Facile Synthesis and Morphological Analysis of Si-Zr-C-O Fiber Felts with High-Thermal Resistance

Silicon carbide (SiC) fibers with excellent oxidation resistance, high tensile strength, elastic modulus at high temperature are mainly used as a reinforcing material for ceramic matrix composites (CMCs). The polymer-derived SiC fibers are generally manufactured by the processes of melt-spinning, curing, and pyrolysis using polycarbosilane (PCS) as a ceramic precursor. The polymer-derived SiC fibers can be largely divided into amorphous SiC fibers and polycrystalline SiC fibers depending on the oxidation resistance temperature, and various manufacturing methods have been studied to fabricate high-performance polycrystalline SiC fibers. PCS for the spinning is mainly synthesized in autoclave and modified with organometallic compounds by reflux system. These methods showed good polymerization results, such as increases in molecular weight and ceramic yield due to the reaction between PCS and the zirconium source. However, there is a disadvantage that it requires a lot of time with specific equipment. Therefore, in the present study, a zirconium-added PCS solution for electrospinning was prepared by simple and easy blending method. In this studies, Si-Zr-C-O fiber mats were easily and simply fabricated via combination of solution blend and electrospinning methods. The various analyses were performed to verified that the blending method had the same effect as the autoclave or reflux methods.<br/>In this study, Si-Zr-C-O fiber mats were easily and simply fabricated via combination of solution blend and electrospinning methods. The various analyses were performed to verified that the blending method had the same effect as the autoclave or reflux methods. Also, the zirconium added SiC fiber felts were heat-treated at 1500°C or 1600°C for 1 h in an Ar atmosphere to investigate thermal-degradation behaviors. Si-Zr-C-O fiber felts retained blackness and flexibility, whereas SiC fiber felts were thermal-degraded and discolored to gray. Moreover, the results confirmed that the growth of crystalline size (approximately calculated via XRD analysis) was significantly inhibited by the presence of zirconium. Therefore, zirconium acetylacetonate as a zirconium source was cross-linked with the PCS structure via the blending method and its role for heat resistance was exhibited at high temperature.