Analysis of branching structure in polyethylene resins synthesized with constrained-geometry catalyst systems, using Monte Carlo simulation

With the development of homogeneous constrained geometry catalyst (CGC) sys tems, production of ethylene polymers having long-chain branches has become possible. The unique molecular structure of these polymers delivers increa sed physical properties (narrow molecular weight and comonomer composition distribution) without sacrificing processability (long-chain branching). Th e true branching structure in these resins has not been clearly understood yet. Monte Carlo simulation can be used to study the branching structure of these polymers. From our simulation results, it appears that branching dis torts the molecular weight distribution and forms a high molecular weight t ail. More importantly, Monte Carlo techniques permit one to analyze the bra nching structure of these polymers. It was found that the polymer chains in the high molecular weight tail are highly branched.