溶剂效应和链转移效应对乙烯-醋酸乙烯酯共聚行为及支化结构的影响  

Insight in Solvent and Chain Transfer Effects on Copolymerization Behavior and Branched Structure of Ethylene-Vinyl Acetate Copolymer

作　　者：肖长发 李永江 范金华 李宇虹 Changfa Xiao;Yongjiang Li;Jinhua Fan;Yuhong Li(R&D Center,Sinopec Chongqing SVWChemical Co.,LTD,Chongqing 401254,China)

机构地区：[1]中国石化集团重庆川维化工有限公司研发中心,重庆401254

出　　处：《高分子材料科学与工程》2022年第1期36-42,共7页Polymer Materials Science & Engineering

摘　　要：基于溶液共聚法,制备出高醋酸乙烯酯含量和高分子量的乙烯-醋酸乙烯酯共聚物(EVM),研究了溶剂效应对乙烯-醋酸乙烯酯共聚行为和支化结构演化的影响,建立了基于链转移效应调控共聚物支化结构和相对分子质量的方法。研究结果显示,在醋酸乙烯酯(VAc)高转化率条件下,以链转移常数最低的叔丁醇为溶剂有利于提高EVM相对分子质量。进一步研究了叔丁醇中EVM分子链支化结构随聚合时间的演化规律,揭示出醋酸乙烯酯单元所含乙酰氧酯基为主要支化位点。其研究可为调控EVM分子结构、实现高性能EVM的工业化生产提供理论基础和实践参考。Ethylene-vinyl acetate copolymers(EVM)with high content of vinyl acetate and high molecular weight were prepared by solution copolymerization.A method of regulating the branched structures and molecular weight of the copolymers based on chain transfer effects was established by the study of solvent effects on the copolymerization behavior and branching evolution.The results show that tert-butyl alcohol with the lowest chain transfer constant is beneficial to increase molecular weight of EVM,under the condition of high conversion of vinyl acetate(VAc).The branching evolution of EVM in tert-butanol with polymerization time is further studied,which reveals that the acetoxyl groups in the vinyl acetate unit are the main branching sites.This study can provide the theoretical basis and practical reference for regulating the molecular structure of EVM and realizing the industrial production of high-performance EVM.

关 键 词：乙烯-醋酸乙烯酯 支化 醇解 乙酰化 

分 类 号：TQ317[化学工程—高聚物工业]