| 摘要 |
Block copolymers are made by first polymerizing a C5-C9 branched chain olefin to form a crystalline homopolymer segment, which is then contacted with ethylene in the presence of a catalyst system made by adding a titanate ester to a mixture of a compound of a Group IVA-VIA transition metal and an organic compound of a Group I-III metal, thereby forming a block of ethylene-butene-1-branched chain olefin non-crystalline polymer, the catalyst system having converted part of the ethylene to butene-1 during the course of the reaction. The reaction sequence may be repeated several times, and the order in which the homopolymer and terpolymer blocks are made may be reversed. The Examples describe the use of catalyst mixtures of titanium tetrapropionate, titanium trichloride and triethylaluminium to prepare block copolymers containing units of ethylene, butene-1, and 4-methylpentene-1 or 3-methylbutene-1. |
