STUDY ON THE SEQUENCE STRUCTURE OF SBR BY 13C—NMR METHOD Ⅰ. ASSIGNMENT FOR UNSATURAT CARBONS SPECTRA*

The sequence structures of emulsion-processed SBR and solution-processed (by lithium catalyst) SBR were investigated by ~(13)C-NMR spectroscopy. Seventeen peaks within unsaturated carbon region were recorded under the adopted experimental conditions. Assignments for these peaks were made by empirical-parameter-evaluation method.     

丙烯酸β-羧乙酯-苯乙烯共聚合的研究

<正> 丙烯酸酯类聚合物是一类性能优良的橡胶、涂料和粘合剂,酯的结构不同可得到性能各异的均聚物和共聚物。 丙烯酸β-羧乙酯(APA)是一种具有多种反应功能的丙烯酸酯单体,结构式为:CH_2=CH—COOCH_2CH_2COOH,其双键可发生加成聚合,制得的大分子带有反应性酯基和羧基侧基,以其制备反应性大分子具有广泛的应用前景。我们研究了丙烯酸β-羧     

THE EFFECT AND FUNCTION OF AliBu_2OR'''' ON BUTADIENE-PROPYLENE ALTERNATING COPOLYMERIZATION CATALYZED BY VO(OR)_2Cl-AIiBu_3 SYSTEM

Four kinds of AliBu_2OB' with different R' were synthesized. The effect of AliBu_2OR'/AliBu_3 mole ratio on the conversion, the [η] of copolymer and catalytic efficiency were studied. The conversion was increased obviously and the catalytic efficiency was 2.7 times higher than before. The effect of the amount of AliBu_2OR' on the valence state of vanadium ion and the change of the valence state of vanadium ion with reaction temperature and time were studied. The VIS and IR spectra of the trinary-component catalyst system were measured. The model of active center including AliBu_2OR' was proposed. The function of AliBu_2OB was explained.     

丙烯酸β-羧乙酯-苯乙烯共聚物缩合异烟肼的合成及其水解释放研究

<正> 大分子载体药物是精细高分子合成的一个重要研究领域,作为药物载体的大分子骨架需有良好的生物相容性及控制释放能力。本文采用具有较长柔性侧支链的丙烯酸β-羧乙酯(APA)-苯乙烯(St)共聚物作载体,并通过羧基与抗结核药物异烟肼反应,制备出毒性较低并能控制释放的大分子载体异烟肼药物。     

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

The effect of five ethers on alternating copolymerization of br(?)adiene 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.     

STUDY ON THE SEQUENCE STRUCTURE OF SBR BY 13C-NMR METHOD Ⅱ. PEAK ASSIGNMENT FOR ALIPHATIC CARBONS SPECTRA

The study on ~(13)C-NMR spectra of aliphatic carbon region of emuision-processed and solution-processed (by lithium catalyst) SBR was carried out. The assignments for more than thirty odd peaks observed experimentally were made by using "corresponding analysis" method, combined with the empirical parameters reported in literature. The peak intensifies were calculated based on BemouUian statistic assumption.     

丙烯酸丁酯-醋酸乙烯酯共聚物胶乳粒子的结构和性能

电镜观察表明,丙烯酸丁酯-醋酸乙烯酯共聚物胶乳粒子均为核-壳结构,若配料比不同,含量大者为核,而加料方式不同,则先加者先聚合成核.微观结构不同,可明显地影响胶膜的力学性能、T_g和耐水性.根据胶乳粒子微观结构的观察结果,认为当醋酸乙烯酯>50mol%时,共聚的引发和成核是在水相中进行的.     

钴系催化剂合成液体聚丁二烯的13C-NMR研究—端基、支化结构以及α-烯烃调聚机理

本文研究了Co(Nap)₂-Al(i-Bu)₃-PhCCl₃催化体系合成的液体聚丁二烯(PB)的¹³C-NMR谱以及α-烯烃调节分子量的PB¹³C-NMR谱,观察到TPB的端基结构,据此探讨了链引发机理,证明了α-烯烃是PB分子量的调节剂。根据化学位移计算和分子量测定结果,确认PB存在支化结构,并探讨了支化机理。     

钴系丁二烯苯乙烯共聚合及共聚物序列结构的研究

<正> 高顺式丁苯胶的合成研究已有二、三十年的历史。除了存在共聚物的苯乙烯结合量偏低以及混有一定量的均聚苯乙烯等问题外,共聚物分子链上各结构单元偏离无规分布可能是一个重要原因。 1983年古川淳二等曾用C-NMR方法对镍系高顺式丁苯共聚物分子链上顺-1,4(C)、反-1,4(T)、1,2结构(V)、苯乙烯(St)四种结构单元的键接几率做过分析。例如,