异戊二烯-环己烷-乙醚体系负离子聚合产物的微观结构

Microstructure of product obtained from anionic polymerization of isoprene using Et2O as polar additive

研究了在１５ ～３０ ℃下，以正丁基锂为引发剂，环己烷为溶剂，乙醚为极性调节剂的异戊二烯负离子聚合产物的微观结构。结果表明：在同一乙醚／ 正丁基锂摩尔比值下， 随聚合温度升高，试样的３ ，４ － 结构摩尔分数降低；在同一温度下，随乙醚用量的增加，３ ，４ － 结构摩尔分数增加；以乙醚为极性添加剂时，聚合物分子链上含有３ ，４ － 和１ ，４ － 结构， 不含１ ，２ － 结构； 以乙醚为溶剂时， 聚合物分子链上含有３ ，４ － 、１ ，４ － 及１ ，２ － 结构。此外，还建立了２ 个微观结构摩尔分数与乙醚用量间的定量关系式，求得了综合平衡常数、络合指数和综合活化能。

Anionic polymerization of isoprene using cyclohexane as solvent, Et2O as polar additive and n-BuLi as initiator was carried out and the microstructures of its product are investigated. The results showed that the mole fraction of 3,4-structure in polyisoprene decreased with increasing temperature at a certain /;the mole fraction of 3,4-structure increased with increasing the quantity of Et2O at a certain temperature; 1,2-structure was not found when Et2O was used as additive . Two quantitative relationships between the mole fraction of 3,4-structure and the mole ratio of to were derived.The complex equilibrium constant ,coordination index and complex activation energy were also obtained.