抗氧剂对PMMA树脂热氧化稳定性的影响及动力学分析

摘要

The behavior of several antioxidants in poly（methyl methacrylate） （PMMA） was studied using thermo gravimetric analyzer（TG） and the kinetics of thermal degradation was analyzed with Kissinger, Flynn-Wall-Ozawa and Flynn methods. It showed that four kinds of antioxidant 1010, 1076, 702, and BHT increased the initial thermal degradation temperature by 70 ℃ at a content of 0. 5 wt ‰. Further increasing the loading, the change was moderate. The kinetics analysis showed that the antioxidant could only improve the thermal Oxidative stability at the initial period of degradation（the weight loss less than 30 %）, after which the stabilizing effect of antioxidant on PMMA was reduced due to the antioxidant escaped from the system at a higher temperature than the melting point of antioxidant.%采用热重分析，研究了抗氧剂种类及用量对聚甲基丙烯酸甲酯（PMMA）热氧化稳定性的影响，并采用Kissinger、Flynn-Wall—Ozawa和Flynn法对其热氧化降解行为进行了动力学分析。结果表明，抗氧剂1010、1076、702和BHT的用量为0．5‰时就能够显著提高PMMA热氧化稳定性，使其起始热分解温度提高70℃左右，而抗氧剂用量进一步提高对改善PMMA的热稳定性意义不大；动力学分析表明，抗氧剂的加入能够提高PMMA质量损失率小于30％时的热降解活化能，而热分解后期由于降解温度高于抗氧剂熔点，抗氧剂气化逸出，抗氧剂不能有效提高PMMA后期热降解活化能，未能达到提高PMMA整体热稳定性的目的。