摘要
碳化硅基复合材料是理想的高温结构材料,以聚碳硅烷(PCS)作为碳化硅陶瓷的先驱体,二乙烯基苯(DVB)为交联体,通过改变二者的配比研究了PCS与DVB的交联反应以及PCS/DVB交联体的热裂解过程。通过傅立叶红外光谱详细研究了PCS/DVB配比变化对PCS与DVB的交联反应和交联体微观结构的影响,PCS/DVB配比最终决定碳化硅陶瓷的产率,当PCS/DVB配比为1∶0.5时,经1500℃热裂解后碳化硅陶瓷产率最高,达到63.1%,热裂解产物为纳米碳化硅,粒径为10-40nm。用SEM和XRD研究了不同PCS/DVB配比交联体热裂解产物的微观结构和相组成,通过热重分析研究了PCS/DVB配比为1∶0.5时交联体的热裂解过程,在400-800℃,PCS/DVB交联体失重显著,在800℃热裂解过程基本完成,PCS/DVB配比为1∶0.5时能够制备出纳米碳化硅基复合材料。
Silicon carbide matrix composites are the most promising candidates for high temperature structural materials, which exhibit an excellent oxidation resistance because of the formation of a protective layer of silica which limits further oxidation. Polycarbosilane （PCS） and divinylbenzene （DVB） were selected as a precursor to silicon carbide ceramics and a cross-linking reagent for PCS, respectively. The cross-linking properties and pyrolysis of PCS and DVB were investigated by changing the mass ratios of PCS/DVB. The effects of the mass ratios of PCS/DVB variables on cross-linking properties and microstructures were characterized by FTIR. The mass ratio of PCS/DVB has a great effect on silicon carbide ceramic yield. The cured PCS/DVB with a mass ratio of 1 ： 0.5 has the highest ceramic yield （63.1%） at the temperature up to 1500℃ and its pyrolyzates consist of nano silicon carbide with a diameter of 10-40 nm. The microstructures of the products pyrolyzed at 1500 ℃ were characterized by SEM and XRD. The pyrolysis behavior of the cured PCS/DVB with a mass ratio of 1 ： 0.5 was characterized by thermogravimetry in nitrogen atmosphere. The pyrolysis main weight loss begins at 400 ℃ and is completed by 800 ℃. PCS/DVB with a mass ratio of 1 ： 0. 5 is the best precursor for the fabrication of nano SiC matrix composites.
出处
《材料科学与工程学报》
CAS
CSCD
北大核心
2009年第3期421-425,共5页
Journal of Materials Science and Engineering
基金
国家自然科学基金资助项目(50672004)
国家"863"计划资助项目(2008AA03Z513)
关键词
先驱体
聚碳硅烷
二乙烯苯
交联
纳米SIC
precursor
polycarbosilane
divinylbenzene
cross-linking
nano silicon carbide
