Résumé
Silicon carbide (SiC) has attracted interest for environmental andenergy applications due to its high temperature properties. Futureindustrial challenges for SiC, particularly in aeronautics, requireto tune the materials composition and shape on demand. Theseinherent difficulties can be overcome by synthetic paths wheremolecular chemistry and chemistry of materials are combined, likethe Polymer-Derived Ceramics route. The chemistry, processingproperties and reactivity (thermal and chemical) of related polymerscan be controlled and tailored to supply, after shaping andpyrolysis processes, ceramics with the desired compositional phasedistribution and homogeneity. This method is used to prepareboron-modified SiC. Polymers were synthesized by the reaction ofallylhydridopolycarbosilane (AHPCS) with borane dimethylsulfide.We demonstrate that the boron content has an effect on the chemistryand processability of precursors, as well as the properties ofthe resulting materials. This study gives us informations about thechemical and physical properties of boron-modified SiC precursors based on infrared, NMR spectroscopies and elemental analyses.Their pyrolysis behavior is investigated by solid-state NMR coupledwith TGA. Final materials are characterized by XRD, elementaryanalysis, Raman spectroscopy. Applications of PDC route to processceramic matrix composite will be discussed.