Access Journals (Sweden)

    Souza P.R.N.

    2002-01-01

    Full Text Available A strong metal support interaction (SMSI effect was observed on Pd/Nb2O5 and Pd/TiO2 catalysts, and it produces small, exposed Pd ensembles. A decrease in the trans/cis 2-butene ratio was observed after reduction at 773 K. Selectivity changes were ascribed to the decoration model. Theoretical models were developed based on semi-empirical molecular-orbital calculations for 1,3-butadiene and Pd n clusters. Experimental results are in agreement with our theoretical model, which proposes a greater stabilization of the cisoid intermediate on small Pd ensembles.

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

    OpenAIRE

    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 wt.-%, respectively) in the two kinds of used PS-co-MA samples afforded a good compatibility between the PS phases of the two polymers. On the other hand, the presence of polar anhydride groups allo...

  14. Self-Assembled Poly(butadiene)-b-Poly(ethylene oxide) Polymersomes as Paclitaxel Carriers

    OpenAIRE

    Li, Shuliang; Byrne, Belinda; Welsh, JoEllen; Palmer, Andre F.

    2007-01-01

    In this work, self-assembled poly(butadiene)-b-poly(ethylene oxide) (PB-PEO) polymersomes (polymer vesicles) and worm micelles were evaluated as paclitaxel carriers. Paclitaxel was successfully incorporated into PB-PEO polymersomes and worm micelles. The loading capacity of paclitaxel inside PB-PEO colloids ranged from 6.7-13.7% w/w, depending on the morphology of copolymer colloids and the molecular weight of diblock copolymer. Paclitaxel loaded OB4 (PB219-PEO121) polymersome formulations we...

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

    Science.gov (United States)

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

    2009-06-01

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

  16. 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.

  17. 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.

  18. 国内外丙烯腈供需现状和发展趋势%Global Supply & Demand Situation and Developing Trend of Acrylonitrile

    Institute of Scientific and Technical Information of China (English)

    吴宇红

    2012-01-01

    介绍了丙烯腈的国内外供需现状,分析了未来丙烯腈装置的投资计划及下游应用领域的需求情况,并预测了未来丙烯腈供需状况。估计到2015年全球丙烯腈产能将出现过剩,投资还需谨慎。%The global supply and demand situation of acrylinitrile was introduced.Based on anaysis of acrylinitrile plant investment plans and demand situation of downstream application filelds,the supply and demand situation of acrylonitrile in the future was predicted.It is predicted that global acrylonitrile capability would be surplus by 2015,so investment on acrylonitrile needs discretion.

  19. Dynamic and kinetic aspects of the adsorption of acrylonitrile on Si(001)-2x1

    International Nuclear Information System (INIS)

    Using scanning tunnelling microscopy (STM), photoelectron and photoabsorption spectroscopies, we have examined how acrylonitrile (H2C=CH-C≡N) reacts with the Si(001)-2x1 surface for coverages ranging from ∼1012 molecules/cm2 to ∼1014 molecules/cm2. At 300 K, in the very low coverage regime (below 1013 molecules/cm2), filled- and empty-state STM images show that the molecule bridges, via its β carbon and nitrogen ends, two silicon dangling bonds, across the trench separating two dimer rows. A cumulative-double-bond unit (C=C=N) is formed. The 300 K STM image results from the dynamic flipping of the molecule between two equivalent equilibrium positions, which can be seen when the molecular motion is slowed down at 80 K. For coverages larger than 1013 molecules/cm2, for which STM does not show ordered adsorption any more, the adsorption kinetics were observed in real-time using valence band photoemission and resonant Auger yield, associated with N 1s x-ray absorption spectroscopy (NEXAFS). At 300 K, these techniques point to a situation more complex than the one explored by STM at very low coverage. Three species (cyano-bonded, vinyl-bonded, and cumulative-double-bond species) are detected. Their distribution does not vary with increasing coverage. All dimerization-related surface states are quenched at saturation. The uptake rates versus coverage relationship points to the presence of a mobile precursor. Finally, the paper discusses a possible mechanism leading to the formation of cross-trench C=C=N unit at low coverage, and the reasons why the product branching ratio changes with increasing coverage

  20. Nanofibrous poly(acrylonitrile-co-maleic acid) membranes functionalized with gelatin and chitosan for lipase immobilization.

    Science.gov (United States)

    Ye, Peng; Xu, Zhi-Kang; Wu, Jian; Innocent, Christophe; Seta, Patrick

    2006-08-01

    Nanofibrous membranes with an average diameter of 100 and 180 nm were fabricated from poly(acrylonitrile-co-maleic acid) (PANCMA) by the electrospinning process. These nanofibrous membranes contain reactive groups which can be used to covalently immobilize biomacromolecules. Two natural macromolecules, chitosan and gelatin, were tethered on these nanofibrous membranes to fabricate dual-layer biomimetic supports for enzyme immobilization in the presence of 1-ethyl-3-(dimethyl-aminopropyl) carbodiimide hydrochloride (EDC)/N-hydroxyl succinimide (NHS). Lipase from Candida rugosa was then immobilized on these dual-layer biomimetic supports using glutaraldehyde (GA), and on the nascent PANCMA fibrous membrane using EDC/NHS as coupling agent, respectively. The properties of the immobilized lipases were assayed. It was found that there is an increase of the activity retention of the immobilized lipase on the chitosan-modified nanofibrous membrane (45.6+/-1.8%) and on the gelatin-modified one (49.7+/-1.8%), compared to that on the nascent one (37.6+/-1.8%). The kinetic parameters of the free and immobilized lipases, K(m) and V(max), were also assayed. In comparison with the immobilized lipase on the nascent nanofibrous membrane, there is an increase of the V(max) value for the immobilized lipases on the chitosan- and gelatin-modified nanofibrous membranes. Results also indicate that the pH and thermal stabilities of lipases increase upon immobilization. The residual activities of the immobilized lipases are 55% on the chitosan-modified nanofibrous membrane and 60% on the gelatin-modified one, after 10 uses. PMID:16584770

  1. Chitosan-tethered poly(acrylonitrile-co-maleic acid) hollow fiber membrane for lipase immobilization.

    Science.gov (United States)

    Ye, Peng; Xu, Zhi-Kang; Che, Ai-Fu; Wu, Jian; Seta, Patrick

    2005-11-01

    A protocol was used to prepare a dual-layer biomimetic membrane as support for enzyme immobilization by tethering chitosan on the surface of poly(acrylonitrile-co-maleic acid) (PANCMA) ultrafiltration hollow fiber membrane in the presence of 1-ethyl-3-(dimethylaminopropyl) carbodiimide hydrochloride (EDC)/N-hydroxylsuccin-imide (NHS). The chemical change of the chitosan-modified PANCMA membrane surface was confirmed with Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy. Lipase from Candida rugosa was immobilized on this dual-layer biomimetic membrane using glutaraldehyde (GA), and on the nascent PANCMA membrane using EDC/NHS as coupling agent. The properties of the immobilized enzymes were assayed and compared with those of the free one. It was found that both the activity retention of the immobilized lipase and the amount of bound protein on the dual-layer biomimetic membrane (44.5% and 66.5 mg/m2) were higher than those on the nascent PANCMA membrane (33.9% and 53.7 mg/m2). The kinetic parameters of the free and immobilized lipases, Km and Vmax, were also assayed. The Km values were similar for the immobilized lipases, while the Vmax value of the immobilized lipase on the dual-layer biomimetic membrane was higher than that on the nascent PANCMA membrane. Results indicated that the pH and thermal stabilities of lipase increased upon immobilization. The residual activity of the immobilized lipase after 10 uses was 53% on the dual-layer biomimetic membrane and 62% on the nascent PANCMA membrane. PMID:15919112

  2. Modeling contaminant transport and remediation at an acrylonitrile spill site in Turkey

    Science.gov (United States)

    Şengör, S. Sevinç; Ünlü, Kahraman

    2013-07-01

    The August 1999 earthquake in Turkey damaged three acrylonitrile (AN) storage tanks at a plant producing synthetic fiber by polymerization. A numerical modeling study was carried out to analyze the groundwater flow and contaminant (AN) transport at the spill site. This study presents the application of a numerical groundwater model to determine the hydrogeological parameters of the site, where such data were not available during the field surveys prior to the simulation studies. The two- and three-dimensional transient flow and transport models were first calibrated using the first 266 days of observed head and concentration data and then verified using the remaining 540-day observed data set. Off-site migration of the contaminant plume was kept under control within the site boundaries owing to the favorable geology of the site, the characteristics of the local groundwater flow regime and the pumping operations. As expected, the applied pump-and-treat system was effective at high-permeability zones, but not fully effective at low-permeability zones. The results of long-term simulations for unconfined aquifer showed that the size of the plume in the high permeability zone shrank significantly due to the dilution by natural recharge. However, in the low permeability zone, it was not significantly affected. The study showed that accurate and sufficient data regarding the source characteristics, concentration and groundwater level measurements, groundwater pumping rates and their durations at each of the extraction points involved in the pump-and-treat system along with the hydrogeological site characterization are the key parameters for successful flow and transport model calibrations.

  3. Modification of fiber properties through grafting of acrylonitrile to rayon by chemical and radiation methods

    Directory of Open Access Journals (Sweden)

    Inderjeet Kaur

    2013-11-01

    Full Text Available Fibrous properties of rayon has been modified through synthesis of graft copolymers of rayon with acrylonitrile (AN by chemical method using ceric ammonium nitrate (CAN/HNO3 as a redox initiator and gamma radiation mutual method. Percentage of grafting (Pg was determined as a function of initiator concentration, monomer concentration, irradiation dose, temperature, time of reaction and the amount of water. Maximum percentage of grafting (160.01% using CAN/HNO3 was obtained at [CAN] = 22.80 × 10−3 mol/L, [HNO3] = 112.68 × 10−2 mol/L and [AN] = 114.49 × 10−2 mol/L in 20 mL of water at 45 °C within 120 min while in case of gamma radiation method, maximum Pg (90.24% was obtained at an optimum concentration of AN of 76.32 × 10−2 mol/L using 10 mL of water at room temperature with total dose exposure of 3.456 kGy/h. The grafted fiber was characterized by FTIR, SEM, TGA and XRD studies. Swelling behavior of grafted rayon in different solvents such as water, methanol, ethanol, DMF and acetone was studied and compared with the unmodified rayon. Dyeing behavior of the grafted fiber was also investigated.

  4. 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.

  5. 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.

  6. 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.

  7. Thermodynamic calculations for molecules with asymmetric internal rotors--application to 1,3-butadiene.

    Science.gov (United States)

    Wong, Bryan M; Raman, Sumathy

    2007-03-01

    We present quantum mechanical partition functions, free energies, entropies, and heat capacities of 1,3-butadiene derived from ab initio calculations. Our technique makes use of a reaction path-like Hamiltonian to couple all 23 vibrational modes to the large-amplitude torsion, which involves heavy asymmetric functional groups. Ab initio calculations were performed at the B3LYP, MP2, and CCSD(T) levels of theory and compared with experimental values as a reference case. By using the ab initio potentials and projected frequencies, simple perturbative expressions are presented for computing the couplings of all the vibrational modes to the large-amplitude torsion. The expressions are particularly suited for programming in the new STAR-P software platform which automatically parallelizes our codes with distributed memory via a familiar MATLAB interface. Using the efficient parallelization scheme of STAR-P, we obtain thermodynamic properties of 1,3-butadiene for temperatures ranging from 50 to 500 K. The free energies, entropies, and heat capacities obtained from our perturbative formulas are compared with conventional approximations and experimental values found in thermodynamic tables. PMID:17226834

  8. 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.

  9. 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.

  10. 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.

  11. Ethanol-to-Butadiene Conversion over SiO2-MgO Catalysts: Synthesis-Structure-Performance Relationships

    NARCIS (Netherlands)

    Angelici, C.

    2015-01-01

    The work presented in this PhD Thesis provides new insights into the underlying reasons that make SiO2-MgO materials excellent catalysts for the ethanol-to-butadiene Lebedev process. In particular, the preparation technique of choice affects the structural properties of the resulting SiO2-MgO materi

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

    Science.gov (United States)

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

  13. THE EFFECT OF ETHERS ON ALTERNATING COPOLYMERIZATION OF BUTADIENE AND PROPYLENE CATALYZED BY VANADIUM-ALUMINUM SYSTEM

    Institute of Scientific and Technical Information of China (English)

    SU Dan; YU Dingsheng; HU Liping; JIAO Shuke

    1988-01-01

    The effect of five ethers on alternating copolymerization of butadiene and propylene were investigated. It was found that under appropriate conditions, by adding ether into reaction system, the conversion could be increased by 10-20% and the catalytic efficiency doubled at -45℃. The interaction between ether and active center was also studied.

  14. 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.

  15. Emissions of benzene, toluene, xylenes and 1,3-butadiene from a representative portion of the Australian car fleet

    Science.gov (United States)

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

    The exhaust emissions of the air toxics benzene, toluene, total xylenes and 1,3-butadiene have been measured in the cold transient (CT), cold stabilised (CS) and hot transient (HT) phases of the Australian Design Rule (ADR) 37/00 Drive cycle for 19 pre-1986 non-catalyst-equipped vehicles fuelled with leaded petrol, and 56 post-1985 catalyst-equipped vehicles fuelled with unleaded petrol. Per vehicle exhaust emissions, averaged over the 3 phases of the ADR 37/00 test, of 1,3-butadiene, benzene, toluene, and total xylenes for the older vehicles were about 19, 139, 240 and 164 mg km -1 respectively. The corresponding emissions for the better 46 of the 56 post-1985 vehicles tested were 1.7, 28.1, 36.4, and 27.0 mg km- 1 respectively. The remaining 10 high polluting post-1985 vehicles had emission rates comparable to those vehicles not equipped with catalytic converters, suggesting that about 20% of post-1985 vehicles have malfunctioning or poorly operating catalysts. For the non-catalyst-equipped, pre-1986 vehicles, CS and HT emissions were about 60% of the CT emissions. For the better 46 post-1985 vehicles, average emissions during the CS and HT phases were about 20-25%, 12-16%, 11-14%, and 7-13% of the CT emissions for benzene, toluene, the xylenes, and 1,3-butadiene, respectively. The emissions from a small number (9) of non-catalyst-equipped, pre-1986 vehicles were determined using unleaded and leaded petrol. The emissions of all four target compounds were found to be significantly lower when unleaded petrol was substituted for leaded petrol. The greatest percentage emission reductions were observed for the CT phase, ranging from 25% for 1,3-butadiene to 35% for toluene. Emissions averaged over the 3 phases were reduced by 10% for 1,3-butadiene and by 16-18% for the aromatic compounds. Per vehicle total (heat build and hot soak) evaporative emissions of 1,3-butadiene, benzene, toluene and xylenes from pre-1985 vehicles during the Sealed Housing Evaporative

  16. The Protective Value of Hesperidin in Mitigating the Biochemical Perturbations and Trace Element alterations induced by Acrylonitrile in Rats

    Directory of Open Access Journals (Sweden)

    N. M. Abdallah*, N. E. Amien**, M. R. Mohamed*, A. S. Nada**, M. A. Mohamed

    2013-07-01

    Full Text Available Objective: Acrylonitrile (a chemical pollutant has been reported to induce harmful effects in humans. Therefore, this study was designed to evaluate the protective effects of hesperidin, a natural bioflavonoid, against the toxicity induced by acrylonitrile (AN in rats. Material&Methods: This study includes determination of serum total scavenger capacity “TSC”, liver enzymes (aspartate transaminase “ASAT”, alanine transaminase “ALAT” and alkaline phosphatase “ALP”, total proteins, albumin, glucose, creatinine, urea and lipid profile. Moreover, liver and kidney homogenate glutathione content “GSH”, catalase, superoxide dismutase “SOD”, glutathione peroxidase “GPx”, malondialdehyde “MDA” and some minerals were estimated. Results: revealed that administration of AN (orally 50mg/ kg b.wt. induced alterations in TSC level as well as liver, kidney and lipid profiles. In addition, a decrease in GSH-content and catalase, SOD and GPx activities was observed with an increase in MDA levels in both liver and kidney. There was disturbance in certain minerals such as Cu, Zn, Fe, Se, Ca, Mg and Mn. Conclusion: particularly, Hesperidin administration (orally 200 mg/kg b.wt. ameliorates the oxidative stress induced by AN, consistent with the reported antioxidant activity of hesperidin

  17. Dye-sensitized solar cell with poly(acrylic acid-co-acrylonitrile)-based gel polymer electrolyte

    International Nuclear Information System (INIS)

    Highlights: ► A nontoxic, easily synthesized poly(acrylic acid-co-acrylonitrile) showed suitable transmittance for dye-sensitized solar cell. ► A cell with relatively large active area fabricated with this polymer material showed acceptable efficiency. ► The gel polymer matrix affected the charge recombination, I3− diffusion, double layer capacitance, and electron lifetime in the cell. - Abstract: A non-conducting, nontoxic poly(acrylic acid-co-acrylonitrile) (PAA) was prepared and used as a supporting matrix for the electrolyte of dye-sensitized solar cells (DSSCs). DSSCs of active area 0.80 cm × 1.10 cm fabricated with PAA, 0.5 M LiI, 0.05 M I2, 0.5 M 3-tert-butylpyridine, and 0.1 M 1-methyl-3-propylimidazolium iodide in 3-methoxypropionitrile solvent showed an average solar energy conversion efficiency of 1.61% under simulated sunlight illumination of 100 mW cm−2, AM 1.5. The effects of the gel polymer matrix on the electrochemical properties of DSSCs were studied using the electrochemical impedance spectroscopy. Relative to the non-gel reference cells, the results showed a decrease in charge recombination, ionic diffusion, and double layer capacitance and an increase in electron lifetime. These results could play an important role in determining the future direction for the development of high-performance gel polymer electrolytes.

  18. 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.

  19. Acrylonitrile potentiates hearing loss and cochlear damage induced by moderate noise exposure in rats

    International Nuclear Information System (INIS)

    The diversity of chemical and drugs that can potentiate noise-induced hearing loss (NIHL) has impeded efforts to predict such interactions. We have hypothesized that chemical contaminants that disrupt intrinsic antioxidant defenses hold significant risk for potentiating NIHL. If this is true, then acrylonitrile (ACN) would be expected to potentiate NIHL. ACN, one of the 50 most commonly used chemicals in the United States, is metabolized via two pathways that are likely to disrupt intrinsic reactive oxygen species (ROS) buffering systems: (1) it conjugates glutathione, depleting this important antioxidant rapidly; (2) a second pathway involves the formation of cyanide, which can inhibit superoxide dismutase. We hypothesized that moderate noise exposure, that does not produce permanent hearing loss by itself, could initiate oxidative stress and that ACN could render the inner ear more sensitive to noise by disrupting intrinsic antioxidant defenses. Temporary and persistent effects of ACN alone (50 mg/kg, sc 5 days), noise alone (95 or 97 dB octave band noise, 4 h/day for 5 days), or ACN in combination with noise were determined using distortion product otoacoustic emissions (DPOAEs) and compound action potential (CAP) amplitudes. Histopathological damage to hair cells resulting from these treatments was also investigated using surface preparations of the organ of Corti. Individually, neither ACN nor noise exposures caused any permanent hearing or hair cell loss; only a reversible temporary threshold shift was measured in noise-exposed animals. However, when given in combination, ACN and noise induced permanent threshold shifts (13-16 dB between 7 and 40 kHz) and a decrease in DPOAE amplitudes (up to 25 dB at 19 kHz), as well as significant outer hair cell (OHC) loss (up to 20% in the first row between 13 and 47 kHz). This investigation demonstrates that ACN can potentiate NIHL at noise levels that are realistic in terms of human exposure, and that the OHCs are the

  20. 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

  1. 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)

  2. 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.

  3. Fluorescence efficiency and visible re-emission spectrum of tetraphenyl butadiene films at extreme ultraviolet wavelengths

    Science.gov (United States)

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

    2011-10-01

    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 to 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 re-emits 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.

  4. Conversion of far ultraviolet to visible radiation: absolute measurements of the conversion efficiency of tetraphenyl butadiene

    Science.gov (United States)

    Vest, Robert E.; Coplan, Michael A.; Clark, Charles W.

    Far ultraviolet (FUV) scintillation of noble gases is used in dark matter and neutrino research and in neutron detection. Upon collisional excitation, noble gas atoms recombine into excimer molecules that decay by FUV emission. Direct detection of FUV is difficult. Another approach is to convert it to visible light using a wavelength-shifting medium. One such medium, tetraphenyl butadiene (TPB) can be vapor-deposited on substrates. Thus the quality of thin TPB films can be tightly controlled. We have measured the absolute efficiency of FUV-to-visible conversion by 1 μm-thick TPB films vs. FUV wavelengths between 130 and 300 nm, with 1 nm resolution. The energy efficiency of FUV to visible conversion varies between 1% and 5%. We make comparisons with other recent results. Work performed at the NIST SURF III Synchrotron Ultraviolet Radiation Facility,.

  5. Tetraphenyl-butadiene films: VUV-Vis optical characterization from room to liquid argon temperature

    Science.gov (United States)

    Francini, R.; Montereali, R. M.; Nichelatti, E.; Vincenti, M. A.; Canci, N.; Segreto, E.; Cavanna, F.; Di Pompeo, F.; Carbonara, F.; Fiorillo, G.; Perfetto, F.

    2013-09-01

    A thin film of Tetraphenyl-butadiene (TPB) deposited onto the surface delimiting the active volume of the detector and/or onto the photosensor's optical window is the most common solution to down convert argon VUV scintillation light in current and planned liquid argon based experiments for dark matter searches and neutrino physics. Characterization of the main features of TPB coatings on different, commonly used substrates is reported, as a result of measurements at the specialized optical metrology labs of ENEA and University of Tor Vergata. Measured features include TPB emission spectra with lineshape and relative intensity variation recorded as a function of the film thickness and for the first time down to LAr temperature, as well as optical reflectance and transmittance spectra of the TPB coated substrates in the wavelength range of the TPB emission.

  6. Wavelength Shifting Efficiency of Tetraphenyl Butadiene (TPB) at Extreme Ultraviolet Wavelengths

    Science.gov (United States)

    Benson, Christopher; Orebi Gann, Gabriel; Gehman, Victor

    2015-10-01

    Tetraphenyl Butadiene (TPB) is a commonly used wavelength shifter (WLS) in neutrino and dark matter liquid noble gas scintillator detectors. Thin films of wavelength shifters are used to shift ultraviolet scintillation light into the visible spectrum for event reconstruction. The wavelength shifting efficiency of TPB is a function of the incident ultraviolet photon wavelength and is an important parameter for detector design, simulation and reconstruction. The wavelength shifting efficiency and emission spectrum has been previously measured down to 120 nm [Gehman et al., 2011]. To build liquid noble gas scintillator detectors with lighter elements (Ne, He) that use TPB as a WLS medium, the wavelength shifting efficiency must be known closer to 80 nm. This talk will present the current status and preliminary results from a set of measurements that will improve the precision of the efficiency of 120 nm, and extend the data to wavelengths as low as 45 nm.

  7. 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.

  8. 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.

  9. 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.

  10. 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

    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......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...... 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.%)....

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

    Science.gov (United States)

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

    2016-01-01

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

  12. 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.

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

    International Nuclear Information System (INIS)

    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: ► Styrene-butadiene-styrene block copolymer (SBS) was modified with tri-steps. ► The tri-steps are epoxidation, ring opening reaction and layer-by-layer assembly. ► Modified SBS membrane for wound dressing is evaluated. ► Membranes are sterile semipermeable with bactericidal activity and transparent. ► Membranes can be considered for shallow wound with low exudates.

  14. 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.

  15. The use of poly(vinylpyridine-co-acrylonitrile) in polymer electrolytes for quasi-solid dye-sensitized solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Li, Minyu [Beijing National Laboratory for Molecular Sciences (BNLMS), Key Laboratory of photochemistry, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100080 (China); Graduate School of Chinese Academy of Sciences, Beijing 100039 (China); Feng, Shujing; Fang, Shibi; Xiao, Xurui; Li, Xueping; Zhou, Xiaowen; Lin, Yuan [Beijing National Laboratory for Molecular Sciences (BNLMS), Key Laboratory of photochemistry, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100080 (China)

    2007-04-01

    Poly(vinylpyridine-co-acrylonitrile) (P(VP-co-AN)) was used to form polymer electrolytes for dye-sensitized solar cells (DSSCs). The effects of P(VP-co-AN) on the photovoltaic performances of DSSCs have been investigated with nonaqueous electrolytes containing alkali-iodide and iodine. It was found that the effect of P(VP-co-AN) on V{sub oc} closely related to its amount in the electrolyte. Lower amount of P(VP-co-AN) was benefit for the construction of a solar cell containing P(VP-co-AN) with higher energy conversion efficiency. Chemically crosslinking solidification with backbone polymer P(VP-co-AN) amount of 3% fabricated quasi-solid DSSCs with 10% increased conversion efficiencies with relative to that of the initial liquid DSSCs. (author)

  16. The use of poly(vinylpyridine-co-acrylonitrile) in polymer electrolytes for quasi-solid dye-sensitized solar cells

    International Nuclear Information System (INIS)

    Poly(vinylpyridine-co-acrylonitrile) (P(VP-co-AN)) was used to form polymer electrolytes for dye-sensitized solar cells (DSSCs). The effects of P(VP-co-AN) on the photovoltaic performances of DSSCs have been investigated with nonaqueous electrolytes containing alkali-iodide and iodine. It was found that the effect of P(VP-co-AN) on V oc closely related to its amount in the electrolyte. Lower amount of P(VP-co-AN) was benefit for the construction of a solar cell containing P(VP-co-AN) with higher energy conversion efficiency. Chemically crosslinking solidification with backbone polymer P(VP-co-AN) amount of 3% fabricated quasi-solid DSSCs with 10% increased conversion efficiencies with relative to that of the initial liquid DSSCs

  17. 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.

  18. 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.

  19. Use of Yb-based catalyst for AGET ATRP of acrylonitrile to simultaneously control molecular mass distribution and tacticity.

    Science.gov (United States)

    Ma, Jing; Chen, Hou; Zhang, Min; Wang, Chunhua; Zhang, Ying; Qu, Rongjun

    2012-08-01

    Yb-based catalyst was used for the first time for atom transfer radical polymerization using activators generated by electron transfer (AGET ATRP) of acrylonitrile (AN) with 2-bromopropionitrile (BPN) as initiator, 2, 2'-bipyridine (bipy) as ligand, and tisn(II) bis(2-ethylhexanoate) (Sn(EH)2) as reducing agent in the presence of air. With respect to AGET ATRP of AN catalyzed by CuBr2, an evident increase of polymer tacticity was observed for AGET ATRP of AN. The increase of syndiotacticity became more and more pronounced than the increase of isotacticity of polyacrylonitrile (PAN) along with YbBr3 content. The block copolymer PAN-b-PMMA with molecular weight at 60,000 and polydispersity at 1.36 was successfully prepared. PMID:24364980

  20. Selective hydrogenation of 1,3-butadiene on platinum-copper alloys at the single-atom limit.

    Science.gov (United States)

    Lucci, Felicia R; Liu, Jilei; Marcinkowski, Matthew D; Yang, Ming; Allard, Lawrence F; Flytzani-Stephanopoulos, Maria; Sykes, E Charles H

    2015-01-01

    Platinum is ubiquitous in the production sectors of chemicals and fuels; however, its scarcity in nature and high price will limit future proliferation of platinum-catalysed reactions. One promising approach to conserve platinum involves understanding the smallest number of platinum atoms needed to catalyse a reaction, then designing catalysts with the minimal platinum ensembles. Here we design and test a new generation of platinum-copper nanoparticle catalysts for the selective hydrogenation of 1,3-butadiene,, an industrially important reaction. Isolated platinum atom geometries enable hydrogen activation and spillover but are incapable of C-C bond scission that leads to loss of selectivity and catalyst deactivation. γ-Alumina-supported single-atom alloy nanoparticle catalysts with <1 platinum atom per 100 copper atoms are found to exhibit high activity and selectivity for butadiene hydrogenation to butenes under mild conditions, demonstrating transferability from the model study to the catalytic reaction under practical conditions. PMID:26449766

  1. 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.

  2. 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.

  3. Quantitative characterization of the sequential mers distribution in styrene-butadiene copolymers by {sup 13} C; Caracterizacao quantitativa da distribuicao sequencial dos meros em copolimeros de estireno e butadieno por RMN de {sup 13} C

    Energy Technology Data Exchange (ETDEWEB)

    Canevarolo, Sebastiao [Sao Carlos Univ., SP (Brazil). Dept. de Engenharia de Materiais

    1996-06-01

    Various types and grades of styrene-butadiene co-polymers were analysed by {sup 13} C-NMR: random SBR, blocked SSBR (a styrene block is introduced in the random SBR chain) and SBS triblock copolymers. It was determined the styrene content (%), the styrene-butadiene mers distribution in terms of the S-B and B-S-B sequences content (characteristics of the random portions of the chain) and also the isomers content in the butadiene phase. (author)

  4. 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.

  5. Atmospheric oxidation of isoprene and 1,3-butadiene: influence of aerosol acidity and relative humidity on secondary organic aerosol

    Directory of Open Access Journals (Sweden)

    M. Lewandowski

    2014-11-01

    Full Text Available The effects of acidic seed aerosols on the formation of secondary organic aerosol (SOA have been examined in a number of previous studies, several of which have observed strong linear correlations between the aerosol acidity (measured as nmol H+ per m3 air sample volume and the percent change of secondary organic carbon (SOC. The measurements have used several precursor compounds representative of different classes of biogenic hydrocarbons including isoprene, monoterpenes, and sesquiterpenes. To date, isoprene has displayed the most pronounced increase in SOC, although few measurements have been conducted with anthropogenic hydrocarbons. In the present study, we examine several aspects of the effect of aerosol acidity on the secondary organic carbon formation from the photooxidation of 1,3-butadiene, as well as extending the previous analysis of isoprene. The photooxidation products measured in the absence and presence of acidic sulfate aerosols were generated either through photochemical oxidation of SO2 or by nebulizing mixtures of ammonium sulfate and sulfuric acid into a 14.5 m3 smog chamber system. The results showed that, like isoprene and β-caryophyllene, 1,3-butadiene SOC yields linearly correlate with increasing acidic sulfate aerosol. The observed acid sensitivity of 0.11% SOC increase per nmol m−3 increase in H+ was approximately a factor of three less than that measured for isoprene. The results also showed that the aerosol yield decreased with increasing humidity for both isoprene and 1,3-butadiene, although to different degrees. Increasing the absolute humidity from 2 to 12 g m−3 reduced the 1,3-butadiene yield by 45% and the isoprene yield by 85%.

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

    OpenAIRE

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

    2013-01-01

    The disposal of solid waste is a serious problem worldwide that is made worse in developing countries due to inadequate planning and unsustainable solid waste management. In Mexico, only 2% of total urban solid waste is recycled. One non-recyclable material is poly (styrene-co-butadiene), which is commonly used in consumer products (like components of appliances and toys), in the automotive industry (in instrument panels) and in food services (e.g. hot and cold drinking cups and glasses). In ...

  7. VAPOR-PHASE CATALYTIC CONVERSION OF ETHANOL INTO 1,3-BUTADIENE ON Cr-Ba/MCM-41 CATALYSTS

    Directory of Open Access Journals (Sweden)

    N. La-Salvia

    2015-06-01

    Full Text Available AbstractAl-MCM-41, 16%Ba/Al-MCM-41 and 1.4%Cr-16%Ba/Al-MCM-41 were used as catalysts in the vapor-phase catalytic conversion of ethanol. Physical-chemical properties of the catalysts and the effect of barium and chromium on the Al-MCM-41 activity and 1,3-butadiene yield were studied. The catalysts were characterized by X-ray diffraction (XRD, N2 physisorption (BET method, CO2chemisorption and Fourier transform infrared spectroscopy (FT-IR. When ethanol was completely converted on Al-MCM-41 and 16%Ba/Al-MCM-41, the reaction products showed a high selectivity for ethylene (90-98%. However, on the 1.4%Cr-16%Ba/Al-MCM-41 catalyst, a greater number of reaction products were obtained such as ethylene, acetaldehyde, diethyl ether and 1,3-butadiene. The maximum 1,3-butadiene yield obtained from ethanol reaction was 25% at 723 K and W/FEtOH = 15 g h mol-1. The latter result was obtained in a single step and without addition of reaction promoters (e.g., acetaldehyde, crotonaldehyde, hydrogen in the feed stream to the reactor.

  8. High-Temperature Measurements and a Theoretical Study of the Reaction of OH with 1,3-Butadiene

    Energy Technology Data Exchange (ETDEWEB)

    Vasu, Subith [Stanford Univ., CA (United States); Zador, J. [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Davidson, David F. [Stanford Univ., CA (United States); Hanson, Ronald K. [Stanford Univ., CA (United States); Golden, David [Stanford Univ., CA (United States); Miller, James A. [Sandia National Lab. (SNL-CA), Livermore, CA (United States)

    2010-07-27

    The reaction of hydroxyl (OH) radicals with 1,3-butadiene (C4H6) was studied behind reflected shock waves over the temperature range 1011-1406 K and at pressures near 2.2 atm. OH radicals were produced by shock-heating tert-butyl hydroperoxide, (CH3)3-CO-OH, and were monitored by narrow line width ring dye laser absorption of the well-characterized R1(5) line of the OH A-X (0,0) band near 306.7 nm. OH time histories were modeled using a comprehensive 1,3-butadiene oxidation mechanism, and rate constants for the reaction of OH with 1,3-butadiene were extracted by matching modeled and measured OH concentration time histories. Detailed error analyses yielded an uncertainty estimate of ±13% at 1200 K for the rate coefficient of the target reaction. The current data extends the temperature range of the only previous high-temperature study for this reaction. The rate coefficient and the branching fractions for the H-abstraction channels of the target reaction were also calculated over the temperature range 250-2500 K using variational transition-state theory based on QCISD(T)/cc-pV∞Z//B3LYP/6-311++G(d,p) quantum chemistry. The calculations are in good agreement with the experimental results above 1200 K.

  9. Delayed light emission of Tetraphenyl-butadiene excited by liquid argon scintillation light. Current status and future plans

    Science.gov (United States)

    Segreto, E.; Machado, A. A.; Araujo, W.; Teixeira, V.

    2016-02-01

    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, re-emits photons not only with a very short decay time, but also with slower ones due to triplet states de-excitations. This fact can strongly contribute to clarifying the anomalies in liquid-argon scintillation light reported in the literature since the 1970s. Precision measurements of the properties of TPB, when excited by Vacuum Ultra Violet photons are being carried on at the Brazilian Synchrotron Light Laboratory in Campinas (State of São Paulo).

  10. The Structure of the Free Volume in Poly(styrene-co-acrylonitrile) from Positron Lifetime and Pressure Volume Temperature (PVT) Experiments

    OpenAIRE

    Dlubek, Gunter; Bondarenko, Vladimir; Al-Qaradawi, Ilham Y.; Kilburn, Duncan; Krause-Rehberg, Reinhard

    2004-01-01

    Summary: The structure of the free volume and its temperature dependence between 25 and 190 °C of copolymers of styrene with acrylonitrile, SAN (0 to 50 mol-% AN), is studied by pressure volume temperature (PVT) experiments and positron annihilation lifetime spectroscopy (PALS). In this second part of the work, PALS data are reported from which the temperature dependence of the mean size and size distribution of local free volumes (subnanometer size holes) is analysed. The mean hole volume, v...

  11. 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].

  12. 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.

  13. Devulcanization of styrene butadiene rubber by microwave energy: Effect of the presence of ionic liquid

    Directory of Open Access Journals (Sweden)

    S. Seghar

    2015-12-01

    Full Text Available In this study, styrene butadiene rubber (SBR was devulcanized using microwave irradiation. In particular, effect of ionic liquid (IL, pyrrolidinium hydrogen sulfate [Pyrr][HSO4], on the devulcanization performance was studied. It was observed that the evolution of the temperature reached by rubber powder exposed to microwave irradiation for different energy values was favored by the presence of ionic liquid [Pyrr][HSO4] significantly over the whole range of the microwave energy values. Beyond the threshold point of 220 Wh/kg, the soluble fraction after devulcanization sharply increased with increasing devulcanization microwave energy. For the powder mixed with [Pyrr][HSO4], the increase was more significant. Furthermore, the crosslink density was observed to decrease slowly with the microwave energy up to 220 Wh/kg, beyond which the crosslink density decreased significantly for the rubber impregnated with IL. For the rubber with IL, significant and continuous increase in Tg with microwave energy values was observed in comparison with the SBR where no change in transition temperature was observed. Mechanical shearing of rubber gums in the two-roll mill favored the devulcanization process, which indicated that the combination of mechanical loading with microwave energy and IL is an efficient procedure allowing an optimal devulcanization of rubbers.

