聚甲基丙烯酸甲酯/蒙脱土纳米复合材料的热分解

采用TG、DTA研究聚甲基丙烯酸甲酯(PMMA)及聚甲基丙烯酸甲酯/蒙脱土纳米复合材料(PMNC)在N2气氛条件下的热降解行为.结果表明,在N2中,PMMA有一个失重阶段,而PMNC为两个失重阶段.利用改进的Coats-Redfern积分法计算PMMA及PMNC的热分解动力学参数,PMMA热分解的平均表观活化能E为160.58kJ/mol,指前因子的对数值lnA为28.07,其热分解的机理函数为三维扩散方程.PMNC第一个阶段的平均表观活化能E为258.731 kJ/mol,lnA为45.623 1,第二个阶段的平均表观活化能E为199.897 kJ/mol,lnA为27.482 4,其热分解的机理函数均为二维扩散方程.

Thermal decomposition of polymethylmethacrylate/montmorillonite nano-composites

Thermal degradation behavior of polymethylmethacrylate(PMMA) and PMMA/montmorillonite nano-composites(PMNC) in N2-ambient was investigated by using TG and DTA.The result showed that,in N2-ambient,there was only one weight-losing stage with the PMMA and with the PMNC,however,there were two such stages.Kinetic parameters of the thermal decomposition of PMMA and PMNC were evaluated by using improved Coats-Redfern integration,showing that the average apparent activation energy E of PMMA thermal decomposition being 160.58 kJ/mol,logarithmic forth-directing factor ln A=28.07,and mechanism function of its thermal decomposition-the solution of a three-dimensional diffusion equation.The average apparent activation energy E of PMNC at first stage was 258.731 kJ/mol and its ln A=45.623 1;at second stage E=199.897 kJ/mol,ln A=27.482 4,and its mechanism function of thermal decomposition was the solution of two-dimensional diffusion as at the first stage.