LIVING FREE-RADICAL GRAFT-COPOLYMERS .1. PREPARATION AND PROPERTIES

Polymers substituted with thio groups are useful for the photochemical synthesis of graft copolymers. Such copolymers have been prepared by the initial conversion of backbone polymers containing chlorinated sub stituents into polymers containing diethyldithiocarbamate (TC), isopro pyl xanthate (IX) or mercaptobenzothiazole (BT) functionality. The pho tochemical reaction of monomers with these products produced graft cop olymers. A variety of halogenated polymers were investigated as starti ng materials for these syntheses, including poly(vinyl chloride), chlo rinated poly(vinyl chloride), chlorinated polyethylene, chlorobutyl ru bber and neoprene. Characteristics of the grafting reactions, includin g ''pseudo-living'' behavior and tandem grafting aspects, were investi gated. Glass transitions of the grafted polymers were found to vary un iformly with composition for most of the grafted products.