Allylhydridopolycarbosilane (AHPCS) as matrix resin for C/SiC ceramic matrix composites

Abstract

In present study, partially allyl-substituted hydridopolycarbosilane (5 mol% allyl) [AHPCS] has been characterized by spectral techniques and thermal analysis. The DSC studies show that, the polymer is self-cross-linking at lower temperatures without any incorporation of cross-linking agents. The spectral and thermal characterizations carried out at different processing stages indicate the possibility of extensive structural rearrangement accompanied by the loss of hydrogen and other reactions of C and Si containing species resulting in the conversion of the branched chain segment into a 3D SiC network structure. AHPCS gave ceramic residue of 72% and 70% at 900 and 1500 °C respectively in argon atmosphere. XRD pattern of 1500 °C heat-treated AHPCS, indicates the formation of silicon carbide with the particle size of 3–4 nm. AHPCS was used as matrix resin for the preparation of C/SiC composite without any interfacial coating over the T-300 carbon fabric reinforcement. Flexural strength value of 74–86 MPa for C/SiC specimen with density of 1.7 g/cm 3 was obtained after four infiltration and pyrolysis cycles.