Pyrolytic conversion of an Al-Si-N-C precursor prepared via hydrosilylation between [Me(H)SiNH]₄ and [HAlN(alIyl)] _m[HAlN(ethyl)]_n

An iminoalane-silazane polymer (ISP), an Al-Si-N-C precursor, has been synthesized via Ptcatalyzed hydrosilylation between poly(allyl iminoalane-co-ethyl iminoalane) ([HAlN(allyl)]_m[HAlN (ethyl)] _n, AE-alane) and l,3,5,7-tetrahydro-1,3,5,7-tetramethylcyclotetrasilazane {[Me(H)SiNH] ₄, TCS}. The IR and ¹H NMR spectra of ISP indicate that the relative amounts of the allyl groups decrease slightly in comparison with those of AE-alane, suggesting that hydrosilylation occurs partially. TG analysis up to 900 °C reveals that the ceramic yield of ISP is 83.1 mass%. It is suggested that the high ceramic yield can be ascribed to cross-linking reactions occurring during pyrolysis. Possible reactions during pyrolysis are hydrosilylation, polymerization of the C=C bonds in the allyl groups and dehydrocoupling among the SiH groups, NH groups and AlH groups in ISP. The pyrolyzed residue at 1700 °C contains crystalline AIN, 2H-SiC, β-SiC and β-Si₃N₄ and amorphous carbon, as revealed by solid-state nuclear magnetic resonance (NMR) spectroscopy, Raman spectroscopy and X-ray diffraction (XRD) analysis.