Copolymerization of Vinyl Chloride by Organometallic Compounds

ABSTRACT The copolymerizations of vinyl chloride with o-olefin or acrylic compounds were investigated with organometallic compounds as catalysts. In general, organoaluminium compounds need to be treated with a complexing agent such as tetrahydrofuran prior to use. Otherwise the former reacts with polyvinyl chloride and loses its activity. The copolymer of vinyl chloride and propylene was thus obtained. The properties of the copolymer produced are almost the same as of that produced by conventional radical polymerization. Vinyl chloride is capable of .copolymerizing with acrylonitrile without any complexing agent, since the latter monomer acts as a complexing agent. Transtion metal compounds are useful cocatalysts for enhancing catalytic activity. It was found that the use of equimolar or greater amounts of organoaluminium compounds yields. a 1: 1 -copolymer regardless of monomer composition, whereas a smaller amount of the catalyst produces random copolymers. This fact is interpreted by an assumption that the copolymerization takes place between free acrylonitrile and a ternary complex of vinyl chloride, acrylonitrue and aluminium compound.