Abstract - Poehlein - 9417306 Emulsion and dispersion polymerization are free radical processes that are used to produce polymeric dispersions with particle diameters that can vary from less than 100 nanometers (nm) to more than 10 microns. Commercial products that involve these polymer dispersions can be found in areas such as surface coating, adhesives, flocculants, bioactive materials, analytical column packing, engineering plastic tougheners, and additives in other products. A primary driving force for the increased utilization of emulsion polymers has been environmentally motivated - replacement of organic solvent based systems with those having water as the continuous phase. This increased interest in polymeric dispersions or latexes has resulted in more research aimed at understanding and controlling the complex phenomena that occur in multiphase polymerization reactions. Recent work at Georgia Tech has involved the study of emulsion copolymerization with comonomers which have significantly different solubilities in the water phase. This work will be continued in order to better understand the nature of the oligomeric radicals formed in the water phase and how they influence the surface characteristics of the polymer particles and the structure of the copolymer molecules formed. The preliminary studies will be expanded by varying the size and concentration of seed particles, the influence of chain transfer agents and the solvency of the continuous phase for the monomer pairs. This work will be expanded into the area of dispersion polymerization in an effort to quantify the reaction rates in both phases and how these rates influence competitive particle growth and the mix of copolymer molecules produced. Batch, semi-batch and continuous stirred-tank reactors will be used. Another area of research is related to free radical graft reactions. This will focus on the fundamentals of graft reaction kinetics in solution and emulsion systems. Both oil- and water-soluble initiator s in emulsion polymerization will be tried to examine the influence of non-uniform radical distribution on grafting in latex particles.
