Polymer Reaction Engineering, Vol.3, No.2, 93-130, 1995
ETHYLENE-VINYL ACETATE EMULSION COPOLYMERIZATION - MONOMER PARTITIONING AND PRELIMINARY MODELING
Steps towards the development of a mathematical model capable of describing ethylene-vinyl acetate emulsion copolymerization are presented here. In order to develop this model a thorough understanding of ethylene partitioning was first required. Ethylene solubility data were collected over the temperature and pressure ranges of interest (20-50 degrees C, 0-500 psig). This involved the assembly of an apparatus capable of measuring gas solubility and compressibility at the conditions of interest. The technique reported here allowed the determination of the partitioning behaviour of ethylene under a variety of simulated emulsion conditions. An empirical partitioning model and a more rigorous approach based on thermodynamics are discussed. These modelling techniques are applicable to any gas/liquid emulsion system. The thermodynamic model is then included in the full emulsion process model. The proposed model, although at its preliminary stages, is supported by experimental kinetic data and can satisfactorily predict copolymer composition, molecular weight development, particle size and number, and rate of polymerization.