Abstract
Polycondensation reaction of 70PhSiO3/2•30Ph2SiO2/2 (Ph=C2H5) polysiloxane has been almost completed by treating the corresponding gel with a diethyl ether-aqueous NaOH immiscible two phase liquids. The phenyl-modified siloxane gel is dissolved in diethyl ether phase which is immiscible with an NaOH aqueous solution. After stirring the immiscible solution vigorously, the glass-ether phase is extracted and then subjected to evaporation to leave glass precursor. The phenyl-modified siloxane glass is prepared by melting the precursor at 200°C over 1 h, in which the polycondensation reaction of siloxane network is almost completed. It is found that the obtained siloxane glass shows a softening temperature around 80°C and this value remains unchanged even after heat-treatment over 200 h at 200°C.
