| 摘要 |
Crystalline polymers of 1,3-butadiene having substantially syndiotactic -1,2 structure are prepared by processes which comprise polymerising butadiene in the presence of a freshly prepared catalyst formed by contacting a halide of a metal of Group VIII of the Mendeleef Periodic Table with an aluminium trialkyl or a mixture thereof with an aluminium dialkyl halide in which the molar ratio of trialkyl to dialkylhalide is 0.8:1 to 9:1. The metal halides may be chlorides, bromides or iodides, which may be used in the form of complexes with pyridine, pyrrole, morpholine, aliphatic amines, nitriles, amides, alkyl phosphines, phosphates and phosphites. Specified trialkyls are trimethyl, triethyl, tripropyl and triisobutyl aluminium. Specified dialkyl halides are diethyl and diisobutyl aluminium chloride. Polymerisation may be effected in the presence of benzene, toluene, xylene or excess butadiene. Examples describe the polymerisation of butadiene in benzene in the presence of catalysts formed from (1,2,3 and 4) cobalt chloride/pyridine complex and triethyl aluminium; (5) cobalt chloride/pyridine complex and triisobutyl aluminium; (6) cobalt iodide/pyridine complex and triethyl aluminium; (7) cobalt chloride/triethyl phosphine complex and triethyl aluminium; (8, 9 and 10) cobalt chloride and triethyl aluminium; (11) nickel chloride, (12) palladium chloride and (13) platinum chloride and triethyl aluminium; and cobalt chloride/pyridine complex with (14, 17, 18 and 19) triethyl aluminium and diethyl aluminium chloride, (15) triisobutyl aluminium and diethyl aluminium chloride, and (16) triisobutyl aluminium and diisobutyl aluminium chloride. The catalysts may be aged before use. The polymers may be made into shaped articles such as films and fibres.
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