摘要
采用傅立叶红外光谱和紫外光谱的技术,研究了在极性溶剂CH_2Cl_2中异丁烯阳离子聚合的引发体系乙酸叔丁酯/三氧化硼/二氧甲烷中,各组分间的作用及组分配比对活性中心结构的影响,发现Lewis酸与酯的比值不同,体系中存在络合竞争,以至存在一种或两种(或以上)活性中心;当Lewis酸与酯之比很小时,活性中心失活,并由此探讨其聚合机理。
The cationic polymerization of isobutylene initiated by tert-butylacetate/boron trichloride/methane dichloride was investigated by means of FTIR and UV techniques. Experimental results show that there is a competing complexation among two complexes of H_2O/BCl_3 and CH_3COO-t-Bu/BCl_3. When the ratio of Lewis acid to ester was varied, one or more initiating centers would exist alone or simultaneously in the polymerization system. If the ratio of BCl_3 to CH_3COO-t-Bu was beyond a certain minimum value, the initiating center would lose its activity and was unable to initiate the polymerization. According to above competition reaction the mechanism of isobutylene polymerization in this system is proposed.
基金
国家自然科学基金
关键词
聚异丁烯
阳离子聚合
活性
光谱
isobutylene, cationic polymerization, living, infrared spectros copy, ultraviolet spectroscopy.
