Main events occurring in styrene microemulsion polymerization

A previously presented model with four states (conversion, active and inactive particles and micelles) is further tested with conversion versus time experimental data at 50, 60, and 70°C, to recognize the main events occurring in styrene microemulsion polymerization. The S-shaped conversion–with no overprediction- and the bell-shaped active particles number concentration–evidencing diffusive effects at late stages–versus time data, are well described by the proposed model. It was found that: (i) transfer of monomer and surfactant from micelles to particles occurs, (ii) the capture of radicals by micelles is the only cause of particle nucleation, (iii) the rate coefficient of radical-entry-to-micelles is much smaller than that of exit-from-particles, and (iv) no coagulation between particles was detected. The Arrhenius dependency on temperature of the kinetic rate parameters is also reported. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41720.