Modeling and optimization of fed-batch emulsion copolymerization of styrene and butyl acrylate in the presence of a chain transfer agent.

This paper deals with modelling and optimization of a semi-batch emulsion copolymerization reactor of styrene and butyl acrylate in the presence of n-C12 mercaptan as chain transfer agent (CTA). The model is developed using reaction rate laws available in the literature. The population balance equations are based on a new approach which reduces significantly the number of equations involved and consequently the computation time. The model allows predicting of (i) the global monomer conversion, (ii) the microstructure, the number and weight average molecular weights, and the glass transition temperature of the resulting macromolecules, and (iii) the average particle diameters. A subset of the most influential parameters of the model is identified using a parameter estimability approach. The resulting model is then validated and used to determine the optimal feed policy which enables to produce core-shell latex particles with a designed glass temperature profile at high conversion. The set of optimal solutions is determined by means of a mutiobjective optimization approach. Finally, the unique solution to be implemented is obtained by using a decision making strategy.