摘要 |
<p>Polyalkenamers having a high content of cis double bonds useful e.g. for shoe soles, tyres and belts are prepd. by polymerising cyclooctene or 1,5-cyclooctadiene in the presence of a catalyst system consisting of (A) an organosilicon cpd. of formula R4-nSi(Y)n (where R is alkyl, alkenyl or aryl; Y is alkylidenyl, alkoxy, aryloxy, or aralkoxy; and n is at least 2), (B) a tungsten halide of formula Rm-n WXn (where X is chlorine or bromine; R is alkoxy, aryloxy, haloalkoxy, alkaryloxy or acetylacetonyl; m is 6 when X is chlorine, and is 5 when X is bromine; and n is 3-6), and (C) an organoaluminium cpd. of formula AlR1R2R3 (where R1-3 are each alkyl, aralkyl or halogen). Polymers contg. ca. 90% cis double bonds are obtd. and the catalyst has a high activity.</p> |