裂解SiOC陶瓷内涂层改善炭气凝胶复合材料抗氧化性能研究（英文）  

Oxidation Resistance Improvement of Carbon Aerogel Composites by Pyrolyzed SiOC Ceramic Inner Coating

作　　者：冯军宗[1] 吕亚楠[1] 姜勇刚[1] 冯坚[1] 

机构地区：[1]国防科学技术大学新型陶瓷纤维及其复合材料重点实验室,湖南长沙410073

出　　处：《稀有金属材料与工程》2016年第S1期274-277,共4页Rare Metal Materials and Engineering

基　　金：National Natural Science Foundation of China((51172279,51302317);Aid Program for Science and Technology Innovative Research Team in Higher Educational Institutions of Hunan Province;Aid Program for Innovative Group of National University of Defense Technology

摘　　要：为了提高炭纤维增强炭气凝胶隔热复合材料的抗氧化性能,以二甲基二乙氧基硅烷和甲基三甲氧基硅烷为原料配制SiOC先驱体溶胶并浸渍炭气凝胶复合材料,经凝胶老化、溶剂交换、干燥、裂解得到含SiOC内涂层炭气凝胶复合材料,重复以上步骤得到不同复合次数的抗氧化复合材料。研究表明随着复合次数增加,复合材料密度和热导率增加,复合3次的密度为0.77g/cm3(未复合之前为0.20g/cm3),热导率为0.33W/m·K(未复合之前为0.11W/m·K)。在空气中1600℃,20min抗氧化测试,质量损失率随着复合次数增加而减小,复合3次的质量损失率为10.33%,线收缩率为1.16%。通过浸渍有机硅溶胶,裂解转化后可在纳米多孔炭气凝胶复合材料内部形成内涂层,明显改善其抗氧化性能。To modify the oxidation resistance of carbon fiber-reinforced carbon aerogel composites for thermal insulators, Si OC precursor sol was prepared using dimethyldiethoxylsilane(DMDES) and methyltrimethoxysilane(MTMS) as raw materials; then the carbon aerogel composites were impregnated with the Si OC precursor sol, after gelation, aging, solvent exchanging, ambient drying, and pyrolysis, Si OC ceramic inner coating was deposited in the carbon aerogel composites. Anti-oxidation composites were obtained by repeating this procedure for several cycles. Results show that, for the composite deposited with three cycle Si OC coatings, the density is 0.77 g/cm3(0.20 g/cm3 for the aerogel composite without Si OC coating) and the thermal conductivity at 25 °C is 0.33 W/m·K(0.11 W/m·K without Si OC coating). The mass loss after 1600 °C, 20 min heat treatment in air decreases with increasing the depositing cycles. For the composite with three cycle Si OC coatings, the mass loss is 10.33% and the linear shrinkage is 1.16%. It evidently indicates that infiltrating organic-inorganic silica sol and then carbonizing to form Si OC coatings on the inside and outside surface of the nano-porous carbon aerogel composites can improve their oxidation resistance properties.

关 键 词：炭气凝胶 隔热复合材料 SiOC陶瓷 抗氧化 

分 类 号：TB332[一般工业技术—材料科学与工程] TB306