CONVERSION DEPENDENT MORPHOLOGY PREDICTIONS FOR COMPOSITE EMULSION POLYMERS .1. SYNTHETIC LATTICES

Phase structure develops within composite latex particles during the polymerization process and is potentially dependent upon both the latex recipe and the polymerization process characteristics. An equilibrium thermodynamic approach is presented to predict the particle morphology as a function of the extent of conversion of a seed latex polymerization reaction. The discussion highlights the role of the monomer as it influences the phase compositions and interfacial tensions throughout the polymerization. It is found that a number of different particle morphologies possess nearly the same total interfacial energy throughout a significant portion of the polymerization reaction and that it is quite likely that occluded structures will form in addition to the more fully phase-separated structures, such as core-shell and hemispheres. Detailed methods to predict the probabilities of forming a variety of different morphologies are presented.