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。
The polycarbosilane (PCS), the precursor of SiC fiber, is synthesized at 450°C 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 SiC4 and SiC3H structure units containing Si-CH3, Si-CH2-Si, and Si-H groups. Elemental analysis provides an empirical formula of SiC1.87H7.13O0.03. 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.
出处
《国防科技大学学报》
EI
CAS
CSCD
北大核心
2005年第2期20-23,共4页
Journal of National University of Defense Technology
基金
国家自然科学基金资助项目(50082007)
关键词
聚二甲基硅烷
高压
聚碳硅烷
组成
结构
polydimethylsilane, high pressure, polycarbosilane, c omposition, structure
