首页 | 本学科首页   官方微博 | 高级检索  
     检索      

烯烃可控/活性正离子聚合新方法与新工艺及其应用
引用本文:吴一弦,周琦,杜杰,王楠.烯烃可控/活性正离子聚合新方法与新工艺及其应用[J].高分子学报,2017(7).
作者姓名:吴一弦  周琦  杜杰  王楠
作者单位:北京化工大学化工资源有效利用国家重点实验室 北京100029
基金项目:国家自然科学基金,中国石油化工股份公司资助项目
摘    要:<正>离子聚合是高分子科学中重要的聚合方法之一,也是制备聚异丁烯或丁基橡胶等关键材料不可或缺的聚合方法.本文总结了异丁烯、苯乙烯及其衍生物等单体可控/活性正离子聚合的新引发体系、聚合反应特征的调节与转化、水相介质中正离子聚合新方法与新工艺、微观分子混合与正离子聚合新工艺及其用于设计合成异丁烯基聚合物.这些方法与技术是发展高效节能与绿色减排先进聚合物生产技术的重要途径,部分研究成果已在产业化中得到应用与验证.发展可控/活性正离子聚合新体系、新方法与新工艺,为实现绿色低碳高分子化工过程及相关产品工程(新结构、新功能、高性能与高品质)提供了新思路与新技术.

关 键 词:正离子聚合  可控/活性聚合  聚异丁烯  丁基橡胶

Controlled/Living Cationic Polymerization of Olefins:System,Process and Application
Yi-xian Wu,Qi Zhou,Jie Du,Nan Wang.Controlled/Living Cationic Polymerization of Olefins:System,Process and Application[J].Acta Polymerica Sinica,2017(7).
Authors:Yi-xian Wu  Qi Zhou  Jie Du  Nan Wang
Abstract:Cationic polymerization is one of the most important polymerization methods in polymer science.Polyisobutylene (PIB) and butyl rubber (IIR) with excellent properties in gas barrier,chemical and thermal stability,and resistance to oxidation are useful materials for automotive manufacture and medical equipment.These polymers can be merely produced by cationic polymerization of isobutylene or its copolymerization with a small amount of isoprene under strictly anhydrous conditions.The living cationic polymerizations of olefins,such as isobutylene,styrene and its derivatives,have been achieved to synthesize the corresponding polymes with theoretical molecular weight and chlorine terminal groups by using BCl3 or TiCl4 as coinitiator since 1980's.This feature article is aimed to summarize the novel initiating systems for the controlled/living cationic polymerizations,transformation of polymerization character,cationic polymerization in aqueous medium with high efficiency,cationic polymerization in rotating packed bed reactor and their applications.A simple but effective FeCl3-based initiating system with low toxicity has been developed to achieve living cationic polymerization of isobutylene in the presence of isopropanol at-80 ℃ at much lower coinitiator concentration.It has been recognized that the living cationic polymerization could be converted to the chain-transfer dominated process,in which the rate of β-proton elimination from-CH3 groups in the growing chain ends and the chain transfer reaction to monomer were dependent on the concentrations of the complex of Lewis acid with nucleophiles or free nucleophile molecules and polymerization temperature.Based on this observation,a series of initiating systems have been developed for direct synthesis of highly reactive polyisobutylenes with more than 90 mol% of exo-olefin terminal groups.On the other hand,the cationic stereospecific polymerization of styrene and p-methylstyrene has been achieved by mediating the tightness of the growing ion pair,conformation of the last two units of the propagating polymer segment and the approaching direction of the incoming monomer,leading to formation of high molecular weight polymers with predominant isotacticity of more than 80% for meso dyad (m).The long-chain branched isotactic-rich polystyrene was in situ synthesized via cationic stereospecific polymerization of styrene by introducing a small amount of isoprene as a comonomer and branching sites as well.The environmental problems demand clean reaction processes and do use environmental friendly reaction media,in which water is no doubt the most valuable green medium.We presented the first example of highly effective cationic polymerization of IB using classic Lewis acid-based initiating systems in aqueous medium.The new continuous process of cationic polymerization in aqueous medium has been further scaled up for preparing high molecular weight PIB or butyl rubber.The cationic polymerization in the high-gravity environment generated by a rotating packed bed reactor has been successfully conducted for the first time to produce high molecular weight butyl rubber.The controlled/living cationic polymerization provides a cost-effective method to synthesize polymers with designed architecture and will be beneficial for the resulting polymer product engineering,including new chemical structure and topology,new functionality,high performance and high quality.
Keywords:Cationic polymerization  Controlled/Living polymerization  Polyisobutylene  Butyl rubber
本文献已被 CNKI 万方数据 等数据库收录!
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号