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无机材料学报

无机材料学报

• 研究论文 • 上一篇    下一篇

聚硼硅氮烷的合成及其热解产物的组成及结构

唐 云, 王 军, 李效东, 李文华, 王 浩   

  1. (国防科技大学CFC国防科技重点实验室, 长沙 410073)
  • 收稿日期:2007-05-15 修回日期:2007-08-19 出版日期:2008-05-20 网络出版日期:2008-05-20

Synthesis of Polyborosilazane and Composition and Structure of the Pyrolyzed Products

TANG Yun, WANG Jun, LI Xiao-Dong, LI Wen-Hua, WANG Hao   

  1. (State Key Laboratory of Advanced Ceramic Fibers \& Composites, National University of Defense Technology, Changsha 410073, China)
  • Received:2007-05-15 Revised:2007-08-19 Published:2008-05-20 Online:2008-05-20

PDF (PC)

1999

被引次数

22 | 3

摘要： 以甲基氢二氯硅烷、三氯化硼、六甲基二硅氮烷为起始原料, 采用共缩合原理合成了聚硼硅氮烷(PBSZ)先驱体, 将PBSZ分别在N2和NH3/N2气氛中高温热解得到SiBNC陶瓷. 利用元素分析、XPS、NMR、FT-IR、XRD等分析手段对PBSZ及其陶瓷产物的组成、结构和热稳定性进行了表征. 结果表明, 先驱体的结构骨架为-Si-N-B-, 其中B、N以硼氮六环的形式存在, C以Si-CH3形式存在. 1000℃时两种气氛中陶瓷产率分别为63wt%和61wt%, 1500～1850℃之间失重分别为3.8wt%和10.0wt%. 所得陶瓷的主要相组成均为Si3N4、BN和SiC, 并且均能在1700℃以上保持非晶, 在1850℃时部分结晶. N2中热解产物比NH3/N2中热解产物有更好的稳定性, 更不易结晶.

关键词: SiBNC陶瓷, 先驱体转化法, 聚硼硅氮烷, 耐高温

Abstract: Polyborosilazane (PBSZ), a precursor to SiBNC ceramic, was synthesized via cocondensation approach using methyldichlorosilane (MeHSiCl2), boron trichloride (BCl3) and hexamethydisilazane (HMDZ) as starting materials. SiBNC ceramics were obtained by pyrolysing the as-synthesized PBSZ in N2 or NH3/N2 atmospheres. The chemical composition, structure and high temperature properties of the polymer and ceramics were investigated byusing EA, XPS, FTIR, NMR, and XRD. The results indicate that the backbone of PBSZ is -Si-N-B- linkage in the form of borazine and C is in the form of Si-CH3. The ceramic yield of the PBSZ pyrolysed at 1000℃ in N2 and NH3/N2 atmospheres is 63wt% and 61wt%, respectively. The products show excellent high temperature stability which are fully amorphous to 1700℃. Furthermore, only partial crystallization, giving a mixture of Si3N4, BN and SiC phases, is observed heating at 1850℃. The weight loss of SiBNC ceramics pyrolyzed in NH3/N2 and N2 atmospheres from 1500℃　to 1850℃ is about 10.0wt% and 3.8wt%, respectively. The N2 pyrolyzed products show better stability than the NH3/N2 pyrolyzed products and have less tendency to crystalline at higher temperature.

Key words: SiBNC ceramics, polymer prolysis, polyborosilazane, high temperature resistance

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