Thermooxidative stability of polymethyl methacrylate containing nanoparticles of silica/titania and silica/zirconia

The influence of silica/titania and silica/zirconia nanoparticles on thermooxidative degradation of PMMA was studied by non-isothermal thermogravimetry. Kinetic parameters describing the length of the oxidation induction periods were obtained from the treatment of the dependence of oxidation onset temperature on heating rate. Using these parameters, the protection factors of nanoparticles have been calculated. It was found that SiO(2)/TiO(2) nanoparticles increase the thermooxidation stability of PMMA where the stabilizing effect, expressed as the protection factor, depends on temperature only slightly. The stabilizing effect of SiO(2)/ZrO(2) is much stronger than that of SiO(2)/TiO(2) and decreases with increasing temperature. (c) 2008 Institute of Chemistry, Slovak Academy of Sciences.