Carbocationic polymerization of isobutylene by using supported Lewis acid catalyst on polypropylene

Summary This paper describes a new class of supported Lewis acid catalysts which are based on partially crystalline polypropylene. The Lewis acid, such as EtAlCl₂, is chemically bonded to the side chain of polypropylene and serves as catalyst for the cationic polymerization of isobutylene. This type supported catalyst can be easily recovered and reused for many reaction cycles without significant loss of its reactivity. The unique features of the structure of polypropylene offers the catalyst with high surface area and good mobility which account for the high catalytic activity. In addition, polypropylene is chemically and physically stable during the processes.