SYNTHESIS AND USE OF POLYSILOXANEIMIDES IN GAS-SEPARATION MEMBRANES

Polysiloxaneimides are synthesized by a two-stage scheme via polyconde nsation of aromatic dianhydrides and siloxane-containing diamines in t he presence or in the absence of an aromatic diamine as comonomer, fol lowed by cyclization of intermediate polyamido acids. The influence of the structural features of polymers (the length of the oligosiloxane unit and the nature of the arylene units in the main chain of the poly mer, as well as replacement of methyl groups in siloxane units by trif luoropropyl groups) on gas-separation properties of membranes prepared from them is studied.