| 摘要 |
Block copolymers are made by the sequential polymerization of different olefins, or mixtures of olefins in the gas phase in the presence of a stereospecific catalyst, e.g. the reaction product of delta-titanium chloride and diethyl aluminium chloride. The catalyst may be used on a fixed, mobile or fluidized bed, and may be supported by a performed polymer. The examples describe the preparation of ethylenepropylene, ethylene-butene-1 and propylenebutene -1 block copolymers. |
