Synthesis and Pyrolysis of Polyaluminosilazane

Abstract

Polyaluminosilazane was synthesized by the reaction of perhydropolysilazane with (ethyl acetoacetate) aluminumdiisopropoxide. The chemical structure of this polymer was investigated by infrared spectroscopy and nuclear magnetic resonance and it was found that this polymer contains some Al-N bonds. Amorphous SiAlON was obtained by pyrolysis of this polymer in a stream of anhydrous ammonia to 1000°C with a high ceramic yield. Crystallization to fine crystalline β′-SiAlON or mixture of J′-SiAlON and mullite proceeded on heat treatment at 1500°C under N₂. These results indicate that polyaluminosilazane is a good precursor for SiAlON-based materials.