Microemulsion polymerization. 2. Influence of monomer partitioning, termination, and diffusion limitations on polymerization kinetics

We investigate the polymerization kinetics of microemulsions prepared With the cationic surfactant dodecyltrimethylammonium bromide and the hydrophobic monomers n-butyl methacrylate, tert-butyl methacrylate, n-hexyl methacrylate, and styrene. Our previous model for microemulsion polymerization kinetics cannot account for the kinetics of these systems. Using the results of small-angle neutron scattering monomer partitioning studies and an extended kinetic model to analyze the data, the failure of the original kinetic model is shown to be due to a combination of nonlinear monomer partitioning, nonnegligible bimolecular termination, and, in some cases, diffusion limitations to propagation.