引用本文: | 程祥珍,肖加余,谢征芳,等.聚二甲基硅烷高压合成聚碳硅烷的组成与结构分析[J].国防科技大学学报,2005,27(2):20-23.[点击复制] |
CHENG Xiangzhen,XIAO Jiayu,XIE Zhengfang,et al.Composition and Structure Characterization of Polycarbosilane Synthesized from Polydimethylsilane under High Pressure[J].Journal of National University of Defense Technology,2005,27(2):20-23[点击复制] |
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聚二甲基硅烷高压合成聚碳硅烷的组成与结构分析 |
程祥珍, 肖加余, 谢征芳, 宋永才, 王应德 |
(国防科技大学 航天与材料工程学院,湖南 长沙 410073)
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摘要: |
以聚二甲基硅烷(PDMS)为原料,在高压釜内450℃下反应6h,制备了聚碳硅烷(PCS)先驱体。对其组成及结构进行了表征,推测了PCS的大致结构模型。研究表明,PCS分子包含Si-CH3、Si-CH2-Si、Si-H组成的SiC4、SiC3H等结构单元,实验式为SiC1.87H7.13O0.03。与常压高温裂解制备的软化点相近的PCS相比,二者的元素组成基本一致,高压合成的PCS具有较高的分子量和硅氢含量,但支化度略高。 |
关键词: 聚二甲基硅烷 高压 聚碳硅烷 组成 结构 |
DOI: |
投稿日期:2004-10-31 |
基金项目:国家自然科学基金资助项目(50082007) |
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Composition and Structure Characterization of Polycarbosilane Synthesized from Polydimethylsilane under High Pressure |
CHENG Xiangzhen, XIAO Jiayu, XIE Zhengfang, SONG Yongcai, WANG Yingde |
(College of Aerospace and Materials Engineering, National Univ. of Defense Technology, Changsha 410073, China)
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Abstract: |
The polycarbosilane (PCS),the precursor of SiC fiber,is synthesized at 450℃ for 6h in an autoclave by thermal decomposition of polydimethylsilane (PDMS). The composition and structure of the PCS are characterized by softening point, element analysis, IR, molecular weight distribution, and NMR. Structure model of PCS is therefore proposed. IR and NMR show the presence of SiC4and SiC3H structure units containing Si-CH3, Si-CH2-Si, and Si-H groups. Elemental analysis provides an empirical formula of SiC1.87 H7.13O0.03. Compared with the PCS with close softening point synthesized at normal pressure, the PCS synthesized in the autoclave has a approximate elemental composition, higher Si-H bond content, higher molecular weight, but lower ratio of SiC3H and SiC4. |
Keywords: polydimethylsilane, high pressure, polycarbosilane, composition, structure |
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