9 - Synthesis of Polyolefins with a Terminal Functional Group

Abstract

This chapter summarizes three general methods used in the preparation of polyolefins with a terminal functional group. They are based on living transition metal coordination polymerization, in situ chain transfer reaction during transition metal coordination polymerization, and chemical modification of the polymer having an unsaturated chain end. The combination of metallocene catalysis and in situ chain transfer reaction is the most effective and convenient route. Chemistry can be easily extended to many polyolefin structures, including copolymers and terpolymers. This drop-in technology only needs minor modifications of current commercial polymerization processes. The chapter reveals that it would be convenient and beneficial to replace the current hydrogen chain transfer agent with borane or p-methylstyrene (p-MS)/H2 chain transfer agents. Such a process not only allows the control of polymer molecular weight and chain-end saturation, it also provides a reactive functional group at the polymer chain end for further reactions. The chapter further mentions that living polymerization is a very expensive process from the commercial viewpoint. One catalyst site can only produce one polymer chain.