SiO_2/蔗糖杂化溶胶制备SiC纤维前驱体

Preparation of Si/C Fiber Precursors from SiO_2/Sucrose Hybrid Sols

采用溶胶凝胶法以正硅酸乙酯与蔗糖进行杂化,制得SiO2/蔗糖杂化溶胶,陈化后用拉丝法制得SiO2/蔗糖杂化纤维。研究了杂化溶胶陈化中的黏度变化与成纤性能,采用SEM分析研究了杂化纤维微观形貌。结果表明,SiO2/蔗糖杂化溶胶具有良好的成纤性能,可通过拉丝制得形态良好的杂化纤维;采用TG和DSC分析研究了杂化纤维热性能。结果表明,通过杂化改善了蔗糖的耐热性能;XRD光谱分析结果表明,杂化纤维为非晶态结构,经800℃处理后有碳化石墨微晶生成。

SiO2/sucrose hybrid sol was prepared from sol-gel of TEOS and sucrose,and SiO2/sucrose hybrid ferbers were prepared by drawing method.The change in viscosity and the spinnablity of the hybrid sols were studied.The morphology of the hybrid fibers was characterized by SEM;the thermal properties of the hybrid fibers were characterized by TG and DSC,and the crystalline property of the hybrid fibers was characterized by XRD.The results showed that the SiO2/sucrose hybrid sols had good spinnability,and the hybrid fibers had excellent appearance.The heat resistance of sucrose was improved in the hybrid.The hybrid fibers were amorphous and some micro-crystals of graphite were formed after they had been heated to 800 ℃.