膨胀阻燃聚丙烯的热降解动力学及热寿命分析

Kinetic Study and Thermal Lifetime Analysis on Thermal Degradation of Intumescent Flame Retardant Polypropylene

利用双辊混炼机制备了共混型阻燃聚丙烯(PP)材料,并用热重(TG-DTG)方法研究了PP、PP/MPP和PP/MPP/PER在N2气氛下以不同升温速度时的热降解动力学行为,以此探讨阻燃性能与热降解行为的关系。试验发现,加入阻燃剂后材料的初始分解温度提前;利用Kissinger法和Flynn-Wall法求取了材料的活化能,发现两种方法求取的结果相一致,并且添加阻燃剂后,材料的活化能明显提高;热降解残留物的红外光谱分析结果表明MPP复配PER后,保留了更多的PP特征峰;说明阻燃剂提前分解成炭、隔热、隔氧,阻止了PP的进一步氧化分解;材料的寿命分析发现,添加阻燃剂后,材料的热寿命都明显提高。

The intumescent flame retardant polypropylene composites have been prepared by using two roll mill, and with different heating rate, the thermal degradation kinetics behaviors of PP and flame retardant PP composites in nitrogen atmosphere were studied by means of TG. The relation between flame retarding property and thermal degradation was studied. It was showed that with flame retardant agent added, the initial decomposition temperature of PP occurred in advance. The thermal degradation of materials have been simulated by Kissinger and Flynn- Wall method, activation energies got by the two method were similar, and the activation energies of flame retardant PP were higher than that of PP. It was showed that the flame retardant agents advance PP to decompose into carbon, insulate it from heat and oxygen, and hold back its further oxidation and decomposition. The lifetimes of materials added flame retardant agents were much longer than that of pure PP obtained by isothermal TG.