Kinetics of Styrene and Butyl Acrylate Polymerization in Anionic Microemulsions in Presence of Layered Silicates

Abstract

The effect was studied of various layered silicates (sodium montmorillonite and different organomodified montmorillonites) on kinetics of styrene (St) and butyl acrylate (BuA) in anionic (sodium dodecyl sulfate) microemulsion polymerization. The dependence of the polymerization rate on the conversion exhibits two rate intervals. The presence of layered silicates affects the conversion and polymerization rate of both St and BuA. The size of polymer particles increases with polarity of Cloisite and the increase is more pronounced in poly(butyl acrylate) particles. The kinetic, colloidal and molecular weight parameters are influence both by the monomer and layered silicate polarities. Different approaches (Ugelstadt, Nomura and Gilbert models) were used for evaluation of polymerization kinetics. The desorption constants (kdes) decrease in presence of the studied layered silicates (Cloisite Na, Cloisite 30B, Cloisite 20A). The decreasing values of the desorption constants in the presence of clays; demonstrate a clear effect, which implies the decreasing of the probability of the radical exit from particles in the presence of the layered silicates.