前驱体聚合物转化法制备SiBNC陶瓷纤维的热解过程研究

Pyrolysis of Polymer-Derived SiBNC Ceramic Fibers

采用前驱体聚合物转化法制备SiBNC陶瓷纤维。通过高温热失重分析(TGA)、色谱-质谱联用技术(GC-MS)、傅里叶变换红外光谱(FTIR)以及元素分析(EA)等手段对前驱体纤维的热解过程进行了研究。研究结果表明,前驱体纤维从室温升至1500℃的过程中出现三段明显的热失重区域,结合FTIR和GC-MS分析可知在室温至800℃的升温过程中化学结构出现显著变化,并且主要逸出了甲胺和甲烷气体,同时EA结果显示碳含量明显下降,当热解温度达到800℃时陶瓷化转变过程基本完成。1600℃时热解得到的SiBNC陶瓷纤维主要结构为B-N、Si-N。

SiBNC ceramic fibers were prepared by a polymer derived ceramic route.The pyrolysis process of precursor fibers was investigated via TGA,FTIR,GC-MS and EA.The results showed that there were three weight loss ranges during the pyrolysis ofpreceramic polymer fibers in nitrogen atmosphere.Observed in combination with FTIR and GC-MS techniques,the chemical structure changed significantly due to the release of methylamine and methane in the temperature range from room temperature to 800 ℃,and the EA results exhibited that the carbon content decreased obviously.The ceramization was completed when the temperature was up to 800 ℃.Bonds of B-N and Si-N existed in the structure of the resultant SiBNC ceramic fibers pyrolyzed at 1600 ℃.