甘蔗渣对聚甲基丙烯酸甲酯热降解的影响

目的分析生物质材料对塑料废弃物热降解的影响,以聚甲基丙烯酸甲酯(PMMA)为对象,探讨甘蔗渣对其热分解行为和动力学的作用。方法利用溶液共混法制备PMMA/甘蔗渣混合物,采用热失重法研究其在氮气中的热分解过程,通过最大失重速率法和Ozawa等失重法计算PMMA热分解反应的动力学参数活化能和频率因子。结果甘蔗渣使得PMMA的初期热分解温度明显降低,但是PMMA的热分解活化能和频率因子却都显著增加。最大失重速率法的计算结果表明,PMMA加入甘蔗渣后的热分解活化能增加了26.2 k J/mol,等失重法的结果显示活化能和频率因子分别为168.14 k J/mol和28.41 min-1,比纯PMMA相应地增大了72.6 k J/mol和12.52 min-1。结论甘蔗渣的加入对PMMA的热降解有显著的影响,使其热分解变得困难,因此有必要进一步探讨其他生物质对PMMA热分解的影响。

Influence of Sugar Cane Bagasse on Thermal Degradation of Polymethyl Methacrylate

The work aims to study the effect of sugar cane bagasse on its thermal decomposition and kinetics by selecting polymethyl methacrylate (PMMA) to analyze the influence of bio-based materials on thermal degradation of plastic waste. Thermogravimetric analysis of PMMA/bagasse mixtures, prepared in solution blended process, was conducted to study the thermal degradation process under nitrogen atmosphere. Both the maximum weight loss rate method and Ozawa isoconversional method were used to calculate the activation energy and frequency factor of kinetic parameters for PMMA thermal decomposition. The involvement of sugar cane bagasse resulted in significant decrease of the initial thermal decomposition temperature of PMMA, but the thermal decomposition activation energy and frequency factor of PMMA increased remarkably. The calculation results obtained by using the maximum weight loss rate method showed that the activation energy of thermal decomposition after blending sugar cane bagasse into PMMA increased by 26.2 kJ/mol, and the isoconversional method resulted in the activation energy of 168.14 kJ/mol and frequency factor lnA of 28.41 min-1. They were respectively 72.6 kJ/mol and 12.52 min-1 higher than that of pure PMMA accordingly. Blending of sugar cane bagasse has substantially influenced PMMA''s thermal decomposition as it makes such decomposition become difficult. Thus it is necessary to further explore the influence of other biomasses on thermal degradation of PMMA.