STUDIES ON THE SYNTHESES OF POLYMETALLOXANES AND THEIR PROPERTIES AS A PRECURSOR FOR AMORPHOUS OXIDE .4. PROPERTIES OF SIO2-TIO2 OXIDE FIBERS FROM POLYTITANOSILOXANE

From polytitanosiloxanes (PTS), SiO2-TiO2 oxide fibers with fairly good tensile strength were prepared, and their mechanical and thermal properties were investigated. The precursor fibers PTS-0.5 and PTS-1.0 were obtained by dry spinning of a highly viscous PTS solution which were formed as the reaction mixture of silicic acid (SA) with bis(2,4-pentanedionato)titanium diisopropoxide (PTP) in the molar ratios (SA/PTP) of 0.5 and 1.0. The precursor fibers PTS-0.5 were too brittle to measure their tensile strength, whereas PTS-1.0 and the heat-treated fibers were found to have tensile strength of 130 (precursor), 540 (500-degrees-C), and 450 (900-degrees-C) MPa, respectively. Heat-treatment of the fibers PTS-1.0 at above 1000-degrees-C forms anatase and rutile of titanium dioxide. The crystallization is resulted from the unreacted PTP which is not incorporated into the polymer network.