ORGANOSILICON POLYMERS WITH BIS-ACETYLENIC UNITS - CONDUCTIVITY AND CERAMISATION STUDIES

The transformation poly[(silylene)diacetylene] into ceramic have been studied and SiC obtained with a quantitative yield : all the silicon a toms present in the starting material are converted into SiC. The key step is the crosslinkage of C-4 units into a carbon matrix in which th e R(1)SiR(2) moieties are in the vicinity one to each other allowing t he quantitative transformation into SiC. The carbon content of the res ulting ceramic depends on the nature of R(1) and R(2) groups. The exce ss of carbon has been used for the carboreduction of oxides (TiO2, ZrO 2, HfO2, etc...) and mixed ceramics with interpenetrating network have been obtained : SiC / TiC, SiC / ZrC, etc... Under nitrogen atmospher e, the ceramisation leads to different SiC stems such as SiC / TiN, Si C / AlN, etc,..