Excellent heat resistance of Si-Zr-C-O fibre

In order to obtain the high heat-resistant fibre, Si-Zr-C-O fibre has been developed. Si-Zr-C-O fibre was produced by the use of polyzirconocarbosilan e as the precursor polymer. In this paper, the difference in heat-resistanc e between Si-Ti-C-O and Si-Zr-C-O fibres was clarified. Si-Zr-C-O fibre sho wed excellent heat resistance (up to 1773 K) compared with Si-Ti-C-O fibre (up to 1573 K). Generally speaking, decomposition reaction of this type of fibre proceeds accompained by the release of CO gas which was formed by the reaction between excess carbon and oxygen included in the fibre. In the ca se of Si-Zr-C-O fibre, Zr can strongly capture the oxygen atoms, so that th e aforementioned decomposition hardly proceeds up to 1873 K (ZrO2 + 3C = Zr C + 2CO; Delta G < 0 at over 1906 K). (C) 1999 Kluwer Academic Publishers.