对位芳纶纸热稳定性及其热分解动力学研究

Study on the Thermal Stability and Thermal Decomposition Kinetics of Para-aramid Paper Based Composite

关键词:  对位芳纶纸  对位芳纶沉析纤维  热稳定性  热解产物  热分解动力学

Key Words:para-aramid paper  para-aramid fibrids  thermal properties  thermolysis products  thermal decomposition kinetics

摘要:采用TG-DSC和TG-IR分析由对位芳纶短切纤维和沉析纤维制备的新型对位芳纶纸的热学性能和热分解产物,并借助Coats-Redfern热分析方法探讨其热分解动力学行为。结果表明，该对位芳纶纸热分解过程为三个阶段,100℃以下失去的为结合水,初始分解温度为535℃、TG10%为540℃,800℃时其质量损失为57.2%,且在升温过程中发生裂解但不熔融；热解产物主要为HCN、NO₂、NH₃、NO、CO、CO₂以及H₂O。其热分解特性受升温速率影响较大,随升温速率升高,对位芳纶纸的起始分解温度和终止分解温度均向高温区移动；Coats-Redfern动力学方程适用于计算该复合材料的热分解动力学参数,其拟合直线的相关系数均在0.98以上,反应级数为1,并计算了不同速率下对位芳纶纸的活化能E和频率因子A。

Abstract:Thermal property and thermolysis products of a new kind of para-aramid paper based composite, prepared by para-aramid chopped fibre and fibrids, were analyzed by both TG-DSC and TG-IR, and Coats-Redfern Equation was used to investigate its thermal decomposition kinetics behavior. The results showed that this para-aramid paper based composite had three step decomposition process, and its initial decomposition temperature was above 530℃, its 10% weight loss temperature was 540℃. It was found that this kind of para-aramid paper based composite did not melt during pyrolysis with temperature elevating. The main thermolysis products were HCN, NO₂, NH₃, NO, CO, CO₂ and H₂O. Its thermal decomposition characteristics was influenced greatly by heating rate, both the initial decomposition temperature and ending decomposition temperature of the sample increased with the increase of heating rate. Coats-Redfern Equation was suitable for calculating its thermal decomposition kinetics parameters, the correlation coefficients of their fitting lines were all above 0.98 and the reaction order was 1. In addition, the activation energy (E) and frequency factor (A) of para-aramid paper based composite under different heating rate were calculated.