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化学学报
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化学学报 ›› 2008, Vol. 66 ›› Issue (11): 1371-1376. 上一篇    下一篇

研究论文

新型SiBNC陶瓷先驱体——聚硼硅氮烷的合成与表征

唐云*，王军，李效东，李文华，王浩，谢征芳   

  1. (国防科技大学新型陶瓷纤维及其复合材料国防科技重点实验室 长沙 410073)
  • 投稿日期:2007-04-19 修回日期:2007-10-23 发布日期:2008-06-14
  • 通讯作者: 唐云

Synthesis and Characterization of Polyborosilazane as Novel Precursor to SiBNC Ceramic

TANG, Yun*; WANG, Jun; LI, Xiao-Dong; LI, Wen-Hua; WANG, Hao; XIE, Zheng-Fang   

  1. (State Key Laboratory of Advanced Ceramic Fibers & Composites, National University of Defense Technology, Changsha 410073)
  • Received:2007-04-19 Revised:2007-10-23 Published:2008-06-14
  • Contact: TANG, Yun

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以甲基氢二氯硅烷、三氯化硼、六甲基二硅氮烷为起始原料, 采用共缩合的方法合成了一种新型的可溶可熔的SiBNC陶瓷先驱体——聚硼硅氮烷(PBSZ). 该法合成工艺简单, 且合成收率约为91% (w%). 采用元素分析、傅立叶红外光谱、核磁共振波谱、X射线光电子能谱、动态热机械分析、热重分析等对PBSZ的组成、结构和性能进行了表征. 结果表明, 先驱体的主要骨架为—Si—N—B—, 其中, B, N以硼氮六环形式存在, 而C则以Si—CH3形式存在. 该先驱体熔点为69 ℃, 数均分子量为10802, 分子量分散系数为1.50. 此外, 所合成的先驱体具有优良的成型性, 在80 ℃的N2气氛中可纺丝得到15～20 μm的有机纤维, 1000 ℃时相应陶瓷产率约为63% (w%).

关键词: SiBNC陶瓷, 陶瓷纤维, 聚硼硅氮烷, 陶瓷先驱体, 合成

A novel soluble preceramic polymer to SiBNC ceramic, polyborosilazane (PBSZ), was synthesized via a cocondensation approach with a yield of about 91% (w%) by using dichloromethylsilane (MeHSiCl2), boron trichloride (BCl3) and hexamethydisilazane (HMDZ) as the starting materials. The chemical composition, structure and properties of the obtained polymer were investigated using element analysis, FT-IR, NMR, XPS, TMA and TG. The results indicate that the backbone of the polymer is —Si—N—B— linkage in the form of borazine ring and C is in the form of Si—CH3 in the pendant or end group. The melting point, number average molecular weight and polydispersity index of PBSZ is 69 ℃, 10802 and 1.50, respectively. PBSZ shows good processability and PBSZ fibers with diameter of 15～20 μm can be obtained by melt spinning at 80 ℃ in N2 atmosphere. The ceramic yield of the PBSZ at 1000 ℃ in nitrogen atmosphere is 63% (w%), which suggests that the as-achieved polymer can be used as a precursor to SiBNC ceramic fiber.

Key words: SiBNC ceramic, ceramic fiber, polyborosilazane, preceramic polymer, synthesis