Thermodynamic correlation of partial and saturation swelling of styrene-acrylonitrile copolymer particles by styrene and acrylonitrile monomers

Abstract

The possibility of thermodynamic correlation of partial and saturation swelling of styrene-acrylonitrile (SAN) copolymer particles by styrene (St) and acrylonitrile (AN) monomers is investigated. The unknown Flory-Huggins interaction parameters involved in the thermodynamic swelling equations are estimated by fitting the equations to the experimentally observed monomer concentrations. It is shown that the concentration of each monomer in SAN copolymer particles predicted by using the thermodynamic swelling equations with the parameters and constants estimated in this study agrees fairly well with that observed experimentally over a wide range of experimental conditions. The validity and utility of the parameters and constants estimated from saturation swelling are also demonstrated by showing that the experimental results for partial swelling of SAN copolymer particles by AN monomer dissolved in the aqueous phase agree with those predicted by the thermodynamic equation for partial swelling. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 64: 931–939, 1997