STEREOSPECIFIC SYNTHETIC RUBBER BASED ON 1,3-BUTADIENE AND METHOD OF PRODUCING SAME

1294167 Stereospecific butadiene copolymers INSTITUT NEFTEKHIMICHESKOGO SINTEZA IMENI A V TOPCHIEVA AKADEMII NAUK USSR 7 Aug 1970 38107/70 Heading C3P Synthetic rubbery copolymers comprise units derived from butadiene and one or more conjugated cyclic dienes having 5 or 6 carbon atoms in the ring, the butadiene units being at least 90% cis and the content of cyclic units being 3-20 mol. per cent. They are prepared by polymerizing a mixture of butadiene and the cyclic diene in a molar ratio of 95 : 5 to 75 : 25 by means of a catalyst comprising a #-allyl complex of nickel and an electron acceptor selected from halogenoquinones, salts of halogenoacetic acids, chloral, transition metal halides and other Lewis acids. Examples describe the copolymerization of butadiene with 1,3 - cyclohexadiene, 1,3 - cyclopentadiene, 2- methyl - 1,3 - cyclohexadiene and 1 - methyl- 2,4-cyclopentadiene in the presence of bis-(#- crotylnickel halides), #-pentenylnickel chloride or bis-(#-allylnickel bromide), and nickel trichloroacetate, chloral, chloranil, nickel chloride or an acid aluminosilicate.