SYNTHESIS AND GAS PERMEATION BEHAVIOR OF ORGANOSILICON-CONTAINING POLY(P-ALLYLSTYRENE)S

New synthetic routes for silicon-containing styrene derivatives were i nvestigated using p-allylstyrene (AST) as starting material. Lithium d iisopropylamide induced a lithiation reaction of AST to form p-(1-lith ioallyl)styrene (LiAST) without any side reaction such as polymerizati on under appropriate reaction conditions. Utilizing this carbanion as intermediate, synthesis of organosilicon-containing AST monomers was c arried out. By adding trimethylsilyl chloride to the reaction system, mono-trimethylsilylated AST, [p-(3-trimethylsilyl-1-propenyl)styrene; SAS] and bis(trimethylsilylated) AST, [p-[1,3-bis(trimethylsilyl)-2-pr openyl]styrene; BSAS] were obtained by one pot. The yields of SAS and BSAS attained up to 91.7% and 88.5%, respectively under the appropriat e reaction conditions. Radical polymerization of these monomers procee ded smoothly to form high molecular weight polymers without any gel fo rmation even in bulk polymerization. The resulting polymers showed goo d membrane formabilities. Permeabilities of oxygen were in the range o f 17-26 Barrers, keeping their selectivities against nitrogen through these membranes to be 3.3-3.5.