Core-Shell ZrO2/PMMA Composites via Dispersion Polymerization in Supercritical Fluid: Synthesis, Characterization and Mechanism

Zirconia (ZrO2) particles of average size 200 nm were synthesized by sol-gel method and formation of composites with poly(methyl methacrylate) (PMMA) via in situ radical dispersion polymerization in supercritical carbon dioxide (scCO(2)) using a commercially available stabilizer poly(dimethylsiloxane)-g-pyrrolidone carboxylic acid (Monosil PCA). ZrO2 particles were first surface-modified by the silane coupling agent methacryloxypropyltrimethoxysilane (MPTMS), which is capable of copolymerizing with methyl methacrylate (MMA) and provide a reactive C=C bond. SEM results revealed uniform morphological characteristics of the composite materials and good dispersions of the ZrO2 particles. TEM analysis confirmed the core-shell morphology. The incorporation of ZrO2 particles in the composites was endorsed by FT-IR. The composites were also confirmed by TGA and XRD. The hybrid composites possess interesting thermal and optical transparency characteristics because of the uniform incorporation of ZrO2 particles in the polymer matrix. In principle, this simple and environmentally friendly synthetic procedure can be employed to prepare other inorganic oxide containing polymer composites. (C) 2011 Wiley Periodicals, Inc. J Appl Polym Sci 123: 1176-1183, 2012