Syndiotactic Polymer of Allylcyclopentane by A Metallocene Catalyst

Syndiospecific (co)polymerization of some higher α-olefins was performed by using a metallocene catalyst. Homopolymers of allylcyclopentane, 4-methyl-1-pentene, and allylcyclohexane are highly syndiotactic. The results of the copolymerization of allylcyclopentane with 1-hexene, 1-octene, or 1-decene showed that the incorporation of a linear higher α-olefin interfered with the syndiospecificity of the catalyst, and the melting point of the resulting copolymer decreased with the incorporation of the comonomer. In contrast, the copolymer of allylcyclopentane with 4-methyl-1-pentene or allylcyclohexane maintained the high syndiotacticity, and the melting point also remained almost unchanged no matter how much the comonomer was incorporated. It followed that the “shape” of the monomer had a significant influence on the structure of the copolymer. The monomers employed in copolymerization with a similar “shape” gave a copolymer with a similar microstructure.