THERMAL-STABILITY AND HARDNESS OF NEW POLYACRYLATE-SIO2 HYBRID SOL-GEL MATERIALS

The thermal stability, density and hardness of new polyacrylate-SiO2 hybrid glasses, derived from poly [methyl methacrylate-co-3 (trimethoxysilyl)propyl methacrylate] or poly[3-(trimethoxysilyl)propyl methacrylate] and tetraethyl orthosilicate via the sol-gel approach, were found to depend greatly on the organic-inorganic composition and the thermal history of the materials but little on the copolymer composition. Higher stability, density and hardness can be achieved by increasing the content of SiO2 in the hybrid materials. Thermal treatment of the materials at 200-degrees-C increased the bulk density and hardness by almost-equal-to 16% and by factor of 2-3, respectively, without decomposition of the polymer backbones.