Poly(vinyl acetate)-clay hybrids prepared via emulsion polymerization, assisted by a nonionic surfactant

Hybrid materials containing poly(vinyl acetate) and montmorillonite (MMT) were prepared using an one-batch emulsion polymerization recipe, assisted by a nonionic surfactant. To explain the results of our experiments, a thorough investigation of the specific interactions between the compounds was done, in the wet as well as the dried state of the end-products. In dispersion, polymer-surfactant interactions were found to be driven by hydrophobic coupling into superficial (mixt) admicelles. Another important finding is that the amount of clay used in the recipes and its relative concentration with respect to the other reaction partners influences drastically the morphological units in the end-products. For low [MMT], well-defined, spherical particles are formed. At the other extreme, for high [MMT], production of polymeric, water-swollen aggregates is favored. A small amount of reformed MMT tactoids was detected in all casted hybrid films, indicating that most of the inorganic is dispersed in the organic phase.