Prediction of resin textural properties by vinyl/divinyl copolymerization modeling

The production of polymeric resins through free-radical copolymerization is an interesting procedure from an economic standpoint; however, its mathematical representation is of great complexity. In the present study, modeling tools were used to describe the copolymerization of styrene with ethylene glycol dimethacrylate (EGDMA) beyond the gel point. Balance of species and sequences, method of moments, and numerical fractionation technique were applied in the model's kinetic description. Diffusion effects were also taken into account. The concept of elementary gel structures (EGSs) was used in order to predict textural properties of polymer particles, such as specific surface area and swollen gel volume. Suspension copolymerizations were carried out in the presence of toluene/heptane mixtures, and data on these reactions were used to assess the model's predictability. Reactivity parameters showed similarities to styrene/divinylbenzene systems. Agreement between the model and experimental data improved when diffusion effects were considered. The fitted apparent coiling factors for dry particles were found in the range of 0.368-0.406, and a linear correlation was obtained between this parameter and toluene fraction (a good solvent), being consistent with the pore formation phenomenon. (C) 2017 Elsevier Ltd. All rights reserved.