摘要
以三氯化硼和六甲基二硅氮烷为原料制备了聚硼氮烷预聚体,再经高分子化制备了可溶的氮化硼陶瓷前驱体—聚硼氮烷。该法合成工艺简单,反应温和。采用凝胶渗透色谱、核磁共振氢谱、傅里叶红外光谱、热失重分析仪、元素分析等对预聚体高分子化过程中的分子量变化、高分子化机理、聚硼氮烷的裂解过程、所得陶瓷的元素组成进行了研究。结果表明,高分子化过程中主要发生了六甲基二硅氮烷脱除和转氨基反应。所得聚硼氮烷重均分子量为7 582,氮气下1 000℃时的陶瓷产率为41.6 wt%,陶瓷化转变主要发生在400～600℃,800℃时陶瓷化转变基本进行完毕,800℃氨气下裂解得到低C含量的白色氮化硼陶瓷,进一步在1 500℃氩气中裂解可得到结晶度较高的氮化硼陶瓷。
Soluble preceramic polymer to BN ceramic, polyborazine, was synthesized via condensation of boron trichloride and hexamethydisilazane followed by a polymerization process. The average molecular weight and structure of the prepolymer during polymerization, mechanism of polymerization, pyrolysis process, and chemical composition of the obtained ceramic were investigated using gel permeation chromatography, 1H NMR, infrared spectra, thermogravimetric analysis and element analysis. The results indicate that hexamethydisilazane and NH3 were released during the polymerization process. The average weight molecular and ceramic yield （ 1 000℃ in N2 ） of the polyborazine are 7 582 and 41.6 wt% respectively. The ceramic mainly formed at the temperature range of 400 to 600℃ and white BN ceramic with low carbon content was obtained after pyrolyzed in NH3 at 800℃.
出处
《宇航材料工艺》
CAS
CSCD
北大核心
2013年第4期39-44,共6页
Aerospace Materials & Technology
关键词
氮化硼陶瓷
聚硼氮烷
高分子化
陶瓷前驱体
裂解
Boron nitride ceramic, Polyborazine, Polymerization, Preceramic polymer, Pyrolysis
