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Vinyl acetate (VAc) was polymerized in microemulsion using sodium bis(2-ethylhexyl) sulfosuccinate (AOT) as surfactant and n-butanol (n-BuOH) as the cosurfactant (1:1, wt/wt) with potassium persulfate (KPS) as initiator. The effects of monomer, surfactant, and initiator concentration, as well as the temperature on the kinetics, particle size, and molar masses were studied. It was observed that polymerization rate increases as monomer, initiator, and temperature increases; however, the opposite was observed as surfactant concentration increases. Average particle diameters (Dp)< 50 nm and polymers with weight average molar masses (Mw) between 2.7×10 5 and 7.5×10 5 g/mol were obtained. For low amounts of stabilizing agents (AOT and n-BuOH), a bimodal molar mass distribution (MMD) was obtained. As nbutanol concentration increased, Mw decreases and a monomodal MMD was observed, which can be explained because chain transfer events are promoted by the presence of n-BuOH. A thermodynamic model was implemented to simulate the partitioning of VAc in the presence of n-BuOH between the phases throughout polymerization. It was found from simulations that microemulsion droplets are depleted fast at 5 % conversion and, due to the high water solubility of VAc, most of the monomer (70 %) and n-BuOH (97 %) reside in the aqueous phase at the beginning of polymerization, which indicates that both homogeneous and micellar nucleation are present.

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