Chapter 4: PMMA-based Montmorillonite Nanocomposites by Soap-free Emulsion Polymerization

This chapter introduces the current development in the exfoliated montmorillonite (MMT)/poly(methyl methacrylate) (PMMA)-based nanocomposites fabricated by soap-free emulsion polymerization. MMT is hydrophilic in nature and MMA monomer is slightly soluble in water. By using the soap-free emulsion polymerization of MMA in the presence of MMT, MMT can be exfoliated during micellation stage, resulting in the formation of exfoliated MMT/PMMA nanocomposite latex particles. To lower T_g of the MMT/PMMA nanocomposites by copolymerizing with methylacrylate, the resulting nanocomposite latices can be cast into films, which were found to have superior tensile properties, low permeability and high flame retardation. This chapter will illustrate their fabrication methods, structure, novel properties and applications.