DYNAMIC MODELING OF LIMITED PARTICLE COAGULATION IN EMULSION POLYMERIZATION

In emulsion polymerization, a limited degree of particle coagulation m ay occur. Particle coagulation is caused by a loss of colloidal stabil ization when the surface coverage of emulsifier on the particles drops below a critical value. It has been demonstrated experimentally in a previous article that the time scale for particle coagulation is small compared to the time scale for particle growth by polymerization and absorption of monomer. This indicates that the coagulation process can probably be described by von Smoluchowski kinetics. Based on this res ult, a comprehensive dynamic model for the simulation of limited parti cle coagulation in emulsion polymerization has been developed. It has been shown that there is a reasonable agreement between simulations wi th the dynamic model and experimental data (e.g., conversion time hist ory, particle number, and particle size distribution). (C) 1996 John W iley & Sons, Inc.