Isothermal emulsion polymerization of n-butyl methacrylate with KPS and redox initiators: Nucleation

Nucleation is a very important stage of emulsion polymerization due to its significant influence on the latex particle diameter, particle diameter distribution, and molecular weight. In this study, we evaluated the effect of thermal and redox initiators on the nucleation and reaction kinetics with a model emulsion system comprised of n-butyl methacrylate, sodium lauryl sulfate, water, initiators, and other additives. Our previous study has demonstrated that a micellar nucleation mechanism plays a role in both initiator systems. In the present study, we further explored secondary nucleation using these two types of initiator systems, that is, homogeneous nucleation, which exists in the redox-initiated process, and micellar nucleation which is the main nucleation mechanism for the thermal-initiated system. The investigation also illustrates that coagulative nucleation in the redox-initiated emulsion system results in a greater extent of monodispersed particle diameter distributions, much smaller particle diameters, and lower molecular weights for the final latex. (c) 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 48275.