聚氯乙烯电缆料老化前后的火灾危险性研究

Study on fire hazard of pre-aging and post-aging PVC cable materials

利用微型燃烧量热计(MCC)、热重分析(TGA)、实时红外光谱(RTFTIR)以及热重-红外联用技术(TG-FT-IR)研究了PVC电缆料老化前后火灾危险性的变化。MCC结果表明,老化后的PVC的最大热释放速率增加了56.3%,总热释放量从10.6kJ/g增加到16.8kJ/g,点燃温度也由302℃提前到282℃。TG-FTIR和RTFTIR的分析结果显示,PVC的主要降解产物有水、碳氢化合物、二氧化碳和一氧化碳。PVC达到最大降解速率的温度约为240℃,与MCC、TG的结果相符合。PVC的裂解气体中包含CO2和CO,还有剧毒气体HCl。这些实验数据说明PVC材料在使用过程中火灾危险性加大,为老城区电气线路和设备的改造提供了理论依据和实验基础。

The fire hazard of pre-aging and post-aging PVC cable materials was investigated using microscale combustion calorimetry（MCC）,thermogravimetric analysis（TGA）,thermogravimetric analysis-infrared spectrometry（TG-FTIR） and real time FTIR.MCC data indicated that the peak heat release rate（PHRR） of post-aging PVC cable materials increased by 56.3% compared to pre-aging PVC cable materials,the total heat release increased from 10.6 kJ/g to 16.8kJ/g and the ignition temperature decreased from 302℃ to 282℃.The TG-FTIR and RTFTIR results suggested that the main pyrolysis products of PVC cable materials were water,hydrocarbons,CO2,CO,et al.The maximum decomposition rate of PVC cable materials appeared at around 240℃,which corresponded well with MCC and TGA.The pyrolysis products of PVC cable materials contained CO2,CO and toxic HCl.It is concluded that the fire hazard of PVC cable materials increases during the course of use.