Modelling and Simulation of an emulsion copolymerisation process

Radical emulsion copolymerization is one of the most widely diffused processes aimed to produce paints easy to use because of their low viscosity. At industrial scale, such processes require a high performance control of all the operating variables. Particularly, the repeatability of an emulsion polymerization process within narrow limits is one of the most desirable features because it allows for controlling also other important product qualities. Other important full plant requirements are the minimization of reactants dosing times and the preparation of a latex at the highest possible concentration. In this work, the first step of a complex industrial copolymerization process has been modeled. Since different monomer types are involved, it has been necessary to propose a complete set of rate constants for all the traditional steps of the radical emulsion reactions chain. These parameters have then been inserted in a system of ordinary differential equations expressing all balances and control actions aimed to simulate the full plant synthesis. Finally, the proposed model has been experimentally validated through the comparison with a reaction calorimetry test carried out in an indirectly cooled semibatch reactor (RC1, 1L, Mettler Toledo). Obtained results have confirmed the reliability of the theoretical model