Block copolymerization of ethylene oxide and acrylonitrile and the influence of block length of polyacrylonitrile on the thermal behavior and morphology of block copolymer

A bifunctional initiator with the characteristics of anionic and charge transfer polymerization using p-aminophenol as parent compound is useful for synthesis of block copolymers. A block copolymer of ethylene oxide and acrylonitrile (PEO-b-PAN) is prepared by this method. In the first step, p-aminophenol potassium with protected amine group initiated polymerization of ethylene oxide (EO) to yield polyethylene oxide (PEO) with Schiffs base end groups. The charge transfer complexes (CTC) consisted of the PEO prepolymers with aniline group, which is formed by acidolysis of Schiffs base, and benzophenone (BP) initiated the polymerization of acrylonitrile under UV irradiation. Successful blocking has been confirmed by a strong change in the molecular weight of the prepolymer PEO and the block copolymer as well as IR, DSC, and NMR. The block copolymerization are strongly dependent on the polarity of the solvents. The effect of length of PAN block on glass transition temperature of PAN and the crystallinity of PEO block were discussed. © 1996 John Wiley & Sons, Inc.     

两相体系中催化氢化丙烯腈制备丙腈

膦配体TPPTS(三-间磺酸钠-三苯基膦)的水溶性很好,有关其过渡金属配合物催化剂的应用与研究活跃。近年来,对丙烯腈C=C双键加氢的研究多集中在以钯为中心金属的多相催化体系上,已报道的有聚硅氧烷钯体系,膦酸锆负载钯体系,高分子负载钯．金属氧化物催化剂,SiO2负     

铈对低负载Pd/Al2O3催化剂加氢丙烯腈的改性效应

钯基催化剂对烯烃及烯烃类衍生物有很好的加氢活性。但钯催化剂价格昂贵,单一的钯容易中毒失活,研究表明：掺入稀土氧化物能够提高钯催化剂在载体上的分散度,增大其氧化及氢化活性,提高催化剂的寿命及稳定性。但稀土助剂对双键选择性加氢影响的研究却很少有报     

Fe/MgO催化剂上乙腈和甲醇选择性合成丙烯腈

丙烯腈(AN)是一种重要的有机合成单体,自从1960年美国Sohio公司开发出以丙烯、氨和空气为原料的丙烯氨氧化生产丙烯腈的SOHIO工艺以来,目前全球95％以上的丙烯腈是通过SOHIO路线生产的。而乙腈(ACN)是丙烯氨氧化制丙烯腈的主要副产物,每吨丙烯腈副产25～     

丙烯腈在Cu(100)表面化学吸附的密度泛函理论研究

利用密度泛函方法, 模拟金属铜原子簇Cu₁₄(9,4,1)的(100)表面, 对丙烯腈(CH₂＝CHCN)在Cu(100)面上不同吸附位的吸附状况进行了理论研究. 结果表明: 丙烯腈分子通过端位N原子垂直吸附在金属表面上为弱化学吸附, 部分电荷从丙烯腈分子转移至铜金属簇; 由N原子的孤对电子与金属铜形成弱σ共价键; 顶位是最佳吸附位, 吸附能为40.7391 kJ•mol^－1, N原子与金属表面间的平衡距离为0.2279 nm; 其次为桥位和穴位, 吸附能分别为36.2513和30.2158 kJ•mol^－1, 平衡距离为0.2194和0.2886 nm; 吸附后C≡N键的强度降低, 活化了丙烯腈分子. 化学吸附使体系的熵减小, 是由于丙烯腈分子的平动和转动因吸附而被限制.     

交联聚苯乙烯-二乙烯基苯与丙烯腈的辐照接枝

聚苯乙烯系列的树脂颗粒有很强的耐辐照性,采用预辐照法所需剂量很大。苯环有共轭π结构,它的π电子是非定域的,辐射时苯基吸收的能量虽然足以使键断裂,但由于能量很快在整个分子重新分布,把能量集中于某一键使其断裂几率是很低的,所以采用预辐照接枝法所需的吸收剂量很大,相关     

Free Radical Polymerization of Acrylonitrile in Green Ionic Liquids

Free radical polymerization of acrylonitrile (AN) in ionic liquid, 1-butyl-3-methylimidazolium tetrafluoroborate ([bmim][BF₄]), 2,2;m1-azobisisobutyronitrile (AIBN) as initiator was investigated. Early investigations on polymerizations using ionic liquids indicate that they serve as especially good solvents to achieve high molecular weight polymers. Free radical polymerizations result in higher molecular weight polymers, for ionic liquids have low chain transfer constants and act to stabilize the active radical during the process of polymerization. The thermal stability of polymers synthesized in ionic liquids have be improved obviously than that in traditional solvents.     

丙烯腈中杂质的分析

This paper describes an enective method for the analysis of organic impurities in acrylonitrile using mixedstationary phases.This method has the characteristics of good separation,satisfactory repeatability and shortanalysis time.     

草酸处理对丙烷氨氧化催化剂Sb-V-O结构和催化性能的影响

以不同量的草酸处理钒的起始原料,采用共沉淀法制备了VSb3混合氧化物催化剂,运用N2低温吸附、X射线衍射、X射线光电子能谱和H2程序升温还原等方法对催化剂进行了表征,并考察了其在丙烷氨氧化反应中的催化性能.结果表明,草酸的处理可使所得样品中V处于较低的价态,从而有利于活性相SbVO4的生成.当草酸/V(摩尔比)为3时,所制VSb3混合氧化物中存在较多的活性相SbVO4,且其表面具有适量Sb和V的分布,使催化剂具有良好的氧化/还原性能平衡,因而在丙烷氨氧化反应中表现出更高的活性和丙烯腈选择性.     

多组分Mo-Bi-Fe-O催化剂上丙烯氨氧化研究进展

综述了多组分Mo_Bi_Fe_O催化剂上丙烯氨氧化研究进展 ,包括反应机理、催化剂设计、晶格氧迁移、活性位模型与协同效应四个方面