  14. 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.

  15. Synthesis of Cyclododecatriene from 1,3-Butadiene by Trimerization over Amine-Titanium Complex Catalyst

    Energy Technology Data Exchange (ETDEWEB)

    Park, Da Min; Kim, Gye Ryung; Lee, Ju Hyun; Kim, Geon-Joong [Inha University, Incheon (Korea, Republic of); Cho, Deuk Hee [Korea Research Institute of Chemical Technology, Daejeon (Korea, Republic of)

    2013-06-15

    The new complex catalysts were synthesized by the reaction of titanium compounds (titanium chloride or titanium butoxide) and diamines in this work, and they showed very high catalytic activities for the cyclododecatriene (CDT) synthesis from 1,3-butadiene through trimerization. CDT synthetic reaction was performed in an autoclave reactor, and the effects of reaction temperature, type of catalyst, catalyst amount added into the system, the mole ratio of Al/Ti and immobilization method were investigated on the yield of product CDT. The titanium complex catalyst combined to diamine with 1:1 ratio showed high selectivity to CDT more than 90%. The ratio of TTT-CDT/TTC-CDT isomers in the product revealed as different values, depending on the type of diamine combined to titanium and Ti/diamine ratios. Those homogeneous complexes could be used as a heterogenized catalyst after anchoring on the supports, and the immobilized titanium catalyst retained the catalytic activities for several times in the recycled reactions without leaching. The carbon support containing titanium has exhibited superior activity to the silica support. Especially, when the titanium complex was anchored on the support which was fabricated by the hydrolysis of tripropylaminosilane itself, the resulting titanium catalyst showed the highest BD conversion and CDT selectivity.

  16. SYNTHESIS AND PHARMACOLOGICAL EFFECTS OF BUTADIENE AND CYCLOPENTADIENE ADDUCTS OF METHANDROSTENOLONE IN RATS

    Directory of Open Access Journals (Sweden)

    FAZEL SHAMSA

    2006-06-01

    Full Text Available In this study the reactivity of methandrostenolone or [(17b-17-hydroxy-17-methylandrosta-1, 4-diene-3-one], as a dienophil in a Diels-Alder type cycloaddition reaction was investigated. The purpose of this approach was to investigate whether the 1-dehydro position of methandrostenolone 1 undergoes a cycloaddition reaction with dienes, such as 1, 3 butadiene or cyclopentadiene, and to investigate the biological behavior of the reaction adducts, i.e, compound 3 {(17b-17-hydroxy-17-methyl androsta [1a, 2a] cyclohex 3’, 4-diene-3-one} and compound 4 {(17b-17-hydroxy-17-methyl androsta [1a, 2a] cyclohex (2’,5’ methylene 3’, 4-diene-3-one}, relative to compound 1. The results indicated that thedDiels-Alder reactionddid notpproceed under the usual circumstances of high pressure and temperature, but could proceed in the presence of a Lewis acid (AlCl3. The structures of compounds 3 and 4 were confirmed by spectroscopic methods. The androgenic behavior of compounds 3 and 4 in comparison to compound 1 in the apomorphine test indicated that both compounds were almost devoid of androgenic activity, but prevented apomorphine mediated penile erection in male rats in a similar manner as cyproterone acetate.

  17. 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.

  18. 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.

  19. 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.

  20. 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

  1. 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.

  2. 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.

  3. 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.

  4. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Guo Baochun [Department of Polymer Materials and Engineering, South China University of Technology, Guangzhou 510640 (China)], E-mail: psbcguo@scut.edu.cn; Lei Yanda; Chen Feng; Liu Xiaoliang; Du Mingliang; Jia Demin [Department of Polymer Materials and Engineering, South China University of Technology, Guangzhou 510640 (China)

    2008-12-30

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

  6. 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.

  7. 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.

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

    Science.gov (United States)

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

    2015-11-01

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

  9. Effect of water on hydrogenation of 1,3-butadiene over Au (1 1 1): A joint theoretical and experimental study

    Energy Technology Data Exchange (ETDEWEB)

    Bu, Weida; Zhao, Liang, E-mail: Liangzhao@cup.edu.cn; Zhang, Zhicheng; Zhang, Xin; Gao, Jinsen; Xu, Chunming

    2014-01-15

    The effect of water on the hydrogenation of 1,3-butadiene over Au (1 1 1) was investigated based on density functional theory calculations and the results were compared with experimental study on the same reaction over Au/γ-Al{sub 2}O{sub 3} catalysts prepared by different methods. All possible adsorption sites and geometry structures of hydrogen, water and 1,3-butadiene on Au (1 1 1) were considered in the adsorption energy calculations to obtain the optimized adsorption modes. The hydrogenation of 1,3-butadiene was found to be only feasible with dissociated H atoms adsorbed over Au (1 1 1). Our adsorption calculations suggest that H{sub 2}O tended to block the active sites and inhibited the adsorption step, fully consistent with the rapid 1,3-butadiene conversion drop from above 40% to below 10% at low water concentration (<1200 ppm) in experiments. The transition state calculations indicate that water had little impact on the reaction step given slight change of energy barrier from 0.62 eV to 0.55 eV for the major route. This result validated the experimental finding that the conversion of 1,3-butadiene on Au/γ-Al{sub 2}O{sub 3} catalysts had only a slight decrease in a high water concentration range.

  10. 丙烯腈生产的高效精制工艺优化%Optimization of Efficient Refining Technology of Acrylonitrile Process

    Institute of Scientific and Technical Information of China (English)

    吴金海

    2011-01-01

    Cation exchange resin D001 was chosen to adsorb oxazole from acrylonitrile. The equilibrium adsorption capacity of resin D001 was 37. 08 mg · g-1. The adsorpion rate was above 99% with input flow rate of 2. 0 BV ? h-1 and temperatune of 20 °C , and desorpion rate was 100% with 5% HC1 as desorption reagent, 5% HC1 volume of 1. 2 BV, the elution flow rate of 1. 0 BV ? h-1 , soaking time of 6 h. By adding refining process of cation exchange resin, the content of oxazole in acrylonitrile of finished product tower was controlled above 40 mg · g-1 , the content of oxazole in acrylonitrile was controlled below 1 mg · g-1 , and the yield of acrylonitrile was increased above 0. 5%, which realized the efficient refinery of acrylonitrile.%采用阳离子交换树脂D001去除丙烯腈中(口恶)唑。D001的平衡吸附量为37.08 mg·g-1,在20℃、30℃、40℃、50℃下,D001对(口恶)唑的吸附符合Langmuir吸附等温方程。在进料流量为2.0 BV·h-1、体系温度为20℃时,丙烯腈中(口恶)唑的去除率达99%以上。采用5%的HCl为洗脱剂,在其用量为1.2 BV、洗脱速度为1 BV·h-1、浸泡时间为6 h的条件下,(口恶)唑的脱附率可达100%。在丙烯腈生产工艺中增加离子交换树脂吸附(口恶)唑工艺部分,可控制成品塔丙烯腈中(口恶)唑的含量在40 mg·g-1以上、丙烯腈产品中(口恶)唑的含量在1 mg·g-1以下,而且丙烯腈收率提高0.5%以上,实现了丙烯腈的高效精制。

  11. The effect of trichloroethylene and acrylonitrile on RNA and ribosome synthesis and ribosome content in Saccharomyces cells.

    Science.gov (United States)

    Lochmann, E R; Ehrlich, W; Mangir, M

    1984-04-01

    The effects of trichloroethylene (TCE) and acrylonitrile (ACN) on growth, RNA synthesis, ribosome synthesis, and ribosome content were tested in yeast cells. TCE causes a delay of the growth of a cell culture (prolongation of the lag phase), but does not cause inhibition. Cells exposed to increasing concentrations of ACN show increasing damage, so that, at a certain point of the growth curve, cell division stops altogether. Similar results were obtained when RNA synthesis was investigated: After treatment with TCE, the maximum RNA synthesis of the cell culture was retarded, but subsequently reached the same level as the untreated control cells. In the presence of ACN, however, the rate of RNA synthesis was lowered with increasing ACN concentrations. The same effect was observed upon investigation of ribosome synthesis: Whereas TCE produces only a slight effect, treatment with increasing concentrations of ACN leads to a substantial decrease in ribosome synthesis, and finally to total inhibition. Parallel to this, the content of free and membrane-bound ribosomes is diminished. Obviously, the decrease in ribosome content is caused not only by an inhibition of ribosome synthesis, but also by a degradation of existing ribosomes, as well as by induction of a ribosome-associated RNase. PMID:6714140

  12. Preparation of Mesoporous Carbons from Acrylonitrile-methyl Methacrylate Copolymer/Silica Nanocomposites Synthesized by in-situ Emulsion Polymerization

    Institute of Scientific and Technical Information of China (English)

    BAO Yongzhong; ZHAO Wenting; HUANG Zhiming

    2013-01-01

    Acrylonitrile-methyl methacrylate (AN-MMA) copolymer/silica nanocomposites were synthesized by in-situ emulsion polymerization initiated by 2,2′-azobis(2-amidinopropane) dihydrochloride absorbed onto colloidal silica particles,and the mesoporous carbon materials were prepared through carbonization of the obtained AN-MMA copolymer/silica nanocomposites,followed by HF etching.Thermogravimetric analysis of AN-MMA copolymer/silica nanocomposites showed that the carbon yield of copolymer was slightly decreased as silica particle incorporated.N2 adsorption-desorption,scan electron microscopy (SEM) and transmission electron microscopy (TEM) were used to characterize the structure and morphology of the mesoporous carbon materials.Both SEM and TEM results showed that disordered mesopores were formed in the obtained carbon material mainly through templating effect of silica nanoparticles.The diameter of mesopores was mainly distributed in the range from 5 nm to 15 nm.The mean pore diameter and total pore volume of the material increased as the mass fraction of silica in the nanocomposites increased from 0 to 24.93%.The significant increase of the mean pore diameter and the decrease of surface area for the carbon material prepared from the nanocomposite with 24.93% silica were caused by partial aggregation of silica nanoparticles in the polymer matrix.

  13. 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.

  14. 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.

  15. 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 ].

  16. 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.

  17. 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.

  18. 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. PMID:27305765

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

    Science.gov (United States)

    Khabaz, Fardin; Khare, Rajesh

    2015-11-01

    Asphalt, a soft matter consisting of more than a thousand chemical species, is of vital importance for the transportation infrastructure, yet it poses significant challenges for microscopic theory and modeling approaches due to its multicomponent nature. Polymeric additives can potentially enhance the thermo-mechanical properties of asphalt, thus helping reduce the road repair costs; rational design of such systems requires knowledge of the molecular structure and dynamics of these systems. We have used molecular dynamics (MD) simulations to investigate the volumetric, structural, and dynamic properties of the neat asphalt as well as styrene-butadiene rubber (SBR) modified asphalt systems. The volume-temperature behavior of the asphalt systems exhibited a glass transition phenomenon, akin to that observed in experiments. The glass transition temperature, room temperature density, and coefficient of volume thermal expansion of the neat asphalt systems so evaluated were in agreement with experimental data when the effect of the high cooling rate used in simulations was accounted for. While the volumetric properties of SBR modified asphalt were found to be insensitive to the presence of the SBR additive, the addition of SBR led to an increase in the aggregation of asphaltene molecules. Furthermore, addition of SBR caused a reduction in the mobility of the constituent molecules of asphalt, with the reduction being more significant for the larger constituent molecules. Similar to other glass forming liquids, the reciprocal of the diffusion coefficient of the selected molecules was observed to follow the Vogel-Fulcher-Tammann (VFT) behavior as a function of temperature. These results suggest the potential for using polymeric additives for enhancing the dynamic mechanical properties of asphalt without affecting its volumetric properties. PMID:26451630

  20. 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

  1. Mechanical performance of styrene-butadiene-rubber filled with carbon nanoparticles prepared by mechanical mixing

    Energy Technology Data Exchange (ETDEWEB)

    Saatchi, M.M. [Department of Chemical and Petroleum Engineering, Sharif University of Technology, P.O. Box 11155-9465, Tehran (Iran, Islamic Republic of); Shojaei, A., E-mail: akbar.shojaei@sharif.edu [Department of Chemical and Petroleum Engineering, Sharif University of Technology, P.O. Box 11155-9465, Tehran (Iran, Islamic Republic of)

    2011-09-15

    Highlights: {yields} We compare influence of carbon blacks and carbon nanotube on properties of SBR. {yields} We model mechanical behavior of SBR nanocomposites by the micromechanical model. {yields} Mechanical properties of carbon black/SBR is greatly dominated by bound rubber. {yields} Mechanical properties of SBR/nanotube is governed by big aspect ratio of nanotube. - Abstract: Reinforcement of styrene-butadiene-rubber (SBR) was investigated using two different carbon blacks (CBs) with similar particle sizes, including highly structured CB and conventional CB, as well as multi-walled carbon nanotube (MWCNT) prepared by mechanical mixing. The attempts were made to examine reinforcing mechanism of these two different classes of carbon nanoparticles. Scanning electron microscopy and electrical conductivity measurement were used to investigate morphology. Tensile, cyclic tensile and stress relaxation analyses were performed. A modified Halpin-Tsai model based on the concept of an equivalent composite particle, consisting of rubber bound, occluded rubber and nanoparticle, was proposed. It was found that properties of CB filled SBR are significantly dominated by rubber shell and occluded rubber in which molecular mobility is strictly restricted. At low strains, these rubber constituents can contribute in hydrodynamic effects, leading to higher elastic modulus. However, at higher strains, they contribute in stress hardening resulting in higher elongation at break and higher tensile strength. These elastomeric regions can also influence stress relaxation behaviors of CB filled rubber. For SBR/MWCNT, the extremely great inherent mechanical properties of nanotube along with its big aspect ratio were postulated to be responsible for the reinforcement while their interfacial interaction was not so efficient.

  2. Measurement of acrolein and 1,3-butadiene in a single puff of cigarette smoke using lead-salt tunable diode laser infrared spectroscopy

    Science.gov (United States)

    Thweatt, W. Dave; Harward, Charles N., Sr.; Parrish, Milton E.

    2007-05-01

    Acrolein and 1,3-butadiene in cigarette smoke generally are measured using two separate analytical methods, a carbonyl derivative HPLC method for acrolein and a volatile organic compound (VOC) GC/MS method for 1,3-butadiene. However, a single analytical method having improved sensitivity and real-time per puff measurement will offer more specific information for evaluating experimental carbon filtered cigarettes designed to reduce the smoke deliveries of these constituents. This paper describes an infrared technique using two lead-salt tunable diode lasers (TDLs) operating with liquid nitrogen cooling with emissions at 958.8 cm -1 and 891.0 cm -1 respectively for the simultaneous measurement of acrolein and 1,3-butadiene, respectively, in each puff of mainstream cigarette smoke in real time. The dual TDL system uses a 3.1 l volume, 100 m astigmatic multiple pass absorption gas cell. Quantitation is based on a spectral fit that uses previously determined infrared molecular line parameters generated in our laboratory, including line positions, line strengths and nitrogen-broadened half-widths for these species. Since acrolein and ethylene absorption lines overlap and 1,3-butadiene, ethylene and propylene absorption lines overlap, the per puff deliveries of ethylene and propylene were determined since their overlapping absorption lines must be taken into account by the spectral fit. The acrolein and 1,3-butadiene total cigarette deliveries for the 1R5F Kentucky Reference cigarette were in agreement with the HPLC and GC/MS methods, respectively. The limit of detection (LOD) for 1,3-butadiene and acrolein was 4 ng/puff and 24 ng/puff, respectively, which is more than adequate to determine at which puff they break through the carbon filter. The retention and breakthrough behavior for the two primary smoke constituents depend on the cigarette design and characteristics of the carbon filter being evaluated.

  3. 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

  4. Ethanol-to-Butadiene Conversion over SiO2-MgO Catalysts: Synthesis-Structure-Performance Relationships

    OpenAIRE

    Angelici, C.

    2015-01-01

    The work presented in this PhD Thesis provides new insights into the underlying reasons that make SiO2-MgO materials excellent catalysts for the ethanol-to-butadiene Lebedev process. In particular, the preparation technique of choice affects the structural properties of the resulting SiO2-MgO materials considerably and therefore the distribution, i.e. nature and amount, of acidic-basic sites. Given the complex cascade of elementary steps required, striking a precise balance in the latter is k...

  5. 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 each...... 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...

  6. VAPOR-PHASE CATALYTIC CONVERSION OF ETHANOL INTO 1,3-BUTADIENE ON Cr-Ba/MCM-41 CATALYSTS

    OpenAIRE

    N. La-Salvia; J. J. Lovón-Quintana; G.P. VALENÇA

    2015-01-01

    AbstractAl-MCM-41, 16%Ba/Al-MCM-41 and 1.4%Cr-16%Ba/Al-MCM-41 were used as catalysts in the vapor-phase catalytic conversion of ethanol. Physical-chemical properties of the catalysts and the effect of barium and chromium on the Al-MCM-41 activity and 1,3-butadiene yield were studied. The catalysts were characterized by X-ray diffraction (XRD), N2 physisorption (BET method), CO2chemisorption and Fourier transform infrared spectroscopy (FT-IR). When ethanol was completely converted on Al-MCM-41...

  7. Influence of acid-base properties on the Lebedev ethanol-to-butadiene process catalyzed by SiO2-MgO materials

    OpenAIRE

    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 depend significantly on the synthesis method. To assess the specific requirements for butadiene production in terms of active sites and to link their presence to the specific preparation method ap...

  8. Comparison between phosphine and NHC-modified Pd catalysts in the telomerization of butadiene with methanol – a kinetic study combined with model-based experimental analysis

    OpenAIRE

    Hopf, Lisa; Recker, Sebastian; Niedermaier, Matthias; Kiermaier, Stephan; Strobel, Vinzent; Maschmeyer, Dietrich; Cole-Hamilton, David; Marquardt, Wolfgang; Wasserscheid, Peter; Haumann, Marco

    2015-01-01

    The authors thank the European Community within its project SYNFLOW (FP7; grant agreement n8 NMP2-LA-2010-246461) for financial support. The telomerization of butadiene with methanol was investigated in the presence of different palladium catalysts modified either with triphenylphosphine (TPP) or 1,3-dimesityl-imidazol-2-ylidene (IMes) ligand. When pure butadiene was used as substrate, a moderate selectivity for the Pd-TPP catalyst toward the desired product 1-methoxy-2,7-octadiene (1-Mode...

  9. Low-temperature 1 3-butadiene Hydrogenation over Supported Pt/3d/gamma-Al2O3 Bimetallic Catalysts

    Energy Technology Data Exchange (ETDEWEB)

    W Lonergan; X Xing; R Zheng; S Qi; B Huang; J Chen

    2011-12-31

    Low-temperature 1,3-butadiene hydrogenation is used as a probe reaction to investigate the hydrogenation activity over several {gamma}-Al{sub 2}O{sub 3} supported Pt/3d (3d = Co, Ni, Cu) bimetallic catalysts. Batch and flow reactor studies are employed to quantify the kinetic activity and steady-state conversion, respectively, of each catalyst. Transmission electron microscopy (TEM) is utilized to characterize particle sizes and extended X-ray absorption fine structure (EXAFS) measurements are performed to verify the Pt-3d bimetallic bond formation. Pulse carbon monoxide chemisorption measurements are also performed to characterize the number of active sites. Additionally, density functional theory (DFT) calculations are included to determine the binding energies of 1,3-butadiene and atomic hydrogen on the corresponding model surfaces. The binding energies of the adsorbates are found to correlate with the hydrogenation activity, allowing for use of such correlation to potentially predict hydrogenation catalysts with enhanced activity based on the binding energies of the adsorbates of interest.

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

    Science.gov (United States)

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

    2013-01-01

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

  11. Inhalation toxicity studies with 1,3-butadiene 3 two year toxicity/carcinogenicity study in rats

    Energy Technology Data Exchange (ETDEWEB)

    Owen, P.E.; Glaister, J.R.; Gaunt, I.F.; Pullinger, D.H.

    1987-05-01

    Groups of 110 male and 110 female CD (Sprague-Dawley) rats were exposed to atmospheres containing 0 (control), 1000 or 8000 ppm v/v butadiene for 6 hr/day and 5 days/week. Ten of each sex from each group were killed at 52 weeks. The study was terminated when it was predicted that survival would drop to 20% to 25%. High dose rats had wet, ruffled fur and showed slight incoordination during the first exposure each week. During the second year, mortality in both treated female groups was increased because of humanitarian sacrifice of animals with large subcutaneous masses, while increased mortality in the high dose males was accompanied by an increase of the severity of nephropathy. Body weight was slightly lower than controls in both sexes at the high dose, but statistically significant only over the first 12 weeks. There were no effects in hematological analyses or tests of neuromuscular function that definitely could be associated with treatment. Liver weights at both doses were increased in both sexes with no associated pathological change. Kidney weight was increased in males at the high dose, together with an increase in the severity of nephrosis. There were increases in the incidences of pancreatic exocrine adenoma; uterine sarcoma; Zymbal gland carcinoma; mammary tumors; thyroid follicular cell tumors; and testis Leydig-cell tumors. These data suggest the butadiene is a weak oncogen to the rat under the conditions of exposure used in this study.

  12. Use of 1-alkyl-3-methylimidazolium L-lactates as both ligand and reaction media for AGET ATRP of acrylonitrile

    Energy Technology Data Exchange (ETDEWEB)

    Chen Hou, E-mail: lduchenhou@hotmail.com [School of Chemistry and Materials Science, Ludong University, Yantai 264025 (China); Liu Delong; Chen Lingfang; Qu Rongjun [School of Chemistry and Materials Science, Ludong University, Yantai 264025 (China)

    2011-08-15

    Graphical abstract: Chiral ionic liquids, [C{sub 2}mim][LLA], [C{sub 4}mim][LLA] and [C{sub 6}mim][LLA] were firstly applied as both ligand and reaction media for atom transfer radical polymerization using activators generated by electron transfer (AGET ATRP) of acrylonitrile (AN) with ascorbic acid (VC) as reducing agent in the presence of air. A small but clear increase of polyacrylonitrile (PAN) isotacticity was observed for AGET ATRP ofANin [C6mim][LLA] than in [C6mim][BF4]. PAN isotacticity markedly increased with the content of [C{sub 6}mim][LLA]. Compared with in [C{sub 2}mim][LLA] and [C{sub 4}mim][LLA], the rate of AGET ATRP of AN in [C{sub 6}mim][LLA] was fastest and the polymerization was best controlled. Well-defined PAN with molecular weight at 76,590, relatively narrower distribution at 1.27 and higher isotacticity at 0.37 was successfully prepared in [C{sub 6}mim][LLA]. Highlights: {yields} Chiral ionic liquids, [C{sub 2}mim][LLA], [C{sub 4}mim][LLA] and [C{sub 6}mim][LLA] were firstly applied as both ligand and reaction media for AGET ATRP of AN in the presence of air. {yields} A small but clear increase of polymer isotacticity was observed for AGET ATRP of AN in [C{sub 6}mim][LLA] than in [C{sub 6}mim][BF{sub 4}]. {yields} Well-defined PAN with molecular weight at 76,590, relatively narrower distribution at 1.27 and higher isotacticity at 0.37 was successfully prepared in [C{sub 6}mim][LLA]. - Abstract: Chiral ionic liquids, [C{sub 2}mim][LLA], [C{sub 4}mim][LLA] and [C{sub 6}mim][LLA] were firstly applied as both ligand and reaction media for atom transfer radical polymerization using activators generated by electron transfer (AGET ATRP) of acrylonitrile (AN) with ascorbic acid (VC) as reducing agent in the presence of air. A small but clear increase of polyacrylonitrile (PAN) isotacticity was observed for AGET ATRP of AN in [C{sub 6}mim][LLA] than in [C{sub 6}mim][BF{sub 4}]. PAN isotacticity markedly increased with the content of [C{sub 6}mim

  13. Use of Yb-based catalyst for AGET ATRP of acrylonitrile to simultaneously control molecular mass distribution and tacticity

    International Nuclear Information System (INIS)

    Yb-based catalyst was used for the first time for atom transfer radical polymerization using activators generated by electron transfer (AGET ATRP) of acrylonitrile (AN) with 2-bromopropionitrile (BPN) as initiator, 2, 2′-bipyridine (bipy) as ligand, and tisn(II) bis(2-ethylhexanoate) (Sn(EH)2) as reducing agent in the presence of air. With respect to AGET ATRP of AN catalyzed by CuBr2, an evident increase of polymer tacticity was observed for AGET ATRP of AN. The increase of syndiotacticity became more and more pronounced than the increase of isotacticity of polyacrylonitrile (PAN) along with YbBr3 content. The block copolymer PAN-b-PMMA with molecular weight at 60,000 and polydispersity at 1.36 was successfully prepared. - Graphical abstract: Yb-based catalyst was used for the first time for AGET ATRP of AN with BPN as the initiator, bipy as the ligand, and Sn(EH)2 as the reducing agent in the presence of air. With respect to AGET ATRP with CuBr2 as catalyst, an obvious increase of polymer tacticity was observed for AGET ATRP of AN. The increase of syndiotacticity became more and more pronounced than the increase of isotacticity of polyacrylonitrile (PAN) along with YbBr3 content. The block copolymer PAN-b-PMMA with molecular weight at 60000 and polydispersity at 1.36 was successfully prepared. Highlights: ► Yb-based catalyst was used for the first time for AGET ATRP of AN. ► The reaction simultaneously controls polydispersity and tacticity of PAN. ► Well-defined block copolymer PAN-b-PMMA was successfully prepared.

  14. Use of Yb-based catalyst for AGET ATRP of acrylonitrile to simultaneously control molecular mass distribution and tacticity

    Energy Technology Data Exchange (ETDEWEB)

    Ma Jing; Chen Hou, E-mail: lduchenhou@hotmail.com; Zhang Min; Wang Chunhua; Zhang Ying; Qu Rongjun

    2012-08-01

    Yb-based catalyst was used for the first time for atom transfer radical polymerization using activators generated by electron transfer (AGET ATRP) of acrylonitrile (AN) with 2-bromopropionitrile (BPN) as initiator, 2, 2 Prime -bipyridine (bipy) as ligand, and tisn(II) bis(2-ethylhexanoate) (Sn(EH){sub 2}) as reducing agent in the presence of air. With respect to AGET ATRP of AN catalyzed by CuBr{sub 2}, an evident increase of polymer tacticity was observed for AGET ATRP of AN. The increase of syndiotacticity became more and more pronounced than the increase of isotacticity of polyacrylonitrile (PAN) along with YbBr{sub 3} content. The block copolymer PAN-b-PMMA with molecular weight at 60,000 and polydispersity at 1.36 was successfully prepared. - Graphical abstract: Yb-based catalyst was used for the first time for AGET ATRP of AN with BPN as the initiator, bipy as the ligand, and Sn(EH){sub 2} as the reducing agent in the presence of air. With respect to AGET ATRP with CuBr{sub 2} as catalyst, an obvious increase of polymer tacticity was observed for AGET ATRP of AN. The increase of syndiotacticity became more and more pronounced than the increase of isotacticity of polyacrylonitrile (PAN) along with YbBr{sub 3} content. The block copolymer PAN-b-PMMA with molecular weight at 60000 and polydispersity at 1.36 was successfully prepared. Highlights: Black-Right-Pointing-Pointer Yb-based catalyst was used for the first time for AGET ATRP of AN. Black-Right-Pointing-Pointer The reaction simultaneously controls polydispersity and tacticity of PAN. Black-Right-Pointing-Pointer Well-defined block copolymer PAN-b-PMMA was successfully prepared.

  15. 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 ...

  16. 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

  17. Reaction pathways by quantum Monte Carlo: Insight on the torsion barrier of 1,3-butadiene, and the conrotatory ring opening of cyclobutene

    Science.gov (United States)

    Barborini, Matteo; Guidoni, Leonardo

    2012-12-01

    Quantum Monte Carlo (QMC) methods are used to investigate the intramolecular reaction pathways of 1,3-butadiene. The ground state geometries of the three conformers s-trans, s-cis, and gauche, as well as the cyclobutene structure are fully optimised at the variational Monte Carlo (VMC) level, obtaining an excellent agreement with the experimental results and other quantum chemistry high level calculations. Transition state geometries are also estimated at the VMC level for the s-trans to gauche torsion barrier of 1,3-butadiene and for the conrotatory ring opening of cyclobutene to the gauche-1,3-butadiene conformer. The energies of the conformers and the reaction barriers are calculated at both variational and diffusional Monte Carlo levels providing a precise picture of the potential energy surface of 1,3-butadiene and supporting one of the two model profiles recently obtained by Raman spectroscopy [Boopalachandran et al., J. Phys. Chem. A 115, 8920 (2011), 10.1021/jp2051596]. Considering the good scaling of QMC techniques with the system's size, our results also demonstrate how variational Monte Carlo calculations can be applied in the future to properly investigate the reaction pathways of large and correlated molecular systems.

  18. Pathway and Surface Mechanism Studies of 1,3-butadiene Selective Oxidation Over Vanadium-Molybdenum-Oxygen Catalysts

    Energy Technology Data Exchange (ETDEWEB)

    William David Schroeder

    2002-05-27

    The partial oxidation of 1,3-butadiene has been investigated over VMoO catalysts synthesized by sol-gel techniques. Surface areas were 9-14 m{sup 2}/g, and compositions were within the solid solution regime, i.e. below 15.0 mol % MoO{sub 3}/(MoO{sub 3} + V{sub 2}O{sub 5}). 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{sup +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 V{sub 2}O{sub 5}-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 V{sub 2}O{sub 5}, solid solutions of Mo in V{sub 2}O{sub 5}, V{sub 9}Mo{sub 6}O{sub 40}, 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% MoO{sub 3}/(V{sub 2}O{sub 5} + MoO{sub 3}), determined by EDS analysis.

  19. Carbon Nanotube-thermally Reduced Graphene Hybrid/Styrene Butadiene Rubber Nano Composites: Mechanical, Morphological and Dielectric Studies

    Directory of Open Access Journals (Sweden)

    Jiji Abraham

    2015-07-01

    Full Text Available Styrene Butadiene Rubber composites with mixture of carbon nanotube and thermally reduced graphene were prepared and morphological, mechanical and dielectric properties of the composites were studied. Aim of this study is to understand the dispersion and reinforcement behaviour of hybrid filler in rubber matrix. Improved mechanical properties in the presence of graphene are due to the good dispersion and improved compatibility with the matrix. The formation of a mixed filler network showed a synergistic effect on the improvement of electrical as well as various mechanical properties. This method provides a simple route to enhance the dispersion of carbon nanotubes and to improve the electrical property of the polymer composites. It is concluded that introduction of thermally reduced graphene to CNT-SBR composites can improve the mechanical properties of the composites up to an optimum concentration of the graphene after that performance will be diminished due to the agglomeration of graphene.

  20. Processing of styrene butadiene rubber-carbon black nanocomposites with gradation of crosslink density: Static and dynamic mechanical characterization

    International Nuclear Information System (INIS)

    The concentrations of sulfur and accelerator were varied in the nanocomposites of carbon black (CB)-filled styrene-butadiene rubber (SBR) matrix to introduce the gradation of the crosslink density. These curatives were varied from 1 to 11 phr (per hundred rubber) along the span of 3-mm thick sheet using the construction-based layering method. The static and dynamic mechanical characterizations of these functionally graded polymeric nanocomposites (FGPNCs) were carried out. With increasing crosslink density along thickness, hardness and modulus increase while the ultimate properties like tensile strength and elongation at break droop down. The dynamic mechanical analysis of FGPNCs exhibits the increment in the storage modulus than the uniformly dispersed polymeric nanocomposites (UDPNCs) employing the same average amount of curatives. The peak position of tan δmax remains at the same temperature while the value mitigates in FGPNCs. In FGPNCs, tan δ peak intimates the broadness in the transition region

  1. Processing of styrene butadiene rubber-carbon black nanocomposites with gradation of crosslink density: Static and dynamic mechanical characterization

    Energy Technology Data Exchange (ETDEWEB)

    Ahankari, S.S. [Advanced Nano Engineering Materials Laboratory, Materials Science Programme, Indian Institute of Technology Kanpur, Kanpur 208016 (India); Kar, Kamal K. [Advanced Nano Engineering Materials Laboratory, Materials Science Programme, Indian Institute of Technology Kanpur, Kanpur 208016 (India); Advanced Nano Engineering Materials Laboratory, Materials Science Programme and Department of Mechanical Engineering, Indian Institute of Technology Kanpur, Kanpur 208016 (India)], E-mail: kamalkk@iitk.ac.in

    2008-09-15

    The concentrations of sulfur and accelerator were varied in the nanocomposites of carbon black (CB)-filled styrene-butadiene rubber (SBR) matrix to introduce the gradation of the crosslink density. These curatives were varied from 1 to 11 phr (per hundred rubber) along the span of 3-mm thick sheet using the construction-based layering method. The static and dynamic mechanical characterizations of these functionally graded polymeric nanocomposites (FGPNCs) were carried out. With increasing crosslink density along thickness, hardness and modulus increase while the ultimate properties like tensile strength and elongation at break droop down. The dynamic mechanical analysis of FGPNCs exhibits the increment in the storage modulus than the uniformly dispersed polymeric nanocomposites (UDPNCs) employing the same average amount of curatives. The peak position of tan {delta}{sub max} remains at the same temperature while the value mitigates in FGPNCs. In FGPNCs, tan {delta} peak intimates the broadness in the transition region.

  2. Comparison of nano CaCO{sub 3} and flyash filled with styrene butadiene rubber on mechanical and thermal properties

    Energy Technology Data Exchange (ETDEWEB)

    S. Mishra; N.G. Shimpi

    2005-10-01

    Different particle sizes (21, 15, 9 nm) of CaCO{sub 3} were synthesized by in-situ deposition technique and confirmed by X-ray diffraction method. The nano CaCO{sub 3} was added from 0.1 wt % to 0.5 wt % in the styrene butadiene rubber (SBR). Rubber nanocomposties were compounded on two-roll mill and molded in compression molding machine. Mechanical properties such as tensile strength, elongation at break, modulus at 300 % elongation, hardness, specific gravity, swelling index, flame retardency and abrasion resistance were studied. These results were compared with flyash filled SBR. There was an improvement in properties of rubber nanocomposites because of uniform dispersion of nano CaCO{sub 3} particles in the matrix that intercalates the rubber chains. Hence degree of crosslinking increases multifold in comparison to commercial CaCO{sub 3} and flyash.

  3. Study of the reinforcement of rubber styrene-butadiene with mesoporous silices by solid-state nuclear magnetic resonance

    International Nuclear Information System (INIS)

    The knowledge about the interaction rubber/filler for the rubber reinforced with carbon black of silica is important to understand the physical properties, which determine the reinforcement. This paper presents a comparative study of the interactions between styrene butadiene rubber (SBR) and silica for a silica Ultrasil type and mesoporous silica MCM-41 type prepared by different procedures, based on solid state nuclear magnetic resonance: 1H MAS NMR; 13C MAS NMR, 13C CP/MAS, 29Si MAS and 29Si CP/MAS NMR. Mesoporous silica synthesized under certain specific conditions showed better interaction with the rubber than the ultrasil VN3 silica, commonly used as a reinforcement load. Mechanical tests for the SBR vulcanised with this silica indicate an important increase for values of elongation and tearing resistance, but an increase in the vulcanization time in it is compared with the SBR vulcanise with Ultrasil

  4. OSHA's approach to risk assessment for setting a revised occupational exposure standard for 1,3-butadiene.

    Science.gov (United States)

    Grossman, E A; Martonik, J

    1990-06-01

    In its 1980 benzene decision [Industrial Union Department, ALF-CIO v. American Petroleum Institute, 448 U.S. 607 (1980)], the Supreme Court ruled that "before he can promulgate any permanent health or safety standard, the Secretary [of Labor] is required to make a threshold finding that a place of employment is unsafe--in the sense that significant risks are present and can be lessened by a change in practices" (448 U.S. at 642). The Occupational Safety and Health Administration (OSHA) has interpreted this to mean that whenever possible, it must quantify the risk associated with occupational exposure to a toxic substance at the current permissible exposure limit (PEL). If OSHA determines that there is significant risk to workers' health at its current standard, then it must quantify the risk associated with a variety of alternative standards to determine at what level, if any, occupational exposure to a substance no longer poses a significant risk. For rulemaking on occupational exposure to 1,3-butadiene, there are two studies that are suitable for quantitative risk assessment. One is a mouse inhalation bioassay conducted by the National Toxicology Program (NTP), and the other is a rat inhalation bioassay conducted by Hazelton Laboratories Europe. Of the four risk assessments that have been submitted to OSHA, all four have used the mouse and/or rat data with a variety of models to quantify the risk associated with occupational exposure to 1,3-butadiene. In addition, OSHA has performed its own risk assessment using the female mouse and female rat data and the one-hit and multistage models.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:2401254

  5. Single-Atom Pd₁/Graphene Catalyst Achieved by Atomic Layer Deposition: Remarkable Performance in Selective Hydrogenation of 1,3-Butadiene.

