In situ radical polymerization of methyl methacrylate in a solution of surface modified TiO2 and nanoparticles

Abstract

Surface modified TiO2 nanoparticles dissolved in toluene were encapsulated in PMMA by in situ radical polymerization of methyl methacrylate initiated by 2,2'-azobisisobutyronitrile. The surface modification of the TiO2 nanoparticles (average diameter of 4.5 nm) was achieved by the formation of a charge transfer complex between TiO2 nanoparticles and 6-palmitate ascorbic acid. The surface modified TiO2/nanoparticles were characterized using UV-Vis and FTIR spectroscopy, while the obtained polymer nanocomposites were characterized using reflection and H-1 NMR spectroscopy, as well as gel permeation chromatography. The influence of the TiO2 nanoparticles on the thermal properties of the PMMA matrix was investigated using thermo-gravimetric analysis and differential scanning calorimetry. The glass transition temperature of the polymer was not influenced by the presence of the nanoparticles while the thermal stability was significantly improved.