Studies on the Cationic Copolymerization of α-Pinene and Styrene with Complex SbCl3/AlCl3Catalyst Systems. I. Effects of the Polymerization Conditions on the Copolymerization Products

The copolymerization products of α-pinene and styrene were prepared with the compound catalyst system SbCl3/AlCl3 by changing the Sb/Al ratio, feeding monomer ratio, solvent, and polymerization temperature. The compositions of the copolymerization products were quantitatively characterized by the method of the combination of micro-ozonization and thin-layer chromatography in terms of the contents of the homopolymers and the copolymers containing high or low mole fractions of α-pinene, the yields of pure copolymer, and the monomer unit ratios (F 1) of copolymers. The results show that it was easier to obtain the higher yield (up to 80%) of the pure copolymer with the complex catalyst system than with AlCl3 alone. The F 1 values could be controlled between 30 and 56% under the following polymerization conditions: Sb/Al  1/2, α-pinene/styrene  70%, and the conversion of styrene  90%.