    Science.gov (United States)

    Yan, Huan; Cheng, Hao; Yi, Hong; Lin, Yue; Yao, Tao; Wang, Chunlei; Li, Junjie; Wei, Shiqiang; Lu, Junling

    2015-08-26

    We reported that atomically dispersed Pd on graphene can be fabricated using the atomic layer deposition technique. Aberration-corrected high-angle annular dark-field scanning transmission electron microscopy and X-ray absorption fine structure spectroscopy both confirmed that isolated Pd single atoms dominantly existed on the graphene support. In selective hydrogenation of 1,3-butadiene, the single-atom Pd1/graphene catalyst showed about 100% butenes selectivity at 95% conversion at a mild reaction condition of about 50 °C, which is likely due to the changes of 1,3-butadiene adsorption mode and enhanced steric effect on the isolated Pd atoms. More importantly, excellent durability against deactivation via either aggregation of metal atoms or carbonaceous deposits during a total 100 h of reaction time on stream was achieved. Therefore, the single-atom catalysts may open up more opportunities to optimize the activity, selectivity, and durability in selective hydrogenation reactions. PMID:26268551

  6. VUV-Vis optical characterization of Tetraphenyl-butadiene films on glass and specular reflector substrates from room to liquid Argon temperature

    OpenAIRE

    Francini, R.; Montereali, R. M.; Nichelatti, E.; Vincenti, M. A.; Canci, N.; Segreto, E.; F. Cavanna; 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...

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. Production,research and development of oil-extended styrene-butadiene rubber%充油丁苯橡胶生产及研发现状

    Institute of Scientific and Technical Information of China (English)

    白玉光; 王玉瑛; 李树丰

    2011-01-01

    充油丁苯橡胶具有加工性能好、生热低、低温挠屈性好等特点,尤其用于胎面胶时,具有优异的牵引性能和耐磨耗性,在乳聚丁苯橡胶(ESBR)的生产中占据重要位置.本文概述了目前国内充油丁苯橡胶的生产及消费情况,并对国内充油丁苯橡胶的研发现状进行了小结,对充油丁苯橡胶的发展提出了建议.%Oil-extended styrene-butadiene rubber is a leading rubber during ESBR production because of its good processability, low heat generation, cold flexibility, especially excellent traction and abrasion loss as tread rubber. This paper briefly describes production, consumption, research and development of oil-extended styrene-butadiene rubber in China, and proposes some advices on oil-extended styrene-butadiene rubber development.

  14. 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.

  15. 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

  16. Ruthenium-Catalyzed Asymmetric Hydrohydroxyalkylation of Butadiene: The Role of the Formyl Hydrogen Bond in Stereochemical Control

    Science.gov (United States)

    Grayson, Matthew N.; Krische, Michael J.; Houk, K. N.

    2016-01-01

    The catalyst generated in situ from RuH2(CO)(PPh3)3, (S)-SEGPHOS, and a chiral phosphoric acid promotes asymmetric hydrohydroxyalkylation of butadiene and affords enantioenriched α-methyl homoallylic alcohols. The observed diastereo- and enantioselectivities are determined by both the chiral phosphine and chiral phosphate ligands. Density functional theory calculations (M06/SDD-6-311G(d,p)-IEFPCM(acetone)//B3LYP/SDD-6-31G(d)) predict that the product distribution is controlled by the kinetics of carbon-carbon bond formation, and this process occurs via a closed-chair Zimmerman-Traxler-type transition structure (TS). Chiral phosphate-dependent stereoselectivity arising from this TS is enabled through a hydrogen bond between the phosphoryl oxygen and the aldehyde formyl proton present in TADDOL-derived catalysts. This interaction is absent in the corresponding BINOL-derived systems and the opposite sense of attack on the aldehyde occurs. Additional factors influencing stereochemical control are determined. PMID:26107070

  17. Plane-interface-induced lignin-based nanosheets and its reinforcing effect on styrene-butadiene rubber

    Directory of Open Access Journals (Sweden)

    C. Jiang

    2014-09-01

    Full Text Available Lignin was viewed as a spherical microgel in aqueous alkali. While spread out in a monolayer or adsorbed on a surface, lignin was made up of flexible, disk-like molecules with approximately the same thickness of 2 nm. According to this principle, we employed the lamina of montmorillonite (MMT as a plane template to anchor cationic lignin (CL on its two sides, resulting in the formation of CL-MMT hybrid materials (CLM. The isotherm adsorption behavior and structure characteristics of CLM were studied. The results showed that CLM was individually dispersed nanosheets with a thickness of about 5 nm when the mass ratio of CL to MMT is more than 2:1 and prepared at acidic or neutral pH. Compared to the cocoagulation of lignin and styrene-butadiene rubber (SBR, CLM obviously accelerated the coagulation rate, due to the reduction of surface activity of CL restricted by MMT. The nanoscale dispersion of CLM in SBR matrix significantly improved the tensile strength of CLM/SBR nanocomposites to 14.1 MPa by adding only 10 phr CLM and cardanol glycidyl ether (CGE as compatibilizer. Dynamic mechanical analysis (DMA showed that the glass transition temperature of SBR/CLM nanocomposites decreased with increasing CLM loading. Correspondingly, a special interfacial structure was proposed.

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

    Science.gov (United States)

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

    2015-09-01

    The present work investigated the influence of organoclay (organo-montmorillonite, OMMT) on the phase separation behavior and morphology evolution of solution polymerized styrene-butadiene rubber (SSBR)/low vinyl content polyisoprene (LPI) blends with rheological methodology. It was found that the incorporation of OMMT not only reduced the droplet size of the dispersion phase, slowed down the phase separation kinetics, also enlarged the processing miscibility window of the blends. The determination on the wetting parameters indicated that due to the oscillatory shear effect, the OMMT sheets might localize at the interface between the two phases and act as compatibilizer or rigid barrier to prevent domain coarsening, resulting in slow phase separation kinetics, small droplet size, and stable morphology. The analysis of rheological data by the Palierne model provided further confirmation that the addition of OMMT can decrease the interfacial tension and restrict the relaxation of melt droplets. Therefore, a vivid "sea-fish-net" model was proposed to describe the effect of OMMT on the phase separation behavior of SSBR/LPI blends, in which the OMMT sheets acted as the barrier (net) to slow down the domain coarsening/coalescence in phase separation process of SSBR/LPI blends.

  19. 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.

  20. 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.

  1. 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.

  2. Wavelength-shifting materials for the use in RICH detectors - p-terphenyl and tetraphenyl-butadiene revisited

    CERN Document Server

    Koczon, P; Joram, C; Solevi, P; D¨urr, M; H¨ohne, C

    2010-01-01

    P-terphenyl (PT) and tetraphenyl-butadiene (TPB) in form of thin films have been investigated as possible wavelength shifting material for application in Ring Imaging Cherenkov (RICH) detectors. Films of dierent thickness were evaporated onto borosilicate windows of photomultiplier tubes (PMT) and the quantum eciency of the modified PMTs was determined as a function of wavelength. Gain factors for the number of measured photoelectrons in dependence on the cuto wavelength (energy) for application in Cherenkov counters were established. Using PT, a strong increase in quantum eciency between 200 nm and 300 nm was observed leading to gain factors as high as 1.71 ± 0.11 for a cutoff energy of 6.2 eV. Due to strong absorption in the wavelength range between 300 nm and 400 nm, TPB shows inferior results. No significant thickness dependence was observed for films thicker than 600 nm. Film morphology and wavelength dependent fluorescence was measured to back the results. Simulations encourage the use on flat panel mu...

  3. 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...

  4. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Shojaei, Akbar, E-mail: akbar.shojaei@sharif.edu [Department of Chemical and Petroleum Engineering, Sharif University of Technology, P.O. Box 11155-9465, Tehran (Iran, Islamic Republic of); Faghihi, Morteza [Department of Chemical and Petroleum Engineering, Sharif University of Technology, P.O. Box 11155-9465, Tehran (Iran, Islamic Republic of)

    2010-02-15

    Effect of organoclay (OC) on the performance of styrene-butadiene rubber (SBR)/phenolic resin (PH) blend prepared by two-roll mill was investigated. The influence of OC content ranging between 2.5 and 30 phr on the performance of SBR/PH was investigated using X-ray diffraction (XRD), scanning electron microscopy (SEM), interfacial energy analysis, tensile, dynamic mechanical, swelling, cure rheometry and thermogravimetric analysis (TGA). It was found that the OC is mainly localized in the SBR phase of SBR/PH blend through the kinetically favored mechanism relevant to rubber chains. The results also demonstrated the positive role of PH on the dispersion of OC. Both PH and OC showed accelerating role on the cure rate of SBR and increased the crosslinking density of the rubber phase. Additionally, the mechanical and dynamic mechanical properties of SBR were influenced by incorporation of both PH and OC. TGA showed that the OC improves thermal stability of SBR vulcanizate, while it exhibits a catalytic role in presence of PH.

  6. Transport properties of carboxylated nitrile butadiene rubber (XNBR)-nanoclay composites; a promising material for protective gloves in occupational exposures.

    Science.gov (United States)

    Mirzaei Aliabadi, Mostafa; Naderi, Ghasem; Shahtaheri, Seyed Jamaleddin; Forushani, Abbas Rahimi; Mohammadfam, Iraj; Jahangiri, Mehdi

    2014-01-01

    This study was conducted in response to one of the research needs of National Institute for Occupational Safety and Health (NIOSH), i.e. the application of nanomaterials and nanotechnology in the field of occupational safety and health. In order to fill this important knowledge gap, the equilibrium solubility and diffusion of carbon tetrachloride and ethyl acetate through carboxylated nitrile butadiene rubber (XNBR)-clay nanocomposite, as a promising new material for chemical protective gloves (or barrier against the transport of organic solvent contaminant), were examined by swelling procedure. Near Fickian diffusion was observed for XNBR based nanocomposites containing different amounts of nanoclay. Decontamination potential is a key factor in development of a new material for reusable chemical protective gloves applications, specifically for routine or highly toxic exposures. A thermal decontamination regime for nanocomposite was developed for the first time. Then, successive cycles of exposure/decontamination for nanocomposite were performed to the maximum 10 cycles for the first time. This result confirms that the two selected solvents cannot deteriorate the rubber-nanoclay interaction and, therefore, such gloves can be reusable after decontamination. PMID:24581248

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

    Science.gov (United States)

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

    2015-05-28

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

  8. 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.

  9. 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.

  10. 端羧基丁腈橡胶改性环氧树脂的结构与性能%Structual and Properties of Carboxyl-Terminated Poly(Butadiene-co-Acrylonitrile) Modified Diglycidyl Ether of Bisphenol-A Epoxy Resin

    Institute of Scientific and Technical Information of China (English)

    刘敬成; 张胜文; 周琼; 刘仁; 刘晓亚; 王春林

    2010-01-01

    用液体端羧基丁腈橡胶(CTBN)对固体环氧树脂(EP)进行改性,合成了CTBN-EP预聚物,研究了CTBN-EP/HTP-305体系的微观形貌、力学性能和热性能.研究结果表明,随着CTBN含量的增大,冲击强度及断裂伸长率显著提高,说明通过CTBN化学预聚改性的EP韧性提高,而体系的拉伸强度和热性能略有下降.动态热机械分析(DMA)测试体系的动态力学性能结果表明,体系出现了两相结构(Tg对应温度分别是-60℃和80℃~100℃).扫描电镜(SEM)分析表明,固化过程中析出了橡胶相并均匀分散在环氧树脂基体中,形成了剪切空洞变形结构.

  11. 端羧基丁腈橡胶改性环氧树脂的结构与性能%Structure and Properties of Carboxyl-Terminated Poly(Butadiene-co-Acrylonitrile) Modified Diglycidyl Ether of Bisphenol-A Epoxy Resin

    Institute of Scientific and Technical Information of China (English)

    石敏先; 黄志雄; 郦亚铭; 杨国瑞

    2008-01-01

    用液体端羧基丁腈橡胶(CTBN)对环氧树脂(EP)进行改性,合成了CTBN/EP预聚物,FT-IR分析表明,在反应中EP的环氧基开环后与CTBN的羧基反应生成了酯键.研究了CTBN/EP/聚醚胺(PEA)体系的力学性能,结果表明,随着CTBN含量的增大,其弯曲强度、拉伸强度降低,冲击强度、断裂伸长率增大,说明CTBN通过化学预聚改性的EP具有良好的韧性.SEM分析表明,固化过程中析出了橡胶相并均匀分散在环氧树脂基体中.

  12. 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℃.

  13. Effects of butadiene-acrylonitrile copolymer/polyvinyl chloride composites filled with aluminum hydroxide and carbon black on vulcanization%氢氧化铝和炭黑对丁腈橡胶-聚氯乙烯复合材料硫化性能的影响

    Institute of Scientific and Technical Information of China (English)

    李来丙; 龚必珍

    2009-01-01

    以氢氧化铝(ATH)为复合材料的添加型阻燃剂填充到丁腈橡胶-聚氯乙烯共聚物(NBR/PVC)体系中,采用不同比例的ATH和炭黑(CB)2种填充剂交替添加,制备出NBR/PVC复合材料;使用Haake 流变仪对NBR/PVC复合材料基体的硫化参数和流变过程进行了研究,并与NBR/PVC纯树脂及含硅酮表面处理的ATH复合材料进行了对比试验.结果表明:使用硅酮对ATH的表面进行处理,虽然对NBR/PVC树脂材料不是非常有效,但能促进体系中无机填充剂和聚合物的空间点阵的交互作用;改变了ATH与树脂的比例,改善了它们的相互作用和加工性能,并通过流变过程得以验证.

  14. The enhanced catalytic performance of cobalt catalysts towards butadiene polymerization by introducing a labile donor in a salen ligand.

    Science.gov (United States)

    Gong, Dirong; Wang, Baolin; Jia, Xiaoyu; Zhang, Xuequan

    2014-03-14

    A family of cobalt complexes supported by a tridentate Schiff base ligand with a labile donor (O, S, N) as a pendant arm (Co1-Co12, formulated as CoL2) were synthesized by the treatment of the corresponding ligands with cobalt acetate tetrahydrate. The resultant complexes were well characterized by elemental analysis, FT-IR, magnetic moment as well as EI-MS. The solid-state structures of Co7 and Co12 were determined by X-ray diffraction and both established a distorted octahedron geometry around the cobalt center. The butadiene polymerization capabilities of the 12 complexes were evaluated and compared in representative cases. Diethylaluminum chloride (AlEt2Cl) was found to be the compatible activator resulting in highly active catalysts for producing polybutadiene of 93.8-98.2% cis-1,4 enchainment with negligible 1,2-structure and trans-1,4 units. It appears that a certain degree of lability of the donor is beneficial for high catalytic activity, generally following the order of O > S > N, and the high cis-1,4 selectivity. Moreover, the remarkable thermal stability of these systems has been achieved: the catalytic systems have the ability of conducting a high level of active and selective polymerization, reaching an upper limit of polymerization temperature of about 70 °C. The enhanced catalytic performances were further rationalized by the established diene polymerization mechanism, which could shed light on developing highly selective and reactive industrially applicable catalysts with an enhanced thermal stability. PMID:24468706

  15. Actinide-to-carbon bonds in Cp2An(alkyl)2, -(butadiene), -(metallacyclopentadiene), and -(cyclobutadiene) complexes

    International Nuclear Information System (INIS)

    The electronic structure of actinide bis(cyclopentadienyl)dialkyl, -butadiene, -metallacyclopentadiene, and -cyclobutadiene complexes is examined. Some Cp*2Th(alkyl)2 complexes display an interesting structural deformation in which a Th-C-C(alkyl) angle (α) opens up considerably. A molecular orbital analysis of Cp2Th(C2H5)2 traces the deformation to the characteristic shape of the d/sub σ/ fragment orbital of Cp2Th(C2H5)+. The potential energy curve for the ethyl pivoting was found to be very soft, with a shallow minimum at α ∼ 1600. Nonrigidity of the ethyl orientation indicates that not only an α hydrogen but also a β hydrogen can come close to Th without a loss of Th-C bond strength; the discussion should provide a theoretical basis for understanding important aspects of C-H activation chemistry involving actinide centers. The Cp2An(s-cis-C4H6) complex was calculated to be 0.74 eV (Th) or 0.42 eV (U) more stable than its s-trans-C4H6 isomer, in contrast to the analogous Cp2Zr(C4H6) complex where the stability of the two geometrical isomers was well-balanced. The σ2,π character of the s-cis-C4H6 coordination to An is somewhat less pronounced than that in the Zr congener, in harmony with the X-ray structures, while highly negative charges are accumulated on the s-cis-C4H6 terminal carbons

  16. 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.

  17. Effect of magnetic and thermal properties of iron oxide nanoparticles (IONs) in nitrile butadiene rubber (NBR) latex

    International Nuclear Information System (INIS)

    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. - Highlights: • We synthesized IONs with high magnetization saturation (Ms). • High Ms 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 potential for the

  18. 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.

  19. Water-responsive mechanically adaptive nanocomposites based on styrene-butadiene rubber and cellulose nanocrystals--processing matters.

    Science.gov (United States)

    Annamalai, Pratheep K; Dagnon, Koffi L; Monemian, Seyedali; Foster, E Johan; Rowan, Stuart J; Weder, Christoph

    2014-01-22

    Biomimetic, stimuli-responsive polymer nanocomposites based on a hydrophobic styrene-butadiene rubber (SBR) matrix and rigid, rod-like cellulose nanocrystals (CNCs) isolated from cotton were prepared by three different approaches, and their properties were studied and related to the composition, processing history, and exposure to water as a stimulus. The first processing approach involved mixing an aqueous SBR latex with aqueous CNC dispersions, and films were subsequently formed by solution-casting. The second method utilized the first protocol, but films were additionally compression-molded. The third method involved the formation of a CNC organogel via a solvent exchange with acetone, followed by infusing this gel, in which the CNCs form a percolating network with solutions of SBR in tetrahydrofuran. The thermomechanical properties of the materials were established by dynamic mechanical thermal analysis (DMTA). In the dry state, all nanocomposites show much higher tensile storage moduli, E', than the neat SBR or the SBR latex. E' increases with the CNC content and depends strongly on the processing method, which appears to influence the morphology of the SBR nanocomposites produced. The highest E' values were observed for the solution cast samples involving an SBR latex, where E' increased from 3 MPa for the neat SBR to ca. 740 MPa for the nanocomposite containing 20% v/v CNCs. Upon submersion in deionized water, a dramatic reduction of E' was observed, for example from 740 to 5 MPa for the solution-cast nanocomposite containing 20% v/v CNCs. This change is interpreted as a disengagement of the percolating CNC network, on account of modest aqueous swelling and competitive hydrogen bonding of water molecules with the CNCs. It is shown that the method of preparation also influenced the swelling behavior and kinetics of modulus switching, consistent with different arrangements of the CNCs, which serve as channels for water absorption and transport within the

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. Simultaneous determination of acrylonitrile, carbon disulfide, methyl ethyl ketone, and isobutanol leachates by purge and trap- gas chromatography-mass spectrometry

    International Nuclear Information System (INIS)

    According to the Mexican General Law of the Ecological Equilibrium and Environmental Protection, issued by the National Institute of Ecology, some chemicals such as acrylonitrile, methyl ethyl ketone, carbon disulfide, and isobutanol must be monitored in industrial residues because of their toxicity. This report describes an analytical method for the simultaneous determination of these four analytes in leachates. A purge and trap concentrator coupled to a computerized gas-chromatograph-mass selective detector was used to achieve the analysis. Quantitation measurements were based on the internal standardization method, using the area ratios of the molecular ions of the analytes and the internal standard obtained by deconvolution of the data. The scope of this method as well as the validation data is reported. The method is reliable in spite of the fact that, in some cases, the analytes or the standard coeluted with other compounds of the samples. Because the data acquisition is carried out in the scan mode it is possible to detect and identify other substances in the samples. (Author)

  5. THE DISSOCIATIVE RECOMBINATION OF PROTONATED ACRYLONITRILE, CH2CHCNH+, WITH IMPLICATIONS FOR THE NITRILE CHEMISTRY IN DARK MOLECULAR CLOUDS AND THE UPPER ATMOSPHERE OF TITAN

    International Nuclear Information System (INIS)

    Measurements on the dissociative recombination (DR) of protonated acrylonitrile, CH2CHCNH+, have been performed at the heavy ion storage ring CRYRING located in the Manne Siegbahn Laboratory in Stockholm, Sweden. It has been found that at ∼2 meV relative kinetic energy about 50% of the DR events involve only ruptures of X-H bonds (where X = C or N) while the rest leads to the production of a pair of fragments each containing two heavy atoms (alongside H and/or H2). The absolute DR cross section has been investigated for relative kinetic energies ranging from ∼1 meV to 1 eV. The thermal rate coefficient has been determined to follow the expression k(T) = 1.78 x 10-6 (T/300) -0.80 cm3 s-1 for electron temperatures ranging from ∼10 to 1000 K. Gas-phase models of the nitrile chemistry in the dark molecular cloud TMC-1 have been run and results are compared with observations. Also, implications of the present results for the nitrile chemistry of Titan's upper atmosphere are discussed.

  6. 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.

  7. COMPOSITE PROCESS OF ZINC ELECTRODEPOSITION AND ACRYLONITRILE ELECTROPOLYMERIZATION%锌/聚丙烯腈复合镀层的研究

    Institute of Scientific and Technical Information of China (English)

    张卫国; 周旻; 姚素薇; 张瑜

    2001-01-01

    通过金属锌的电沉积与丙烯腈(AN)电聚合的复合过程,获得有机大分子链掺杂的金属基复合镀层——锌/聚丙烯腈(PAN)复合镀层.考察了电沉积条件对电镀及电聚合过程的影响,并测定了复合镀层组成及性能.性能测试结果表明,复合镀层的胶接性能较纯锌镀层有显著提高.%In this paper,a metal matrix composite coating containingmacromolecular chain of polymer,zinc/polyacrylonitrile (PAN) composite coating,were obtained through a composite process of zincic electrodeposition and acrylonitrile (AN) electrochemically initiated polymerization (EIP).Investigations were carried out into the function of PAN content in coatings and plating condition.And the properties of the films were studied.Compared with the pure zinc coating,the composite coating showed well glued performance.

  8. 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.

  9. 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.

  10. Low-Temperature 1,3-Butadiene Hydrogenation over Supported Pt/3d/gamma-Al2O3 Bimetallic Catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Lonergan, William W; Xing, X; Zheng, Renyang; Qi, Suitao; Huang, B; Chen, Jingguang

    2011-02-02

    Low-temperature 1,3-butadiene hydrogenation is used as a probe reaction to investigate the hydrogenation activity over several γ-Al{sub 2}O{sub 3} supported Pt/3d (3d = Co, Ni, Cu) bimetallic catalysts. Batch and flow reactor studies are employed to quantify the kinetic activity and steady-state conversion, respectively, of each catalyst. Transmission electron microscopy (TEM) is utilized to characterize particle sizes and extended X-ray absorption fine structure (EXAFS) measurements are performed to verify the Pt–3d bimetallic bond formation. Pulse carbon monoxide chemisorption measurements are also performed to characterize the number of active sites. Additionally, density functional theory (DFT) calculations are included to determine the binding energies of 1,3-butadiene and atomic hydrogen on the corresponding model surfaces. The binding energies of the adsorbates are found to correlate with the hydrogenation activity, allowing for use of such correlation to potentially predict hydrogenation catalysts with enhanced activity based on the binding energies of the adsorbates of interest.

  11. Methoxy Silane in Styrene-butadiene Synthetic Resin%甲氧基硅烷在丁苯合成树脂的研究

    Institute of Scientific and Technical Information of China (English)

    王平; 舒畅; 蓝晓; 钟凤清

    2012-01-01

    The star styrene-butadiene copolymerization were synthesized by using styrene and butadiene as monomers, n-BuLi as initiator, Methyl-trimethoxy-silane as coupling agent and cyclohexane as solvent by anionic polymerization. The effect of quantity of coupling agent, feed stock times, polymerization temperature and polymerization time on the coupling efficiency(CE%) and average branching number(BN) were investigated.%以苯乙烯、丁二烯为单体,N—BuLi为引发剂,环己烷为溶剂,甲基三甲氧基硅烷为偶联剂,通过负离子聚合和偶联反应,制备含有多种嵌段水平的星形r苯透明抗冲树脂。并初步探讨了偶联剂加入量、加料次数、温度、时间和基峰分子量与偶联效率、支化度(臂数)的关系。

  12. 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.)

  13. 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.

  14. Theoretical Investigation into Electronic Structures and Charge Transfer Properties of π-Conjugated System with Different Combinations of Thiophene and Vinyl/Butadiene

    Institute of Scientific and Technical Information of China (English)

    赵春梅; 李春荣; 马妍; 赵蔡斌; 王文亮

    2012-01-01

    A series of combinations of thiophene and vinyl/butadiene were investigated by ab initio and DFT methods to explore their electronic structures and charge transfer properties. The results show that increasing thiophene ring and vinyl number is a rational strategy to raise the HOMO energy levels and lower the LUMO energy levels. Mov- ing the vinyl from the periphery to the core has the slight effect on the HOMO and LUMO energy levels. Further- more, replacing the middle vinyl and end-capped vinyl of 3b (T5V4) with the butadiene can lower LUMO energy levels and then facilitate the electron injection. Above all, the close hole and electron reorganization energies (2h and λ-e) are observed from these compounds. However, the λes are smaller than their respective λhs in some com- pounds, which is relatively rare in organic materials. Especially, the promising ambipolar material 3c (T5B4) is recommended theoretically for possessing the equivalent minimum Ah (0.24 eV) and 2e (0.24 eV). The absorption wavelengths exhibit red shifts with the increasing of the thiophene ring and the vinyl number under the same con- figuration, which correspond to the reverse order of AEH_L and Eg. The linear relationships are found between experimental lowest singlet excited energies (Eexp) with theoretical values AEH-L and Eg.

  15. 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

  16. 1,3-Butadiene, styrene and lymphohematopoietic cancer among male synthetic rubber industry workers--Preliminary exposure-response analyses.

    Science.gov (United States)

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

    2015-11-01

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

  17. Zinc oxide nanorod assisted rapid single-step process for the conversion of electrospun poly(acrylonitrile) nanofibers to carbon nanofibers with a high graphitic content

    Science.gov (United States)

    Nain, Ratyakshi; Singh, Dhirendra; Jassal, Manjeet; Agrawal, Ashwini K.

    2016-02-01

    The effect of incorporation of rigid zinc oxide (ZnO) nanostructures on carbonization behavior of electrospun special acrylic fiber grade poly(acrylonitrile) (PAN-SAF) nanofibers was investigated. ZnO nanorods with high aspect ratios were incorporated into a PAN-N,N-dimethylformamide system and the composite nanofibers reinforced with aligned ZnO rods up to 50 wt% were successfully electrospun, and subsequently, carbonized. The morphology and the structural analysis of the resultant carbon nanofibers revealed that the rigid ZnO nanorods, present inside the nanofibers, possibly acted as scaffolds (temporary support structures) for immobilization of polymer chains and assisted in uniform heat distribution. This facilitated rapid and efficient conversion of the polymer structure to the ladder, and subsequently, the graphitized structure. At the end of the process, the ZnO nanorods were found to completely separate from the carbonized fibers yielding pure carbon nanofibers with a high graphitic content and surface area. The approach could be used to eliminate the slow, energy intensive stabilization step and achieve fast conversion of randomly laid carbon nanofiber webs in a single step to carbon nanofibers without the application of external tension or internal templates usually employed to achieve a high graphitic content in such systems.The effect of incorporation of rigid zinc oxide (ZnO) nanostructures on carbonization behavior of electrospun special acrylic fiber grade poly(acrylonitrile) (PAN-SAF) nanofibers was investigated. ZnO nanorods with high aspect ratios were incorporated into a PAN-N,N-dimethylformamide system and the composite nanofibers reinforced with aligned ZnO rods up to 50 wt% were successfully electrospun, and subsequently, carbonized. The morphology and the structural analysis of the resultant carbon nanofibers revealed that the rigid ZnO nanorods, present inside the nanofibers, possibly acted as scaffolds (temporary support structures) for

  18. Technical scheme for integration of DCC unit and acrylonitrile unit%DCC装置和丙烯腈装置一体化技术方案

    Institute of Scientific and Technical Information of China (English)

    刘福安; 朱校春; 王飞

    2013-01-01

    The technical scheme for integration of DCC unit and acrylonitrile unit is presented.The internal mutual feedstock supply,the comprehensive utilization of steam and sour gas treatment technologies of the integrated unit are analyzed.The analysis of internal feedstock supply has found that the volume of intermediate storage tanks for propylene can be reduced,and the temperature of propylene from gas stripper to acrylonitrile unit is raised by 5℃.As the result,the unit energy consumption is lowered.The study of comprehensive steam utilization has concluded that a 4.0 MPa steam boiler can be saved and the steam utilization can be improved.The analysis of DCC sour gas treatment technology has concluded that the application of this technology can save a LO-CAT sulfur recovery unit for DCC unit.All these analysis demonstrate that the application of this integration technology offers good economic benefits.1.39 × 108 RMB ¥ of capital investment can be saved from no installation of a 4.0 MPa steam boiler and a LO-CAT sulfur recovery unit.The conversion of sour gas into on-spec sulfuric acid and increasing of propylene feed supply temperature can add an economic benefit of 3.67 × 106 RMB ¥ a year.%提出DCC装置和丙烯腈装置一体化技术方案,对该技术方案的物料直供、蒸汽综合利用以及酸性气处理技术进行了具体的分析.通过物料互供分析,可以适当减少丙烯的中间储存罐容,提高丙烯从气分装置进丙烯腈装置的温度约5℃,降低装置运行能耗;通过蒸汽综合利用分析,可省去一台4.0 MPa的中压蒸汽锅炉,同时还能提高蒸汽的利用效率;通过对DCC装置酸性气处理技术的分析,发现该技术方案可省去一套与DCC装置配套的LO-CAT硫黄装置.分析表明该组合技术方案有很好的经济效益,省去的一台4.0 MPa中压蒸汽锅炉和一套LO-CAT硫黄装置可为企业节约工程投资1.39×108 RMB¥;酸性气转化为合格硫酸产品和提高丙烯

  19. Differential metabolism of acrylonitrile to cyanide is responsible for the greater sensitivity of male vs female mice: role of CYP2E1 and epoxide hydrolases

    International Nuclear Information System (INIS)

    Acrylonitrile (AN) is a potent toxicant and a known rodent carcinogen. AN epoxidation to cyanoethylene oxide (CEO) via CYP2E1 and its subsequent metabolism via epoxide hydrolases (EH) to yield cyanide is thought to be responsible for the acute toxicity and mortality of AN. Recent reports showed that male mice are more sensitive than females to the acute toxicity/mortality of AN. The present work was undertaken to assess the metabolic and enzymatic basis for the greater sensitivity of male vs female mice to AN toxicity. Male and female wild-type and CYP2E1-null mice received AN at 0, 2.5, 10, 20, or 40 mg/kg by gavage. Cyanide concentrations were measured at 1 or 3 h after dosing. Current data demonstrated that cyanide levels in blood and tissues of AN-treated wild-type mice of both sexes were significantly greater than in vehicle-treated controls and increased in a dose-dependent manner. In contrast, cyanide levels in AN-treated CYP2E1-null mice were not statistically different from those measured in vehicle-treated controls. Furthermore, higher levels of cyanide were detected in male wild-type mice vs females in association with greater sensitivity of males to the acute toxicity/mortality of this chemical. Using Western blot analysis, negligible difference in CYP2E1 expression with higher levels of soluble and microsomal EH (sEH and mEH) was detected in the liver of male vs female mice. In kidneys, male mice exhibited higher expression of both renal CYP2E1 and sEH than did female mice. In conclusion, higher blood and tissue cyanide levels are responsible for the greater sensitivity of male vs female mice to AN. Further, higher expression of CYP2E1 and EH in male mice may contribute to greater formation of CEO and its subsequent metabolism to yield cyanide, respectively

  20. 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。

  1. 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.

  2. Copper-catalyzed retro-aldol reaction of β-hydroxy ketones or nitriles with aldehydes: chemo- and stereoselective access to (E)-enones and (E)-acrylonitriles.

    Science.gov (United States)

    Zhang, Song-Lin; Deng, Zhu-Qin

    2016-07-26

    A copper-catalyzed transfer aldol type reaction of β-hydroxy ketones or nitriles with aldehydes is reported, which enables chemo- and stereoselective access to (E)-α,β-unsaturated ketones and (E)-acrylonitriles. A key step of the in situ copper(i)-promoted retro-aldol reaction of β-hydroxy ketones or nitriles is proposed to generate a reactive Cu(i) enolate or cyanomethyl intermediate, which undergoes ensuing aldol condensation with aldehydes to deliver the products. This reaction uses 1.2 mol% Cu(IPr)Cl (IPr denotes 1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene) as the catalyst in the presence of 6.0 mol% NaOtBu cocatalyst at room temperature or 70 °C. A range of aryl and heteroaryl aldehydes as well as acrylaldehydes are compatible with many useful functional groups being tolerated. Under the mild and weakly basic conditions, competitive Cannizzaro-type reaction of benzaldehydes and side reactions of base-sensitive functional groups can be effectively suppressed, which show synthetic advantages of this reaction compared to classic aldol reactions. The synthetic potential of this reaction is further demonstrated by the one-step synthesis of biologically active quinolines and 1,8-naphthyridine in excellent yields (up to 91%). Finally, a full catalytic cycle for this reaction has been constructed using DFT computational studies in the context of a retro-aldol/aldol two-stage mechanism. A rather flat reaction energy profile is found indicating that both stages are kinetically facile, which is consistent with the mild reaction conditions. PMID:27397647

  3. 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

  4. 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.

  5. 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

    International Nuclear Information System (INIS)

    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

  6. Comparative study of the monomer grafting: ethylene, acetylene, 1,3-butadiene and estyrene in the matrix of recycled polytetrafluoroethylene (PTFE)

    International Nuclear Information System (INIS)

    In this study it is used the recycled polytetrafluoroethylene (PTFE), that with the gamma radiation under inert atmosphere or in presence of air, it is obtained free radicals and a posterior the monomer grafting (ethylene, acetylene, styrene or 1.3 butadiene), obtaining the copolymer polytetrafluoroethylene-g-monomer. It is studied the obtention of the polymer by two methods: by direct way, via grafting, where the polymer is irradiated in presence of monomer, and via grafting when the polymer is irradiated in absence of monomer and under inert or air. The characterization of the copolymer was performed by the techniques of infrared region absorption spectroscopy with Fourier transformation (FTIR), thermogravimetric (TGA) and derivative thermogravimetry (DTG), and percentage of mass grafting (DOG)

  7. 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 ...

  8. 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...

  9. 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.

  10. 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%.

  11. 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.

