二氧六环调节聚异戊二烯微观结构的研究

A Study on Regulating the Microstructure of Polyisoprene in the Presence of Dioxane

研究了在 2 0～ 50℃下 ,以环己烷为溶剂、n -BuLi为引发剂、二氧六环 (DOX)为极性添加剂的异戊二烯阴离子聚合产物的微观结构。试验表明 :聚异戊二烯的 3,4 -结构含量随温度升高而减小 ,在同一温度下 ,随二氧六环用量增加而增大 ;当R =[DOX]/[n -BuLi]=50时 ,出现 1 ,2 -结构 ,温度越高 ,出现 1 ,2 -结构时的R值越大 ,且1 ,2 -结构含量随R增大而增加。另外 ,还求出了该聚合体系的综合活化能、综合平衡常数K′、络合指数n′及 1 ,2 -结构、3,4 -结构含量与温度的关系式。

The anionic polymerization of isoprene at 20～50 ℃ using cyclohexane as solvent,dioxane(DOX) as polar additive and n-BuLi as initiator was carried out and the microstructure of its product was investigated.The results show that the 3,4-structure contents in polyisoprene decrease with increase in temperature,and increase with increase in DOX amount at the same temperature.The 1,2-structure will appear when R equals 50,and the 1,2-structure contents increase with increase in DOX amount.The relationships of comprehensive equilibrium constant K′ and the coordination solvated index n′ vs temperature,the amount of complex activation energy are obtained.