Apatite-forming ability and mechanical properties of PTMO-modified CaO–SiO2–TiO2 hybrids derived from sol–gel processing

Hydrolysis and polycondensation of triethoxysilane end-capped Poly (tetramethylene oxide) (Si-PTMO), tetraethoxysilane (TEOS), tetraisopropyltitanate (TiPT) and calcium nitrate (Ca(NO3)2) gave transparent monolithics of PTMO-modified CaO–SiO2–TiO2 hybrids. The samples with (TiPT)/(TEOS+TiPT) molar ratios from 0 to 0.20 under constant ratio of (Si-PTMO)/(TEOS+TiPT) of 2/3 in weight were prepared. It was found that the incorporation of TiO2 component into a PTMO–CaO–SiO2 hybrid results in an increase in the apatite-forming ability in a simulated body fluid: the hybrids with (TiPT)/(TEOS+TiPT) of 0.10 and 0.20 in mol formed an apatite on their surfaces within only 0.5 day. It seemed that, within the range of compositions studied, the TiO2 content little affects the overall mechanical properties: Youngʹs modulus were 52–55 MPa, tensile strength, 7–9 MPa, and strain at failure, about 30%. Thus, the organic–inorganic hybrids exhibiting both fairly high apatite-forming ability and high capability for deformation were obtained. These hybrid materials may be useful as new kind of bioactive bone-repairing materials.