  12. Principais aspectos da polimerização do 1,3-butadieno Principles aspects of butadiene 1,3 polymerization

    Directory of Open Access Journals (Sweden)

    Denise S. S. Nunes

    2005-11-01

    Full Text Available Atualmente, há uma grande demanda pelo polibutadieno com alto teor de unidades 1,4-cis, devido às suas excelentes propriedades físicas, tais como alta resistência à abrasão, baixo desenvolvimento de calor, baixa resistência ao rolamento, maior resistência à tensão, alta resistência à fadiga, baixa histerese e alta resistência à fratura. Tais características fazem com que esse elastômero seja cada vez mais utilizado na indústria pneumática. Assim, este trabalho apresenta uma breve revisão sobre a polimerização do 1,3-butadieno com diferentes sistemas catalíticos, sendo os sistemas à base de lantanídeos o principal foco desta revisão, pois esses sistemas são os mais estereoespecíficos para a polimerização 1,4-cis do butadieno.Nowadays, there is a great demand for polybutadiene with high contents of cis groups owing to its excellent physical properties, such as high abrasion resistance and low heat build up. These characteristics make this elastomer one of the most used in pneumatic industry. Thus, this paper presents a brief review about the 1,3-butadiene polymerization by different catalysts systems, with the systems based on lanthanides being the main focus, as they are the most stereospecific for cis-1,4 polymerization of butadiene.

  13. 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.

  14. 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

    2015-11-01

    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. PMID:25727266

  15. Between Ni(mnt)2 and Ni(tfd)2 dithiolene complexes: the unsymmetrical 2-(trifluoromethyl)acrylonitrile-1,2-dithiolate and its nickel complexes.

    Science.gov (United States)

    Jeannin, Olivier; Delaunay, Jacques; Barrière, Frédéric; Fourmigué, Marc

    2005-12-26

    A novel 1,2-dithiolate ligand, that is, the 2-(trifluoromethyl)acrylonitrile-1,2-dithiolate, abbreviated here as tfadt, is prepared from the corresponding cyclic dithiocarbonate. This ligand, substituted with both a CN and a CF(3) group, is compared with the well-known maleonitrile- and bis(trifluoromethyl)ethane-1,2-dithiolates. The preparation, electrochemical properties, and X-ray crystal structures of the square-planar nickel complexes, in both their dianionic diamagnetic [Ni(tfadt)(2)](2)(-) and their monoanionic paramagnetic [Ni(tfadt)(2)](*)(-) forms, are reported, as n-Bu(4)N(+), PPh(4)(+), and (18-crown-6)Na(+) salts, respectively. In the [(18-crown-6)Na](2)[Ni(tfadt)(2)] salt, each CN moiety of the [Ni(tfadt)(2)](2)(-) dianion is coordinated to a (18-crown-6)Na(+) cation through a CN...Na interaction [N...Na = 2.481(3) A], affording an "axle with wheels" model where two MeOH molecules act as axle caps. On the other hand, in [(18-crown-6)Na][Ni(tfadt)(2)], each (18-crown-6)Na(+) cation is coordinated on both sides by the CN groups of two monoanionic [Ni(tfadt)(2)](*)(-) complexes with N...Na(+) distances at 2.434(5) and 2.485(4) A, giving rise to heterobimetallic chains with alternating (18-crown-6)Na(+) and [Ni(tfadt)(2)](*)(-) ions. These two examples demonstrate the attractive ability of the CN moieties in the [Ni(tfadt)(2)](2)(-)(,)(*)(-) complexes to coordinate metallic cationic centers. The paramagnetic salts of the anionic [Ni(tfadt)(2)](*)(-) complex follow Curie-type law in the 2-300 K temperature range, indicating the absence of intermolecular magnetic interactions in the solid state. The complexes are found in their trans form in all crystal structures, while density functional theory calculations establish that both forms have essentially the same energy. A cis-trans interconversion process is observed by variable-temperature NMR on the dianionic [Ni(tfadt)(2)](2)(-) complex with a coalescence temperature T(c) of 260 K and a free energy of

  16. Study of ageing effects in polymer-in-salt electrolytes based on poly(acrylonitrile-co-butyl acrylate) and lithium salts

    International Nuclear Information System (INIS)

    Highlights: • Properties of freshly cast and aged poly(AN-co-BuA) – LiTFSI electrolytes are studied. • For fresh electrolytes, conductivity increases and Tg decreases with increasing salt content. • Ageing of polymer-in-salt electrolytes results in a drop of conductivity and a rise of Tg. • Ageing effects can be explained by changes of properties of amorphous salt domains. • Precipitation of salt is observed in electrolytes containing over 84 wt.% of LiTFSI. • Electrolytes with mixture of LiI and LiTFSI are more stable than those with LiTFSI only. -- Abstract: Polymer electrolytes composed of an acrylonitrile and butyl acrylate copolymer poly(AN-co-BuA) with addition of LiN(CF3SO2)2 (LiTFSI) or LiI and LiTFSI salt mixture are studied by impedance spectroscopy, DSC, Raman spectroscopy, X-ray diffraction, SEM and TEM. Impedance study shows that the ionic conductivity of the electrolytes containing LiTFSI is strongly dependent on the salt content and transition from “salt-in-polymer” to “polymer-in-salt” regime is observed at high salt content. Gradual changes of physical properties of the studied polymer electrolytes are observed in the course of their prolonged storage under argon atmosphere. These include the increase of glass transition temperature and decrease of ionic conductivity. In order to study the effects of this ageing process, measurements on samples of electrolyte films were repeated after several months. Precipitation of salt, which occurred at the nanometer length scale is observed with the aid of electron microscopy in electrolytes containing more than 84 wt.% of salt. Crystalline salt is not observed in electrolytes with lower amount of salt – however, the results indicate the structural changes of salt aggregates, which strongly influence transport of ions through the electrolyte. For preparation of electrolytes with mixed LiTFSI and LiI salts, a mixture of salts (16 wt.% LiI, 84 wt.% LiTFSI) is used, which exhibits the

  17. (Cyclopentadienylamine)scandium(2,3-dimethyl-1,3-butadiene) : A 1,3-diene complex of scandium with Sc(I)- and Sc(III)-like reactivity

    NARCIS (Netherlands)

    Beetstra, D.J.; Meetsma, A.; Hessen, B.; Teuben, J.H

    2003-01-01

    The scandium 2,3-dimethyl-1,3-butadiene complex [eta(5),eta(1)-C5H4(CH2)(2)NMe2]Sc(C6H10) (2) reacts with PhCN via initial nitrile insertion into the Sc-diene bond to give a dimeric mu(2)-imido species, but with a 2,2'-bipyridine via the elimination of the free diene. The latter shows that 2 can be

  18. Thermal [4 + 2] Cycloadditions of 3-Acetyl-, 3-Carbamoyl-, and 3-Ethoxycarbonyl-Coumarins with 2,3-Dimethyl-1,3-butadiene under Solventless Conditions: A Structural Study

    Directory of Open Access Journals (Sweden)

    Itzia I. Padilla-Martínez

    2010-03-01

    Full Text Available The thermal [4+2] cycloadditions of 3-acetyl-, 3-carbamoyl, and 3-ethoxycarbonylcoumarins with 2,3-dimethyl-1,3-butadiene under solvent free conditions are reported, as well as the epoxidation reactions of some adducts. Discussion is focused on the structural features of the Diels-Alder adducts and their epoxides, based upon NMR, X-ray, and mass spectral data, and supported by ab initio theoretical calculations.

  19. 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.

  20. 丁二烯橡胶门尼粘度比对与统计分析%The Comparison and Statistical Analysis of Butadiene Rubber Mooney Viscosity

    Institute of Scientific and Technical Information of China (English)

    李淑萍; 黄世英; 汤妍雯; 曹帅英

    2015-01-01

    CNAS-RL02:2012《能力验证规则》中规定,申请认可和已获认可的实验室,根据检验领域和项目,选择1次/1年或1次/2年的周期参加相关项目的能力验证或测量审核,没有能力验证计划的项目可选择与权威机构进行比对,也可以选择参加权威机构组织的实验室间比对,证明其检验项目在该领域的检验能力。为此,国家合成橡胶质量监督检验中心策划组织46家合成橡胶行业所属的实验室,开展了丁二烯橡胶门尼粘度的比对工作。丁二烯橡胶门尼粘度实验室间的比对,比对结果统计与分析采用稳健统计技术,Z值绝对值平均值均小于0.87,满意结果在95%以上,有2个离群结果,占样本总数的4.4%,各实验室的测试水平较以往有大幅度提升。%《The ability to verify the rules》 of CNAS-RL02:2012 specifies:The laboratory ask for recognition and accredited laboratory,according to the test area and project,could select once a year or 2 years to participate in the ability verification or measurement audit of relevant projects,the labs without proof test projects can prove their test capacity through comparison with authority laboratories organized by authority. Therefore,national quality supervi-sion and inspection center of synthetic rubber planned and organized 46 laboratories in synthetic rubber industry, carried out the butadiene rubber Mooney viscosity comparison work. Comparison of butadiene rubber Mooney vis-cosity between the laboratories,each participating laboratory used Mooney viscometer calibrated with standard mate-rial,the average of Z absolute values was below 0. 87,satisfactory results exceeded 95%,two results deviated from the group,accounting for 4. 4% of the total number of samples,the laboratory test level has been increased greatly than in the past.

  1. 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

  2. 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

  3. 无机盐对丙烯腈与N-乙烯基吡咯烷酮共聚物溶液黏度的影响%EFFECT OF INORGANIC SALTS ON VISCOSITY OF ACRYLONITRILE/N-VINYLPYRROLIDONE COPOLYMER SOLUTIONS

    Institute of Scientific and Technical Information of China (English)

    陈厚; 王成国; 蔡华甦

    2003-01-01

    Effect of inorganic salts on viscosities of dimethyl sulphoxide(DMSO)solutions of acrylonitrile(AN)/N-vinylpyrrolidone(N-VP) copolymer was discussed. Viscosity was determined by revolving viscosimeter. It was shown that solution viscosity decreased quickly with addition of KCl and NaCl and the effect of NaCl was more prominent than KCl. As the concentration of KCl and NaCl beyond 0.025mol*L-1, the viscosity tended to increase. The viscosity increased considerably with addition of FeCl3 and CuCl2. The change of solution viscosity became less obvious with addition of ZnCl2.With increasing temperature, the viscosity of copolymer solution containing NaCl decreased most quickly and the copolymer solution containing FeCl3 decreased most slowly.

  4. Infrared absorption of trans-1-chloromethylallyl and trans-1-methylallyl radicals produced in photochemical reactions of trans-1,3-butadiene and C Script-Small-L {sub 2} in solid para-hydrogen

    Energy Technology Data Exchange (ETDEWEB)

    Bahou, Mohammed; Wu, Jen-Yu; Tanaka, Keiichi [Department of Applied Chemistry and Institute of Molecular Science, National Chiao Tung University, 1001 Ta-Hsueh Rd., Hsinchu 30010, Taiwan (China); Lee, Yuan-Pern [Department of Applied Chemistry and Institute of Molecular Science, National Chiao Tung University, 1001 Ta-Hsueh Rd., Hsinchu 30010, Taiwan (China); Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617, Taiwan (China)

    2012-08-28

    The reactions of chlorine and hydrogen atoms with trans-1,3-butadiene in solid para-hydrogen (p-H{sub 2}) were investigated with infrared (IR) absorption spectra. When a p-H{sub 2} matrix containing C Script-Small-L {sub 2} and trans-1,3-butadiene was irradiated with ultraviolet light at 365 nm, intense lines at 650.3, 809.0, 962.2, 1240.6 cm{sup -1}, and several weaker ones due to the trans-1-chloromethylallyl radical, Bullet (CH{sub 2}CHCH)CH{sub 2}C Script-Small-L , appeared. Observed wavenumbers and relative intensities agree with the anharmonic vibrational wavenumbers and IR intensities predicted with the B3PW91/6-311++g(2d, 2p) method. That the C Script-Small-L atom adds primarily to the terminal carbon atom of trans-1,3-butadiene is in agreement with the path of minimum energy predicted theoretically, but in contrast to the reaction of C Script-Small-L + propene in solid p-H{sub 2}[J. Amicangelo and Y.-P. Lee, J. Phys. Chem. Lett. 1, 2956 (2010)] in which the addition of C Script-Small-L to the central C atom is favored, likely through steric effects in a p-H{sub 2} matrix. A second set of lines, intense at 781.6, 957.9, 1433.6, 2968.8, 3023.5, 3107.3 cm{sup -1}, were observed when the UV-irradiated C Script-Small-L {sub 2}/trans-1,3-butadiene/p-H{sub 2} matrix was further irradiated with IR light from a SiC source. These lines are assigned to the trans-1-methylallyl radical, Bullet (CH{sub 2}CHCH)CH{sub 3}, produced from reaction of 1,3-butadiene with a H atom resulted from the reaction of C Script-Small-L atoms with solid p-H{sub 2} exposed to IR radiation.

  5. Pengaruh suhu vulkanisasi terhadap sifat mekanis vulkanisat karet alam dan karet akrilonitril-butadiena

    Directory of Open Access Journals (Sweden)

    Norma Arisanti Kinasih

    2015-12-01

    Full Text Available Natural and acrylonitrile-butadiene rubbers possess different vulcanization characteristics. Selection of the vulcanization system and temperature affects the mechanical properties of vulcanized natural rubber (NR and acrylonitrile-butadiene rubber (NBR. In the present work, the effect of vulcanization temperature (150, 160, 170 and 180oC on the mechanical properties of NR and NBR vulcanizates was studied. The effect of different vulcanization system (semi efficient, efficient and sulfur donor was studied in NR blends, while the effect of different acrylonitrile content (26, 28 and 33 wt % was studied in NBR blends. The NBR curing characteristics and mechanical properties data showed that vulcanization at low temperature (150oC was suitable for low acrylonitrile-NBR, whereas that at high temperature (170oC was suitable for high acrylonitrile-NBR. In addition, the semi efficient system at low temperature vulcanization (150oC was suitable for natural rubber.

  6. Optimal design of acrylonitrile removal column for one-step condensate%一步法蒸发冷凝水脱单塔设计优化研究

    Institute of Scientific and Technical Information of China (English)

    任健; 梅诗宇; 李健辉; 章渊昶; 祝铃钰; 姚克俭

    2013-01-01

    建立了脱单塔系统的费用模型,确定影响脱单塔设计优化的关键变量为废水进料温度、塔内件型式和丙烯腈脱除率,对一步法蒸发冷凝水脱单塔系统的操作与设备费用进行分析.以总成本最小为目标,完成三个关键变量与系统总成本的关联,以操作费用和设备成本最小确定关键变量的选择方案,并对工业设计进行指导.结果表明,当选择圆筒型散装填料作为塔内件时,系统的总费用比选择板式塔要低.将理论计算结果用于工业设计,优化设计点是若干设计工况中的最佳点.%A cost model of the single tower is established,in which feed temperature of wastewater,column internal and acrylonitrile recovery are determined as key variables to analyze the operation and capital costs of acrylonitrile removal system for one-step condensate. To obtain the minimum total cost, the correlations between these three key variables and the total cost are analyzed. The operation and capital costs are minimized to choose the optimal case which could conduct industrial design. The results show that the total cost of the plant using random cylindrical packing column is lower than that using tray column. Applying the optimization results to industrial design,the optimized point is the best circumstance of several design conditions.

  7. 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%。

  8. Enhancement of light yield and stability of radio-pure tetraphenyl-butadiene based coatings for VUV light detection in cryogenic environments

    Science.gov (United States)

    Baudis, L.; Benato, G.; Dressler, R.; Piastra, F.; Usoltsev, I.; Walter, M.

    2015-09-01

    The detection of VUV scintillation light in (liquid) argon (LAr) 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 light yield 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/cm2, resulting in a 3.6 times higher light yield compared to uncoated VM2000. Its performance was stable in long-term measurements, performed up to 100 days in liquid argon. This coated reflector was also investigated concerning radioactive impurities and found to be suitable for current and upcoming low-background experiments. Therefore it is used for the liquid argon veto in Phase II of the GERDA neutrinoless double beta decay experiment.

  9. Iminopyridine-Based Cobalt(II and Nickel(II Complexes: Synthesis, Characterization, and Their Catalytic Behaviors for 1,3-Butadiene Polymerization

    Directory of Open Access Journals (Sweden)

    Quanquan Dai

    2016-01-01

    Full Text Available A series of iminopyridine ligated Co(II (1a–7a and Ni(II (1b–7b complexes were synthesized. The structures of complexes 3a, 4a, 5a, 7a, 5b, and 6b were determined by X-ray crystallographic analyses. Complex 3a formed a chloro-bridged dimer, whereas 4a, 5a, and 7a, having a substituent (4a, 5a: CH3; 7a: Br at the 6-position of pyridine, producing the solid structures with a single ligand coordinated to the central metal. The nickel atom in complex 5b features distorted trigonal-bipyramidal geometry with one THF molecule ligating to the metal center. All the complexes activated by ethylaluminum sesquichloride (EASC were evaluated in 1,3-butadiene polymerization. The catalytic activity and selectivity were significantly influenced by the ligand structure and central metal. Comparing with the nickel complexes, the cobalt complexes exhibited higher catalytic activity and cis-1,4-selectivity. For both the cobalt and nickel complexes, the aldimine-based complexes showed higher catalyst activity than their ketimine counterparts.

  10. Temperature dependence of alpha-induced scintillation in the 1,1,4,4-tetraphenyl-1,3-butadiene wavelength shifter

    Science.gov (United States)

    Veloce, L. M.; Kuźniak, M.; Di Stefano, P. C. F.; Noble, A. J.; Boulay, M. G.; Nadeau, P.; Pollmann, T.; Clark, M.; Piquemal, M.; Schreiner, K.

    2016-06-01

    Liquid noble 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 gas 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 in TPB and nuclear-recoil events in noble liquid detectors.

  11. VUV-Vis optical characterization of Tetraphenyl-butadiene films on glass and specular reflector substrates from room to liquid Argon temperature

    Science.gov (United States)

    Francini, R.; Montereali, R. M.; Nichelatti, E.; Vincenti, M. A.; Canci, N.; Segreto, E.; Cavanna, F.; Di Pompeo, F.; Carbonara, F.; Fiorillo, G.; Perfetto, F.

    2013-09-01

    The use of efficient wavelength-shifters from the vacuum-ultraviolet to the photo-sensor'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 lineshape and relative intensity variation recorded as a function of the film thickness and for the first time down to LAr temperature, as well as optical reflectance and transmittance spectra of the TPB coated substrates in the wavelength range of the TPB emission.

  12. 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

    2012-10-01

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

  13. 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.

  14. 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.

  15. Dissociative double-photoionization of butadiene in the 25-45 eV energy range using 3-D multi-coincidence ion momentum imaging spectrometry.

    Science.gov (United States)

    Oghbaie, Shabnam; Gisselbrecht, Mathieu; Laksman, Joakim; Månsson, Erik P; Sankari, Anna; Sorensen, Stacey L

    2015-09-21

    Dissociative double-photoionization of butadiene in the 25-45 eV energy range has been studied with tunable synchrotron radiation using full three-dimensional ion momentum imaging. Using ab initio calculations, the electronic states of the molecular dication below 33 eV are identified. The results of the measurement and calculation show that double ionization from π orbitals selectively triggers twisting about the terminal or central C-C bonds. We show that this conformational rearrangement depends upon the dication electronic state, which effectively acts as a gateway for the dissociation reaction pathway. For photon energies above 33 eV, three-body dissociation channels where neutral H-atom evaporation precedes C-C charge-separation in the dication species appear in the correlation map. The fragment angular distributions support a model where the dication species is initially aligned with the molecular backbone parallel to the polarization vector of the light, indicating a high probability for double-ionization to the "gateway states" for molecules with this orientation. PMID:26395707

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

    Science.gov (United States)

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

    2015-07-01

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

  17. 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.

  18. 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

  19. 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

  20. 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.

  1. Thermodynamic Calculation and Analysis of Converting Butene to Butadiene by Oxidative Dehydrogenation%丁烯氧化脱氢制丁二烯体系的热力学计算与分析

    Institute of Scientific and Technical Information of China (English)

    程亮亮; 黄剑锋; 马应海

    2015-01-01

    In the reaction system of converting butene to butadiene by oxidative dehydrogenation, the standard enthalpy, the gibbs free energy and the equilibrium constants of each reaction were calculated. The equilibrium composition of the reaction system was calculated by the principle of Gibbs free energy minimization. The results show that the oxidative dehydrogenation reaction and the complete oxidation reaction can both proceed completely, but the yield of butadiene can be limited by the thermodynamic equilibrium. Therefore, in order to improve the yield of butadiene, it is crucial to develop catalysts with high performance, and the generation reaction of COx can be completely inhibited by kinetically controlling.%计算了正丁烯氧化脱氢制丁二烯体系中各反应的标准摩尔反应焓、标准摩尔吉布斯自由能、平衡常数,并利用 Gibbs 自由能最小法计算了反应体系的热力学平衡组成。结果表明,正丁烯的氧化脱氢与完全氧化反应在热力学上均可完全进行,但是丁二烯的产率受热力学平衡限制。因此,提高丁二烯产率的关键在于开发高性能的催化剂,从动力学上角度充分抑制 COx的生成反应。

  2. 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.

  3. 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.

  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

    2016-01-01

    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 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. PMID:26999148

  5. From Sugars to Wheels: The Conversion of Ethanol to 1,3-Butadiene over Metal-Promoted Magnesia-Silicate Catalysts.

    Science.gov (United States)

    Shylesh, Sankaranarayanapillai; Gokhale, Amit A; Scown, Corinne D; Kim, Daeyoup; Ho, Christopher R; Bell, Alexis T

    2016-06-22

    1,3-Butadiene (1,3-BD) is a high-value chemical intermediate used mainly as a monomer for the production of synthetic rubbers. The ability to source 1,3-BD from biomass is of considerable current interest because it offers the potential to reduce the life-cycle greenhouse gas (GHG) impact associated with 1,3-BD production from petroleum-derived naphtha. Herein, we report the development and investigation of a new catalyst and process for the one-step conversion of ethanol to 1,3-BD. The catalyst is prepared by the incipient impregnation of magnesium oxide onto a silica support followed by the deposition of Au nanoparticles by deposition-precipitation. The resulting Au/MgO-SiO2 catalyst exhibits a high activity and selectivity to 1,3-BD and low selectivities to diethyl ether, ethylene, and butenes. Detailed characterization of the catalyst shows that the desirable activity and selectivity of Au/MgO-SiO2 are a consequence of a critical balance between the acidic-basic sites associated with a magnesium silicate hydrate phase and the redox properties of the Au nanoparticles. A process for the conversion of ethanol to 1,3-BD, which uses our catalyst, is proposed and analyzed to determine the life-cycle GHG impact of the production of this product from biomass-derived ethanol. We show that 1,3-BD produced by our process can reduce GHG emissions by as much as 155 % relative to the conventional petroleum-based production of 1,3-BD. PMID:27198471

  6. 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.

  7. A preliminary regional PBPK model of lung metabolism for improving species dependent descriptions of 1,3-butadiene and its metabolites.

    Science.gov (United States)

    Campbell, Jerry; Van Landingham, Cynthia; Crowell, Susan; Gentry, Robinan; Kaden, Debra; Fiebelkorn, Stacy; Loccisano, Anne; Clewell, Harvey

    2015-08-01

    1,3-Butadiene (BD), a volatile organic chemical (VOC), is used in synthetic rubber production and other industrial processes. It is detectable at low levels in ambient air as well as in tobacco smoke and gasoline vapors. Inhalation exposures to high concentrations of BD have been associated with lung cancer in both humans and experimental animals, although differences in species sensitivity have been observed. Metabolically active lung cells such as Pulmonary Type I and Type II epithelial cells and club cells (Clara cells)(1) are potential targets of BD metabolite-induced toxicity. Metabolic capacities of these cells, their regional densities, and distributions vary throughout the respiratory tract as well as between species and cell types. Here we present a physiologically based pharmacokinetic (PBPK) model for BD that includes a regional model of lung metabolism, based on a previous model for styrene, to provide species-dependent descriptions of BD metabolism in the mouse, rat, and human. Since there are no in vivo data on BD pharmacokinetics in the human, the rat and mouse models were parameterized to the extent possible on the basis of in vitro metabolic data. Where it was necessary to use in vivo data, extrapolation from rat to mouse was performed to evaluate the level of uncertainty in the human model. A kidney compartment and description of downstream metabolism were also included in the model to allow for eventual use of available urinary and blood biomarker data in animals and humans to calibrate the model for estimation of BD exposures and internal metabolite levels. Results from simulated inhalation exposures to BD indicate that incorporation of differential lung region metabolism is important in describing species differences in pulmonary response and that these differences may have implications for risk assessments of human exposures to BD. PMID:26079054

  8. 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.

  9. Transport characteristics of organic solvents through carbon nanotube filled styrene butadiene rubber nanocomposites: the influence of rubber-filler interaction, the degree of reinforcement and morphology.

    Science.gov (United States)

    Abraham, Jiji; Maria, Hanna J; George, Soney C; Kalarikkal, Nandakumar; Thomas, Sabu

    2015-05-01

    The transport behaviour of some aromatic and aliphatic solvents through carbon nanotube filled styrene butadiene rubber composites has been investigated. The aim of the present work is to investigate the role of the sorption technique in analysing the compatibility and the reinforcing effect of MWCNTs as a filler in the SBR matrix. It also focuses on the investigation of the relationship between the dispersion of CNTs in the SBR matrix and its transport behaviour. The diffusion and transport of organic solvents through the membranes have been investigated in detail as a function of CNT content, nature of solvent and temperature in the range of 28-60 °C. Solvent uptake, diffusion, sorption and permeation constants were investigated and were found to decrease with the increase of CNT loading. Transport properties could be related to the morphology of the nanocomposites. At high concentration CNT particles form a local filler-filler network in the rubber matrix. As a result, the transport of solvent molecules through the polymer is hindered. The rubber-solvent interaction parameter, enthalpy and entropy of sorption have also been estimated from the transport data. The values of rubber-solvent interaction parameters obtained from the diffusion experiments have been used to calculate the molecular mass between the crosslinks of the network polymer. The better reinforcement at higher filler loading was confirmed from the cross-link density values. The extent of reinforcement was evaluated using Kraus and Cunneen and Russel equations. The Affine and Phantom models for chemical crosslinks were used to predict the mobility of the crosslinks. The Phantom model gave better fitting indicating that the chains can move freely through one another, i.e. the junction points fluctuate over time around their mean position without any hindrance from the neighbouring molecule. The diffusivity datas of the systems have shown dependence on the temperature and microstructure of the

  10. Butadiene-isoprene copolymerization with diglycoldimethyl ether as modifier%以二乙醇二甲醚(2 G)为调节剂的丁二烯-异戊二烯共聚合

    Institute of Scientific and Technical Information of China (English)

    任艳; 王玉荣; 张春庆; 刘海峰; 郑仰才; 任春晓

    2006-01-01

    @@ Polymerizations of conjugated diolefins are interesting topics in rubber and thermoplastic elastomer industries. Especially the copolymerization of butadiene(Bd) and isoprene (Ip) takes an important place in tire. Many investigations on rare earth catalysts system for the copolymerization have been reported, but rarely reported on that of using alkyllithium as initiator. In the research, it is reported a study on the copolymerization of Bd and Ip at 50 ℃ in the presence of diglycoldimethyl ether(2 G)and n-BuLi as initiator, cyclohexane as solvent.

  11. 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

  12. 稀土催化剂上丁二烯气相聚合的宏观动力学研究%Studies on Macro-kinetics of Gas Phase Polymerization of Butadiene with Rare-earth Catalyst

    Institute of Scientific and Technical Information of China (English)

    方东宇; 孙建中; 周其云; 冯博

    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.

  13. 氢化度与丙烯腈含量对HNBR硫化胶性能的影响%Effect of Acrylonitrile Content and Hydrogenation on Properties of Hydrogenated Nitrile Rubber(HNBR) Vulcanizates

    Institute of Scientific and Technical Information of China (English)

    张成龙; 李再峰; 白延光; 王宁; 李岩峰; 熊召举

    2013-01-01

    研究了氢化度和丙烯腈含量对氢化丁腈橡胶(HNBR)硫化特性、力学性能、热老化性能以及热性能的影响.利用核磁共振(NMR)考察了不同型号HNBR橡胶的交联性能;并采用凝胶色谱法(GPC)对生胶的分子量和分子量分布进行了测定,给出了橡胶门尼黏度与其分子量和分子量分布之间的关系.结果表明,随着氢化度与丙烯腈含量的增加,Tg升高;硫化胶的交联密度随着不饱和度和丙烯腈含量的增加而增加;氢化度升高,硫化胶的拉伸强度变化不大,扭断伸长率和撕裂强度降低,100%定伸增加;丙烯腈含量升高,硫化胶的拉伸强度、撕裂强度和100%定伸提高,扯断伸长率变化不大.%In this paper, effects of crylonitrile content and hydrogenation on vulcanization characteristics, physical performances, thermal aging performance and thermal properties of hydrogenated nitrile rubber (HNBR) were investigated. Crosslinking density of vulcanizates was tested by the nuclear magnetic resonance (NMR), and crosslinking properties of different types of HNBR rubber were investigated further. Relative molecular weight and molecular weight distribution of raw material were tested by GPC. The relationship between molecular weight distribution and mooney viscosity of rubber was given. The glass-transition temperature is enhanced with an increase in the acrylonitrile content and hydrogenation, and the crosslinking density raises with the increase of the acrylonitrile and double bond content. High unsaturated HNBR shows low break elongation, tear strength, higher stress at 100% , and tensile strength is improved little. With the incensement in crylonitrile content, tensile strength and tear strength are improved, stress at 100% is increased, however, break elongation has little change.

  14. Method Development and Validation for Determining 1,3-Butadiene in Human Blood by Gas Chromatography-Mass Spectrometry and Head-Space Gas Chromatography%Method Development and Validation for Determining1,3-Butadiene in Human Blood by Gas Chromatography-Mass Spectrometry and Head-Space Gas Chromatography

    Institute of Scientific and Technical Information of China (English)

    ZHANG Su-jing; SHEN Bao-hua; ZHUO Xian-yi

    2013-01-01

    To develop a simple,validated method for identifying and quantifying 1,3-butadiene (BD) in human blood by gas chromatography-mass spectrometry (GC-MS) and head-space gas chromatography (HS-GC).BD was identified by GC-MS and HS-GC,and quantified by HS-GC.The method showed that BD had a good linearity from 50 to 500 μg/mL (r>0.99).The limits of detection and quantification were 10 μg/mL and 50 μg/mL,respectively.Both the intra-day precision and inter-day precision were <6.08%,and the accuracy was 96.98%-103.81%.The method was applied to an actual case,and the concentration of BD in the case was 242 μg/mL in human blood.This simple method is found to be useful for the routine forensic analysis of acute exposure to BD.

  15. Treatment Process Transformation of Wastewater From Styrene Butadiene Rubber Production%丁苯橡胶生产废水整改的必要性及工艺路线

    Institute of Scientific and Technical Information of China (English)

    胡雍; 刘伟; 高勇

    2014-01-01

    The properties of wastewater from styrene butadiene rubber production were discussed as well as its influence on operation of wastewater treatment unit; the pilot of wastewater treatment and comparison of the water quality data were carried out by using a variety of techniques, the suitable process route for treating styrene butadiene rubber production wastewater was determined, the pretreated water can meet the biochemical system of sewage plant.%论述了某化工厂丁苯橡胶生产废水的特性及对厂区污水处理场运行的影响;通过采用各种工艺技术对该废水进行小试并对水质数据比对,得出适合丁苯橡胶生产废水改造的工艺路线,使经预处理后的水质不会对污水处理场生化系统造成冲击。

  16. The effect of graphene oxide on the polymerization of acrylonitrile and its rheological properties%氧化石墨烯对丙烯腈聚合及溶液流变性能的影响

    Institute of Scientific and Technical Information of China (English)

    巩娜娟; 吕永根; 杨常玲; 陆叶涛

    2013-01-01

    Graphene oxide modified polyacrylonitrile (GO/PAN) was prepared by in situ polymerization. The effects of the GO on the polymeration of acrylonitrile and the rheological properties of PAN solution were studied. The results showed that GO slightly hindered the polymerization, and the molecular weight and conversion rate of GO/PAN solution decreased with the increasing content of GO. GO facilitated the fluidity of PAN solution. All the storage modulus, loss modulus and viscosity of the GO/PAN solution decreased with the increasing content of GO, and the GO/PAN solution is prone to be viscous with increasing content of GO.%采用原位聚合法制备了氧化石墨烯/聚丙烯腈(GO/PAN)共聚物,研究了GO对丙烯腈聚合及PAN纺丝溶液流变性能的影响.结果表明,GO对聚合反应有一定的抑制作用,GO/PAN的相对分子质量和转化率均随着GO质量分数的增加而减小;GO的加入增加了PAN的流动性,GO/PAN溶液的储能模量、损耗模量和粘度均随着GO质量分数的增加而减小,并且随着GO质量分数的增加更倾向于粘性.

  17. Morphology, mechanical, cross-linking, thermal, and tribological properties of nitrile and hydrogenated nitrile rubber/multi-walled carbon nanotubes composites prepared by melt compounding: The effect of acrylonitrile content and hydrogenation

    International Nuclear Information System (INIS)

    The purpose of this work was to prepare nanocomposites by mixing multi-walled carbon nanotubes (MWCNT) with nitrile and hydrogenated nitrile elastomers (NBR and HNBR). Utilization of transmission electronic microscopy (TEM), scanning electron microscopy (SEM), and small- and wide-angle X-ray scattering techniques (SAXS and WAXS) for advanced morphology observation of conducting filler-reinforced nitrile and hydrogenated nitrile rubber composites is reported. Principal results were increases in hardness (maximally 97 Shore, type A), elastic modulus (maximally 981 MPa), tensile strength (maximally 27.7 MPa), elongation at break (maximally 216%), cross-link density (maximally 7.94 x 1028 m-3), density (maximally 1.16 g cm-3), and tear strength (11.2 kN m-1), which were clearly visible at particular acrylonitrile contents both for unhydrogenated and hydrogenated polymers due to enhanced distribution of carbon nanotubes (CNT) and their aggregated particles in the applied rubber matrix. Conclusion was that multi-walled carbon nanotubes improved the performance of nitrile and hydrogenated nitrile rubber nanocomposites prepared by melt compounding.

  18. Evaluation of the detoxication efficiencies for acrylonitrile wastewater treated by a combined anaerobic oxic-aerobic biological fluidized tank (A/O-ABFT) process: Acute toxicity and zebrafish embryo toxicity.

    Science.gov (United States)

    Na, Chunhong; Zhang, Ying; Deng, Minjie; Quan, Xie; Chen, Shuo; Zhang, Yaobin

    2016-07-01

    Acrylonitrile (ACN) wastewater generated during ACN production has been reported to be toxic to many aquatic organisms. However, few studies have evaluated toxicity removal of ACN wastewater during and after the treatment process. In this study, the detoxication ability of an ACN wastewater treatment plant (WWTP) was evaluated using Daphnia magna, Danio rerio and zebrafish embryo. This ACN WWTP has a combined anaerobic oxic-aerobic biological fluidized tank (A/O-ABFT) process upgraded from the traditional anaerobic oxic (A/O) process. Moreover, the potential toxicants of the ACN wastewaters were identified by gas chromatography-mass spectrometry (GC-MS). The raw ACN wastewater showed high acute and embryo toxicity. 3-Cyanopyridine, succinonitrile and a series of nitriles were detected as the toxic contributors of ACN wastewater. The A/O process was effective for the acute and embryo toxicity removal, as well as the organic toxicants. However, the A/O effluent still showed acute and embryo toxicity which was attributed by the undegraded and the newly generated toxicants during the A/O process. The residual acute and embryo toxicity as well as the organic toxicants in the A/O effluent were further reduced after going through the downstream ABFT process system. The final effluent displayed no significant acute and embryo toxicity, and less organic toxicants were detected in the final effluent. The upgrade of this ACN WWTP results in the improved removal efficiencies for acute and embryo toxicity, as well as the organic toxicants. PMID:27037768

  19. Poly(methyl methacrylate-acrylonitrile-ethyl acrylate) terpolymer based gel electrolyte for LiNi0.5Mn1.5O4 cathode of high voltage lithium ion battery

    Science.gov (United States)

    Sun, Ping; Liao, Youhao; Xie, Huili; Chen, Tingting; Rao, Mumin; Li, Weishan

    2014-12-01

    A novel gel polymer electrolyte (GPE), based on poly(methyl methacrylate-acrylonitrile-ethyl acrylate) (P(MMA-AN-EA)) terpolymer, is designed to match LiNi0.5Mn1.5O4 cathode of 5 V lithium ion battery. The performances of the synthesized P(MMA-AN-EA) terpolymer and the corresponding membrane and GPE are investigated by scanning electron microscope, energy dispersive spectroscopy, nuclear magnetic resonance spectra, Fourier transform infrared spectra, thermogravimetric analyzer, electrochemical impedance spectroscopy, linear sweep voltammetry, and charge/discharge test. It is found that the pore structure of P(MMA-AN-EA) membrane is affected by the dose of pore forming agent, polyethylene glycol (PEG400). The membrane with 3 wt% PEG400 presents the best pore structure, in which pores are dispersed uniformly and interconnected, and exhibits the largest electrolyte uptake, resulting in the highest ionic conductivity of 3.82 × 10-3 S cm-1 for the corresponding GPE at room temperature. The GPE has improved compatibility with lithium anode and is electrochemically stable up to 5.2 V (vs. Li/Li+). The high voltage LiNi0.5Mn1.5O4 cathode using the resulting GPE exhibits excellent cyclic stability, maintaining 97.9% of its initial discharge capacity after 100 cycles compared to that of 79.7% for the liquid electrolyte at 0.5 C.

