侧烷基对聚有机硅氧烷膜透气性的影响

EFFECT OF ALKYL SIDE GROUPS ON GAS PERMEATION OF POLYORGANOSILOXANE MEMBRANES

合成了带有不同体积大小侧烷基的聚有机硅氧烷,并研究侧基结构对这些高分子膜透气性的影响。结果表明,支链烷基比正构烷基在改善氧氮间的选择性同时,一般要相应对透气性的损失要小得多。对于侧基的异常透气性影响,提出了气体分子透过高分子链节新的机理假设。

Polyorganosiloxanes with alkyl side groups of varying sizes were synthesized,and the gas permeation through membranes based on these polymers was atudied as the function of the structure of side groups.As a consequence the presence of branched alkyl groups im- proves the selectivity between oxygen and nitrogen,while the corresponding sacrifice in gas permeability,which usually accompanies the improvement of selectivity,is much smaller than the cases in which normal alkyl groups are used. Considering this discrepancy in the effects of side groups on gas permeation,a hypothe- sis is proposed for the mechanism of gas molecule's transport in polymer linkage.