Modeling of the Activators Regenerated by Electron Transfer Copolymerization of Styrene-Acrylonitrile with Prediction of the Bivariate Molecular Weight DistributionCopolymer Composition Distribution Using Parallel Computing and Probability Generating Functions

A mathematical model of the activators regenerated by electron transfer atom transfer radical polymerization copolymerization of styrene-acrylonitrile (SAN) is developed for the first time that calculates the bivariate molecular weight distribution (MWD)-copolymer composition distribution (CCD) of the copolymer. In addition, the model calculates the overall MWD, the overall CCD, average molecular weights and composition, and conversion. The model is implemented in the open-source programming language Julia, a high-level language designed for scientific computing, which is easy to use and that performs very fast calculations. The probability generating function technique is used to process the infinite population balances of the system. The mathematical model, composed of a very large system of equations, is solved by applying parallel computing to speed up its execution. In this way, the distributions of polymer properties are calculated in a very efficient manner. The evolution of the joint MWD–CCD and other molecular properties along the reaction path is analyzed under different operating conditions. The model allows obtaining very detailed insights into the copolymer microstructure during the polymerization reaction.