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化学学报
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化学学报 ›› 2008, Vol. 66 ›› Issue (21): 2397-2402. 上一篇    下一篇

研究论文

铝含量对含铝碳化硅陶瓷先驱体结构和性能的影响

赵大方 李效东* 王海哲 郑春满 王 浩

  

  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:2008-02-22 修回日期:2008-05-09 发布日期:2008-11-14
  • 通讯作者: 李效东

Effects of Aluminum Content on the Structure and Properties of Precursor for SiC(Al) Ceramics

ZHAO, Da-Fang LI, Xiao-Dong* WANG, Hai-Zhe ZHENG, Chun-Man WANG, Hao   

  1. (State Key Laboratory of New Ceramic Fibers and Composites, School of Aerospace and Materials Engineering,
    National University of Defense Technology, Changsha 410073)

  • Received:2008-02-22 Revised:2008-05-09 Published:2008-11-14
  • Contact: LI, Xiao-Dong

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被引次数

2 | 2

采用不同比例的乙酰丙酮铝[Al(AcAc)3]与聚硅碳硅烷(PSCS)反应制备含铝碳化硅陶瓷的先驱体聚铝碳硅烷(PACS). 采用气相凝胶色谱(GPC)、化学分析和红外等手段对不同铝含量的PACS组成和结构进行了表征, 研究了铝含量对PACS结构和性能的影响. 结果表明, 随着铝含量的增加, PACS的氧含量增加, 分子量分布变宽, 主要活性基团Si—H键的含量降低, PACS的可纺性降低. 当Al(AcAc)3/PSCS(质量比)大于20%以后, PACS不可纺. 热重-差热分析(TG-DTA)的研究表明: 当制备PACS的Al(AcAc)3/PSCS(质量比)大于4%, PACS在N2中400～560 ℃之间的失重明显降低. 铝含量在0.4～0.7 wt%的PACS, 制备的Si-Al-C-O纤维抗张强度最高. Al(AcAc)3/PSCS＝6 wt%时制备的PACS, 烧结的SiC(Al)纤维最致密.

关键词: 聚铝碳硅烷, Al含量, 陶瓷产率, 碳化硅

A series of polyaluminocarbosilane (PACS) as precursors for SiC(Al) ceramics were prepared from polysilacarbosilane (PSCS) and aluminum acetylacetonate [Al(AcAc)3] by various ratios. The PACS containing various amount of aluminum were characterized by chemical analysis, gel permeation chromatograms (GPC) and FTIR. And effects of aluminum content on the structure and properties of PACS were investigated. With increasing aluminum content, PACS would have higher oxygen content, broader molecular weight distribution, lower Si—H content and worse spinnability. When Al(AcAc)3/PSCS was more than 20%, PACS could not be melting spun. Moreover, when PACS was prepared by Al(AcAc)3/PSCS＞4 wt%, the weight loss in N2 from 400 to 560 ℃ decreased. The Si-Al-C-O fibers derived from PACS with 0.4 wt%～0.7 wt% aluminum content show high tensile strength. The SiC(Al) fiber derived from PACS obtained from Al(AcAc)3/PSCS＝6 wt% was the best sintered.

Key words: polyaluminocarbosilane, aluminum content, ceramic yield, silicon carbide