method for homopolymerisation of butadiene - isoprene or pentadien (1.3) - (1.3) and the mischpolymerisation of butadiene - isoprene or pentadien (1.3) - (1.3). of butadiene or isoprene (1.3) with ethylene

摘要

1406461 Allyl uranium compounds in mono- and diolefin polymerization; polybutadiene SNAM PROGETTI SpA 21 Nov 1972 [26 Nov 1971 10 Oct 1972] 53815/72 Heading C3P Conjugated diolefins and monolefins are homo- and copolymerized in the presence of a catalyst comprising a compound of the formula wherein each of the Rs is a hydrogen atom or C 1-10 hydrocarbon radical, X is a halide and n is 1, 2 or 3. The process may be carried out in an inert solvent and under an inert atmosphere. A co-catalyst may be present, which is a Lewis acid. A preferred polymeric product is a polybutadiene which (a) is gel-free, (b) has an ultimate tensile strength of 220 to 250 kg/cmSP2/SP when vulcanized under certain specified conditions, (c) a cis-1,4 content above 98% and (d) a semi-crystallization time of less than 10 minutes determined at -20‹ C. In the examples, butadiene, isoprene, 1,3-pentadiene, butadieneisoprene, butadiene-1,3-pentadiene, ethylene, and ethylene-butadiene or -isoprene mixtures are polymerized in toluene or hexane using (C 3 H 5 ) 3 UCl, (C 3 H 5 ) 3 UI, (C 3 H 5 ) 2 UCl 2 or (C 3 H 5 ) 3 - UBr (formed in situ from (C 3 H 5 ) 4 U and Br 2 ) as catalyst and in some cases, as co-catalysts, AlI 3 , AlCl 3 , AlCl 3 .O(C 2 H 5 ) 2 , BCl 3 , Al(C 2 H 5 ) 3 , Al(C 2 H 5 )Cl 2 , or TiCl 4 .