SOLUTION POLYMERIZATION PROCESS FOR MAKING HIGH-DENSITY POLYETHYLENE LONG-CHAIN BRANCHING

摘要

A polymerization process includes contacting an ethylene feed containing ethylene monomers with a catalyst feed containing a hafnium-based or zirconium-based single-site catalyst in a solution so as to polymerize the ethylene monomers into long-chain branched high density polyethylene having on average a long-chain branch/polymer chain less than 10 and greater than 0.25. A polymerization composition includes ethylene; a hafnium-based or zirconium-based single-site catalyst; and a long-chain branched high density polyethylene polymerization product, where the long-chain branched high density polyethylene has on average a long-chain branch/polymer chain less than 10 and greater than 0.25; and where at least one of the ethylene, the catalyst, and the product is in solution.