摘要 |
Isoprene polymers and copolymers are prepared by a polymerization process carried out in the absence of solvents and in the presence of a catalytic system comprising (a) at least one element or compound of an element pertaining to Group IIIB of the Periodic Table, (b) at least one aluminium alkyl derivative, (c) at least one organic halogen derivative or at least one halide of an element able to exist in at least two valency states with the halide corresponding to a higher state than the minimum, or at least one halogen or at least one hydrogen halide acid, (d) at least one compound containing one or more hydroxyl groups of which the hydrogen can be substituted, the ratio of component (b) to component (a) being equal to or less than 20. |