  20. 丁腈橡胶应力加速老化行为的研究%Study of Stress Accelerated Aging Behavior of Sulfured Nitrile-butadiene Rubber

    Institute of Scientific and Technical Information of China (English)

    熊英; 付宝强; 郭少云; 芦忠

    2012-01-01

    The storage life of nitrile-butadiene rubber (NBR) was calculated according to Arrhenius equation by using high temperature accelerated aging method and the criterion of elongation. The aging behavior of NBR under different stress was studied and the aging mechanism was discussed. The results showed that stress has important impact on aging behavior of NBR; when there is no stress, NBR's storage life is over 19 years according to Arrhenius equation; its storage life reduces 50% under bending stress; its storage life is less than 2 years under tensile-bending stress. This is because stress will induce the orientation and deformation of NBR molecular chain, and change and restrain its bond lengths and bond angles, which also reduce the breaking activation energy of the molecular chain, accelerate the aging process, and shorten the storage life or the service life of NBR.%以丁腈橡胶为例,采用高温加速老化法,以拉伸断裂伸长率作为贮存寿命指标,通过Arrhenius方程对丁腈橡胶贮存寿命的推算,研究了不同应力作用下丁腈橡胶的老化行为,并初步探讨了应力作用下丁腈橡胶的老化机理.结果表明,应力作用对丁腈橡胶的老化行为有较大影响,当丁腈橡胶不承受任何应力作用时,采用Arrhenius方程推算其在常温下的贮存寿命超过19a;受弯曲应力作用时,其贮存寿命降低了50%;在拉伸应力和弯曲应力同时作用时,其贮存寿命小于2a.原因是在应力作用下丁腈橡胶的分子链发生取向变形,键长和键角发生改变并受到约束,分子链的断裂活化能降低、老化进程加快,寿命缩短.

  1. Model for calculation of benzene and 1,3-butadiene concentrations in ambient air from geographic information, including biofuel burning and traffic; Modell foer beraekning av bensen- och 1,3-butadienhalter i omgivningsluft utifraan geografisk information om bland annat biobraensleeldning och trafik

    Energy Technology Data Exchange (ETDEWEB)

    Modig, Lars; Hagenbjoerk-Gustafsson, Annika; Jonsson, Lennart; Olsson, David; Forsberg, Bertil [Umeaa Univ., Faculty of Medicine, Dept. of Public Health and Clinical Medicine, Occupational and Environmental Medicine, Umeaa (Sweden); Stroemgren, Magnus [Umeaa Univ., Faculty of Social Sciences, Dept. of Geography and Economic History, Umeaa (Sweden)

    2012-07-01

    The aim of the project was to apply a type of statistical calculation model, 'Land Use Regression (LUR)', to predict the concentrations of air pollutants benzene and 1,3-butadiene in a number of urban areas with a high proportion of small-scale biofuel burning in and around Umeaa.

  2. In vivo doses of butadiene epoxides as estimated from in vitro enzyme kinetics by using cob(I)alamin and measured hemoglobin adducts: An inter-species extrapolation approach

    Energy Technology Data Exchange (ETDEWEB)

    Motwani, Hitesh V., E-mail: hitesh.motwani@mmk.su.se; Törnqvist, Margareta

    2014-12-15

    1,3-Butadiene (BD) is a rodent and human carcinogen. In the cancer tests, mice have been much more susceptible than rats with regard to BD-induced carcinogenicity. The species-differences are dependent on metabolic formation/disappearance of the genotoxic BD epoxy-metabolites that lead to variations in the respective in vivo doses, i.e. “area under the concentration-time curve” (AUC). Differences in AUC of the most gentoxic BD epoxy-metabolite, diepoxybutane (DEB), are considered important with regard to cancer susceptibility. The present work describes: the application of cob(I)alamin for accurate measurements of in vitro enzyme kinetic parameters associated with BD epoxy-metabolites in human, mouse and rat; the use of published data on hemoglobin (Hb) adduct levels of BD epoxides from BD exposure studies on the three species to calculate the corresponding AUCs in blood; and a parallelogram approach for extrapolation of AUC of DEB based on the in vitro metabolism studies and adduct data from in vivo measurements. The predicted value of AUC of DEB for humans from the parallelogram approach was 0.078 nM · h for 1 ppm · h of BD exposure compared to 0.023 nM · h/ppm · h as calculated from Hb adduct levels observed in occupational exposure. The corresponding values in nM · h/ppm · h were for mice 41 vs. 38 and for rats 1.26 vs. 1.37 from the parallelogram approach vs. experimental exposures, respectively, showing a good agreement. This quantitative inter-species extrapolation approach will be further explored for the clarification of metabolic rates/pharmacokinetics and the AUC of other genotoxic electrophilic compounds/metabolites, and has a potential to reduce and refine animal experiments. - Highlights: • In vitro metabolism to in vivo dose extrapolation of butadiene metabolites was proposed. • A parallelogram approach was introduced to estimate dose (AUC) in humans and rodents. • AUC of diepoxybutane predicted in humans was 0.078 nM h/ppm h

  3. In vivo doses of butadiene epoxides as estimated from in vitro enzyme kinetics by using cob(I)alamin and measured hemoglobin adducts: An inter-species extrapolation approach

    International Nuclear Information System (INIS)

    1,3-Butadiene (BD) is a rodent and human carcinogen. In the cancer tests, mice have been much more susceptible than rats with regard to BD-induced carcinogenicity. The species-differences are dependent on metabolic formation/disappearance of the genotoxic BD epoxy-metabolites that lead to variations in the respective in vivo doses, i.e. “area under the concentration-time curve” (AUC). Differences in AUC of the most gentoxic BD epoxy-metabolite, diepoxybutane (DEB), are considered important with regard to cancer susceptibility. The present work describes: the application of cob(I)alamin for accurate measurements of in vitro enzyme kinetic parameters associated with BD epoxy-metabolites in human, mouse and rat; the use of published data on hemoglobin (Hb) adduct levels of BD epoxides from BD exposure studies on the three species to calculate the corresponding AUCs in blood; and a parallelogram approach for extrapolation of AUC of DEB based on the in vitro metabolism studies and adduct data from in vivo measurements. The predicted value of AUC of DEB for humans from the parallelogram approach was 0.078 nM · h for 1 ppm · h of BD exposure compared to 0.023 nM · h/ppm · h as calculated from Hb adduct levels observed in occupational exposure. The corresponding values in nM · h/ppm · h were for mice 41 vs. 38 and for rats 1.26 vs. 1.37 from the parallelogram approach vs. experimental exposures, respectively, showing a good agreement. This quantitative inter-species extrapolation approach will be further explored for the clarification of metabolic rates/pharmacokinetics and the AUC of other genotoxic electrophilic compounds/metabolites, and has a potential to reduce and refine animal experiments. - Highlights: • In vitro metabolism to in vivo dose extrapolation of butadiene metabolites was proposed. • A parallelogram approach was introduced to estimate dose (AUC) in humans and rodents. • AUC of diepoxybutane predicted in humans was 0.078 nM h/ppm h

  4. Inlfuence of Different Toughness Agents on Weatherability of Acrylonitrile-Styrene Copolymer%不同增韧剂对丙烯腈-苯乙烯共聚物耐候性的影响

    Institute of Scientific and Technical Information of China (English)

    贺芳; 黄兴宇; 钱晶; 申娟

    2015-01-01

    Using seven different toughness agents in acrylonitrile-styrene copolymer(SAN Resin)was studied,the influence of high glue powder,acrylic resin(ACR),maleic anhydride grafted EPDM (EPDM–g–MAH),styrene copolymer(MBS),ethylene butyl acrylate(EBA),maleic anhydride grafted PE–LD(PE–LD–g–MAH)and ethylene methyl acrylate(EMA) on mechanical properties of acrylonitrile styrene copolymer(SAN resin)was respectively researched. And temperature test machine and xenon lamp climate chamber were used to analysis of the influence of different toughness agents on the weatherability of SAN. The results show that compared with other toughness agents,the impact strength of SAN resin with MBS is the best. The impact strength of SAN resin is decreasing with the lower temperature,EBA and EPDM–g–MAH could improve the impact strength of SAN resin in low temperature. And Xenon lamp aging test results show that the SAN resin will appear the phenomenon of xanthochroia after xenon lamp aging test,but EPDM–g–MAH,MBS and EBA could improve the light resistance properties of SAN resin,and the effect of EPDM–g–MAH is the best.%采用7种增韧剂:高胶粉、丙烯酸酯类树脂(ACR),马来酸酐接枝三元乙丙橡胶(EPDM–g–MAH),苯乙烯三元共聚物(MBS),乙烯丙烯酸丁酯(EBA),马来酸酐接枝低密度聚乙烯(PE–LD–g–MAH),乙烯–甲基丙烯酸酯(EMA)对丙烯腈-苯乙烯共聚物(SAN)进行增韧改性,通过高低温实验箱和氙灯人工气候试验箱来研究各增韧剂对SAN耐候性的影响。结果表明,添加增韧剂MBS的SAN冲击强度最高;随着温度的降低,SAN的冲击强度是下降的, EBA,EPDM–g–MAH能改善SAN的低温冲击强度;氙灯光照老化试验结果表明,SAN经过光照老化后都会出现黄变现象,而添加了EPDM–g–MAH,MBS,EBA的SAN的耐光照老化性能都有所提高,其中添加了EPDM–g–MAH的耐光照老化性最好。

  5. 高负荷下臭氧催化氧化深度处理丙烯腈废水运行特性%Operation characteristics of catalytic ozonation under the high load condition for the treatment of acrylonitrile wastewater

    Institute of Scientific and Technical Information of China (English)

    陈中英

    2015-01-01

    采用臭氧催化氧化技术对大庆炼化公司丙烯腈废水进行深度处理,处理能力为20 m3/h。在实际进水COD远远高于设计进水浓度条件下,臭氧催化氧化装置对COD的去除总量大大高于设计值(1 kg/h),平均为1.88 kg/h。在高负荷条件下,该装置处理效果优于预期,但同时也存在催化剂污染等问题。通过每周1次的定期气水联合反洗,可保证装置稳定运行并维持良好的处理效果。%Catalytic ozo nation technology has been used for the advanced treatment of the acrylonitrile wastewater from Daqing Branch,Oil Refinery Chemical Co.,CNPC,whose treatment capacity is 20 m3/h. Under the condition that the COD of actual influent is much higher than the designed influent concentration ,the total amount of COD removing capacity is averagely 1.88 kg/h,much higher than the initially designed value,1 kg/h. Under the high load condition,the treatment effect of this system is better than what was expected,but in the meanwhile,problems,such as catalyst pollution,etc.,have occurred. By means of periodic air-water backwashing once a week,the system can run steadily and keep good treatment effect.

  6. 腈纶皂化制备电流变液悬浮粒子的研究%Studies on Saponification of Acrylonitrile Terpolymer for Suspending Particles of Electrorheological Fluids

    Institute of Scientific and Technical Information of China (English)

    吴孟强; 陈艾

    2001-01-01

    In order to prepare suspending particles for electrorheological fluids, hetergeneous hydrolysis of acrylonitrile terpolymer is conducted in presence of saponifying agent(sodium hydroxide) in this paper. The effects of the saponification conditions such as the amount of added sodium hydroxide, time duration and temperature on the degree of saponification are studied in detail. Meanwhile, the conversion of nitrile groups is discussed with the result that the saponification of nitrile groups of the terpolymer initially yields amide groups, then slows down to carboxylic groups. The research sets a way for the preparation of dispersing particles of water-free electrorheological fluids tentatively used for controlling light transmittance.%为了制备无水电流变液用悬浮粒子,研究了腈纶在碱性条件下的多相水解。详细考察了皂化试剂氢氧化钾的用量,皂化时间和温度等皂化条件对皂化程度的影响; 讨论了氰基转化过程。研究结果表明,在皂化初期,腈纶分子链上的氰基转化为酰胺基,然后缓慢转化为羧基。给出了一条制备无水电流变液用悬浮粒子的方法,并初步考察了该类电流变液的控光特性。

  7. 淀粉丙烯腈接枝共聚物皂化制备吸水剂%The Preparation Technology of Water-Absorbent by the Saponification of the Graft Copolymer of Starch and Acrylonitrile

    Institute of Scientific and Technical Information of China (English)

    顾正彪; 吴嘉根

    2001-01-01

    通过对淀粉丙烯腈接枝共聚物(SPAN)皂化制备吸水剂HSPAN的研究表明:HSPAN为水不溶性凝胶,但具有很强的吸水能力.以氢氧化钾皂化,酸作沉淀剂,经洗涤、分散和干燥制备HSPAN的工艺路线较为理想.皂化工艺条件在用碱量为SPAN中接枝链部分摩尔数的1.1倍、皂化温度95°C以上、皂化时间大于3h,且HSPAN的平板干燥温度在70°C时最好.当SPAN接枝百分率在70%左右时,制得的HSPAN吸水率最高.%Studies on the Preparation Technology of Water-absorbent (HSPAN)by the Saponification of the graft Copolymer of Starch and Acrylonitrile (SPAN) showed that, HSPAN was a kind of gel which was insoluble in water but could absorb a great amount of water. The best technology for the preparation of HSPAN was that,after SPAN was saponified by potassium hydroxide, precipited by sulfuric acid, washed and dispersed in water again, HSPAN was obtained by drying it on a plate. Moreover, the best conditions were that,the quantity of potassium hydroxide used in saponification was 1.1 as much as the mole of polyacrylonitrile in SPAN, saponifying temperature over 95°C, reaction time more than 3 h and drying temperature at 70°C. In addition, the highest water-absorbing capacity could be obtained from the SPAN in which grafted ratio was 70% or so.

  8. NMR measurement of identical polymer samples by round robin method. 4. Analysis of composition and monomer sequence distribution in poly(methyl methacrylate-co-acrylonitrile) leading to determinations of monomer reactivity ratios

    Energy Technology Data Exchange (ETDEWEB)

    Hatada, Koichi; Kitayama, Tatsuki; Terawaki, Yoshio [Osaka Univ., Toyonaka (Japan). Faculty of Engineering Science] [and others

    1995-11-01

    In order to assess the reliability of NMR measurement of polymers, {sup 1}H and {sup 13}C NMR data for three copolymers of methyl methacrylate (MMA) and acrylonitrile (AN) prepared with AIBN were collected from 46 spectrometers whose resonance frequencies for {sup 1}H NMR measurements ranging from 90 to 500 MHz. {sup 1}H and {sup 13}C NMR spectra were measured in nitrobenzene-d{sub 5} at 110degC and acetonitrile-d{sub 3} at 70degC, respectively. Standard deviations ({sigma}`s) for chemical shift measurements of the {sup 1}H and {sup 13}C NMR signals were 0.003-0.008 ppm and 0.03-0.05 ppm, respectively. Compositions of the copolymers were determined from the relative intensities of the signals due to the OCH{sub 3} (MMA) and CH (AN) protons, and the {sigma} values for the determinations were 3.7-9.5%. The compositions determined from {sup 13}C NMR (C = O for MMA unit, CN for AN unit) agreed well with those obtained from {sup 1}H NMR. Monomer reactivity ratios r{sub ij} (i,j = 1 or 2) for a penultimate model were determined from monomer feed ratios and triad fractions obtained from the C = O (MMA) and CH (AN) carbon signals. Most of the {sigma} values for r{sub ij} determinations were 5-14%. While r{sub 22} and r{sub 12} are nearly equivalent, r{sub 11} and r{sub 21} are significantly different from each other, indicating a possible existence of the penultimate-unit effect in the copolymerization of MMA and AN. Terminal model reactivity ratios, r{sub 1} and r{sub 2}, determined formally from the compositions of three samples by Fineman-Ross method showed large {sigma} values (22-24%). (author).

  9. Atmospheric oxidation of 1,3-butadiene: characterization of gas and aerosol reaction products and implications for PM2.5

    Science.gov (United States)

    Jaoui, M.; Lewandowski, M.; Docherty, K.; Offenberg, J. H.; Kleindienst, T. E.

    2014-12-01

    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 13BD. Furthermore, a series of oligoesters were detected and found to be produced through chemical reactions occurring in the aerosol phase between compounds bearing alcoholic groups and compounds bearing acidic groups. SOA was analyzed for organic mass to organic carbon (OM /OC) ratio, effective enthalpy of vaporization (Δ Hvapeff), and aerosol yield. The average OM /OC ratio and SOA density were 2.7 ± 0.09 and 1.2 ± 0.05, respectively. The average Δ Hvapeff was -26.08 ± 1.46 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-phase photooxidation products have also been

  10. The Feasibility for the Project of Introducing 25 kt/a Butadiene - Based Chloroprene Rubber (CR) Plant%引进25 kt/a丁二烯法氯丁橡胶(CR)项目可行性探讨

    Institute of Scientific and Technical Information of China (English)

    张泗文

    2001-01-01

    The project of introducing 25 kt/a butadiene - based CR plant is to the advantage of any chloro - alkali enterprise at or near a petrochemical complex. But the introduction of the technology for CR is a key for the project, then the success of the project is entirely dependent on whether marketable and high - tech grades for CR to be produced.%上25 kt/a CR新项目对石化厂或靠近石化厂的氯碱企业有利;但技术引进难度高,引进后能否生产出适销对路且技术含量高的CR品种,决定项目的前途。

  11. 乳聚丁苯橡胶后处理工艺技术改进%Technology improvement in post-processing unit of emulsion polymerization styrene butadiene rubber production

    Institute of Scientific and Technical Information of China (English)

    李愿鹏

    2012-01-01

    乳聚丁苯橡胶生产中,后处理单元是决定产品质量的关键环节.针对后处理单元非计划停车频繁、运行周期短的状况,从工艺、设备、现场管理等方面进行了分析,找出影响后处理单元稳定运行的主要因素并进行了改进.%The post-processing unit is the key link to the quality of products in the emulsion polymerization styrene butadiene rubber production. According to the condition of the frequent unplanned shutdowns and short cycle operation status, the a-nalysis is carried out from technology, equipment, site management, etc. The main factors influencing the stable operation of post-processing unit are found out and improved,

  12. Henry's constants and infinite dilution activity coefficients of propane, propene, butane, isobutane, 1-butene, isobutene, trans-2-butene, and 1,3-butadiene in isobutanol and tert-butanol

    International Nuclear Information System (INIS)

    The Henry's constants and the infinite dilution activity coefficients of propane, propene, butane, isobutane, 1-butene, isobutene, trans-2-butene and 1,3-butadiene in isobutanol at T = (250 to 330) K and tert-butanol at T (300 to 330) K are measured by a gas stripping method. The rigorous formula for evaluating the Henry's constants from the gas stripping measurements is used for data reduction of these highly volatile mixtures. The accuracy of the measurements is about 2% for Henry's constants and 3% for the estimated infinite dilution activity coefficients. In the evaluations for the infinite dilution activity coefficients, the nonideality of the solute such as the fugacity coefficient and the Pointing correction is not negligible, especially at higher temperatures, and the estimation uncertainty in the infinite dilution activity coefficients includes 1% for nonideality

  13. Henry's law constants and infinite dilution activity coefficients of propane, propene, butane, isobutane, 1-butene, isobutene, trans-2-butene, and 1,3-butadiene in 1-pentanol, 2-pentanol, and 3-pentanol

    International Nuclear Information System (INIS)

    Henry's law constants and infinite dilution activity coefficients of propane, propene, butane, isobutane, 1-butene, isobutene, trans-2-butene, and 1,3-butadiene in 1-pentanol, 2-pentanol in the temperature range of (250 to 330) K and 3-pentanol in the temperature range of (260 to 330) K were measured by a gas stripping method. A rigorous formula for evaluating the Henry's law constants from the gas stripping measurements was used for the data reduction of these highly volatile mixtures. The uncertainty is about 2% for the Henry's law constants and 3% for the estimated infinite dilution activity coefficients. In the evaluation of the infinite dilution activity coefficients, the nonideality of the solute such as the fugacity coefficient and Pointing correction factor cannot be neglected, especially at higher temperatures. The estimated uncertainty of the infinite dilution activity coefficients includes 1% for nonideality

  14. MONOMER SORPTION EFFECT AND INTRINSIC KINETIC MODEL FOR GAS PHASE POLYMERIZATION OF BUTADIENE%丁二烯气相聚合过程中的单体吸附效应和本征动力学模型

    Institute of Scientific and Technical Information of China (English)

    赵军子; 孙建中; 等

    2001-01-01

    采用负载型稀土催化剂,在搅拌床反应器内进行丁二烯气相聚合动力学的研究.考察了单体在聚合物小粒子中的吸附效应和单体压力与温度对聚合速率影响,在此基础上,提出了本体系的本征动力学模型.%A self-cleaning stirred bed reactor with double axes was designed to carry out the study on kinetics of gas phase polymerization of butadiene with heterogeneous rare-earth catalyst, especially for solving the problems of 1,4-cis-polybutadiene particles agglomeration and sticking to the wall of reactor. The effect of diffusion resistance on polymerization rate was investigated.The influence of monomer sorption in microparticle was examined in order to determine the local monomer concentration on the polymer shell surrounding the active sites of the catalyst surface.Flory-Huggins' sorption isothermal instead of classic Henry's law was used to characterize the sorption of 1,3-butadiene on 1,4-cis-polybutadiene.Based on the experimental results including the effects of temperature and pressure on polymerization rate,an intrinsic kinetic model was proposed.The simulation result of the model was in good agreement with the experimental data.The model could be applied to similar heterogeneous catalyzed polymerization.

  15. Structure and Sequence Distribution of Butadiene Isoprene Copolymer Prepared by Neodymium Phosphate Catalyst%FTIR与13C NMR研究丁戊共聚物的微观结构及序列分布

    Institute of Scientific and Technical Information of China (English)

    孔春丽; 李杨; 胡雁鸣; 王玉荣

    2012-01-01

    Butadiene and isoprene copolymerization were carried out at 50 ℃ in hexane for 8 h using Nd(P5O7 )3/AlH(i-Bu)2/AlEt2Cl catalyst. The catalyst was aging at 60 ℃ for 2 h before initiation. FTIR method was used to determine the microstructure of butadiene isoprene copolymer. The result showed the copolymer was of high cis-1, 4 content in both polybutadiene unit ( cis-l, 4 = 93. 1% -97. 7% ) and polyisoprene unit ( cis-1, 4 = 97. 0% - 97. 5% ). DSC determination indicated that the copolymer was of excellent low temperature resistance. The butadiene-isoprene copolymers showed only one glass transition temperature ( Tg) from - 107. 2 ℃ to - 64. 4 ℃, which increased with the in-creasement of the isoprene ratio. The correlation deviated from Fox equation, and could be modified as Tg =1.03TgI JF, + TgBWB. The reactivity rate of the copolymer was calculated by Kelen -Tudos method. It turned out that the reactivity rates of butadiene(r,) and isoprene(r2) were 1. 21 and 0. 73, respectively. The product of rx and r2 was close to 1, which indicated the product is a random structure. The C NMR spectrum was used to determine the sequence distribution of the copolymer. The peak position in the aliphatic carbon part showed no difference while the composition changed in the copolymer. The compositions of 4 dyads of random butadiene-isoprene copolymers and the number average sequence length of polybutadiene and polyisoprene were calculated based on the peak area of 13C NMR spec-trum. The data were analyzed and examined in use of the statistical formula under Bernoullian model and Markov model. It turns out that all the data are more identical with Markov model than Bernoullian model. Moreover, the copolymer chains with higher Bd content contain longer polybutadiene segments, while the copolymer chains with higher Ip content contain longer polyisoprene segments.%采用傅立叶变换红外光谱(FTIR)分析了丁戊共聚物的微观结构,发现采用磷酸酯钕体系得到

  16. Preparation and properties of thermoresponsive acrylonitrile-based copolymer nanofibrous membranes%温敏性丙烯腈共聚物纳米纤维膜的制备与性能

    Institute of Scientific and Technical Information of China (English)

    万灵书; 王芳; 李晶; 雷浩; 傅磊; 徐志康

    2011-01-01

    Diblock copolymers of acrylonitrile and N-isopropylaerylamide (NIPAM) were synthesized by reversible addition-fragmentation chain transfer polymerization and the molecular weight distribution was found to be around 1.3. Nanofibrous membranes were prepared from the resultant copolymers by electrospinning. Optimized conditions for the electrospinning were established. FESEM images elucidate that the nanofibers are uniform. Water contact angles on the copolymer membranes show distinct transition upon temperature, which is around 20 ℃. This decreased transition temperature can be attributed to the introduction of a relatively hydrophobic polyacrylonitrile block. Bovine serum albumin adsorptions at different temperatures also confirm the thermoresponsive properties of the membranes, i.e. at lower temperature the fiber surface is more hydrophilic, which is protein-resistant. This thermoresponsive nanofibrious membrane show great potential in intelligent separation.%采用可逆加成断裂链转移可控/‘活性"聚合方法合成了丙烯腈与N-异丙基丙烯酰胺(NIPAM)的嵌段共聚物,通过调控嵌段聚合反应时间可以获得一系列不同嵌段链长的共聚物,分子量分布在1.3左右.运用静电纺丝技术制备了所合成嵌段共聚物的纳米纤维膜,扫描电镜照片表明纳米纤维膜较为均匀且直径可调.研究了纳米纤维膜表面水接触角与荧光标记牛血清清蛋白的吸附现象,接触角结果证实共聚物纳米纤维膜具有一定的温度响应性,且疏水性嵌段的引入导致响应温度较PNIPAM有所降低;蛋白质吸附结果则表明温度较低时纳米纤维膜表面更亲水,蛋白质吸附较少.所制备的温敏性纳米纤维膜可望用作智能分离与吸附材料.

  17. 丙烯腈对小鼠肝组织脂质过氧化反应的影响%Effects of acrylonitrile on lipid peroxidation in the liver tissues of mice

    Institute of Scientific and Technical Information of China (English)

    马国燕; 金娜; 李福轮; 陈亚; 薛红丽; 李芝兰

    2011-01-01

    目的 通过观察丙烯腈( acrylonitrile,AN)对小鼠肝组织脂质过氧化的影响,探讨AN的毒作用机制.方法 将200只成年健康SPF级昆明种雄性小鼠按体重随机分为4组,分别为阴性对照(生理盐水)组和低(1.25 mg/kg)、中(2.50 mg/kg)、高(5.00 mg/kg)剂量AN染毒组,每组50只.采用腹腔注射方式进行染毒,染毒容量为10 mi/kg,1次/d,连续染毒5d.于首日染毒后第7、14、21、28和35天测定其肝组织中丙二醛(MDA)含量、过氧化物歧化酶(SOD)和谷胱甘肽过氧化物酶(GSH-Px)的活力.结果 AN首日染毒后第28天中、高剂量组MDA含量与阴性对照组比较明显升高,有统计学意义(P <0.05,P<0.01),第35天高剂量组MDA含量高于阴性对照组,有统计学意义(P<0.01);第28天高剂量组SOD活力高于阴性对照组(P<0.01);第28天组高剂量组GSH-Px活力显著高于阴性对照组和中剂量组(P<0.01,P<0.05).结论 AN可能通过破坏氧化-抗氧化体系的平衡,诱导小鼠肝组织产生氧化损伤,在首日染毒后第28天时比较明显.%Objective To explore the toxicity mechanism of acrylonitrile( AN ) by observing the lipid peroxidation of the liver tissues in mice. Methods Two hundred adult male mice (6-8 weeks old, SPF grade) were randomly divided into 4 groups according to the body weight, the negative control group (normal saline) , the low-dose AN group (1.2S mg/kg) , the medium-dose AN group (2.50 mg/kg) , and the high-dose AN group (5.00 mg/kg). All mice were treated via dairy intraperitoneal injection for 5 successive days. Malonaldehyde (MDA) concentration and the activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) in the liver tissues were measured on the 7th, 14th, 21st, 28th, and 35th day after the first treatment. Results In comparison with different dose groups within the same period of time showed that the concentrations of MDA increased significantly in medium-and high-dose groups at 28th

  18. Synthesis and catalytic property of 1,3-butadiene of calixarene neodynium complex%杯芳烃钕配合物的合成及其催化丁二烯聚合

    Institute of Scientific and Technical Information of China (English)

    倪旭峰; 张一烽; 沈之荃; 陶骏

    2001-01-01

    Three kinds of calixarene neodynium complexes(C[4]NdCl,C[6]NdCl,C[8]Nd2Cl2) were synthesized. Polymerization of 1,3-butadiene with binary catalytic systems composed of calixarene neodynium/triisobutyl-aluminum and ternary catalytic system composed of calixarene neodynium, triisobutyl-aluminum, and a Lewis acid (Al2Et3Cl3 or Al(i-Bu)2Cl or PhCH2Cl) as the third component was studied. The binary catalysts were found to be active even in the absence of halogen source, the sequence of catalytic activity of calixarene neodynium complexes is C[8]Nd2Cl2>C[6]NdCl>C[4]NdCl. While the ternary system has higher activity especially using Al2Et3Cl3.as the third component, and the polymer obtained has higher cis-1,4 content. The effect of chloride sort and catalyst preparation mode, Cl/Nd ratio, and the reaction temperature on polymerization and polymer microstructure of ternary system use C[8]Nd2Cl2 was investigated. It was found that when Al2Et3Cl3 as the third component and Cl/Nd=1, the catalytic system has highest activity to polymerization of 1,3-butadiene. The cis-1,4 content of polybutadiene is decreased with the increase of reaction temperature. High cis-polybutadiene(96%) formed when polymerization was carried out at 5 ℃.%首次应用新型配体——杯芳烃.钕配合物与三异丁基铝构成催化体系催化丁二烯聚合。研究发现杯[6,8]芳烃钕/Al(i-Bu)3/汽油体系中,当Al/Nd=40~100,50℃时具有中等催化聚合活性,所制得聚丁二烯的粘均分子量为10~20万,顺-1,4结构含量为89%左右。添加适量Al2Et3Cl3,或Al(i-Bu)2Cl能提高催化活性。但不能提高顺-1,4结构含量。降低聚合反应温度,5℃聚合所得产物的顺-1,4结构含量可达96%。

  19. To improve the yield of naphtha pyrolysis butadiene by co-pyrolysis%共裂解提高石脑油裂解丁二烯收率研究

    Institute of Scientific and Technical Information of China (English)

    许江; 孔祥冰; 田亮; 景媛媛; 穆珍珍; 宋帮勇; 杨利斌

    2014-01-01

    A series of co‐pyrolysis tests of naphtha and methyl cyclohexane were carried out to study the products yield changes in pyrolysis of different proportions and at different tempera‐tures .The result showed that comparing with the naphtha pyrolysis alone ,the yield of co‐pyrol‐ysis ethylene decreased w hile the yield of butadiene substantially increased .Relatively high tem‐peratures are benefit for high butadiene yield while smaller drop of ethylene yield .The co‐pyroly‐sis of naphtha and methyl cyclohexane can optimize the pyrolysis gas product distribution and im‐prove the comprehensive added value of products .It can fully rely on existing ethylene pyrolysis unit and subsequent separation system .Meanwhile ,co‐pyrolysis has the advantages of high feasi‐bility ,lower investment and stable operation ,which can meet the requirements of industrial pro‐duction .%开展了一系列石脑油与甲基环己烷共裂解试验,对比分析了不同比例、不同温度下产物收率的变化。结果表明:与石脑油单独裂解相比,共裂解乙烯收率降低,丁二烯收率大幅度提高。在相对较高的温度下进行共裂解,可得到高收率丁二烯,同时,乙烯收率降幅较小。石脑油与甲基环己烷共裂解优化了裂解气相产物分布,提高了产物的综合附加值,可完全依托现有乙烯裂解装置和后分离系统多产丁二烯,可行度高且节省投资,装置操作平稳,可满足工业化生产的要求。

  20. A comprehensive review of occupational and general population cancer risk: 1,3-Butadiene exposure-response modeling for all leukemia, acute myelogenous leukemia, chronic lymphocytic leukemia, chronic myelogenous leukemia, myeloid neoplasm and lymphoid neoplasm.

    Science.gov (United States)

    Sielken, Robert L; Valdez-Flores, Ciriaco

    2015-11-01

    Excess cancer risks associated with 1,3-butadiene (BD) inhalation exposures are calculated using an extensive data set developed by the University of Alabama at Birmingham (UAB) from an epidemiology study of North American workers in the styrene butadiene rubber (SBR) industry. While the UAB study followed SBR workers, risk calculations can be adapted to estimate both occupational and general population risks. The data from the UAB SBR study offer an opportunity to quantitatively evaluate the association between cumulative exposure to BD and different types of cancer, accounting for the number of tasks involving high-intensity exposures to BD as well as confounding associated with the exposures to the multiple other chemicals in the SBR industry. Quantitative associations of BD exposure and cancer, specifically leukemia, can be further characterized by leukemia type, including potential associations with acute myelogenous leukemia (AML), chronic lymphocytic leukemia (CLL), and chronic myelogenous leukemia (CML), and the groups of lymphoid and myeloid neoplasms. Collectively, these multiple evaluations lead to a comprehensive analysis that makes use of all of the available information and is consistent with the risk assessment goals of the USEPA and other regulatory agencies, and in line with the recommendations of the USEPA Science Advisory Board. While a range of cancer risk values can result from these multiple factors, a preferred case for occupational and general population risk is highlighted. Cox proportional hazards models are used to fit exposure-response models to the most recent UAB data. The slope of the model with cumulative BD ppm-years as the predictor variable is not statistically significantly greater than zero for CML, AML, or, when any one of eight exposure covariates is added to the model, for all leukemias combined. The slope for CLL is statistically significantly different from zero. The slope for myeloid neoplasms is not statistically

  1. Caraterização composicional do AES - um copolímero de enxertia de poli(estireno-co-acrilonitrila em poli(etileno-co-propileno-co-dieno Compositional characterization of AES a graft copolymer based on poly(styrene-co-acrylonitrile and poly(etyhlene-co-propylene-co-diene

    Directory of Open Access Journals (Sweden)

    Renato Turchet

    2006-06-01

    Full Text Available O objetivo deste trabalho é a caracterização do AES, um copolímero de enxertia de poli(estireno-co-acrilonitrila, SAN, em poli(etileno-co-propileno-co-dieno, EPDM. Para tanto, o AES foi submetido à extração seletiva de seus componentes: o SAN livre, o EDPM livre, e o copolímero de enxertia EPDM-g-SAN. O AES e suas frações foram caracterizados por espectroscopia de infravermelho, análise elementar, calorimetria diferencial de varredura e ressonância magnética nuclear, RMN¹H e RMN13C. O AES analisado apresenta a seguinte composição em massa: 65% de EPDM-g-SAN, 13% de EPDM livre e 22% de SAN livre. O EPDM apresenta 69,8% em massa de etileno, 26,5% em massa de propileno e 4,6% em massa do dieno, 2-etilideno-5-norboneno, ENB. O SAN apresenta razão em massa acrilonitrila/estireno de 28/72 e distribuição randômica de comonômeros de estireno e acrilonitrila. Estes resultados são concordantes com a composição do AES fornecida pelo fabricante, indicando que a metodologia proposta é adequada.This work aims the characterization of AES, a graft copolymer based on poly(styrene-co-acrylonitrile, SAN, and poly(etyhlene-co-propylene-co-diene, EPDM. AES was submitted to selective extraction of its components: free SAN, EPDM chains and the graft copolymer EPDM-g-SAN. AES and its fractions were characterized by infrared spectroscopy, elemental analysis, differential scanning calorimetry, 13C and ¹H nuclear magnetic resonance. The AES has 65 wt % of EPDM-g-SAN, 13 wt % of free EPDM and 22 wt % of free SAN. EPDM has 69.8 wt % of ethylene, 26.5 wt % of propylene and 4.6 wt % of diene, 2-ethylidene-5-norbonene ENB. SAN presents acrylonitrile/styrene mass ratio of 28/72 and a random distribution of acrylonitrile and styrene comonomers. These results are in agreement with the composition reported by the AES supplier, indicating that the proposed methodology is adequate.

