(692d) Introducing a “Tetris Model” for Coarse-Grained Simulations of Copolymer Polyethylene Crystallization

Controlling the levels of short chain branches (SCBs) in polyethylene copolymers is a pivotal protocol in modulating crystallization, thereby influencing the ultimate properties of products. However, there are no robust models to explore the impact of short chain branches (SCBs) on copolymer crystallization, particularly its kinetic effects. In this presentation, we introduce a novel simple “Tetris” model for secondary nucleation, designed to predict the growth rate of polyethylene copolymers. Our Tetris stochastic strand-by-strand simulation model is built upon the principles of the Hoffman-Lauritzen (HL) theory for homopolymers, augmented to include polymer strands containing SCBs. Using established input parameters that allowed successful prediction of secondary nucleation by the HL theory for homopolymers, the Tetris simulations can predict copolymer growth rates under isothermal conditions across a broad spectrum of crystallization temperatures and SCB levels without additional adjustable parameters. Moreover, we propose an empirical formula derived from the Tetris simulations to efficiently depict copolymer growth rates, thereby enhancing the practical applicability of our theoretical framework.