The effect of catalyst composition and structure upon the polymerization of butadiene and styrene by organosodium reagents

Abstract

AbstractThe polymerizations of butadiene and of styrene by various organosodium reagents combined with sodium isopropoxide (or methylphenyl carboxide) and sodium chloride have been compared. In general a reagent which is a good promoter of 1,4‐polymerization of butadiene is a poor agent for isotactic polymerization of styrene and vice versa. Also, rapid polymerization of styrene seems unrelated to stereospecific polymerization of styrene. m‐Xylylsodium, combined with sodium isopropoxide and sodium chloride, was a preferred agent for isotactic polymerization of styrene but did not induce enough 1,4‐polymerization of butadiene to qualify as an alfin catalyst. Catalysts of this type might be called “albyl” systems in order to differentiate them from alfin catalysts. A definite relationship exists between the structure of the reagent and the polymer it produces. Therefore, adsorption of the monomer on the surface of the catalyst is probably the controlling and most important factor in polymerization induced by these reagents.