水相活性/可控正离子聚合机理及其共聚合制备聚异丁烯基弹性体的研究

The traditional cationic polymerizations usually proceed in an organic solvent under strictly anhydrous and low temperature circumstance with high energy consumption. Due to the merits of low energy consumption and environment friendly, cationic polymerization in aqueous phase has been recognized as the important direction of development for the present polyisobutylene industry. However, the living/controlled cationic polymerization of isobutylene has not yet achieved in aqueous phase, the polyisobutylene with special structure and property cannot be synthesized in aqueous phase by molecular design. This project will adjust the Lewis acidity of co-initiator in monomer droplet by addition of electron donor on the basis of the choice of efficient initiator system, to realize regulation of “loose and tight ion pair” between active centers and counter ions. Combined with ability of continuous polymerization for active center, the basic method of living/controlled cationic polymerization will be established. Subsequently, the cationic polymerization in aqueous phase will also be extended to the copolymerization system. The copolymerization of isobutylene/p-methylstyrene and isobutylene/isoprene will be thoroughly studied. The corresponding copolymerization reaction mechanisms, reaction rate model and the copolymer composition equation will be established on the basis of equal active and stable state assumptions, which provide the important theory basis for the effective regulative copolymer structure. It may lay the important theoretical foundation for high performance new generation of polyisobutylene-based elastomer.

传统的正离子聚合必须在无水无氧和超低温的有机溶剂中进行，聚合条件苛刻、能耗大。以水为反应介质的正离子聚合具有绿色环保和节能降耗等优点，也是目前聚异丁烯产业发展的重要方向。然而目前异丁烯在水相体系还未实现活性/可控聚合，还不能通过分子设计合成具有特定结构和性能的聚合物。本项目在选择高效引发体系的基础上，通过添加给电子体在单体液滴内部实现共引发剂的Lewis酸性调节，实现活性中心与反离子之间“松紧离子对”的调控，并结合活性中心持续聚合的能力提出活性/可控聚合机理。将水相正离子聚合方法拓展到共聚体系，系统研究异丁烯/异戊二烯和异丁烯/p-甲基苯乙烯共聚规律。在活性理论、稳态等假设基础上建立水相悬浮共聚反应速率模型和共聚组成方程，提出共聚反应机理，为实现高性能化聚异丁烯基共聚物的微观序列结构的调控提供指导原则，为高性能新一代聚异丁烯弹性体的开发奠定重要的理论基础。

传统的正离子聚合必须在无水无氧和超低温的有机溶剂中进行，聚合条件苛刻、能耗大。以水为反应介质的正离子聚合具有绿色环保和节能降耗等特点, 是最有可能实现工业化的正离子聚合方法之一，也是目前聚异丁烯产业发展的重要方向。本项目通过实验合成和设计高效耐水性引发剂，研究多种正离子聚合单体（苯乙烯及其衍生物、异丁烯、乙烯基醚类、功能化乙烯基醚类）水相悬浮、乳液和溶液聚合，并提出相应聚合机理，扩展水相正离子聚合新技术。创新点与主要贡献如下：1）通过分子模拟与实验证明，发现醇类引发剂与水一起作用于耐水性共引发剂，形成活性中心的过程存在络合竞争，结合聚合动力学和末端结构分析提出了异丁烯、苯乙烯均聚与共聚等聚合机理；2）通过简单高效的聚合工艺使单体2-羟乙基乙烯基醚达到真正意义上水相可控正离子聚合，并提出2-羟乙基乙烯基醚水相正离子可控溶液聚合机理；3）完成了聚（异丁烯-co-对甲基苯乙烯）无规共聚物基本性能评价与应用性能评价。本项目开发的具有自主知识产权的绿色节能正离子聚合新技术，克服传统正离子聚合需要无水无氧环境和使用有机溶剂等缺点，丰富了阳离子聚合机理，为我国正离子聚合的开发与工业化应用提供新技术。培养博士生2名，硕士生2名。发表SCI论文7篇，授权专利2件，出版译著一部。