12 - New Maleic-anhydride-modified and Long-chain-branched Polyolefins

Abstract

This chapter discusses a facile and clean method to prepare maleic-anhydride (MA)-modified polyolefins with well-defined molecular structure offered by the reactive copolymer approach. The chemistry is benefited by metallocene technology that results in reactive copolymers with narrow molecular weight and composition distributions, as well as controlling the concentration and location of reactive co-monomer incorporation. The reactive groups in the copolymer provide the selective sites for MA modification reaction. Such a reaction minimizes the undesirable side reaction in the polyolefin backbone and preserves its important properties. The chapter discusses the well-defined MA-terminated polyolefins, especially polypropylene (PP) with controllable PP molecular weight and MA units at the polymer chain end. The new PP-MA block copolymers provide detailed information about the effects of PP-MA structure to the compatibility of the reactive PP/nylon blends. The new MA-modified polymers with various molecular structures also offer an excellent opportunity to prepare other segmental polymers. An example presented is the new long-chain branched polypropylene (LCBPP), which has a relatively well-defined molecular structure.