  2. Rapid prototyping of polymeric microstructures with a UV laser

    DEFF Research Database (Denmark)

    Jensen, Martin F.; McCormack, John E.; Helbo, Bjarne;

    2003-01-01

    ion implantation of the master tool to prolong the lifetime has also been investigated. For injection moulding, where the pressure and temperature is higher than in hot embossing a positive laser ablated Acrylonitrile-butadien-styrene co-polymer (ABS) structure was used, which subsequently has been...

  3. 40 CFR 180.960 - Polymers; exemptions from the requirement of a tolerance.

    Science.gov (United States)

    2010-07-01

    ... specified for defining a low-risk polymer in 40 CFR 723.250, as an inert ingredient in a pesticide chemical... Acrylonitrile-butadiene copolymer conforming to 21 CFR 180.22, minimum average molecular weight (in amu), 1,000... Federal Register citations affecting § 180.960, see the List of CFR Sections Affected, which appears...

  4. Media surface properties and the development of nitrifying biofilms in mixed cultures for wastewater treatment.

    OpenAIRE

    Stephenson, Tom; Reid, E.; Avery, L. M.; Jefferson, Bruce

    2013-01-01

    Plastic was tested to select biofilm support media that would enhance nitrification in the presence of heterotrophs. Eight different types (acrylonitrile butadiene styrene, nylon, polycarbonate, polyethylene, polypropylene, polytetraflouroethylene (PTFE), polyvinyl chloride and tufnol) were immersed in an aerobic fed-batch reactor receiving domestic settled wastewater. Nitrification rates did not correlate with biomass concentrations, nor surface roughness of the plastics as measured by atomi...

  5. NBR Demand Up

    Institute of Scientific and Technical Information of China (English)

    Wang Yuying

    2007-01-01

    @@ 1 Output decreased in 2006 By the end of 2006 the capacity of to make NBR (acrylonitrile-butadiene rubber) in China was still maintained at 49.5 thousand t/a, but the output was only 35 thousand tons in 2006, a drop of 9.9% from 2005.

  6. Urinary biomarkers in hexachloro-1:3-butadiene-induced acute kidney injury in the female Hanover Wistar rat; correlation of α-glutathione S-transferase, albumin and kidney injury molecule-1 with histopathology and gene expression.

    Science.gov (United States)

    Swain, Aubrey; Turton, John; Scudamore, Cheryl L; Pereira, Ines; Viswanathan, Neeti; Smyth, Rosemary; Munday, Michael; McClure, Fiona; Gandhi, Mitul; Sondh, Surjit; York, Malcolm

    2011-05-01

    Hexachloro-1:3-butadiene (HCBD) causes kidney injury specific to the pars recta of the proximal tubule. In the present studies, injury to the nephron was characterized at 24 h following a single dose of HCBD, using a range of quantitative urinary measurements, renal histopathology and gene expression. Multiplexed renal biomarker measurements were performed using both the Meso Scale Discovery (MSD) and Rules Based Medicine platforms. In a second study, rats were treated with a single nephrotoxic dose of HCBD and the time course release of a range of traditional and newer urinary biomarkers was followed over a 25 day period. Urinary albumin (a marker of both proximal tubular function and glomerular integrity) and α-glutathione S-transferase (α-GST, a proximal tubular cell marker of cytoplasmic leakage) showed the largest fold change at 24 h (day 1) after dosing. Most other markers measured on either the MSD or RBM platforms peaked on day 1 or 2 post-dosing, whereas levels of kidney injury molecule-1 (KIM-1), a marker of tubular regeneration, peaked on day 3/4. Therefore, in rat proximal tubular nephrotoxicity, the measurement of urinary albumin, α-GST and KIM-1 is recommended as they potentially provide useful information about the function, degree of damage and repair of the proximal tubule. Gene expression data provided useful confirmatory information regarding exposure of the kidney and liver to HCBD, and the response of these tissues to HCBD in terms of metabolism, oxidative stress, inflammation, and regeneration and repair.

  7. Correlation of histopathology, urinary biomarkers, and gene expression responses following hexachloro-1:3-butadiene-induced acute nephrotoxicity in male Hanover Wistar rats: a 28-day time course study.

    Science.gov (United States)

    Maguire, David P; Turton, John A; Scudamore, Cheryl L; Swain, Aubrey J; McClure, Fiona J; Smyth, Rosemary; Pereira, Ines B; Munday, Michael R; York, Malcolm J

    2013-07-01

    Hexachloro-1:3-butadiene (HCBD) causes segment-specific injury to the proximal renal tubule. A time course study of traditional and more recently proposed urinary biomarkers was performed in male Hanover Wistar rats receiving a single intraperitoneal (ip) injection of 45 mg/kg HCBD. Animals were killed on days 1, 2, 3, 4, 5, 6, 7, 10, 14, and 28 postdosing and the temporal response of renal biomarkers was characterized using kidney histopathology, urinary and serum biochemistry, and gene expression. Histopathologic evidence of tubular degeneration was seen from day 1 until day 3 postdosing and correlated with increased urinary levels of α-glutathione S-transferase (α-GST), albumin, glucose, and kidney injury molecule-1 (KIM-1), and increased gene expression of KIM-1, NAD(P)H dehydrogenase, quinone 1, and heme oxygenase (decycling) 1. Histopathologic evidence of tubular regeneration was seen from day 2 postdosing and correlated with raised levels of urinary KIM-1 and osteopontin and increased gene expression of KIM-1 and annexin A7. Traditional renal biomarkers generally demonstrated low sensitivity. It is concluded that in rat proximal tubular injury, measurement of a range of renal biomarkers, in conjunction with gene expression analysis, provides an understanding of the extent of degenerative changes induced in the kidney and the process of regeneration.

  8. Increase in in utero exposure to a migrant, 4,4'-butylidenebis(6-t-butyl-m-cresol), from nitrile-butadiene rubber gloves on brain aromatase activity in male rats.

    Science.gov (United States)

    Satoh, Kanako; Nonaka, Ryouichi; Nakae, Dai; Ogata, Akio

    2010-01-01

    4,4'-Butylidenebis(6-t-butyl-m-cresol) (BBBC) can be eluted from disposable gloves made of nitrile-butadiene rubber and possibly also detected in food. It has been reported that BBBC is an androgen and estrogen antagonist in vitro. Previously, BBBC (1.0 mg/kg body weight (bw)/d) was subcutaneously administered to pregnant rats from gestation days 11 through 18, and the effects on male offspring (postnatal day 102) were examined. Altered levels and turnover of the monoamines dopamine, serotonin, and noradrenalin as well as their metabolites were detected. This report measured the level of serum testosterone following prenatal exposure to BBBC (0.1, 1.0, 10 mg/kg bw/d) in male rats, and measured aromatase activity of the hypothalamus-preoptic area with a close connection to the sexual differentiation and sexual behavior of BBBC-treated rat brains. The serum testosterone level rose depending on exposure, and aromatase activity of the basomedial nucleus of amygdale region was increased in the BBBC-treated group compared with the control. These results suggested that prenatal exposure to BBBC affects the central nervous system of male rat offspring, and BBBC may be an endocrine disrupting-chemical during the fetal period, and might influence the functional development of the brain.

  9. Sum Frequency Generation Vibrational Spectroscopy of 1,3-Butadiene Hydrogenation on 4 nm Pt@SiO 2 , Pd@SiO 2 , and Rh@SiO 2 Core–Shell Catalysts

    KAUST Repository

    Krier, James M.

    2015-01-14

    © 2014 American Chemical Society. 1,3-Butadiene (1,3-BD) hydrogenation was performed on 4 nm Pt, Pd, and Rh nanoparticles (NPs) encapsulated in SiO2 shells at 20, 60, and 100 °C. The core-shells were grown around polyvinylpyrrolidone (PVP) coated NPs (Stöber encapsulation) prepared by colloidal synthesis. Sum frequency generation (SFG) vibrational spectroscopy was performed to correlate surface intermediates observed in situ with reaction selectivity. It is shown that calcination is effective in removing PVP, and the SFG signal can be generated from the metal surface. Using SFG, it is possible to compare the surface vibrational spectrum of Pt@SiO2 (1,3-BD is hydrogenated through multiple paths and produces butane, 1-butene, and cis/trans-2-butene) to Pd@SiO2 (1,3-BD favors one path and produces 1-butene and cis/trans-2-butene). In contrast to Pt@SiO2 and Pd@SiO2, SFG and kinetic experiments of Rh@SiO2 show a permanent accumulation of organic material.

  10. 2-[Hydroxy(2-methoxyphenylmethyl]acrylonitrile

    Directory of Open Access Journals (Sweden)

    M. Bakthadoss

    2012-08-01

    Full Text Available In the title compound, C11H11NO2, the mean planes formed by the benzene ring and the C and N atoms of the acryl group are almost orthogonal to each other, with a dihedral angle of 85.7 (1°. During the structure analysis, it was observed that the unit cell contains large accessible voids, with a volume of 186.9 Å3, which may host disordered solvent molecules. This affects the diffraction pattern, mostly at low scattering angles. Density identified in these solvent-accessible areas was calculated and corrected for using the SQUEEZE routine in PLATON [Spek (2009, Acta Cryst. D65, 148–155]. Despite the presence of the hydroxy group in the molecule, no classical or nonclassical hydrogen bonds are observed in the structure. This may reflect the fact that the O—H group points towards the solvent-accessible void.

  11. Enzymatic surface modification of acrylonitrile fibers

    Science.gov (United States)

    Battistel, Ezio; Morra, Marco; Marinetti, Massimo

    2001-06-01

    The surface of polyacrylonitrile polymer (containing 10% acetate groups) as fibers and finely ground powder have been modified by enzymatic treatment. The enzyme used was a nitrile hydratase, member of the class of nitrile converting enzymes, present in the microorganisms Brevibacterium imperiale and Corynebacterium nitrilophilus. The pendant nitrile groups were selectively converted into the corresponding amides as assessed by XPS analysis. As indicated by the increase of the O/C atomic ratio, the fiber surface showed a significant increase in hydrophilicity. The newly formed amide groups were then able to react with the acid dyes typically used to stain natural fibers, conferring the coloring properties to the otherwise inert polymer surface.

  12. Study on Sulfomethylation of Cellulose Copolymer Copolymerized with Acrylonitrile and Acrylamide%纤维素-丙烯腈-丙烯酰胺共聚物磺甲基化改性研究

    Institute of Scientific and Technical Information of China (English)

    黄统琳; 刘明华; 刘剑锋; 詹怀宇

    2011-01-01

    The nitrile spherical cellulose adsorbent (SCAN) was prepared by sulfomethylating the prepared copolymer of grafting acrylonitrile and acrylamide onto the spherical cellulose beads, doing so is in order to provide reference data for getting higher application value of cellulose. The spherical cellulose beads were prepared by NMMO (N-methylmorpholine-N-oxide) process and sequential cooling technique. The sulfomethylation process was optimized through the orthogonal experiments and single-factor experiments. The results indicate that the adsorbent prepared has a specific surface area of 207.9 m2g-1, and sulfonation degree of 56.32% can be obtained under following optimal operating conditions: the solution pH=12, the mass ratio of HCHO, NaHSO3 and copolymer is 4:6:10, the reaction temperature is 50℃ and the reaction time is 5 h. In addition, the effect of sulfonation degree on the adsorption capacity of SCAN was also studied by using berberine hydrochloride as adsorbate. The results indicate that the increase of sulfonation degree is beneficial to the adsorption capacity, the maximum adsorption capacity of SCAN could reach 16.64 mg-g-1.%研制和开发新型改性纤维素类吸附剂,将是吸附剂研究的一个焦点.研究在球形纤维素珠体接枝丙烯腈和丙烯酰胺的基础上对其进行磺甲基化改性,制备出一种含腈基球形纤维素吸附剂(SCAN),以期为纤维素高值化利用提供参考数据.球形纤维素珠体由NMMO法和程序降温法制备.并通过正交试验和单因素实验进行工艺优化.实验结果表明,SCAN具有较大比表面积—207.9 m2·g-1,且在溶液pH=12,m(HCHO)∶m(NaHSO3)∶m(copolymer)=4∶6∶10,反应温度50℃下反应5h时的磺化度最高,为56.32%,以盐酸小檗碱为吸附质,研究磺化度对吸附剂吸附效果的影响,结果表明,在实验研究的磺化度范围内,磺化度越高,吸附效果越好,最大吸附量达16.64 mg·g-1.

  13. 硅烷偶联剂改性纳米二氧化钛并接枝丙烯腈的机理%Mechanism of nano-TiO2 modified silane coupling agent and grafting acrylonitrile

    Institute of Scientific and Technical Information of China (English)

    王雅珍; 陈国力; 岳成娥; 赵宇; 何子健

    2015-01-01

    主要研究了硅烷偶联剂(KH-560)改性纳米二氧化钛(TiO2)制备TiO2(KH-560)以及TiO2(KH-560)与丙烯腈(AN)接枝聚合生成TiO2(KH-560)-g-AN的反应机理。通过傅里叶变换红外(FT-IR)分析确定了TiO2(KH-560)和TiO2(KH-560)-g-AN的官能团结构。通过X射线光电子能谱(XPS)分析,由TiO2(KH-560)中的氧元素和碳元素结合能的微小变化,引起 C1s、O1s 化学环境的变化,来确定 TiO2(KH-560)的结构;由 TiO2(KH-560)-g-AN的氧元素、碳元素和氮元素的结合能微小变化引起 C1s、O1s、N1s 化学环境的变化,从而确定了TiO2(KH-560)-g-AN的结构。结合FTIR和XPS两者的分析,最终确定TiO2(KH-560)-g-AN的反应机理。%The reaction mechanism of nano-titanium dioxide (TiO2) modified with the silane coupling agent (KH-560) grafted with acrylonitrile(AN) to produce TiO2(KH-560)-g-AN was studied. Functional group structures of TiO2 (KH-560) and TiO2(KH-560)-g-AN were determined by Fourier transform infrared (FT-IR) analysis. The results of X-ray photoelectron spectroscopy (XPS) analysis show that chemical environment of C1s,O1s in TiO2(KH-560) are caused by slight variations of oxygen and carbon element binding energy in TiO2(KH-560). So the structure of TiO2(KH-560) is determined. Chemical environment of C1s,O1s,and N1s in TiO2(KH-560)-g-AN are caused by slight variations of oxygen,carbon,and nitrogen element binding energy in TiO2(KH-560)-g-AN. So the structure of TiO2(KH-560)-g-AN is determined. The graft polymerization mechanism of TiO2(KH-560) and AN is determined ultimately by the analysis of both FT-IR and XPS.

  14. Influence of Small Amount of Co-Monomers on Acrylonitrile Polymerization in Dimethylformamide (DMF) Solution%少量共单体对丙烯腈在DMF中溶液聚合的影响

    Institute of Scientific and Technical Information of China (English)

    谭水龙; 卜志扬; 李伯耿

    2013-01-01

    Polymerization of acrylonitrile (AN) on the presence of small amount of co-monomers such as, itaconic acid (IA), acrylic acid (AA), methacrylic acid (MA), methyl methacrylate (MMA) and acrylamide(AM), were conducted in N,N-dimethylformamide (DMF) solution. The cloudy threshold at which the polymerized mixture becomes heterogeneous was determined for different co-monomer feeds. The cloudy line slope indicates the effect of co-monomer on polyacrylonitrile (PAN) modification. The favorable PAN modification of carbon fiber precursors are ordered as IA > AM > MMA > MA > AA. Then, the co-polymerization kinetics of IA was further studied. With the increase of IA feeding amount, the polymerization rate and polymer molecular weight are both reduced. The reactivity ratio of IA and AN was estimated from experimental data of co-monomer content at different conversion state in a batch reactor by non-linear optimization method. It is found that the co-polymerization of IA-AN in DMF is approximately to be "ideal" with rIA 2.0 and ran 0.5. The accumulated amount of IA in co-polymer declines linearly with conversion when the IA feeding amount is low as demanded by carbon fiber precursors.%研究了丙烯腈与少量衣康酸、丙烯酸、丙烯酸甲酯、甲基丙烯酸甲酯、丙烯酰胺等共单体在N,N-二甲基甲酰胺(DMF)中溶液共聚时的云点阈值.提出共单体云点迹线斜率的概念,用以比较不同共单体对丙烯腈聚合物的改性作用,发现相比其他几种烯类单体衣康酸更适合于用作碳纤维原丝的共单体.同时考察了衣康酸与丙烯腈在DMF中溶液共聚时,其含量对聚合动力学的影响.发现随衣康酸用量的增加,聚合速率与分子量都降低.分析了间歇共聚中共单体含量随转化率的变化,并拟合了该单体对溶液共聚时的竞聚率,发现接近于理想共聚:rIA=2.0、rAN=0.5:且在低共单含量时,共聚物的累积平均共单组成随转化率线性地下降.

  15. Synthesis and Properties of Melt Processable Acrylonitrile-N-vinylimidazole Copolymers and Fiber†%可熔融丙烯腈-N-乙烯基咪唑共聚物及纤维的制备与性能

    Institute of Scientific and Technical Information of China (English)

    韩娜; 李慧慧; 李传宝; 张兴祥; 李伟; 王栋

    2015-01-01

    采用自由基溶液聚合法制备了不同投料摩尔比的丙烯腈( AN)-N-乙烯基咪唑( VIM)共聚物[P(AN-co-VIM)].将 n(AN): n(VIM)为82:18和80:20的 P(AN-co-VIM)共聚物于210~220℃熔融纺丝制备了P(AN-co-VIM)初生纤维.通过傅里叶变换红外光谱、核磁共振(1 H NMR)谱、差示扫描量热分析、X 射线衍射分析和热台显微镜对 P(AN-co-VIM)共聚物的组成、热力学和结晶行为进行了表征.结果表明,自由基溶液聚合法可成功制备 P(AN-co-VIM)共聚物,当 VIM 的摩尔分数大于10%时,共聚物具有可熔融加工性.随着 VIM 摩尔分数的增加,共聚物的熔点降低,当 VIM 含量为20%时,共聚物的熔点从317℃降低至180℃,其分解温度最高为313.7℃.扫描电子显微镜(SEM)和电子单纤维强力测试.结果表明,纤维的表面光滑,断面结构致密,初生纤维的断裂强度为1.58 cN/ dtex,断裂伸长率为11.2%,有望广泛应用于碳纤维领域.%Polyacrylonitrile(PAN) and acrylonitrile(AN)-N-vinylimidazole(VIM) copolymers[ abbreviated as P(AN-co-VIM)] with various n(AN) : n(VIM)(93 : 7—80 : 20) were synthesized by free-radical solution copolymerization in dimethyl formamide ( DMF). The P ( AN-co-VIM) copolymers (82 : 18 and 80 : 20) possessed good melt processability, which were melt spun at the temperature of 210—220 ℃. The crystallinity, thermodynamics behavior and the composition of P(AN-co-VIM) copolymers were studied and characterized by ubbelodhe viscosimeter, Fourier transform infrared spectroscopy( FTIR), nuclear magnetic resonance ( 1 H NMR), differential scanning calorimetry( DSC), X-ray diffraction( XRD) analyses and hot stage microscope. The results revealed that P(AN-co-VIM) could be synthesized successfully by free-radical solution copolymerization. P( AN-co-VIM) could be melt processable as VIM molar fraction is higher than 10% . The melting temperature of P ( AN-co-VIM) shifts continuously to the lower temperature with the

  16. 丙烯腈与N-乙烯基吡咯烷酮在H2O/DMSO混合试剂中共聚反应动力学研究%Kinetics of Copolymerization of Acrylonitrile with N-Vinylpyrrolidone in H2O/Dimethyl Sulphoxide Mixture

    Institute of Scientific and Technical Information of China (English)

    陈厚; 王成国; 梁英; 蔡华甦

    2003-01-01

    Kinetics of copolymerization of acrylonitrile(AN) with N-vinylpyrrolidone(NVP) initiated by azodiisobutyronitrile(AIBN) was investigated in H2O/dimethyl sulphoxide(DMSO) mixture between 50℃ and 70℃ under N2 atmosphere. The rate of copolymerization and particle size were measured respectively. The kinetic equation 0.651±0.123 1.59±0.35 1.17±0.14of copolymerization system is obtained as Rp ∝ cAIBN cAN cNVP at 60℃. The overall activation energy for copolymerization system was computed as 87.3 kJ.mol-1. Effect of additives of hydroquinone and dioxane on copolymerization was discussed. The polymerization is retarded by hydroquinone and accelerated by dioxane, which confirms the free radical copolymerization of AN with NVP.

  17. Synthesis of (Z)-2-Methyl-2-Butenedioic Acid-l-Methyl Ester and Determination of Apparent Reactivity Ratio of Copolymerization with Acrylonitrile%2-甲基-2-丁烯二酸单甲酯的合成及其与丙烯腈二元共聚的表观竞聚率的测定

    Institute of Scientific and Technical Information of China (English)

    杨俊锋; 陆国林; 谭久青; 黄晓宇; 陈惠芳; 潘鼎

    2008-01-01

    以柠糠酸酐为原料,合成了一种可以与丙烯(AN,acrylonitrile)共的新单体:2-甲基-2-丁烯二酸单甲酯(MBAME).以偶氮二异丁腈(AIBN,2,2'-azobis isobutyronitrle)为引发剂,70℃下引发MBAME与AN在N,N-二甲基甲酰胺(DMF,N,N-dimethylformamide)中进行无规共聚,通过Fineman-Ross法测定了两者在DMF溶液聚合体系的表观竞聚率,γ1(AN)=7.985,γ2(MBAME)=0.599,有助于优化聚丙烯腈基碳纤维用树脂的生产工艺.

  18. 共聚物-深剂体系的气液平衡:新UNIFAC基团热力学模型与实验研究%Vapor-Liquid Equilibrium of Copolymer+solvent Systems:Experimental Data and Thermodynamic Modeling with New UNIFAC groups

    Institute of Scientific and Technical Information of China (English)

    Rogério A.G. Sé; Martín Aznar

    2008-01-01

    Vapor-liquid equilibrium (VLE)data for copolymer solutions are necessary for several chemical processes.However,VLE data for copolymer solutions in the published report are rare.In this study.experimental VLE data for binary systems copolymer+solvent were obtained using a gravimetric-sorption apparatus.The studied systems were hexane+poly(21%acrylonitrile-co-butadiene),hexanc+poly(33%acrylonitrile-co-butadiene),hexane+poly(51%acrylonitrile-co-butadiene),hexanc+poly(23%styrene-co-butadiene),hexane+poly(45%styrene-co-butadiene),and benzene+poly(44%styrene-co-methyl methacrylate)in the range 50-70℃.The experimental data were correlated with the UNIFAC and Elbro-FV group contribution models for the activity coefficient.Two sets of functional groups had been used to represent the monomers in copolymers:literature groups and new proposed groups.The mean deviations between experimental and calculated mass fractions about 2.4%with ElbroFV and 13.3%witll Zhong were observed when the groups proposed in this study were USed.and of 3.5%for E1bro-FV and 13.2%for Zhong when literature groups were used.

  19. Synthesis of star-shaped solution-polymerized styrene-butadiene rubber using 1,1-diphenylhexyllithium%1,1-二苯基己基锂合成星形溶聚丁苯橡胶

    Institute of Scientific and Technical Information of China (English)

    陈波; 穆春雨; 白玉; 徐利民; 赵素合; 张兴英

    2011-01-01

    1,1 -diphenylhexyllithium ( DPHL) was prepared by the addition reaction of n-butyllithium ( n-BuLi) and 1,1 -diphenylethlene ( DPE) , with cyclohexane as solvent, and the factors affecting the yield, stability and initial activity of the product were studied. Linear-shaped solution-polymerized styrene-butadiene rubber (SSBR) was synthesized by ionic polymerization with DPHL as initiator, cyclohexane as solvent, and tetrahydrofuran (THF) as polar regulator. Star-shaped SSBR was subsequently prepared by a coupling reaction, using SnCl4 as the coupling agent. The coupling efficiency was measured. The effects of varying the structure of the chain ends, reaction time, and amount of SnCl4 on the coupling efficiency and the properties of the resulting SSBR were investigated. The results showed that the yield and purity of the DPHL were maximimized when n(DPE)/n(n-BuLi) was 1, the concentration decreased to below 90% of the original value if it was kept over 30 days at 2 t , and the diphenylalkyl group introduced by the initiator was present at the chain end of the polymers. The coupling efficiency was the highest when using the following reaction conditions; a molecular weight of 7. 0 × 104, reaction time of 60 min, and n( Cl- )/n(Li+ ) of 1. 12; it could be increased further by converting the chain ends to butadiene. Compared with that obtained using n-BuLi as an initiator, the star-shaped SSBR initiated by DPHL possessed higher tensile strength, tear strength and elongation at break, lower compression temperature rise, higher tan5 at 0 ℃ and lower tanδ at 60 ℃ .%以环己烷为溶剂,1,1-二苯基乙烯(DPE)与正丁基锂(n-BuLi)反应得到1,1-二苯基己基锂(DPHL),对其产率、稳定性和引发活性进行了研究.然后以DPHL为引发剂,四氢呋喃为结构调节剂,采用负离子聚合方法合成了线形溶聚丁苯橡胶(SSBR);最后以SnC14偶联制备星形SSBR.用凝胶渗透色谱仪、核磁共振对产物进行了表征,考查了端基结

  20. Exposure-response of 1,2:3,4-diepoxybutane-specific N-terminal valine adducts in mice and rats after inhalation exposure to 1,3-butadiene.

    Science.gov (United States)

    Georgieva, Nadia I; Boysen, Gunnar; Bordeerat, Narisa; Walker, Vernon E; Swenberg, James A

    2010-06-01

    1,3-Butadiene (BD) is a known rodent and human carcinogen that is metabolized mainly by P450 2E1 to three epoxides, 1,2-epoxy-3-butene (EB), 1,2:3,4-diepoxybutane (DEB), and 1,2-epoxy-3,4-butanediol. The individual epoxides vary up to 200-fold in their mutagenic potency, with DEB being the most mutagenic metabolite. It is important to understand the internal formation of the individual epoxides to assign the relative risk for each metabolite and to understand the molecular mechanisms responsible for extensive species differences in carcinogenicity. This study presents a comprehensive exposure-response for the formation of the DEB-specific N,N-(2,3-dihydroxy-1,4-butadiyl)valine (pyr-Val) in mice and rats. Using nano-ultra high pressure liquid chromatography-tandem-mass spectrometry allowed analysis of pyr-Val in mice and rats exposed to BD as low as 0.1 and 0.5 ppm BD, respectively, and demonstrated significant differences in the amounts and exposure-response of pyr-Val formation. Mice formed 10- to 60-fold more pyr-Val compared to rats at similar exposures. The formation of pyr-Val increased with exposures, and the formation was most efficient with regard to formation per parts per million BD at low exposures. While formation at higher exposures appeared linear in mice, in rats formation saturated at exposures > or = 200 ppm for 10 days. In rats, amounts of pyr-Val were lower after 20 days than after 10 days of exposure, suggesting that the lifespan of rat erythrocytes may be shortened following exposure to BD. This research supports the hypothesis that the lower susceptibility of rats to BD-induced carcinogenesis results from greatly reduced formation of DEB following exposure to BD.

  1. Scientific Opinion on the safety assessment of the substances (butadiene, ethyl acrylate, methyl methacrylate, styrene copolymer either not crosslinked or crosslinked with divinylbenzene or 1,3-butanediol dimethacrylate, in nanoform, for use in food contact materials

    Directory of Open Access Journals (Sweden)

    EFSA Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids (CEF

    2014-04-01

    Full Text Available This scientific opinion of the EFSA Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids deals with the safety assessment of the additives (butadiene, ethyl acrylate, methyl methacrylate, styrene copolymer either not crosslinked or crosslinked with divinylbenzene or 1,3-butanediol dimethacrylate, in nanoform, (FCM substance Nos 998, 859 and 1043, intended to be used up to 10 % w/w as an impact modifier in rigid (unplasticized polyvinylchloride (PVC. The final material is intended to be used for contact with all food types, at room temperature or lower, for long time storage. The monomers constituting the copolymer are listed in Regulation (EU 10/2011. The migration from PVC of the low molecular weight fraction of the additive below 1000 Da was estimated to be about 0.009 mg/kg food. Considering that these low molecular weight oligomers are made from authorised monomers, which by reaction are expected to lack the reactive functional groups, they do not give rise to safety concern. The migration of the additive in nanoparticle form from the PVC was estimated, using conservative migration modelling, to be about 1 x 10-6 mg/kg food and so consumer exposure would be very low, if any. The CEF Panel concluded that there is no safety concern for the consumer if the substances are used as additives individually or in combination at up to a total of 10 % w/w in rigid PVC used in contact with all food types at ambient temperature or below including long-term storage.

  2. Structure and Properties of Clay/Butadiene-Styrene-Vinyl Pyridine Rubber Nanocomposites%粘土/丁吡橡胶纳米复合材料的结构与性能研究

    Institute of Scientific and Technical Information of China (English)

    何少剑; 王益庆; 张立群

    2013-01-01

    The clay/butadiene-styrene-vinyl pyridine rubber nanocomposites were prepared by latex compounding method,and their structure and properties were investigated. The results showed that,the dispersion of clay in the nanocomposites was good,and the addition level of clay affected the structure of the nanocomposites. As the addition level of clay increased, the storage modulus of the mixed compound and vulcanizate increased gradually, the loss factor of vulcanizate increased as the strain increased,the Shore A hardness and modulus at 100% elongation increased gradually,and the air tightness was improved. The nanocomposites showed the best tensile properties when the addition level of clay was 20 phr.%采用乳液共沉法制备粘土/丁吡橡胶纳米复合材料,并对其结构和性能进行研究.结果表明:粘土/丁吡橡胶纳米复合材料的整体分散效果较好,粘土用量对纳米复合材料的类型有影响;随着粘土用量的增大,粘土/丁吡橡胶混炼胶和硫化胶的储能模量逐渐增大,硫化胶的损耗因子随应变的增大而增大,邵尔A型硬度和100%定伸应力逐渐增大,气密性能提高;当粘土用量为20份时,复合材料的拉伸性能最佳.

  3. Transition to reinforced state by percolating domains of intercalated brush-modified cellulose nanocrystals and poly(butadiene) in cross-linked composites based on thiol-ene click chemistry.

    Science.gov (United States)

    Rosilo, Henna; Kontturi, Eero; Seitsonen, Jani; Kolehmainen, Erkki; Ikkala, Olli

    2013-05-13

    The classic nanocomposite approach aims at percolation of low fraction of exfoliated individual reinforcing nanoscale elements within a polymeric matrix. By contrast, many of the mechanically excellent biological nanocomposites involve self-assembled and space-filled structures of hard reinforcing and soft toughening domains, with high weight fraction of reinforcements. Here we inspect a new concept toward mimicking such structures by studying whether percolation of intercalated domains consisting of alternating rigid and reinforcing, and soft rubbery domains could allow a transition to a reinforced state. Toward that, we present the functionalization of rigid native cellulose nanocrystals (CNCs) by esterification with a dense hydrocarbon chain brush containing cross-linkable double bonds. Composite films with 0-80 wt % of such modified CNCs (mCNCs) within a poly(butadiene) (PBD) rubber matrix were prepared via cross-linking by UV-light initiated thiol-ene click reaction. Transmission electron microscopy showed structures at two length scales, where the mCNCs and PBD form domains having internal aligned self-assemblies of alternating hard mCNCs and soft PBD with periodicity of ca. 40 nm, and where additional PBD connects such domains. Increasing the weight fraction of mCNCs causes an uncommon abrupt transition from PBD-dominated soft materials to significantly reinforced mCNC-dominated mechanical properties, suggesting that the intercalated self-assembled mCNC/PBD domains percolate in PBD upon passing 30-35 wt % of mCNCs. Maximum stress of 16 MPa at mCNC fraction of 80 wt % was obtained. The mechanical properties of the composites show exceptional insensitivity to air humidity. The shown simple concept of percolative intercalated nanocomposites suggests searching for more general biomimetic compositions involving several deformation mechanisms for improved mechanical properties. PMID:23506469

  4. Desempenho físico-químico e mecânico de concreto de cimento Portland com borracha de estireno-butadieno reciclada de pneus Physicochemical and mechanical performance of portland cement concrete with recycled styrene-butadiene tyre-rubber waste

    Directory of Open Access Journals (Sweden)

    Camila Freitas

    2009-01-01

    Full Text Available Physicochemical and mechanical techniques were carried out to characterize three concrete tyre-rubber waste dosages such as 5, 10 and 15%, w/w. The elastomeric material was identified as styrene-butadiene rubber (SBR. It was observed that the growing SBR content in the mixture decreased the concrete performance. The best results were presented by 5% w/w tyre-rubber waste concrete sample. This composition was tested at Mourão hydroelectric powerplant spillway as repairing material.

  5. Effect of acrylonitrile on the expression of Bcl-2 and Bax in spermatogenic cell of mice%丙烯腈对小鼠生精细胞Bcl-2、Bax蛋白表达的影响

    Institute of Scientific and Technical Information of China (English)

    裴凌云; 马国燕; 金娜; 陈亚; 冯玉娟; 党瑜慧; 薛红丽; 李芝兰

    2012-01-01

    Objective To explore the effect of acrylonitrile exposure on the expression of Bcl-2 and Bax in mice spermatogenic cells. Methods Based on body weight, 250 SPF Kunming adult male mice were randomly divided into five groups; negative control group (normal saline 0. 01ml/g), three AN exposure groups (intraperitoneal injection of 1.25, 2. 50 or 5. 00 mg/kg of AN daily for 5 days, respectively) and positive control group (intraperitoneal injection of cyclophosphamide 40mg/kg) . Mice were killed in the 7th, 14th, 21st, 28th and 35th day after the first exposure by cervical dislocation. Immunohistochemical method ( SABC ) was used to detect the expression of Bcl-2 and Bax protein in spermatogenic cells. Results The average optical density values of Bcl-2 at five time points of the AN 2. 50 mg/kg group and the 21th day point of the AN 1. 25 mg/kg group were significantly lower than the negative control group ( P < 0. 05 ) . Except the 21st day point of the AN 1. 25 mg/kg group, the mean optical density values of Bax in all time points of AN exposure groups were significantly higher than the negative control group (P < 0. 05 ). The decreased expression of Bcl-2 protein was most distinct in AN 2. 50mg/kg group and the positive control group at all time points. The expression of Bax protein was significantly increased in all groups at the 14th day point. Conclusion The expression of Bel-2 protein could be weakened in spermatogenic cells induced by AN, especially in the AN 2. 50 mg/kg8roup; while the expression of Bax was enhanced, and the amplitude of change in the 14th day point was more obvious.%目的 探讨丙烯腈(AN)暴露对小鼠睾丸生精细胞Bcl-2、Bax蛋白表达水平的影响.方法 将250只成年健康SPF级昆明种雄性小鼠,按体重随机分为阴性对照组、3个AN染毒组和阳性对照组,阴性对照组用生理盐水,各染毒组分别以1.25、2.50、5.00mg/kg AN腹腔注射(注射剂量为0.01 ml/g BW),每天1次,连续5天,阳性

  6. 丁二烯橡胶(BR)9000门尼黏度标准物质的研制%Preparation of mooney viscosity of butadiene rubber(BR) 9000

    Institute of Scientific and Technical Information of China (English)

    刘俊保; 翟月勤; 赵家琳; 汤妍雯; 笪敏峰; 李淑萍; 曹帅英

    2012-01-01

    对经过筛选、通过均匀性、稳定性检验后符合标准物质定值的丁二烯橡胶样品,采用多家实验室联合定值.并对各家实验室定值的结果按照标准物质定值数据处理程序,进行了异常数据判断、数据正态分布检验、等精度检验、不确定度评估.丁二烯橡胶门尼黏度标准物质定值各实验室的数据在a =0.05的显著水平时,数据无可疑值、处于正态分布、等精度,定值标准物质的标称值为ML(1+4) 100℃(45.6±0.5).该标准物质的研制成功,普遍用于校准门尼黏度计,将会在合成橡胶行业得到广泛的应用,同时为合成橡胶行业生产控制、产品检验、产品贸易、质量仲裁提供技术支撑.%The value of butadiene rubber was defined according with standard material value after preparated, passed by uniformity and stability measure by laboratories. The dispose of proceed of standard material value was used to judge of unusual numbers, inspect of distributed numbers, testy of equal precision, appraised of uncertainty. When remarkable level a =0. 05 of standard material of mooney viscosity after tested by laboratory, the number was certainty, normal distribution and equal precision, the value of standard was (45.6 ±0.5)ML( 1+4) 100 %. Successful preparation of standard material should be supported to control of produce, trade of goods and arbitration of quality.

