CONTROLLING RESIN PROPERTIES IN A GAS PHASE POLYMERIZATION PROCESS.

摘要

Methods for dramatically altering the processability of ethylene copolymers made with a supported phosphinimine polymerization catalyst. The method involves changing the polymerization reactor temperature during the polymerization of ethylene and at least one alpha-olefin when a titanium-based phosphinimine catalyst which comprises a substituted or unsubstituted indenyl ligand and a phosphinimine type ligand is used. An increase in the polymerization temperature leads to a decrease in the copolymer stress exponent, and vice versa.