三甲基硅取代PPO和三苯基硅取代PPO及其气体选择透过性能

讨论了聚２，６－二甲基－１，４－苯撑氧（ＰＰＯ）与三甲基氯硅烷和三苯基氯硅烷的反应，合成了一系列取代含量不同的三甲基硅取代ＰＰＯ（ＴＭＳ－ＰＰＯ）和三苯基硅取代ＰＰＯ（ＴＰＳ－ＰＰＯ）．研究了取代基团不同和取代含量变化对聚合物的气体选择透过性能的影响，发现ＴＭＳ－ＰＰＯ的气体透过系数随三甲基硅取代量加大而增高，分离系数下降；ＴＰＳ－ＰＰＯ的气体透过系数和分离系数都随三苯基硅取代量的增加而下降，ＴＰＳ－ＰＰＯ与ＴＭＳ－ＰＰＯ的气体溶解系数相近，扩散系数差别较大．故二者气体透过系数的不同主要是由于扩散系数的差异．从化学结构与气体透过性能关系的角度来看，若在聚合物分子中引入有较小转动自由能的大基团，则有利于气体分子的扩散透过．

THE GAS PERMSELECTIVITY OF TRIMETHYL SILYLSUBSTITUTED PPO AND TRIPHENYL SILYLSUBSTITUTED PPO

In this paper, 2,6-dimethyl-1,4-phenylene oxidel was modified by trimethyl chlorosilane and triphenyl chlorosilane, and a serfes of silyl-substituted PPO were synthesized. The gas transport behavior in polymeric membrane were studied with changes of group and ratio of substitution. It is found that gas permeability in trimethyl silyl-substituted PPO rises and selectivity decreases, but both decrease in triphenyl silyl-substituted PPO with increasing the ratio of substitutions.Because trimethyl silyl-substituted PPO and triphenyl silyl-substituted PPO have similar gas solubility but various diffusivity, difference between gas permeability is mainly caused by gas diffusion coefficient. From relationship between gas permeability and polymeric chemical structure, gas diffusion process may be increased in polymer if bulky free groups are introduced into polymeric side chain.