Copolymers of dicyclopentadiene and tricyclopentadiene

Series of copolymers of dicyclopentadiene and tricyclopentadiene have been prepared by ringopening metathesis polymerization (ROMP) using a catalytic system of [W(=N-phenyl) (2,6-dimethyl phenolate)(4)]/n-BuLi. Due to the presence of double bonds, the polymers obtained from ROMP are unstable. Thus the hydrogenation reaction is carried out after ROMP using a catalyst of bis(2,4-pentanediono)nickel/triisobutylaluminium. The polymers obtained were characterized by means of H-1 NMR; the results show an agreement with the proposed structure. Glass transition temperature T (g) of the polymers are modulated by the feed mole ratio of dicyclopentadiene and tricyclopentadiene. With the increasing of tricyclopentadiene content, the T (g) of the polymers before hydrogenation increases from 153 to 256A degrees C, and the T (g) of the polymers after hydrogenation increases from 106 to 188A degrees C. In addition, the different ratio of dicyclopentadiene and tricyclopentadiene in polymer main chains offers different packing patterns to the structure of the copolymers, and leads to their different free volumes and occupied volumes.