  7. Physical properties of blended and vulcanizednitrile-butadiene rubber/chloroprene rubber%共混硫化丁腈橡胶-氯丁橡胶的物理性能

    Institute of Scientific and Technical Information of China (English)

    蒋利辉

    2014-01-01

    将丁腈橡胶(NBR)和氯丁橡胶(CR)按不同质量分数共混并硫化,研究了硫化橡胶在自然环境、热空气老化、热油老化等条件下的物理性能,并测定了硫化橡胶与镀铜钢丝的粘合性能.结果表明,随着 CR 质量分数的增大,混炼胶的焦烧时间逐渐缩短.经热空气老化后,NBR 的硬度增加幅度比 CR 的硬度增加幅度大,拉断强度降低幅度则比 CR 的小得多.此外,NBR 的耐油性能优于 CR.就物理性能以及与镀铜钢丝的粘合性能而言,单一 NBR 和单一 CR 优于共混 NBR/CR.%Nitrile-butadiene rubber (NBR)and chloroprene rubber (CR)were blended at differ-ent mass fractions and vulcanized,followed by aging at various conditions.The physical prop-erties of the vulcanized rubbers aged at ambient condition as well as in hot air and hot oil were determined,and their adhesion to Cu-coated steel wires was measured as well.Results indicate that,with the increase of the mass fraction of CR,the scorch time of the gross rubber tends to decline gradually.After being aged in hot air,the hardness of vulcanized NBR tends to rise more noticeably than that of vulcanized CR,while the tensile strength of the vulcanized NBR reduces at a much less extent than that of the vulcanized CR.Moreover,vulcanized NBR exhib-its better resistance against oil than vulcanized CR,while mono NBR and mono CR are advan-tageous over blended NBR/CR in terms of the physical properties and adhesion to Cu-coated steel wire.

  8. Tunable regioselectivity in 1,3-butadiene polymerization by using 2,6-bis(dimethyl-2-oxazolin-2-yl)pyridine incorporated transition metal (Cr, Fe and Co) catalysts

    KAUST Repository

    Gong, Dirong

    2015-05-21

    Tridentate complexes Cr(III)Cl3L, [L = 2,6-bis(dimethyl-2-oxazolin-2-yl) pyridine], Fe(III)Cl3L, Fe(II)Cl2L and Co(II)Cl2L have been prepared and fully characterized. The solid structures of Cr(III)Cl3L, Fe(III)Cl3L and Co(II)Cl2L have been revealed by single crystal X-ray diffraction, and the Cr(III)Cl3L and Fe(III)Cl3L complexes both exhibit a distorted octahedral geometry, while the Co(II)Cl2L complex has a trigonal bipyramidal conformation. Four complexes have been examined in regioselective polymerization of butadiene in combination with MAO in toluene at room temperature. The trans-1,4, cis-1,4 enchainment of resultant polybutadiene are controlled by the metal center. Activated by MAO, complex Cr(III)Cl3L produces high level of trans-1,4 selectivity (trans-1,4 up to 93.3%) with moderate polymer yield, complexes Fe(III)Cl3L and Fe(II)Cl2L both show equal cis-1,4 and trans-1,4 with minor 1,2 selectivity (<10%), and Co(II)Cl2L catalyst displays predominated cis-1,4 selectivity, which can be shifted to 1,2 selectivity by adding PPh3 as an additive. Thus, tuning of the cis-1,4, trans-1,4 and 1,2 selectivity in full range via central metal and additive chosen by these 2,6-bis(dimethyl-2-oxazolin-2-yl) pyridine supported catalysts has been achieved. © 2015 Elsevier B.V. All rights reserved.

  9. Properties of a new thermoplastic elastomer-sulfonated styrene-butadiene rubber ionomers and their blends%热塑性橡胶——磺化丁苯橡胶离聚体的性能及其共混

    Institute of Scientific and Technical Information of China (English)

    敖枝平; 谢洪泉

    2001-01-01

    丁苯橡胶(SBR)作为高不饱和度的橡胶被成功地用硫酸乙酸酐作为磺化剂在石油醚及丁酮混合溶剂配成的浓溶液中磺化,并用乙酸盐中和成离聚体。研究了离聚体及其他聚合物的共混物的熔融流动性及力学性能。结果表明,SBR离聚体能很容易在硬脂酸锌存在下熔融加工,其行为象热塑性橡胶,硬脂酸锌能降低布拉本特(Brabender)混和机的扭矩所表示的熔融粘度,并增加流动活化能和离聚体的拉伸强度。离聚体的磺酸基含量能增加熔融粘度及拉伸强度。用于中和的阳离子的种类明显地影响离聚体的性能。离聚体与聚丙烯或SBS的共混物在拉伸强度上表现出协同效应,而它与聚苯乙烯或顺-1,4聚丁二烯则呈现抵消效应。%Styrene-butadiene rubber(SBR)synthesized from emulsion polymerization was sulfonated successfully by sulfuric acid and acetic anhydride in a mixed solvent of petroleum ether and methy ethyl ketone at high concentration and neutralized with metallic acetate to form ionomer.Melt flow and mechanical properties of the ionomers and of their blends with polypropylene,SBS,polystyrene or cis-1,4 polybutadiene were studied.

  10. Reduction of Noise from Disc Brake Systems Using Composite Friction Materials Containing Thermoplastic Elastomers (TPEs)

    Science.gov (United States)

    Masoomi, Mohsen; Katbab, Ali Asghar; Nazockdast, Hossein

    2006-09-01

    Attempts have been made for the first time to prepare a friction material with the characteristic of thermal sensitive modulus, by the inclusion of thermoplastic elastomers (TPE) as viscoelastic polymeric materials into the formulation in order to the increase the damping behavior of the cured friction material. Styrene butadiene styrene (SBS), styrene ethylene butylene styrene (SEBS) and nitrile rubber/polyvinyl chloride (NBR/PVC) blend system were used as TPE materials. In order to evaluate the viscoelastic parameters such as loss factor (tan δ) and storage modulus (E‧) for the friction material, dynamic mechanical analyzer (DMA) were used. Natural frequencies and mode shapes of friction material and brake disc were determined by modal analysis. However, NBR/PVC and SEBS were found to be much more effective in damping behavior. The results from this comparative study suggest that the damping characteristics of commercial friction materials can be strongly affected by the TPE ingredients. This investigation also confirmed that the specimens with high TPE content had low noise propensity.

  11. Effects of milk and coenzyme Q10 on the interference of acrylonitrile on vascular endothelial functions%牛奶和辅酶Q10对丙烯腈致血管内皮功能紊乱的影响

    Institute of Scientific and Technical Information of China (English)

    郭进; 王卫群; 龚辉

    2011-01-01

    目的 探讨牛奶或辅酶Q10预处理对丙烯腈致大鼠血管内皮功能紊乱的影响.方法 将80只大鼠分为4组:对照组、单纯丙烯腈组、牛奶组、辅酶Q10组.采用灌胃染毒法,对照组仅予玉米油(丙烯腈的溶剂,1 ml/100 g),其他3组予丙烯腈25 mg/kg染毒.牛奶组和辅酶Q10组在染毒前30 min分别给予牛奶、辅酶Q10预处理.染毒12周后检测血清及主动脉组织中诱导型一氧化氮合酶(iNOS)和内皮型一氧化氮合酶(eNOS)的活力.结果 单纯丙烯腈组、牛奶组、辅酶Q10组血清iNOS水平[(42.9±2.5)U/ml、(26.5±4.4)U/ml、(26.7±3.3)U/ml]比对照组[(21.9±1.6)U/ml,P<0.05]升高.主动脉组织中iNOS在单纯丙烯腈组、牛奶组、辅酶Q10组[(0.812±0.008)、(0.773±0.019)、(0.622±0.013)U/mg蛋白]比对照组[(0.540±0.028)U/mg蛋白,P<0.05]高;而辅酶Q10组的主动脉eNOS活力[(0.471±0.011)U/mg蛋白]高于对照组、单纯丙烯腈组和牛奶组[(0.371±0.029)、(0.380±0.016)、(0.425±0.020)U/mg蛋白,P<0.05].结论 牛奶和辅酶Ql0可以缓解丙烯腈致血管内皮功能紊乱作用.%Objective To explore the influences of milk or coenzyme Q10 pretreatment to acrylonitrile on vascular endothelial functions in rats.Methods A total of 80 rats were randomly divided into 4 groups:control group(Con),acrylonitrile exposure group(ACN),milk pretreatment group (M + ACN)and coenzyme Q10 pretreatment group(Q10 + ACN).The experiment was conducted by the method of gavage exposure in rats.Control group was exposed to corn oil;acrylonitrile was administered to other three groups at the doses of 25 mg/kg.The M + ACN and Q10 + ACN groups were pretreated by milk or coenzyme Q10 at 30 minutes before acrylonitrile exposureAfter a 12-week exposure,the activities of inducible nitric oxide synthase(iNOS)and endothelial nitric oxide synthase(eNOS)were measured in serum and aortal tissues.Results As compared with Con group[(21.9 ± 1.6)U/ml],the activity of blood serum i

  12. Investigation of the interfacial bonding in composite propellants. 1,3,5-Trisubstituted isocyanurates as universal bonding agents

    Directory of Open Access Journals (Sweden)

    GORDANA S. USCUMLIC

    2006-05-01

    Full Text Available A series of 1,3,5-trisubstituted isocyanurates (substituents: CH2CH2OH, CH2CH=CH2 and CH2CH2COOH was synthesized according to a modified literature procedure. Experimental investigations included modification of the synthetic procedure in terms of the starting materials, solvents, temperature, isolation techniques, as well as purification and identification of the products. All the synthesized isocyanurates were identified by their melting point and FTIR, 1H NMR and UV spectroscopic data. Fourier transform infrared spectrophotometry was also used to study the interaction between ammonium perchlorate, hydroxyl terminated poly(butadiene, carboxyl terminated poly(butadiene, poly(butadiene-co-acrylonitrile, poly(propylene ether, cyclotrimethylenetrinitramine and the compounds synthesized in this work, which can serve as bonding agents. The results show that tris(2-hydroxyethylisocyanurate is a universal bonding agent for the ammonium perchlorate/carboxyl terminated poly(butadiene/cyclotrimethylenetrinitramine composite propellant system.

  13. Preparation of Activated Nano-sized Kaolin Clay as Styrene Butadiene Rubber Filler%应用于橡胶补强的活性纳米高岭土制备

    Institute of Scientific and Technical Information of China (English)

    杜艳艳; 王燕民; 潘志东

    2013-01-01

    An activated nano-sized kaolin clay was prepared via an effective process with various methods such as chemical pre-intercalation, ultra-fine grinding, acid etching, drying and surface modification with cetyltrimethyl ammonium bromide (CTAB) and hydrogen silicone. The results show that the micron-sized kaolin clay that is pre-intercalated with urea is ground in a high-eneigy density stirred bead mill to prepare the nano-sized particles with the fineness of 70% < 100 nm and the lamella thickness of 10-30 nm effectively. This hybrid method could reduce the energy consumption in the preparation of the nano-sized kaolin clay, compared to the single ultra-fine grinding method. The acid etching treatment increased the specific surface area of the activated nano-sized kaolin clay without the destruction of the layered structure. The particles coated with CTAB and hydrogen silicone oil appeared a superior hydrophobicity. The azeotropic distillation drying could produce the well-dispersive activated nano-sized kaolin clay, compared to the spray drying. In addition, the as-prepared activated nano-sized kaolin clay could be used as a styrene butadiene rubber filler to improve the tensile strength and rate, and reduce the vulcanizing time.%采用化学插层-超细研磨-酸侵渍活化-干燥-表面改性的方法有效地制备了活性纳米高岭土.结果表明:通过化学插层与超细研磨的复合方法可制备70%的颗粒小于100 nm的高岭土,其片厚为10~30 nm.与单纯采用机械研磨的方法相比,该复合方法可以降低超细研磨所需的能耗.经酸侵渍活化处理可增大活性纳米高岭土的比表面积,但未破坏高岭土特有的层状结构.在活性纳米高岭土表面包覆十六烷基三甲基溴化铵和含氢硅油,可使其具有良好的亲油疏水性能.另外,对比喷雾干燥方法,经共沸蒸馏干燥的活性纳米高岭土粉体具有更好的分散性,制得的活性纳米高岭土作

  14. Interlaboratories Comparison of Analysis Data of Styrene Butadiene Rubber(SBR)1502 and Result Analysis%苯乙烯-丁二烯橡胶(SBR)1502实验室间数据比对结果分析

    Institute of Scientific and Technical Information of China (English)

    曹帅英; 魏玉丽; 汤妍雯; 刘俊保; 吴毅

    2013-01-01

    Rules for Proficiency Testing(CNAS-RL02:2007)explicitly stipulates that laboratories to apply for accreditation and accredited laboratories must demonstrate their testing ability in its field, it is the only way to join series of quality activities including ability validation, measurement and verification, comparison data with authorities. National accredited laboratories in the synthetic rubber industry are less, so it is more difficult to organize activities of proficiency testing. In order to satisfy the requirements of production enterprises and related laboratories in synthetic rubber industry, national quality supervision and inspection center of synthetic rubber organized interlaboratories comparison of analysis data of styrene butadiene rubber ( SBR ) 1502, statistics and analysis of comparison results were carried out by robust statistical technique, and all laboratories represented the industrial test level. The measurement results of raw rubber Mooney viscosity, ash, mix Mooney viscosity, tensile modulus at 300%in 50 min were ideal, but measurement results of volatile matter, tensile modulus at 300%in 25 min and 35 min, tensile strength and elongation at break in 35 min showed many problems, two or more laboratories appeared questionable values or outliers, part of the laboratories lacked the ability of chemical analysis and testing. Therefore, the related training content should be strengthen, the experimental instruments should be added,the interlaboratories comparison should be actively carried out.%  《能力验证规则》CNAS-RL02:2007中明确规定,申请认可的实验室和已经通过认可的实验室要证明其在该领域具有的检验能力,参加能力验证、测量审核、与权威机构比对以及多家实验室间数据比对等系列质量活动是必经之路。在合成橡胶行业通过国家认可实验室较少,组织能力验证活动比较困难,为了满足合成橡胶行业有关生产企业及相关实

  15. 端羟基聚丁二烯改性聚醚酯弹性体的合成与表征%Synthesis and Characteristics of Multiblock Terpoly(Ester-Ether-Butadiene) Elastomers

    Institute of Scientific and Technical Information of China (English)

    宋传江; 彭军; 张英伟; 王文志; 黄自华

    2013-01-01

    Terpoly (ester-ether-butadiene) (PBT-co-PTMG/HTPB) was prepared by melt poly-condensation with dimethyl terephthalate (DMT),1,4-butandiol (BD),poly (tetramethylene-oxide glycol) (PTMG) and hydroxyl terminated polybutadiene (HTPB).The chemical structure and molecular weight of the polymers were presented by FT-IR,1H-NMR and GPC.The thermal properties and the physical and mechanical properties were measured.The results show that molecular weights of PBT-co-PTMG/HTPB increase with the content of HTPB increasing,and the maximum molecular weight is more than 8 million.The glass transition temperature moves from-25 ℃ down to -65 ℃ due to HTPB units in the soft segments.It represents the nice resistance to low temperature.Both the tensile strength and elongation at break increase with the content of HTPB when the mass fraction of HTPB is below 10 %,but decrease while the mass fraction of HTPB concentration is higher than 10 % in PBT-co-PTMG/HTPB.%以对苯二甲酸二甲酯(DMT)、1,4丁二醇(BD)、聚四氢呋喃醚(PTMG)和端羟基聚丁二烯(HTPB)为原料,采用熔融缩聚方法一步合成了一系列端羟基聚丁二烯改性的聚醚酯弹性体(PBT-co-PTMG/HTPB).通过红外、核磁和凝胶色谱等分析方法对其分子结构和分子量进行了表征;测定了聚合物的热性能和物理力学性能.结果发现,随着PBT-co-PTMG/HTPB共聚物中端羟基聚丁二烯含量的增加,数均分子量逐渐增大,最高突破8万;玻璃化转变温度由-25℃降低到-65℃,耐低温性能得到明显改善;共聚物力学性能测试结果表明,当HTPB的质量分数在10%以下时,其强度和断裂伸长率随着HTPB含量的增加而变大,但是质量分数超过10%以后,材料的强度和断裂伸长率随其含量的增加而变小.

  16. Application of Environmental Friendly Flame Retardants Made of Gray Aluminum and Boron Mud in Styrene Butadiene Rubber%硼泥、铝灰制备的环保阻燃剂在丁苯橡胶中的应用研究

    Institute of Scientific and Technical Information of China (English)

    仲维娜; 刘大晨

    2012-01-01

    以工业废料铝灰和硼泥制备主要成分为水滑石的环保阻燃剂,并将其添加到丁苯橡胶(SBR)中,研究其对阻燃性能和力学性能的影响.结果表明,随环保阻燃剂用量的增加,SBR的阻燃性能提高.使用硼泥、铝灰制备的环保阻燃剂为主的复配阻燃体系后,阻燃效果更好.但环保阻燃剂的大量使用会导致硫化胶物理机械性能下降,采用偶联剂处理后,SBR力学性能提高.%This research used the environmental friendly flame retardants which were made of some in- dustrial waste, i. e. , Gray aluminum and boron mud and had Layered Double Hydroxide (LDH) as its ma- jor component, and added these flame retardants into styrene butadiene rubber(SBR) to study its effect on the burning behaviour and mechanical characteristics on Emulsion-polymerized styrene butadiene rub- ber. The results showed that the burning behaviour of SBR was improved with increasing amount of these environmental friendly flame retardants. With the mating systems dominated by the environmental friendly flame retardants,it has very good flame residence performance. Using environmental friendly flame retard- ants in large amount will result in reduced physical and mechanical characteristics of vulcanixed rubber, then methods of modified flame retardants and reinforcement of ru6ber are taken into account to improve the mechanical properties of SBR

  17. Effect of bound acrylonitrile content on structure and properties of carbon black reinforced hindered phenol/nitrile rubber composites%丁腈橡胶/受阻酚AO-80/炭黑复合材料中结合丙烯腈量对其结构与性能的影响

    Institute of Scientific and Technical Information of China (English)

    宋洪松; 李静; 曹亚君; 赵秀英; 王松

    2011-01-01

    在结合丙烯腈量不同的丁腈橡胶(NBR)中加入受阻酚AO-80和炭黑,制备了NBR/AO-80/炭黑(NBR/AO-80/CB)复合材料,用差示扫描量热仪、动态力学分析仪及物理机械性能测试等手段对复合材料的热性能、动态力学性能及物理机械性能进行了研究.结果表明,与纯NBR硫化胶相比,NBR/AO-80/CB复合材料的玻璃化转变温度大幅度升高,且随着NBR基质中结合丙烯腈量的增大而向高温方向移动;NBR/AO-80/CB复合材料具有较好的阻尼性能,其损耗峰的峰值高于1.22,有效阻尼温域(损耗因子不小于0.3)大于38 ℃,在不同的参考温度下均具有较宽的有效阻尼频率范围;同时,NBR/AO-80/CB复合材料具有较好的物理机械性能和耐热老化性能,尤其是N 220 S/AO-80/CB复合材料的综合性能最好.%Crosslinked nitrile rubber ( NBR )/hindered phenol (AO-80)/carbon black composites were prepared by mixing AO-80 and carbon black into NBR with different bound acrylonitrile contents. The thermal properties, dynamic mechanical properties and mechanical properties of the composites were characterized by differential scanning calorimetry, dynamic mechanical analysis and tensile tester. The results showed that compared with pure NBR, the glass transition temperature of NBR/AO-80/carbon black composites increased greatly, and shifted to high temperature direction with increasing the bound acrylonitrile content of NBR. NBR/AO-80/carbon black composites showed excellent damping properties: loss factor ( tan δ) was more than 1.22, and the effective damping temperature range( tan δ equal to or more than 0. 3 ) was more than 38 ℃ ,the frequency range with high tan δ was wide at different reference temperatures. NBR/AO-80/carbon black composites had good mechanical properties and thermal aging resistance.Especially, N 220 S/AO-80/carbon black composites were the best in all-round properties.

  18. Estudo da polimerização do 2-metil, 1,3-butadieno via catalisadores lantanídicos: influência do tipo de alquilalumínio, da temperatura reacional e da concentração do catalisador Polymerization of 2-methyl, 1,3-butadiene via lanthanides catalysts: influence from the type of alkylaluminum, concentration and reaction temperature and catalyst

    Directory of Open Access Journals (Sweden)

    André L. C. Simões

    2011-01-01

    Full Text Available Os catalisadores lantanídicos são muito eficientes na polimerização estereoespecífica de dienos, principalmente aqueles à base de neodímio. Neste trabalho será apresentado o estudo da polimerização do 2-metil, 1,3-butadieno com catalisadores à base de neodímio, utilizados comercialmente na polimerização do 1,3-butadieno. Foi estudado o efeito da temperatura, do tipo de alquilalumínio e da concentração de catalisador. As reações foram realizadas em reator de aço inox sob atmosfera inerte, usando como solvente o hexano e uma concentração de 2-metil, 1,3-butadieno de 12%. Foram obtidos polímeros com massas molares na faixa de 1,0 a 1,5 × 105 e teor de unidades repetitivas cis em torno de 97%.The rare earth metals catalysts are very efficient in stereospecific polymerization of dienes, especially those of neodymium. This paper reports on the polymerization of 2-methyl, 1,3-butadiene with catalysts of neodymium, used commercially in polymerization of 1,3-butadiene. Effects were studied from the temperature, type of alkylaluminum, and from the concentration of catalyst. The reactions were carried out in a stainless steel reactor under an inert atmosphere, using hexane as the solvent and a concentration of 12% of 2-methyl, 1,3-butadiene. Polymers were obtained with molecular weight from 1.0 to 1.5 × 105, with ca. 97% of cis repeating units.

  19. Rubber curing chemistry governing the orientation of layered silicate

    Directory of Open Access Journals (Sweden)

    2007-11-01

    Full Text Available The effect of curing systems on the orientation and the dispersion of the layered silicates in acrylonitrile butadiene rubber nanocomposite is reported. Significant differences in X-ray diffraction pattern between peroxide curing and sulfur curing was observed. Intense X-ray scattering values in the XRD experiments from peroxide cured vulcanizates indicate an orientation of the layers in a preferred direction as evinced by transmission electron micrographs. However, sulfur cured vulcanizates show no preferential orientation of the silicate particles. Nevertheless, a closer inspection of transmission electron microscopy (TEM images of peroxide and sulfur cured samples shows exfoliated silicate layers in the acrylonitrile butadiene rubber (NBR matrix. It was revealed in the prevailing study that the use of an excess amount of stearic acid in the formulation of the sulfur curing package leads to almost exfoliated type X-ray scattering pattern.

  20. Вивчення епоксидних новолачних смол на основі карданолу та їх сумішей

    OpenAIRE

    Yadav, Ranjana; Srivastava, Deepak

    2008-01-01

    Cardanol-based novolac-type phenolic resin was synthesized with a mole ratio 1.0:0.5 of cardanol-toformaldehyde using a dicarboxylic acid catalyst such as succinic acid. The cardanol-based novolac-type phenolic resin may further be modified by epoxidation with epichlorohydrin excess at 393 K in a basic medium to duplicate the performance of such phenolic-type novolacs. Carboxyl-terminated butadiene acrylonitrile copolymer (CTBN) has been studied by various researches with diglycidyl ether ...

  1. Development of a rubber toughened epoxy adhesive loaded with carbon nanotubes, for aluminium – polymer bonds

    OpenAIRE

    Salinas-Ruiz , Maria del Mar

    2009-01-01

    This thesis describes the formulation of a ternary thermosetting adhesive which consists of a diglycidyl ether of bisphenol-A (DGEBA) epoxy resin cured with 3,3’-diamino diphenyl sulphone (3,3’-DDS) hardener and modified through the addition of carboxyl- terminated butadiene-acrylonitrile (CTBN) rubber and multi-walled carbon nanotubes (MWCNTs). Processing implications of the novel adhesive in the film form are considered in order to manufacture bonded specimens for characteris...

  2. Rheology of ABS and binary of organo clay nanocomposites; Reologia de nanocompositos de ABS e mistura binaria de argilas montmorilonita organofilicas

    Energy Technology Data Exchange (ETDEWEB)

    Galvan, Danieli; Mazzucco, Mateus; Carneiro, Fabio; Bartoli, Julio R.; Morales, Ana Rita, E-mail: bartoli@unicamp.br [Fac. de Engenharia Quimica/Universidade Estadual de Campinas-DTP/FEQ/UNICAMP-, SP (Brazil); D' Avila, Marcos A. [Fac. de Engenharia Mecanica/Universidade Estadual de Campinas - DEMA/FEM/UNICAMP, SP (Brazil)

    2011-07-01

    nanocomposites of poly(acrylonitrile-butadiene-styrene) and organically modified montmorillonite clays by melt intercalation on a co-rotating twin-screw extruder were prepared and characterized. It was studied the effects of screw torque and a binary mixture of organically modified montmorillonites on the intercalation/exfoliation of organoclays in the polymer matrix, characterized by X-ray diffraction morphological analyses and by capillary and parallel plates rheological analyses. (author)

  3. Rheology of ABS and binary of organo clay nanocomposites

    International Nuclear Information System (INIS)

    nanocomposites of poly(acrylonitrile-butadiene-styrene) and organically modified montmorillonite clays by melt intercalation on a co-rotating twin-screw extruder were prepared and characterized. It was studied the effects of screw torque and a binary mixture of organically modified montmorillonites on the intercalation/exfoliation of organoclays in the polymer matrix, characterized by X-ray diffraction morphological analyses and by capillary and parallel plates rheological analyses. (author)

  4. Influence of the morphology on mechanical properties of toughened epoxies with CTBN

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Presents a toughened-epoxy risen based on diglycidylether of bisphenol A (DGEBA) cured with ethylene-diamine (EDA) and modified with a carboxyl-terminated acrylonitrile-butadiene (CTBN), studies morphologies with different rubber content and analyses the influence of rubber-phase morphology corresponding to different rubber contents on mechanical properties (elastic modulus, uniaxial compression yield stress, shearing strength, uneven tensile strength, critical stress intensity factor Kic and strain energy release rate Gic) of toughened epoxies.

  5. WOOD - PLASTIC COMPOSITES FROM WASTE MATERIALS RESULTED IN THE FURNITURE MANUFACTURING PROCESS

    OpenAIRE

    Camelia COŞEREANU; Dumitru LICA

    2014-01-01

    The paper presents the application of waste materials resulted in the furniture manufacturing process as components for wood-plastic composites. The composites are produced from industrial byproducts, such as shavings and ABS (acrylonitrile butadiene styrene), without coupling agent. The two components are derived from industrial processes of furniture manufacturing: the first one consists of wood residues resulted from planing machine as planer shavings, and the second one from ABS edge band...

  6. ECOLOGICAL AND TECHNOLOGICAL ANALYSIS OF MATERIALS FOR 3D-PRINTING

    OpenAIRE

    Є.О. Бовсуновський; Зінченко, Р. О.

    2016-01-01

    The article analyzes the main materials used for 3D-printing. Particular attention is paid to the study of ecological and technological analysis of the effects of the most widely used material: Polylactic Acid and Acrylonitrile Butadiene Styrene, as well as their professional series and Nylon, Polyethylene Terephthalate, TPE on the environment. The article deals with the characteristic features of the physical properties of materials (material) for their intended purpose, according sharing al...

  7. Effects of melt blended poss nanofillers on pom and ABS thermal stability

    OpenAIRE

    Vilà Ramírez, Narciso

    2014-01-01

    This PhD thesis investigated the incorporation of Polyhedral Oligomeric Silsesquioxanes (POSS) in thermoplastic base materials via melt-blending procedures. Particularly, a focus is taken on the enhancement of the thermal resistance through the addition of different types of POSS on two popular engineering plastics known by their low thermal stability, one being a semi-crystalline copolymer i.e. polyoxymethylene (POM) and the other an amorphous copolymer i.e. acrylonitrile butadiene styren...

  8. Three-dimensional heterostructure of metallic nanoparticles and carbon nanotubes as potential nanofiller

    OpenAIRE

    Kim, Whi Dong; Huh, Jun Young; Ahn, Ji Young; Lee, Jae Beom; Lee, Dongyun; Hong, Suck Won; Kim, Soo Hyung

    2012-01-01

    The effect of the dimensionality of metallic nanoparticle-and carbon nanotube-based fillers on the mechanical properties of an acrylonitrile butadiene styrene (ABS) polymer matrix was examined. ABS composite films, reinforced with low dimensional metallic nanoparticles (MNPs, 0-D) and carbon nanotubes (CNTs, 1-D) as nanofillers, were fabricated by a combination of wet phase inversion and hot pressing. The tensile strength and elongation of the ABS composite were increased by 39% and 6%, respe...

  9. Développement des procédés "verts" pour modifier la surface d'ABS avant sa métallisation

    OpenAIRE

    Magallon Cacho, Lorena

    2009-01-01

    The ABS is a copolymer formed by Acrylonitrile-Butadiene-Styrene used in industry whose surface can be coated with a metallic deposit. The traditional process for depositing metallic films in an auto-catalytic way is know as "Electroless", However, this process uses a sulfo-chromic mixture in the preliminary stage of the surface treatment containing Cr (VI) which is a toxic, polluting agent that needs to be replaced. Therefore, it is necessary to develop new surface modification procedures wi...

  10. SOLID WASTE MANAGEMENT IN TABRIZ PETROCHEMICAL COMPLEX

    OpenAIRE

    M. A. Abduli, M. Abbasi, T. Nasrabadi, H. Hoveidi, N. Razmkhah

    2006-01-01

    Tabriz petrochemical complex is located in the northwest of Iran. Major products of this industry include raw plastics like, polyethylene, polystyrene, acrylonitrile, butadiene, styrene, etc. Sources of waste generation include service units, health and cure units, water, power, steam and industrial processes units. In this study, different types of solid waste including hazardous and non hazardous solid wastes were investigated separately. The aim of the study was to focus on the management ...

  11. Microwave Study of Recycled ABS Resins

    Institute of Scientific and Technical Information of China (English)

    A; M; Hasna

    2002-01-01

    This article provides a review of the research unde rt aken in order to determine the suitability of utilizing microwave technology in the production of Recycled ABS Acrylonitrile Butadiene Styrene resin for mouldin gs. The experimental investigation determined the suitability of the existing re cycled ABS material, the mould material used with respect to performance and lon gevity, potential commercial plant and equipment, end mould compression. Introduction Frequency Characterization of ABS The first ...

  12. Smart Card: Turning Point of Technology

    OpenAIRE

    Abhishek Mahajan; Akash Verma; Dhruv Pahuja

    2014-01-01

    A smart card, chip card, or integrated circuit card (icc) is any pocket-sized card with embedded integrated circuits. Smart Cards are secure portable storage devices used for several applications especially security related ones involving access to system’s database either online or offline. Smart cards are made of plastic, generally polyvinyl chloride, but sometimes polyethylene terephthalate based polyesters, acrylonitrile butadiene styrene orpolycarbonate. This research is chie...

  13. Charpy Impact Test on Polymeric Molded Parts

    OpenAIRE

    Alexandra Raicu

    2012-01-01

    The paper presents the Charpy impact tests on the AcrylonitrileButadiene-Styrene (ABS) polymeric material parts. The Charpy impact test, also known as the Charpy V-notch test, is a standardized strain rate test which determines the amount of energy absorbed by a material during fracture. This is a typical method described in ASTM Standard D 6110. We use for testing an Instron - Dynatup equipment which have a fully integrated hardware and software package that let us capture ...

  14. Propriedades Mecânicas de Blendas de Nylon-6/Acrilonitrila-EPDM-Estireno (AES Compatibilizadas com Copolímero Acrílico Reativo (MMA-MA Mechanical Properties of Nylon-6/Acrylonitrile-EPDM-Styrene (AES Blends Compatibilized with Reactive Acrylic Copolymer (MMA-MA

    Directory of Open Access Journals (Sweden)

    Adriane Bassani

    2002-01-01

    Full Text Available Foram estudadas blendas de nylon-6 com copolímero de acrilonitrila/EPDM/estireno (AES utilizando, como agentes compatibilizantes, uma série de copolímeros reativos de metacrilato de metila-anidrido maleico (MMA-MA. As unidades anidrido maleico (MA, destes copolímeros, podem reagir com os grupos finais de cadeia do nylon-6. Como verificado através de reometria de torque, os copolímeros MMA-MA podem gerar copolímeros in situ na interface das blendas durante o processamento. O principal enfoque deste trabalho foi estudar os efeitos da funcionalidade e concentração dos grupos anidrido maleico do compatibilizante sobre as propriedades mecânicas das blendas. Os resultados mostraram que a incorporação dos copolímeros MMA-MA melhorou significativamente a resistência ao impacto sob entalhe das blendas nylon-6/AES. As blendas contendo copolímero MMA-MA com 1,3% em peso de MA podem ser classificadas como supertenazes e mantêm sua tenacidade em temperaturas abaixo de zero.Blends of nylon-6 with acrylonitrile/EPDM/styrene (AES using a series of methyl methacrylate-maleic anhydride (MMA-MA copolymers as compatibilizing agents were prepared. The maleic anhydride (MA units in the copolymers are capable to react with the nylon-6 end groups. The MMA-MA copolymer has a potencial to form in situ copolymers at the blend interface during melt processing as indicated by torque rheometry tests. This study focuses on the effects of functionality and concentration of the reactive maleic anhydride units of the compatibilizer on the mechanical properties of these blends. The results show that incorporation of the MMA-MA copolymer significantly improves the impact strength of nylon-6/AES blends. The blend containing 1.3wt% of MA in the copolymer is supertough at room temperature, and remains tough at subzero temperatures.

  15. 顶空气相色谱法测定丙烯腈-苯乙烯(AS)塑料中残留的7种单体%Determination of 7 residual monomers in acrylonitrile-styrene plastic by gas chromatography with head space sampler

    Institute of Scientific and Technical Information of China (English)

    朱文亮; 周勇; 陈晓鹏; 谭锦萍; 吴炜亮

    2012-01-01

    A reliable method had been developed for determination of 7 residual monomers in acrylonitrile- styrene (AS) plastic by headspace-gas chromatography. The samples were completely dissolved into N, N-diethylformamide,and then the gas after achieved equilibrium in the headspace bottle was extracted by headspace injection equipment for gas chromatography analysis. The optimum conditions of gas chromatography and headspace injection were obtained by experiments. The optimum conditions of headspace injection were usage of solvent 3mL,heating temperature 120℃ ,time for equilibrium 40min. The average recoveries of 7 residual monomers were 95.71%-106.89%,the detection limits were 0.25N1.0mg/kg. The analysis method not only improved detection efficiency,but also cut down the detection cost. Meanwhile,this method was simple, rapid,accurate,and sensitive.%建立了顸空气相色谱法测定丙烯腈-苯乙烯(AS)塑料中7种残留单体的分析方法。以N,N-二甲基甲酰胺为溶剂溶解AS塑料,于顶空装置中平衡后,进样进行气相分析。通过实验得到了优化的气相色谱分离条件及顶空条件,其中优化的顸空条件为溶剂使用量3mL,加热温度120℃,平衡时间40min。7种残留单体的平均回收率为95.71%-106.89%,检出限为0.25-1.0mg/kg。该方法既提高了检测效率,又降低了检测成本。同时,此方法还具有简便、快速、灵敏、准确等优点.

