MACROMONOMERS BY ACTIVATED POLYMERIZATION OF OXIRANES - SYNTHESIS AND POLYMERIZATION

Macromonomers were obtained by cationic polymerization of propylene oxide and epichlorohydrin proceeding by the activated monomer mechanism with hydroxyethyl acrylate as initiator. Up to DPn similar to 15 for propylene oxide and DPn similar to 20 for epichlorohydrin, polymerization proceeds as a living process, giving with quantitative yields macromonomers with functionality equal to one, controlled molecular weight and narrow molecular weight distribution ((M) over bar(w)/(M) over bar(n) < 1.2) free of side products. In the higher molecular weight region, side reactions become increasingly noticeable. Propylene oxide macromonomers undergo radical homopolymerization. Homopolymerization of macromonomer with (M) over bar(n) = 8 x 10(2) gives graft copolymers with (M) over bar(n) up to 7.2 x 10(3). In copolymerization with styrene, completely soluble graft copolymers with (M) over bar(n) similar to 2 x 10(4) were obtained. Radical copolymerization of epichlorohydrin macromonomers with styrene gives initially soluble products with (M) over bar(n) similar to 6 x 10(4) which are converted in the later stages into insoluble gels, apparently due to the chain transfer to chloromethyl groups of the polyepichlorohydrin chains.