Mechanical behavior of bioactive pdms-modified CaO-SiO_2-TiO_2 hybrid materials: effects of heat treatments and TiO_2 content

摘要

The effects of TiO_2 content and heat treatment on the bioactivity and mechanical behavior of polydimethyl-siloxane(PDMS)-modified CaO-SiO_2-TiO_2 hybrid materials were investigated. Samples were prepared by hydrolysis and polycondensation of PDMS, tetraethoxysilane (TEOS), tetraisopropyltitanate (TiPT) and calcium nitrate. The samples with varying (TiPT)/(TEOS + TiPT) molar ratios from 0 to 0.30 were prepared. The apatite-forming ability in a simulated body fluid (SBF) increased with increasing TiO_2 content. The Young's modulus and strain at failure increased and decreased, respectively, with increasing TiO_2 content. The samples with a fixed molar ratio, (TiPT)/(TEOS + TiPT) = 0.10 were heat-treated at various temperatures from 60 to 300 deg C for 24 h. The Young's modulus and failure strain of the heat-treated samples increased and decreased, respectively, with increasing heat treatment temperature, but the bending strength was found to be independent of treatment temperature. Pore- and crack-free trasparent hybrids exhibiting high apatite-forming ability as well as mechanical properties analogous to those of human cancellous bone were developed. These hybrids may be used as a new kind of bioactive bone-reparing materials.