  16. Development of analytical methods for the gas chromatographic determination of 1,2-epoxy-3-butene, 1,2:3,4-diepoxybutane, 3-butene-1,2-diol, 3,4-epoxybutane-1,2-diol and crotonaldehyde from perfusate samples of 1,3-butadiene exposed isolated mouse and rat livers

    Energy Technology Data Exchange (ETDEWEB)

    Bhowmik, S.; Schuster, A.; Filser, J.G.

    2003-07-01

    Mutagenicity and carcinogenicity of 1,3-butadiene (BD) highly probably results from epoxide metabolites as 1,2-epoxy-3-butene (EB), 1,2:3,4-diepoxybutane (DEB) and 3,4-epoxybutane-1,2-diol (EBD). A further metabolite crotonaldehyde (CA) has also been discussed to be relevant. So far, in BD exposed rodents only EB and DEB concentrations had been quantified. However, the methods used were either not very sensitive or instrumentally expensive. Therefore, the goal of the present work was to establish simple analytical methods selective and sensitive enough to determine all of these compounds and a further secondary BD intermediate, 3-butene-1,2-diol (B-diol), in BD exposed rodent livers. The once-through perfused liver system was chosen for testing the applicability of the methods to be developed, since it enables BD exposures of this quantitatively most relevant metabolising organ near to the in-vivo situation. All the metabolites were extracted from the aqueous perfusion medium and analysed using a gas chromatograph equipped with a mass selective detector (GC/MS) in the PCI mode. (orig.)

  17. 均匀设计优化硒催化氢化丁腈橡胶乳液的研究%Preparation of Selenium-catalyzed Hydrogenated Nitrile-butadiene Rubber with Diimide in Latex Form by Optimization of Uniform Design

    Institute of Scientific and Technical Information of China (English)

    欧浩明; 彭晓宏

    2011-01-01

    以硒粉为催化剂,水合肼和过氧化氢为氧化还原引发体系,进行了常温常压下的丁腈橡胶乳液加氢反应,采用均匀设计法研究了水合肼用量、硒粉用量、过氧化氢用量、二酰亚胺凝胶抑制剂用量、反应温度以及反应时间等对丁腈橡胶氢化度的影响,并利用红外光谱对氢化产物进行了表征.实验结果表明,在适宜的反应条件下,可制得氢化度为90%的氢化丁腈橡胶.%In this paper, nitrile rubber latex was hydrogenated using selenium as catalyst and redox initiation system of hydrazine and hydrogen peroxide in normal temperature and pressure. Influence of amount of hydrazine, selenium, hydrogen peroxide,gel inhibitor and reaction temperature and time were studied by uniform design. The hydrogenated products were characterized by infrared spectrum. The results show that hydrogenated Nitrile-butadiene Rubber of 90% hydrogenation degree was obtained in appropriate reaction conditions.

  18. Reinforcement of Styrene-Butadiene Rubber with Silica Modified by Silane Coupling Agents: Experimental and Theoretical Chemistry Study%硅烷偶联剂改性白炭黑补强丁苯橡胶:实验和量化研究

    Institute of Scientific and Technical Information of China (English)

    任慧; 屈一新; 赵素合

    2006-01-01

    The properties of styrene-butadiene rubber (SBR) reinforced by modified silica was investigated according to national standards. Silica was modified by silane coupling agents KH-570, KH-590, and KH-792. The optimized geometries of molecular modified silica reinforced SBR were obtained by using B3LYP calculation of density functional theory with the 6-31+G basis sets. The natural bond orbital analyses were carried out. The Si-O bond length of silica modified by KH-792 was the shortest and the electronegative of O was the highest. It indicated that the connection between silica and KH-792 was the tightest. Higher tensile strength and elongation of reinforced SBR was obtained by silica modified with the KH-792. It was caused by large delocalization of lone pair electrons of the two N atoms in KH-792. The S-C bond length in silica modified by KH-590 was longer than the ordinary S-C bond length. Then the sulfur free radical (·S·) was produced more easily in vulcanization. The degree of crosslink was increased by the cross-linkage of the rubber molecule and the sulfur free radical. That was why the highest stress and tear strength of reinforced SBR was produced when silane coupling agent KH-590 was used. The calculation results was in accord with experimental data.

  19. Solubility parameter of poly(styrene-co-acrylonitrile)

    Science.gov (United States)

    Wohlfarth, Ch.

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

  20. Intumescent flame retardant prepared by inverse suspension polymerization and its application in styrene-butadiene rubber%用反相悬浮聚合法制备膨胀型阻燃剂及其在丁苯橡胶中的应用

    Institute of Scientific and Technical Information of China (English)

    朱启龙

    2012-01-01

    The sodium polyacrylate-in situ encapsulated intumescent flame retardant ( IFR ) was prepared in the inverse suspension polymerization of sodium acrylate by adding ammonium polyphosphate, pentaerythritol and melamine, and Fourier transform infrared spectroscopy was used to characterize the structure of the flame retardant. The effects of melamine amount and the mass ratio of ammonium polyphosphate to pentaerythritol on the flame retar-dancy of styrene-butadiene rubber ( SBR ) vulcani-zates were investigated, the thermal property of flame retardant SBR was studied by thermogravime-try, and the combustion surface morphology of SBR filled with IFR was observed by scanning electron microscopy. The results showed that when the mass fraction of melamine was 3. 0% in IFR system, the mass ratio of ammonium polyphosphate to pentaerythritol was 4. 00 to 5. 67, the carbon residue yield of the system was the highest and the flame retardan-cy was better. The flame retardancy of SBR with IFR was improved correspondingly. When the IFR mass fraction was 30% in styrene-butadiene rubber vul-canizate, the oxygen index of the flame retardant rubber could achieve up to 27. 5% ; the SBR filled with IFR could form a relatively dense layer of carbon foam when it was burned, indicating that the IFR had a better intumescent flame retardant effect on SBR.%采用反相悬浮法聚合丙烯酸钠,同时将化学膨胀阻燃体系( IFR)三组分聚磷酸铵、季戊四醇和三聚氰胺加入到聚合体系中进行原位包裹,用傅里叶变换红外光谱时聚合产物的结构进行了表征,研究了三聚氰胺用量和聚磷酸铵与季戊四醇配比对丁苯橡胶硫化胶阻燃效果的影响,采用热重法分析了阻燃丁苯橡胶的热性能,并通过扫描电镜观察了添加IFR的丁苯橡胶在燃烧后表面的微现形态.结果表明,三聚氰胺的质量分数为IFR体系的3.0%、聚磷酸铵与季戊四醇的质量比为4.00~5.67时IFR体系的剩炭率最高,阻

  1. 丁二烯装置萃取系统运行周期缩短原因及措施%The Reasons for the Shortening of the Operation Period of the Extractive Distillation System for Butadiene Unit and the Countermeasures

    Institute of Scientific and Technical Information of China (English)

    郑建桥

    2015-01-01

    As extractive distillation tower tray was jammed in butadiene production, and with short operation cycle, the economic benefits of the unit was seriously restricted. In combination with the mechanism of the generation of the polymer like popcorn, and the analysis of the composition of polymer, the reasons for the polymer of the unit were presented. It was put forward that took the strict system of oxygen control, paid attention to the upstream C4 plant raw material quality management, guaranteed measures and medium pressure steam temperature, appropriated to add resistance composite polymerization inhibitor and improved the quality of the solvent can extend the unit production cycle.%针对丁二烯装置生产中出现萃取精馏塔塔盘堵塞,运行周期短,严重制约装置经济效益发挥的问题,结合1,3-丁二烯爆米花状聚合物产生的机理,通过对垢样组成的分析,分析了装置结垢产生的原因,提出并采取了严格系统氧控制、注重上游装置碳四原料质量管理、保证中压蒸汽温度、适当添加复合阻聚剂以及改善溶剂品质等措施,延长了装置的生产运行周期。

  2. 道化学火灾、爆炸危险指数法在1,3丁二烯聚合安全性评价中的应用%Application of dow chemical fires and explosive index analysis method in safety evaluation of 1,3 butadiene polymerization process

    Institute of Scientific and Technical Information of China (English)

    王丽敏; 翟润培; 孙友平; 吕彩霞

    2012-01-01

    道化学火灾、爆炸危险指数法是在化工领域中广泛应用的一种评价方法,根据该法制定的指数选取规则,可对工艺单元火灾爆炸危险性进行量化和分级.以某化工厂3000t/a三聚体生产项目为背景,从工艺过程、危险物质、安全设施设计等方面,对1,3丁二烯聚合过程火灾、爆炸危险性进行分析;定量评价工艺装置及所含物料潜在危险性,得出主装置区、储罐区固有危险等级,分析不同状态下安全补偿系数对降低危险等级的影响,提出相应安全对策措施.%Dow chemical fires and explosive index analysis method is a widely used evaluation method in the field of chemical industry. According to the index selection rules, the fire explosion risk of the technics cell could be quantitated and classified. In this paper,taking the project of 3000t/a trimer production in a chemical factory as the background, the fire explosion hazard in the polymerization process of 1,3 butadiene was analyzed on the process, dangerous substances, safety facilities design and other aspects. According to the quantitative evaluation of the potentially danger for process units and materials, the intrinsic danger levels of main plant area and tank farm were obtained and some safety countermeasures were put forward by analyzing the effect of security compensation factor on danger level in different condition.

  3. Influência do envelhecimento de catalisadores Ziegler-Natta à base de neodímio sobre a polimerização de 1,3-butadieno Influence of ageing of neodymium based Ziegler-Natta catalyst on butadiene polymerization

    Directory of Open Access Journals (Sweden)

    Ivana L. Mello

    2007-03-01

    Full Text Available Catalisadores envelhecidos em diferentes tempos (0, 5, 15, 40, 80 e 160 dias e diferentes temperaturas (10, 25 e 40 °C foram testados na polimerização 1,4-cis do 1,3-butadieno. Avaliou-se a atividade catalítica bem como as características do polímero obtido (massa molecular e microestrutura. Os resultados encontrados mostraram que a variação nas condições de envelhecimento dos catalisadores não influenciou a microestrutura do polímero. O teor de unidades 1,4-cis permaneceu em torno de 98%, de unidades 1,4-trans em torno de 1,4% e de unidades vinílicas em 0,6%. Entretanto, reações utilizando os catalisadores envelhecidos por 40 dias forneceram polibutadieno com maior massa molecular do que os demais catalisadores. Verificou-se também, uma tendência de maiores conversões das polimerizações com os catalisadores envelhecidos a 25 °C.Catalysts aged for different time periods (0, 5, 15, 40, 80 and 160 days and different temperatures (10, 25 and 40 °C were tested in the cis-1,4 polymerization of 1,3-butadiene. The catalytic activity and polymer characteristics (molecular weight and microstructure were evaluated. The results showed that the catalyst ageing did not affect the polymer microstructure. The cis-1,4 content remained at 98%, trans-1,4 at 1,4% and vinyl units at 0,6%. However, the catalysts aged for 40 days produced polybutadienes with higher molecular weight. Also observed was a tendency to an increased polymerization conversion by the catalysts aged at 25 °C.

  4. Valorisation de la coupe C4 de vapocraquage via l'hydrogénation du butadiène, l'isomérisation des butènes et la métathèse, en MTBE ou en propylène Upgrading the C4 Cut from Steam Cracking via the Hydrogenation of Butadiene, the Isomerization of Butenes and Metathesis Into Mtbe Or Propylene

    Directory of Open Access Journals (Sweden)

    Chaumette S.

    2006-11-01

    Full Text Available Le surplus de butadiène au niveau mondial contraint les pétrochimistes à recycler la coupe C4 au vapocraqueur. De plus en plus, le butadiène est hydrogéné avant de recraquer toute la coupe. Une fois hydrogénée, cette coupe peut être beaucoup mieux valorisée, soit en MTBE avec isomérisation des n-butènes (procédé ISO-4, soit en propylène et MTBE en utilisant le procédé META-4. L'étude technico-économique montre que cette dernière voie offre la meilleure rentabilité (TRI = 21,5 %. Si le vapocraqueur est intégré à une raffinerie, les butènes peuvent également être transformés en alkylats ou en MTBE, pour répondre à une demande en octane ou en oxygénés pour les carburants. Ces diverses voies de valorisation sont plus intéressantes que la production de MTBE à partir des butanes via la déshydrogénation de l'isobutane ou que la production du propylène par déshydrogénation du propane. Une étude de sensibilité aux différents prix des produits envisagés permet d'établir des courbes d'isorentabilités, délimitant des zones de prix favorables à l'un ou l'autre des produits, pris deux à deux. The evolution of the outlets for C4 cuts from steam cracking shows quite contradictory results. On one hand, European and Asian petrochemists are more constrained to recycle this type of effluent, which contains butadiene and isobutene, to the steam cracker. Likewise, the demand for isobutene for MTBE production is such that it has to be produced by the dehydrogenation of isobutane. This situation is effectively caused by the surplus of butadiene, a by-product of ethylene, and for which the demand is not increasing as fast as the demand for ethylene. To improve cracking performances during the recycling of the C4 Cut, butadiene is more and more selectively hydrogenated. Under these conditions, rather than cracking it, the new processes could make it possible to better upgrade it. Indeed, after selective hydrogenation, most

  5. Effect of Nano-CaCO3 on Mechanical Properties of Filled Powdered Styrene-Butadiene Rubber Vulcanizate%纳米碳酸钙对填充型粉末丁苯橡胶硫化胶力学性能的影响

    Institute of Scientific and Technical Information of China (English)

    屈国梁; 陈雪梅; 马新胜

    2011-01-01

    Nano-CaCO3 filled styrene-butadiene rubber (SBR) powder P(SBR/CaCO3 ) was prepared with condensation coprecipitation method. The effect of nano-CaCO3 filling amount on the mechanical properties ofP(SBR/CaCO3) vulcanizate was studied. Then the material was compared with the bulk vulcanizate of mixed SBR/nano-CaCO3. It is found that when the nano-CaCO3 filling amount of P (SBR/CaCO3) vulcanizate and SBR/CaCO3 vulcanizate was the same, the mechanical properties of the former were basically superior to the later.When the filling amount of the nano-CaCO3 was 100 phr, the best mechanical properties of P (SBR/CaCO3) vulcanizate could be obtained, while the tensile strength could reach 13. 38 MPa which was obviously better than that of the SBR/CaCO3 one. It was originate from that the nano-CaCO3 in the former had better dispersion and interface bonding force than that in the later, which led to the better mechanical properties.%采用凝聚共沉法制备了纳米碳酸钙填充型粉末丁苯橡胶[P(SBR/CaCO3)],研究了纳米碳酸钙填充量对P(SBR/CaCO3)硫化胶力学性能的影响,并与块状丁苯橡胶/纳米碳酸钙机械混炼胶(SBR/CaCO3)硫化胶的进行了比较.结果表明:当纳米碳酸钙填充量相同时,P(SBR/CaCO3)硫化胶的力学性能基本上都优于SBR/CaCO3硫化胶的,当纳米碳酸钙填充量为100份时,P(SBR/CaCO3)硫化胶的力学性能最佳,其拉伸强度达13.38 MPa,明显好于SBR/CaCO3硫化胶的;纳米碳酸钙在P(SBR/CaCO3)硫化胶中比在SBR/CaCO3硫化胶中具有更好的分散性和界面结合力,因此具有更好的力学性能.

  6. Influência do agente de cloração do catalisador à base de veodímio e da razão molar Cl: Nd na polimerização do butadieno Influence of the chlorinating agent of neodymium based catalysts and Cl: Nd molar ratio on butadiene polymerization

    Directory of Open Access Journals (Sweden)

    Cintia N. Ferreira

    2009-06-01

    Full Text Available Neste trabalho foi utilizado um sistema catalítico composto por hidreto de diisobutilalumínio (DIBAH, versatato de neodímio (NdV e um agente de cloração para avaliar a influência da fonte de cloro e da razão molar Cl:Nd nas características da reação de polimerização (conversão e constante de velocidade de propagação e do polibutadieno (massa molecular e microestrutura. Os agentes de cloração estudados foram cloreto de t-butila (t-BuCl, sesquicloreto de etilalumínio (EASC e cloreto de dietilalumínio (DEAC. As razões molares Cl:Nd utilizadas foram: 1:1, 3:1 e 5:1 para o t-BuCl; 0,5:1, 1:1 e 3:1 para o EASC e 1:1, 1,5:1, 3:1 e 5:1 para o DEAC. Foi observada a existência, para cada agente de cloração, de um valor ótimo de razão molar Cl:Nd para o qual a conversão foi máxima. O DEAC apresentou uma maior conversão em relação aos outros agentes de cloração; em contrapartida, o t-BuCl produziu polibutadienos com maior teor de unidades 1,4-cis e maior massa molecular (n e wIn this work catalyst systems consisting of diisobutylaluminium hydride (DIBAH, neodymium versatate (NdV and a chlorinating agent were employed to study the influence of the chloride source and Cl:Nd molar ratio on 1,3-butadiene polymerization and polybutadiene's characteristics (molecular weight and microstructure. The chloride sources studied were t-butyl chloride, ethylaluminium sesquichloride (EASC and diethylaluminium chloride (DEAC. The Cl:Nd molar ratios used were 1:1, 3:1 e 5:1 for t-butyl chloride; 0.5:1, 1:1 and 3:1 for EASC and 1:1, 1.5:1, 3:1 and 5:1 for DEAC. A maximum value of Cl:Nd molar ratio exists. Moreover, DEAC showed to be more reactive than EASC and t-BuCl but t-BuCl produced higher molecular weight and cis-1,4 units contents.

  7. Efeito do envelhecimento de catalisadores Ziegler-Natta à base de neodímio sobre a polimerização de 2-metil, 1,3-butadieno Effect of aging time of Ziegler-Natta catalysts based on neodimium for 2-methyl, 1,3-butadiene polymerization

    Directory of Open Access Journals (Sweden)

    André Luiz Carneiro Simões

    2013-01-01

    Full Text Available O objetivo deste trabalho foi estudar o efeito do tempo de envelhecimento natural do sistema catalítico versatato de neodímio/hidreto de di-isobutilalumínio/cloreto de t-butila sobre a polimerização de 2-metil, 1,3-butadieno (isopreno. Foram avaliadas a atividade catalítica e conversão, além da massa molar, distribuição de massa molar e microestrutura dos polímeros. Foi objetivo estudar também as características micro e macroestruturais do poli-1,4-cis-isopreno ao longo da polimerização. Os catalisadores envelhecidos apresentaram tempos mais curtos ao longo da polimerização e uma conversão mais alta em relação ao catalisador não envelhecido. Estes resultados em conjunto com a menor atividade catalítica nos catalisadores envelhecidos sugerem a provável desativação de alguns sítios ativos mais sensíveis. Não foi observada influência do envelhecimento do catalisador sobre a microestrutura do polímero. Houve também aumento da massa molar e estreitamento na polidispersão conforme o aumento da conversão.The goal of this work was to study the aging effects of the catalytic system neodymium versatate/diisobutylaluminium hydride/t-butyl chloride on 2-methyl, 1.3-butadiene (isoprene polymerization. The catalytic activity, conversion and polymer characteristics (molar mass, molar mass distribution and microstructure were evaluated. The macro and microstructural characteristics of poly-1.4-cis-isoprene along the polymerization were also studied. The aged catalysts have shorter times along the polymerization and a higher conversion than the non-aged catalyst. Together with the lower catalytic activity for aged catalysts, these results point to possible disabling of the most sensitive active sites. Aging of the catalyst did not affect the polymer microstructure. As the conversion progressed, the molar mass increased with a narrowing in the molecular weight distribution.

  8. 环保型填充油的乳化工艺及对丁苯橡胶充油效果的影响%Emulsification process of environmental-friendly extending oil and its influence on oil-extending effect of styrene-butadiene rubber

    Institute of Scientific and Technical Information of China (English)

    李晶; 王永峰; 吴宇

    2013-01-01

    Environmental-friendly oil-extended styrene-butadiene rubber ( SBR) was prepared with high Mooney viscosity SBR 1723 latex and environmental-friendly extending oil in which the mass fraction of polycyclic aromatic hydrocarbons was less than 3. 0% as materials, and the influences of emulsification process on emulsification effect of extending oil and properties of environmental-frendly oil-extended SBR were investigated. The results showed that the properties of the obtained environmental-friendly oil-extended SBR met the requirements of technical indicators under the conditions of emulsifying temperature 70 ℃ , extending oil/water/emulsi-fier (mass ratio) 100/200/2, stirring rate of agglomeration 163 r/min, agglomerating temperature 65 -70℃ when the emulsification process was used, by which the emulsifier disproportionated rosin acid soap was added into extending oil and stirred first and then the water was added.%以高门尼黏度丁苯橡胶(SBR) 1723基础胶浆和稠环芳烃质量分数低于3.0%的环保型橡胶填充油为原料制备环保型充油SBR,考察了乳化工艺对填充油乳化效果的影响以及所制得的环保型充油SBR的性能.结果表明,在以歧化松香酸钾皂为乳化剂、先将乳化剂加入填充油中搅拌一段时间后再加入水的油乳化方式、油乳化温度为70℃、填充油/水/乳化剂(质量比)为100/200/2以及凝聚时搅拌转速为163r/min、凝聚温度为65~70℃的条件下,所得产品的各项性能指标满足产品标准的要求.

  9. Synthesis and mechanical properties of poly(tetrahydrofuran)-poly(butadiene)-poly(tetrahydrofuran) triblock copolymer%聚四氢呋喃-聚丁二烯-聚四氢呋喃三嵌段共聚物的合成与力学性能

    Institute of Scientific and Technical Information of China (English)

    张万斌; 范晓东; 朱秀忠; 范伟伟

    2015-01-01

    Poly( tetrahydrofuran)-poly( butadiene)-poly( tetrahydrofuran) triblock copolymer was synthesized by cationic ring-opening polymerization of tetrahydrofuran in the presence of hydroxyl-terminated polybutadiene as the macroinitiator,boron trifluo-ride etherate as the catalyst, and few amount of epoxy propane as the ring-opening assistant agent. The chemical structure of target copolymers was characterized by FTIR,1 H-NMR,13 C-NMR and SEC. Triblock copolymer with a molecular weight of 8 066 g/mol was used to prepare elastomer by reacting with TDI. Tensile test indicates that the tensile strength and elongation are increased by 16% and 19% respectively compared with that of elastomer based on HTPB when both are in the same crosslink density.Dynamic mechanical analysis( DMA) reveals that the triblock copolymer cured elastomer exhibits better elasticity and viscosity properties than HTPB,and the glass transition temperature is -55.99 ℃,which is lower than HTPB cured elastomer.%以端羟基聚丁二烯( HTPB)为引发剂,三氟化硼乙醚络合物为催化剂,环氧丙烷为促开环剂,通过四氢呋喃的阳离子开环聚合反应,制备出聚四氢呋喃-聚丁二烯-聚四氢呋喃三嵌段共聚物( PTHF-PB-PTHF)。采用红外光谱、核磁共振氢谱及碳谱、凝胶渗透色谱-激光光散射联用技术,对目标化合物的结构进行了表征。采用相对分子质量为8066 g/mol的PTHF-PB-PTHF与甲苯二异氰酸酯反应制备了交联弹性体,应力-应变试验显示,在相同交联密度下,PTHF-PB-PTHF交联弹性体的拉伸强度及断裂伸长率较纯HTPB交联弹性体分别提高了16%及19%。动态热机械性能分析表明,PTHF-PB-PTHF交联弹性体具有优异的粘弹性能,其玻璃化转变温度为-55.99℃,低于HTPB交联弹性体。

  10. Application of styrene-butadiene rubber/organic montmorillonite nanocomposites synthesized by emulsion coprecipitated method in tire tread%乳液共沉法丁苯橡胶/有机蒙脱土纳米复合材料在轮胎胎面中的应用

    Institute of Scientific and Technical Information of China (English)

    张洪林; 高增亮; 宋国君; 谷正; 王振太; 李正勇; 李天真; 李迎; 邱艳平; 贾凤玲

    2009-01-01

    用乳液共沉法在中试装置上制备了丁苯橡胶/有机蒙脱土(SBR/OMMT)乳液共沉胶,研究了纳米复合材料的微观结构、力学性能、磨耗性能、加工性能等,讨论了其替代SBR在半钢子午线轮胎胎面中的应用效果.透射电子显微镜观察表明制备的乳液共沉胶是一种插层型纳米复合材料,OMMT与橡胶基质结合得较好;乳液共沉胶的拉伸强度、撕裂强度、硬度、回弹性等与SBR 1502基本相当,扯断伸长率和压缩永久变形有所增大,耐磨耗性能大幅度提高;以乳液共沉胶替代SBR 1502及部分炭黑在半钢子午线轮胎胎面中的应用效果良好,胶料的力学性能、加工性能及成品胎性能均能满足工业生产要求.%Styrene-butadiene rubber(SBR)/organic montmorillonite(OMMT) nanocomposites were synthesized by emulsion coprecipitation method in pilot plant. The structure, mechanical properties, abrasion properties and processing properties of the nanocomposites were studied. And the application of the nanocomposites in tread of semi-steel radical tire of SBR 1502 was investingated. The results of transmission electron microscope showed that the purpose products were intercalation nanocomposites, and the bond between OMMT and SBR matrix was better. The SBR/OMMT nanocomposites had similar tensile strength, tear strength, hardness and resilience to SBR 1502, while the elongation at break, compression set and abrasion properties were higher. The effect of SBR/OMMT composites in the application of tread of semi-steel radical tire instead of SBR 1502 and carbon black was good, and the mechanical properties, processing properties of the composites and the performance of the finished tire could meet requirements of production.

  11. Preparation of n-tetradecane-containing microcapsules with different shell materials by phase separation method

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Rui [Department of Chemical Engineering, Tsinghua University, Beijing (China); Zhang, Yan; Zhang, Qingwu [Department of Chemical Engineering, China University of Mining and Technology, Beijing (China); Wang, Xin; Zhang, Yinping [Department of Building Science, Tsinghua University, Beijing (China)

    2009-10-15

    Microcapsules for thermal energy storage and heat-transfer enhancement have attracted great attention. Microencapsulation of n-tetradecane with different shell materials was carried out by phase separation method in this paper. Acrylonitrile-styrene copolymer (AS), acrylonitrile-styrene-butadiene copolymer (ABS) and polycarbonate (PC) were used as the shell materials. The structures, morphologies and the thermal capacities of the microcapsules were characterized using Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and differential scanning calorimetry (DSC). The ternary phase diagrams showed the potential encapsulation capabilities of the three shell materials. The effects of the shell/core ratio and the molecular weight of the shell material on the encapsulation efficiency and the thermal capacity of the microcapsules were also discussed. Microcapsules with melting enthalpy > 100 J/g, encapsulation efficiency 66-75%, particle size<1 {mu}m were obtained for all three shell materials. (author)

  12. Influence of Layer Thickness and Raster Angle on the Mechanical Properties of 3D-Printed PEEK and a Comparative Mechanical Study between PEEK and ABS

    Directory of Open Access Journals (Sweden)

    Wenzheng Wu

    2015-09-01

    Full Text Available Fused deposition modeling (FDM is a rapidly growing 3D printing technology. However, printing materials are restricted to acrylonitrile butadiene styrene (ABS or poly (lactic acid (PLA in most Fused deposition modeling (FDM equipment. Here, we report on a new high-performance printing material, polyether-ether-ketone (PEEK, which could surmount these shortcomings. This paper is devoted to studying the influence of layer thickness and raster angle on the mechanical properties of 3D-printed PEEK. Samples with three different layer thicknesses (200, 300 and 400 μm and raster angles (0°, 30° and 45° were built using a polyether-ether-ketone (PEEK 3D printing system and their tensile, compressive and bending strengths were tested. The optimal mechanical properties of polyether-ether-ketone (PEEK samples were found at a layer thickness of 300 μm and a raster angle of 0°. To evaluate the printing performance of polyether-ether-ketone (PEEK samples, a comparison was made between the mechanical properties of 3D-printed polyether-ether-ketone (PEEK and acrylonitrile butadiene styrene (ABS parts. The results suggest that the average tensile strengths of polyether-ether-ketone (PEEK parts were 108% higher than those for acrylonitrile butadiene styrene (ABS, and compressive strengths were 114% and bending strengths were 115%. However, the modulus of elasticity for both materials was similar. These results indicate that the mechanical properties of 3D-printed polyether-ether-ketone (PEEK are superior to 3D-printed ABS.

  13. Copolymerization of butadiene and isoprene with TMEDA as modifier

    Institute of Scientific and Technical Information of China (English)

    张春庆; 刘炼; 王玉荣

    2003-01-01

    以正丁基锂(n-BuLi)为引发剂,N,N,N',N'-四甲基乙二胺(TMEDA)为调节剂,环己烷为溶剂,通过负离子聚合制备了丁二烯和异戊二烯的共聚物.结果表明,随着TMEDA用量的增加,聚合速度加快,丁二烯单体竞聚率增加,异戊二烯单体竟聚率减少,二者差值逐渐增大,在TMEDA/n-BuLi(摩尔比)不小于0.8时,这种变化趋势变缓,表明共聚物分布不均匀程度增加.

  14. Chemocatalytic Conversion of Ethanol into Butadiene and Other Bulk Chemicals

    NARCIS (Netherlands)

    Angelici, C.; Weckhuysen, B.M.; Bruijnincx, P.C.A.

    2013-01-01

    The development of new and improved processes for the synthesis of bio-based chemicals is one of the scientific challenges of our time. These new discoveries are not only important from an environmental point of view, but also represent an important economic opportunity, provided that the developed

  15. Solubility parameter of poly(styrene-b-butadiene-b-styrene)

    Science.gov (United States)

    Wohlfarth, Ch.

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

  16. Effects of different cations on properties of ionomers of maleated styrene-butadiene-styrene triblock copolymer%阳离子对顺酐化苯乙烯-丁二烯-苯乙烯三嵌段共聚物离聚体性能的影响

    Institute of Scientific and Technical Information of China (English)

    刘大刚; 谢洪泉; 高玉

    2011-01-01

    The ionomers containing different cations, such as sodium, lithium, potassium, calcium,zinc, lead, magnesium, and ethyl ammonium were synthesized from the ionization of maleated styrenebutadiene-styrene triblock copolymer ( SBS ) .Effects of different cations on the thermal, mechanical, oil resistance and adhesive properties of the ionomers were studied. The results showed that, in addition to the glass transition temperatures (Tg) of butadiene and styrene blocks, the ionomers exhibited third Tg, which is due to the dissociation of the ionic domains. For the monovalent alkali metal cation neutralized ionomers, the higher the ionic potential, the higher the dissociation temperature of ionic domains, tensile strength and lap shear strength to iron plates and the order from large to small was Li+ > Na+> K+; for the divalent cation neutralized ionomers, the dissociation temperature of ionic domains decreased in the order of Ca2+> Zn2+>Pb2+ , whereas the tensile strength decreased in the order of Ca2+> Zn2 + > Mg2 + , but all were lower than those of the monovalent alkali metal cation neutralized ionomers. The oil resistance of the divalent cation neutralized ionomers was better than that of the monovalent cation neutralized ionomers or SBS.The lap shear strength of zinc ion neutralized ionomer to iron plates was the highest of all, being 0. 594 MPa.%将顺酐化苯乙烯-丁二烯-苯乙烯三嵌段共聚物(SBS)离子化得到含不同阳离子的离聚体,考察了不同阳离子对离聚体热性能、物理机械性能、耐油性能和粘接性能的影响.结果表明,离聚体有3个玻璃化转变温度(Tg),其中2个是SBS固有的Tg,另一个是离子微区的离解温度;对于含1价阳离子的离聚体,离子电离势越高,离聚体的离解温度、拉伸强度和搭接剪切强度基本越高,即从大到小依次为含锂离聚体、含钠离聚体、含钾离聚体;含2价阳离子离聚体的离解温度从大到小依次为含钙离聚

  17. Pd-Pb/SiO2催化高浓度乙烯基乙炔加氢合成丁二烯%Hydrogenation of high-concentration monovinylacetylene for butadiene production over Pd-Pb/SiO2 catalysts

    Institute of Scientific and Technical Information of China (English)

    张一科; 贾则琨; 张帅; 甄彬; 韩明汉

    2016-01-01

    研究了硅胶负载钯铅双金属催化剂催化高浓度乙烯基乙炔加氢合成丁二烯过程。结果表明,加入适量的铅可起到分隔钯纳米粒子,阻碍钯纳米粒子团聚的作用,从而提高催化剂的催化活性,最佳 Pb/Pd 摩尔比为0.2。继续提高 Pb/Pd 摩尔比时,会生成铅钯合金相,造成催化剂活性降低。X 射线光电子能谱结果表明,催化剂的催化活性与 Pd 3d 的电子结合能呈正相关关系。制备催化剂过程中,还原温度对催化剂的结构和催化性能影响显著。在350℃下还原得到的催化剂中金属氧化物还原不彻底,催化剂活性较低;还原温度为450℃时,则会引起钯纳米粒子烧结,造成催化剂的催化活性和对丁二烯的选择性同时降低;催化剂的最佳还原温度为400℃。在40℃催化乙烯基乙炔反应40 h 后,积炭造成催化剂的孔道堵塞,催化剂失活。因此,需要进一步开展改善催化剂的抗积炭能力和使用寿命方面的研究。%The hydrogenation of high-concentration monovinylacetylene over silica supported Pd-Pb bimetallic catalysts was investigated. It showed that the appropriate presence of Pb can prevent Pd nanoparticles from aggregation, hence facilitated the improvement of catalytic activity, i.e. the optimal molar ratio of Pb to Pd of 0.2. With the molar ratio of Pb to Pd above 0.2, Pd-Pb alloy can be formed, which causes catalytic activity loss. The positive correlation between the catalytic activity and the electron bonding energy of Pd 3d was manifested by X-ray photoelectron spectra. The temperature for PdO reduction exhibited a remarkable influence on the structure and the activity of the catalysts. The PdO reduction at 350℃ of the catalyst was incomplete thus with low activity. At 450℃ of the reduction temperature, it caused Pd nanoparticle sintering, hence with low activity and low butadiene selectivity. As a result, the optimal reduction

  18. The cross linking of EPDM and NBR rubber

    Directory of Open Access Journals (Sweden)

    Samardžija-Jovanović Suzana

    2005-01-01

    Full Text Available In the process of macromolecule cross linking, the choice of type and quantity of the components and the experimental conditions are important to obtain the new cross linked materials with better mechanical and chemical characteristics. The cross linking method depends on the rubber type and structure. Intermolecular cross linking results in the formation elastomer network. The basis of the cross linking process, between ethylene propylene diene rubber (EPDM and acrylonitrile butadiene rubber (NBR, is a chemical reaction. Fillers and other additives are present in different mass ratios in the material. The exploitation properties of the cross linked materials depend on the quantity of additive in the cross linked systems.

  19. Development of recycled plastic composites for structural applications from CEA plastics

    Science.gov (United States)

    Bhalla, Agrim

    Plastic waste from consumer electronic appliances (CEAs) such as computer and printer parts including Polystyrene (PS), Acrylonitrile Butadiene Styrene (ABS), Polystyrene (PS) and PC/ABS were collected using handheld FTIR Spectrophotometer. The blends of these plastics with High Density Polyethylene (HDPE) are manufactured under special processing conditions in a single screw compounding injection molding machine. The blends are thermoplastics have high stiffness and strength, which may enhance the mechanical properties of HDPE like tensile modulus, ultimate tensile strength, tensile break and tensile yield. These composites have a potential to be used for the future application of recycled plastic lumber, thus replacing the traditional wood lumber.

  20. A low-cost lead-acid battery with high specific-energy

    Indian Academy of Sciences (India)

    S K Martha; B Hariprakash; S A Gaffoor; D C Trivedi; A K Shukla

    2006-01-01

    Lightweight grids for lead-acid battery grids have been prepared from acrylonitrile butadiene styrene (ABS) copolymer followed by coating with lead. Subsequently, the grids have been electrochemically coated with a conductive and corrosion-resistant layer of polyaniline. These grids are about 75% lighter than those employed in conventional lead-acid batteries. Commercial-grade 6V/3.5Ah (C20-rate) lead-acid batteries have been assembled and characterized employing positive and negative plates constituting these grids. The specific energy of such a lead-acid battery is about 50 Wh/kg. The batteries can withstand fast charge-discharge duty cycles.