Tuning the carbon content of silicon carbonitride SiCN(O) materials obtained from hydrosilylation-derived polysilazanes

Abstract

Polymer-derived silicon carbonitride SiCN(O) materials with tunable carbon content were obtained from polysilazanes synthesized from silazane monomers, and carbon-containing crosslinkers via the hydrosilylation reaction. The polysilazanes were characterized by ATR-FTIR and Raman spectroscopy in terms of the presence of various functional groups. Three polysilazanes were chosen as preceramic precursors for the materials, and pyrolyzed at 800°C in argon. DRIFT spectroscopy and ²⁹Si MAS NMR confirmed the presence of Si–N bonds in the materials, and Si–C bonds in one sample only, as well as oxygen contamination in the form of Si–O bonds in all samples. Consequently, the obtained materials should be referred to as SiCN(O). Raman spectroscopy and ¹³C MAS NMR indicate that the materials contain the free carbon phase. Elemental analysis revealed that the carbon content in SiCN(O) materials can be adjusted from 25.7 at% to 45.3 at% by selecting appropriate silazane monomers and crosslinkers.