Monte Carlo Computational Modeling of Polypropylene Modification via Grafting Using a Two-Phase Model

Abstract

The grafting reaction of maleic anhydride (MAH) onto polypropylene (PP) has been extensively studied over the last decades. Despite the large volume of published work, there is still no consensus on the reaction mechanism or the effect of phase separation, which arises from the low solubility of MAH in PP. Previous modeling work has reported improvements in the representation of experimental results when considering the existence of a second phase. This work presents a Monte Carlo model of the MAH grafting reaction onto PP, which considers a detailed reaction mechanism consistent with previous literature and a heterogeneous reaction medium with mass transfer between phases. The model is capable of predicting various properties of interest. The model was fitted using genetic algorithms and global optimization techniques, yielding a significant agreement with the experimental data. This approach explains complex process relationships, such as the dependence of the maximum grafting degree on the initial MAH concentration. The model serves as a crucial tool for understanding the reaction mechanism and the impact of process variables on polymer properties.