| abstract |
Provided is a ring-opening polymer of cyclopentene which is characterized by having a cis ratio of the cyclopentene-origin structural units of 30% or greater and a weight-average molecular weight (Mw) of 100,000-1,000,000 and carrying an oxysilyl group at an end of the polymer chain. The ring-opening polymer of cyclopentene can be produced by ring-opening polymerizing cyclopentene in the presence of, for example, a compound of a transition metal belonging to group 6 in the periodic table, an organoaluminum compound represented by general formula (1) and an oxysilyl group-containing olefinic unsaturated hydrocarbon. (R 1 ) 3-x Al(OR 2 ) x (1) In general formula (1), R 1 and R 2 represent a C 1-20 hydrocarbon group; and x satisfies the requirement 0<x<3. |