摘要 |
<p>Polymers of conjugated dienes are made by polymerizing a diene alone, or in admixture with another hydrocarbon monomer, in the presence of a liquid organic diluent, and a catalyst comprising a cobalt and/or nickel compound, and at least one cyclic organic compound which is soluble in the diluent and contains non-conjugated double bonds in the ring structure, and is present in an amount not exceeding 500X10-4% by weight calculated on the diluent. During the polymerization a small amount of water, or a compound of the type M(halogen)x where M=H, or a metal, and X = a whole number equal to the valency of M, may also be present. Dienes mentioned are butadiene and isoprene. The butadiene may be employed as a stream mixed with butene-1, or butene-2. The cobalt and/or nickel compound is preferably used as a catalyst in admixture with an organometallic compound such as an aluminium alkyl halide. The cyclic compound may be bicyclo (2,2,1)-hepta-2, 5-diene. Compounds of the above type may be hydrochloric acid, tin chloride, or aluminium chloride. Exemplified catalyst are aluminium ethyl sesquichloride and the cobalt salt of 2-ethylhexane carboxylic acid, and aluminium diethyl chloride and CoCl2.AlCl3. The polymerization may be terminated by the addition of ethanol in which the antioxidant 2, 21-methylene-bis-(4-methyl-6-tert.-butylphenol) is dissolved. The polymers have almost exclusively a cis-1,4-configuration.</p> |