CATIONIC POLYMERIZATION OF BETA-PINENE

In the reproted experiments, beta -pinene was polymerized with cationic initiators in reactions that were carried out to study the solvent, temperature, initiator, and monomer-to-solvent ratio. Polymers obtained under different conditions were characterized by intrinsic viscosity, softening point, and gel permeation chromatography. Among the catalysts studied TiCl//4 and Et//2AlCl were made the more active by using dichloromethane as the solvent. Initiator concentrations of 2 mmol% produced the highest yield in polymer and a monomer-to-solvent ratio of less than 20% also gave the maximum conversion. Temperatures ranging from minus 80 to 0 degree C had almost no effect on the yield; however, polymerization proceeded readily at low temperatures.