液态聚碳硅烷先驱体制备陶瓷基复合材料的工艺适应性研究

陶瓷先驱体是先驱体浸渍裂解工艺(PIP)制备陶瓷基复合材料的关键,先驱体工艺性能对复合材料制备工艺和材料性能有着决定性的影响。以一种新型液态聚碳硅烷先驱体(VHPCS)为研究对象,利用红外光谱分析差示扫描量热分析、热重分析、X-射线衍射分析等分析手段对VHPCS及其裂解产物的热稳定性进行表征。从PIP工艺角度出发,对VHPCS固化行为和裂解行为进行分析。结果表明,VHPCS中含有活性的Si-H和Si-CH=CH2基团,可在165℃开始固化反应。VHPCS在1000℃的N2气氛下的陶瓷产率为60%,其裂解产物在1000~1300℃内晶相稳定,是比较理想的陶瓷先驱体。

Processing Property of Liquid Polycarbosilane Precursor on Preparation of Ceramic Composites

Ceramic precursor plays an important role in preparing ceramic matrix composites through PIP (Precursor Infiltration and Pyrolysis) method.The properties of precursors have decisive influence on manufacturing process and properties of the composites.A new liquid ceramic precursor VHPCS and its ceramic products were investigated by infrared spectrometry,differential scanning calorimetry,thermal gravimetric analysis and X-ray diffraction.Also,the curing and pyrolysis behavior of VHPCS had been discussed.Results showed that VHPCS contained both Si-H and Si-CH=CH2 reactive groups,and it could be cured above 165 ℃.The ceramic yield of VHPCS at 1000 ℃ in nitrogen atmosphere was 60％ and the pyrolysed products showed well crystal-structure stability in the temperature range of 1000-1300℃.Results showed that VHPCS could be a promising precursor for PIP method.