Synthesis and crystalline structure of polyethylene containing 1,3-cylopentane units in the main chain by ring-opening metathesis copolymerization of cycloolefins following hydrogenation reaction

Polyethylene containing 1,3-cyclopentane units in the main chain was synthesized by ring-opening metathesis copolymerization of cyclopentene (CPE) or cyclooctene with norbornene (NB) following hydrogenation reaction. The copolymer with cis-1,3-cyclopentane units was obtained in good yield. The resulting copolymers showed multiple melting points. Temperature-rising elution fractionation of the copolymers elucidated a broad distribution of the copolymer composition. WAXD and FT-IR analyses of the copolymers showed existence of hexagonal crystal in hydrogenated poly(CPE-co-NB).