酚醛树脂保温板热分解过程的lnln法研究

Study of lnln for thermal decomposition process of phenolic resin insulation board

采用热重分析仪研究酚醛树脂保温板粉体热解行为。采用lnln法探讨等温热解过程动力学,采用Eyring方程探讨热解活化热力学参数。结果表明:酚醛树脂保温板粉体,在800℃内,非等温热解分为四个阶段,各阶段失重率依次为9%、10%、24%、25%;低于523K和高于573K时等温过程热解失重率低于523-573K温度段。lnln法获得酚醛树脂保温板粉体热解表观活化能为40.36 kJ·mol^(-1);Eyring法获得热分解的摩尔活化焓△H≠、摩尔活化熵△S≠分别为35.87 kJ·mol^(-1)和-202 J·mol^(-1)·K^(-1),摩尔活化自由能△G≠值在讨论温度范围内皆为正,表明热解过程需要引入热量并且为非自发分解反应,热解需要经历活化络合态且络合态系统比初始状态更有序。

The pyrolysis behavior of phenolic resin insulation board powder was studied by thermogravimetric analyzer.The kinetics of isothermal pyrolysis was studied by lnln method,and the thermodynamic parameters of pyrolysis activation were studied by Eyring equation.The results show that the non-isothermal pyrolysis of phenolic resin insulation board powder at 800℃is divided into four stages,and the weight loss rate of each stage is 9%,10%,24%and 25%in turn;the weight loss rate of isothermal pyrolysis below 523K and above 573K is lower than the temperature range 523-573K.The apparent activation energy of phenolic resin insulation board was 40.36 kJ·mol^(-1) by lnln method.The molar activation enthalpy△H≠and molar activation entropy△S≠of thermal decomposition obtained by the Eyring method are 35.87 kJ·mol^(-1) and-202 J·mol^(-1)·K^(-1),respectively.The molar activation free energy△G≠are positive in the discussed temperature range,indicating that the pyrolysis process needs to introduce heat and is a non-spontaneous decomposition reaction.The pyrolysis process needs to go through the activation complex state and the complex state system is more ordered than the initial state.