Morphology and thermal properties of clay/PMMA nanocomposites obtained by miniemulsion polymerization

• Electron microscopy allows to characterize the morphology of clay/poly(methyl methacrylate) nanocomposites.
• Miniemulsion polymerization is used to produce the nanocomposites.
• Clay loading determines the thermal and mechanical properties of the nanocomposites.

Miniemulsion polymerization was used as the synthetic method to produce clay/poly(methyl methacrylate) nanocomposites. Two kinds of interfacial interactions clay–polymer particle were observed by electron microscopy, one where the polymer particles are adhered on the surface of the larger fragments of clay, and another where nanometric fragments of clay are encapsulated by polymer particles. Variations in the glass transition temperature (Tg) and thermomechanical properties of the matrix, as function of clay content, were observed. In particular, at the highest clay loading (1.0 wt%) depression of Tg and thermomechanical properties were observed. The increased clay–polymer matrix interfacial area appears to be the conditioning factor that determines such behavior.