University of Connecticut |
Polymer Program SeminarMulticomponent Polymer Latex Particles - Reactions and Phase Separation in Confined Spaces Friday, October 15, 2004 11:00 am , IMS Room 20 Aqueous based dispersions of composite polymers are important items of commerce and find applications in products such as coatings, adhesives, impact modifiers and medical diagnostics. The structure of the polymer particles is controlled at the 20-200 nm levels by manipulating the formulation and process characteristics of the latex polymerization. This gives the experimenter or manufacturer a wide range of variables with which to manipulate the morphology of the particles and thus the ultimate properties of the polymer. We know that the mobility of the growing polymer chains within the latex particles and their location at the time of phase separation are responsible for the final morphology of the particles. The objective of this presentation is to describe the reaction kinetics in the water and polymer particle phases, the diffusion and reaction of polymer radicals within the polymer matrix, and the location of phase separation in the particles. Experimental results for several different latex systems will be presented and compared to morphology predictions from quantitative models. Examples will include systems in which phase separation is reasonably complete and also systems in which there is apparently no phase separation.
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