Synthesis of Polypropylene-graft-poly(methyl methacrylate) Copolymers by the Borane Approach

This paper describes new PP-g-PMMA copolymers which have an isotactic polypropylene (PP) backbone and several poly(methyl methacrylate) (PMMA) side chains. The chemistry involves a graft-from reaction using borane-containing polypropylene and oxygen. The oxidation reaction of the borane groups, such as alkyl-9-BBN, is selective and produces free radicals located at the ends of the side chains on polypropylene. These free radicals are effective initiators for the polymerization of methyl methacrylate. A broad range of PP-g-PMMA copolymers have been prepared without significant homopolymerization. The graft copolymers are useful compatibilizers in i-PP/PMMA polymer blends.