聚碳硅烷/钛体系的热裂解行为研究  

Pyrolysis Behavior Polycarbosilane/Titanium System

作　　者：陈文怡[1] 费腾[1] 

机构地区：[1]武汉理工大学材料研究与测试中心,湖北武汉430070

出　　处：《热加工工艺》2015年第2期76-80,共5页Hot Working Technology

基　　金：湖北省自然科学基金(2013CFB340)

摘　　要：利用Coats-Redfem动力学模型和热重质谱联用TG-MS研究了聚碳硅烷（PCS）/Ti体系的热裂解动力学行为。用X射线衍射和扫描电镜等技术研究了PCS/Ti体系热裂解过程特点和化学反应机理。结果表明,PCS/Ti体系的热解反应过程以一级热分解化学反应为主,可分为3个阶段,300～343℃,活化能227.08 k J·mol-1;343～511℃,活化能34.41 k J·mol^＋-1;511～645℃,活化能为15.76 k J·mol^＋-1。热解反应的表观活化能与热解温度有较大关系,随着反应的进行逐步减小。TG-MS分析表明：PCS热解挥发气体为H2和CH4以及C的碎片。扫描电镜和X射线分析结果表明：热解到1000℃有明显的Si C物相。金属Ti粉与部分C反应形成了Ti C,可获得Ti C/Si C复合陶瓷。The polycarbosilan（PCS）/pyrolysis kinetic behavior of Coats-Redfcm Ti system was studied by using dynamics model and thermal gravimetric mass TG-MS. The Ti features and chemical reaction mechanism PCS system thermal cracking process was analyzed by XRD and SEM. The results show that the pyrolysis reaction PCS/Ti system mainly belongs to one level thermal decomposition reaction. The reaction can be divided into three stages, at 300-343 ℃ ; the activation energy is 227.08 kl. mol^＋-1; at 343-511 ℃, the activation energy is 34.41 kJ·mol^＋-1; at 511～645 ℃, the activation energy of 15.76 KJ·mol^＋-1. The apparent activation energy of the pyrolysis reaction has a greater relationship with the pyrolysis temperature, and gradually decreases as the reaction proceeding. TG-MS analysis shows： PCS pyrolysis vapors of H2 and CIL and C debris; SEM and X-ray analysis show that：the pyrolysis to 1000℃, SiC phase appears; Ti reacting with C formates TiC, then, TiC/SiC composite ceramics can be gotten.

关 键 词：聚碳硅烷 钛 热解动力学 TG-MS TiC/SiC复合陶瓷 

分 类 号：TQ433.437[化学工程]