Core-shell ZrO_2/PMMA composites via dispersion polymerization in supercritical fluid: Synthesis, characterization and mechanism

摘要

Zirconia (ZrO_2) 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). ZrO_2 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 ZrO_2 particles. TEM analysis confirmed the core-shell morphology. The incorporation of ZrO_2 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 ZrO_2 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.