Monte Carlo simulation of long-chain branched polyethylene chains synthesized with dual-site-type catalyst systems

A Monte Carlo model for the polymerization of ethylene with long-chain branch formation using dual-site catalyst systems was developed. It was shown that, unlike single-site catalyst systems, a detailed knowledge of the specifics of catalyst sites and reactor conditions is essential to determine the required probabilities. Therefore, a kinetic model was developed for a CSTR at steady state to simulate the polymerization process. A methodology was also proposed for the calculation of the seven required Monte Carlo model probabilities from the kinetic model. It was shown how the information obtained from the Monte Carlo model complemented the kinetic model results in mapping out the chain microstructure and modeling the polymerization reactor. Eight different dual-site catalyst systems were simulated to evaluate the proposed methodology.