MnO_2催化阻燃聚丙烯体系的热降解动力学研究

Thermal Degradation Kinetics of Flame Retardant PP Catalyzed by MnO_2

制备了新型MnO2催化膨胀阻燃聚丙烯(FR-Mn)材料,并用热重(TG-DTG)方法研究了不同气氛下,其热降解动力学行为。试验发现,升温速率提高,材料的热降解推迟;在氮气气氛下,材料的热降解为两步反应,而空气气氛下,材料的分解更为复杂,失重明显提前。采用Kissinger和Flynn-Wall法求取了材料的热降解参数,结果表明空气气氛下材料的热降解活化能明显低于氮气气氛下的活化能;氮气气氛下,两种方法求得的活化能基本一致;而空气气氛下的活化能相差较远;可能与材料在空气气氛下热降解反应的复杂性有关。

Novel Halogen-free retardant PP （FR-Mn） catalyzed by MnO2 is prepared, and effect of atmosphere on thermal degradation kinetics behaviors of flame retardant PP is studied by means of TGA-DTG. It is found that thermal degradation temperatures rose with the increases of heating rate and the process of thermal degradation in nitrogen is two-step transition state, but that in air is much more complicated, and degradation is occurrs in advance. The thermal degradation of materials is simulated by Kissinger and Flynn-Wall methods, activation energy in air is lower than that in nitrogen. Activity energies of materials in nitrogen by two methods are agreed well; but those in air are different, which perhaps is related to the complicity of thermal degradation of material in air.