Silicon‐Containing Preceramic Polymers

Abstract

Abstract Polymer‐to‐ceramic transformation is a suitable technology to produce a broad spectrum of ceramic‐based composite materials with adjusted chemical, mechanical, and physical properties. Their properties depend on the chemical structure of preceramic polymers, the carbon content of the ceramic, the conditions used for pyrolysis (eg, temperature, atmosphere) as well as the use of additional active or passive fillers. The intimate relationship between the molecular architecture of the precursor and the nano/microstructure as well as the functional and structural properties of the resulting ceramics is one of the most important features of this class of ceramics. Chemical design of precursors, such as polysilanes, polycarbosilanes, polysiloxanes, polysilazanes, and polysilylcarbodiimides, enables the production of nanostructured SiC, SiOC, and SiCN ceramics via thermal conversion in an inert or active atmosphere. A key aspect of a polymer‐derived ceramics (PDCs) route is the possibility to “dissolve” carbon in phases such as Si 3 N 4 and SiO 2 and to create ternary phase ceramics such as SiOC and SiCN, which is only realizable by using single‐source‐precursors techniques. Synthetic routes for silicon‐based polymers as well as their transformation steps to ceramics (namely cross‐linking and pyrolysis) will be presented in this review. A short overview on PDCs as a unique class of ceramics is provided as well. Preceramic polymers, which are used for the synthesis of multinary PDCs such as SiBCN and SiMOCN (M = metal), are also described.