摘要
用热失重分析方法(TGA),研究了氟醚橡胶在氮气中的热分解规律,并探讨了不同升温条件和不同失重阶段氟醚橡胶的热分解动力学.研究结果表明:在氮气中,氟醚橡胶的热分解过程可分为两个阶段;不同升温速率下其热分解反应机理相同;升温速率越大,氟醚橡胶的分解温度越高.应用等转化率法(Friedman微分法),在不假设反应机理函数的情况下,分析了氟醚橡胶热分解在不同转化率时的活化能,其平均值为241.4kJ/mol;同时用Coats-Redfern法分析得出氟醚橡胶在不同升温速率时的热分解动力学参数基本相同.结合两种分析方法提出:氟醚橡胶在氮气中的热分解活化能E为244.3kJ/mol,最理想的热分解反应机理函数为幂函数法则,其积分形式为g(α)=α3/2.
The thermal decomposition characteristics and kinetics of fluoroether rubber were studied by thermogravimetric technique under pure nitrogen atmosphere.The results suggest that all samples with heating rate from 5K/min to 20K/min show a similar characteristic in their TGA curves,two steps take place in their decomposition processes.And as the heating rate increasing,the degradation temperature of the sample moves to be higher.The method of equal conversion rate （Friedman method）was used to determinate the apparent activity energy at different conversion rates,it is found that the average value of the activity energy is 241.4 kJ/mol.Coats-Redfern method was used to discuss the probable degrada-tion mechanism at different heating rate,it indicates that the thermal degradation mechanism of flu-oroether rubber at different heating rates is the same.Combining the two methods,it can be concluded that the most reasonable thermal degradation mechanism of fluoroether rubber is Mampel power law：g （α）=α^3/2 ,and the apparent activity energy is 244.3 kJ/mol.
出处
《四川大学学报（自然科学版）》
CAS
CSCD
北大核心
2015年第1期134-138,共5页
Journal of Sichuan University(Natural Science Edition)
