High 1, 4-cis polybutadiene-polyurethane copolymer and preparation method thereof

Disclosed is a novel high 1, 4-cis polybutadiene-polyurethane copolymer and a preparation method thereof. The present invention provides a high 1, 4-cis polybutadiene-polyurethane copolymer represented by the following formula 1 and having an average molecular weight of at least 100, 000, and a method for preparing the high 1, 4-cis polybutadiene-polyurethane copolymer that includes polymerizing 1, 3-butadiene or butadiene derivatives with a catalyst comprising a rare earth compound, a halogen-containing compound and an organoaluminum compound in the presence of a non-polar solvent, to prepare a polybutadiene having a high 1, 4-cis content of at least 95%; and then introducing a polyurethane group to the polybutadiene. The high 1, 4-cis polybutadiene-polyurethane copolymer thus obtained exhibits low cold flow and high affinity to silica or carbon black in admixture as well as excellent in elasticity and abrasion resistance : where l, m, n and o represent the number of repeating unit, 1 is 94 to 99%, m is 0 to 5%, n is 0 to 5%, l+m+n=100%, l/(m+n) is 15 to 100, o is 1 to 100%; andA and Y are C1-C20 alkyl or aryl, respectively.