High solids content waterborne acrylic/montmorillonite it nanocomposites by miniemulsion polymerization

Waterborne polymer/clay nanocomposites of methyl methacrylate and butyl acrylate have been prepared by miniemulsion polymerization. Two different commercial organically modified clays have been used: Cloisite 15A and Cloisite 30B. Nanocomposites with partially exfoliated structure, observed by wide-angle X-ray diffraction (WAXD), small angle X-ray scattering (SAXS) and transmission electron microscopy (TEM) were obtained by batch miniemulsion polymerization with 2-4 wt.-% clay and 30% solids content. The mechanical, thermal and permeation properties of the nanocomposites showed a substantial improvement. Furthermore, this approach has allowed the production of stable and coagulum free latex with solids content up to 42 wt.-% with partially exfoliated structures.