Processing, Mechanical Characterization, and Alkali Resistance of SiliconBoronOxycarbide (SiBOC) Glass Fibers

A borosilicate sol–gel solution is synthesized using a mixture of methyltriethoxysilane, dimethyldiethoxysilane, and boric acid. SiBOC gel fibers are produced from the as‐synthesized sol–gel solution using a spinning apparatus. Subsequently, SiBOC glass fibers are prepared through pyrolysis under argon atmosphere at 1000°C and 1200°C. Mechanical properties of the SiBOC glass fibers are studied by measuring the tensile strength and the elastic modulus. The results show a high tensile strength −1300 and 1058 MPa, and a high Young modulus −79 and 95.5 GPa, for the fibers prepared at 1000°C and 1200°C, respectively. Furthermore, alkali resistance of the SiBOC fibers is investigated by measuring the tensile strength after soaking them for 20 h in NaOH and Ca(OH)2 solutions at 100°C. For comparison, the same measurements are performed on commercial AR and E glass fibers. The SiBOC fibers show excellent alkaline resistance and perform better than commercial AR fibers. Indeed, SiBOC fibers retain 80%–90% of the initial strength after Ca(OH)2 attack.