PYROLYSIS OF A POLYVINYLSILAZANE, POLYMERIC PRECURSOR FOR SILICON CARBONITRIDE - STRUCTURAL INVESTIGATION BY H-1, C-13, SI-29, N-15 AND N-14 NUCLEAR-MAGNETIC-RESONANCE

This paper presents our strategy for the structural characterization of polymeric precursors and ceramic materials using liquid and solid-state NMR. This study concerns a polyvinylsilazane precursor for silicon carbonitride pyrolyzed under nitrogen; the local environments of all the various atoms H, C, Si and N have been identified and the different sites are quantified; at 1400-degrees-C, the material is constituted with a silicon carbonitride phase and a free carbon phase. The structural evolution of the system leading to the formation of the ceramic material will be presented.