PREPARATION OF SOLUTION POLYMERS USING A COMPLEX OF A BARIUM DI-TERT-ALKOXIDE-HYDROXIDE SALT AND AN ORGANIC LITHIUM COMPOUND AS A CATALYST

摘要

ABSTRACT OF THE DISCLOSUREThis invention relates to the preparation of solutionpolymers and rubbers from vinyl monomers using a new catalystcomplex of a barium di-tert-alkoxide-hydroxide salt and anorganic lithium compound. In particular, homopolymers andcopolymers of butadiene with styrene and/or isoprene, pre-pared with this catalyst, are uniquely characterized by thebutadiene units having a low vinyl content (not over about12%) and a trans-1,4 structure of from about 70 to 81%. Also,the copolymer has a random comonomer sequence distribution.This molecular structure permits elastomers containing littleor no styrene to have sufficient stereoregularity to crystal-lize. Furthermore, the butadiene homopolymer and copolymerwith styrene and/or isoprene exhibit a broad molecular weightdistribution as well as tack and green-strength which arevaluable properties for a rubber to possess when buildingtires.