| 摘要 |
PURPOSE: Provided are halogenated, low-gel, high molecular weight butyl rubbers, and halogenated, low-gel, high molecular weight isoolefin multiolefin copolymers. CONSTITUTION: The halogenated, low-gel, high molecular weight isoolefin multiolefin copolymers comprise a multiolefin content of greater than 2.5 mol %, a molecular weight Mw of greater than 240 kg/mol and a gel content of less than 1.2 wt.%, wherein the copolymer is an isoolefin diene copolymer with optionally, further monomers copolymerized or an isobutene isoprene copolymer with optionally, further monomers copolymerized. Its preparation process comprises the following steps: (a) polymerizing at least one isoolefin, at least one multiolefin, and optionally, further monomers in presence of a catalyst and an organic nitro compound; and (b) contacting the resulting copolymer under halogenation conditions with at least one halogenating agent.
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