MCM-41分子筛负载氯化铝催化丙烯酸甲酯与1-辛烯共聚

Copolymerization of Methyl Acrylate and 1-Octene Catalyzed by the Loaded Aluminum Chloride on MCM-41 Molecular Sieve

以MCM-41分子筛负载氯化铝为催化剂,催化丙烯酸甲酯与1-辛烯共聚合反应,利用称重法测定聚合物产率,利用核磁共振氢谱分析共聚物组成,利用凝胶渗透色谱分析共聚物相对数均分子质量,研究了聚合物产率和共聚物组成随聚合反应时间的变化规律,考察了溶剂、催化剂组成和催化剂用量对共聚合结果的影响及催化剂的循环使用性能.结果表明,聚合物产率随时间呈S形增长,而共聚物组成随时间保持恒定,与氯化铝催化体系规律一致;溶剂由二氯甲烷改变为乙醇或二甲苯主要影响聚合物组成,对聚合物相对数均分子质量及其分布影响不大;催化剂中活性组分的增加有利于增加共聚物中1-辛烯单元的含量,但对聚合物分子量及分子量分布影响不大;催化剂中活性组分含量一定时,随催化剂与单体摩尔比从0.125增加到0.5,共聚物中1-辛烯单元含量增加,继续增大催化剂用量不利于提高共聚物中1-辛烯单元含量.催化剂重复使用3次后仍具有良好的催化活性,将烯烃单元引入共聚物中,获得1-辛烯单元摩尔分数达30.1%的聚(丙烯酸甲酯-co-1-辛烯)共聚物.

The loaded aluminum chloride on MCM-41 molecular sieve was used to catalyze the copolymerization of methyl acrylate and 1-octene.Through detecting the polymer yield by weighing method,the copolymer composition by hydrogen nuclear magnetic resonance spectroscopy,and the relative number average molecular weight by gel permeation chromatography,the relationship of the polymer yield and copolymer composition with the polymerization reaction time,the influence of the catalyst composition and the amount of the catalyst on the copolymerization,as well as the catalyst recycling performance were studied.The results show that the polymer yield increases with time in an S-shape,while the composition of the copolymer almost remains constant with time,which is consistent with the law of the aluminum chloride catalyst system;the solvent(dichloromethane,ethanol or xylene)mainly affects the composition of the polymer,and has little effect on the relative number average molecular weight and distribution of the polymer;the increase of active components in the catalyst is beneficial to increase the 1-octene unit in the copolymer,but has little effect on the molecular weight and molecular weight distribution of the polymer;when the active component content in the catalyst is constant,the increase of the molar ratio of catalyst to monomer from 0.125 to 0.5 is beneficial for increasing the content of 1-octene units in the copolymer.After the catalyst is used for three times,it still has good catalytic activity,and the olefin unit can be introduced into the copolymer to obtain a poly(methyl acrylate-co-1-octene)copolymer with a 1-octene unit content of 30.1%.