Influence of the Precursor Cross-Linking Route on the Thermal Stability of Si−B−C−O Ceramics

• Published in: Chemistry of materials 2008-11, Vol.20 (22), p.7148-7156
• Main Authors: Ischenko, Vladislav, Pippel, Eckhard, Woltersdorf, Jörg, Yappi, B. Rodrigue Ngoumeni, Hauser, Ralf, Fasel, Claudia, Riedel, Ralf, Poli, Fabrizia, Müller, Klaus
• Format: Article
• Language: English
• Subjects: Inorganic Solids and Ceramics; Polymeric Materials; Precursor Routes to Materials (including Polymer-Derived Ceramics)
• ISSN: 0897-4756; 1520-5002
• DOI: 10.1021/cm701916g

The specifics of the cross-linking route of tris(1-(dichloro(methyl)silyl)ethyl)borane to form a preceramic polymer suitable for the subsequent synthesis of Si−B−C−O ceramics has significant influence on the local phase composition and the microstructural features of the resulting samples after their ceramization and subsequent annealing. Cross-linking of tris(1-(dichloro(methyl)silyl)ethyl)borane via hydrolysis used for the preceramic polymer synthesis increases the amount of nanocrystalline SiC in the resulting Si−B−C−O ceramics up to 1400 °C, while cross-linking with polyvalent alcohols allows the homogeneous component distribution to be preserved and the formation of crystalline phases to be retarded. The different contents of bound oxygen in the preceramic polymers, depending on the cross-linking route, may explain the observed different stabilities of amorphous Si−B−C−O against phase separation and crystallization.