Process for the production of liquid low molecular weight polymers of butadiene and styrene with preponderant 1,4-cis-structure

摘要

Liquid copolymers of M.Wt. from 500 to 50,000, and viscosities of from 50 to 15,000 centipoises measured at 50 DEG C., are made by copolymerizing a mixture of butadiene and styrene, butadiene and substituted styrenes, or butadiene and alkylbenzenes in the presence of a diluent and a catalyst comprising a compound of nickel and an alkyl aluminium halide of the general formula, RnAlX(3- n in which R is a C1- 12 alkyl or alkylaryl group, X is a halogen atom, and n is 1 or 2. The molar ratio of the organoaluminium compound to the nickel compound is from 1:0.005 to 1:1. The alkyl aluminium halide may be mixed with hydrides such as lithium or sodium aluminium hydrides. Exemplified catalysts are mixtures of nickelous diacetylacetonate and ethyl aluminium sesquichloride in various proportions. The copolymers are worked up by conventional methods. The copolymers have a high 1,4-cis-structure.