ISOPRENE OR BUTADIENE CIS 1,4-POLYMERIC BI-COMPONENT CATALYST SYSTEM AND POLYMERIZATION PROCESS

摘要

An isoprene or butadiene cis 1,4-selective polymerization catalyst system together with its polymerization method is provided. This catalyst system is composed of NCN-imine pincer type rare earth metal complex of formula [2,6-(CH=N-R 1 ) 2 -4-R 2 -1-C 6 H 2 ]LnX 2 (TBF) n and alkylating reagent. In an hydrocarbon solvent or under bulk conditions, at a polymerization temperature in a range of -20 - 120°C, the conjugated diene is polymerized by using the catalyst system, to produce polyisoprene and polybutadiene having controllable number-average molecular weight, molecular weight distribution of 3.0 or less than, and cis 1,4-content of 95% or more, even 99% or more. The crude rubber and vulcanized rubber of the polyisoprene have high strength, stretching crystallization capability and transparency.