СПОСОБ КОНТРОЛИРУЕМОЙ ПОЛИМЕРИЗАЦИИ ОЛЕФИНОВ

摘要

A method of making polyolefin with a target melt flow index and melt flow rate is disclosed. The method polymerizes one or more olefinic monomers in a single reactor containing a bicomponent catalyst system. The catalyst system includes a first catalyst component and a second catalyst component each characterized by a catalyst productivity and a chain-transfer-agent response. The single reactor has a chain-transfer-agent concentration and a temperature. The productivity of the second catalyst component is substantially different temperature dependent than that of the first catalyst component. The chain-transfer-agent response of the second catalyst component is substantially different sensitive than that of the first catalyst component. The temperature of the reactor is adjusted so that the melt flow ratio approaches the target value. The chain transfer agent concentration in the reactor is adjusted so that the melt index approaches the target value.