基于层次分析法的热塑性聚氨酯及其纳米复合材料火灾危险性综合评价

聚合物的火灾危险性与热、烟、毒的释放密切相关,但采用不同指标对材料的评价结果不一致。以纳米级蒙脱土(MMT)、氢氧化铝(ATH)和聚磷酸铵(APP)为添加剂的热塑性聚氨酯(TPU)纳米复合材料为研究对象,选取其在静态管式炉、稳态管式炉和锥形量热仪中的相关实验数据,以HCN总浓度作为特殊毒性危害指标,CO和CO_2浓度为一般毒性危害指标,以热释放速率峰值、平均热释放速率、总热释放量为热危害指标,以产烟速率峰值、生烟总量为烟危害指标。进一步细分了火灾烟气中不同毒性气体对于火灾风险的影响,并运用层次分析法计算指标权重,综合评价了热塑性聚氨酯及其复合材料的火灾危险性。结果表明,当添加量为6 wt%聚磷酸铵、3 wt%氢氧化铝与3 wt%蒙脱土时,此时复合材料的火灾危险最低,证明了综合热、烟、毒三个层次来降低聚合物材料火灾危险性是可行的。

Fire hazard assessment on thermal polyurethane and its nanocomposites with AHP analysis

Fire risk of polymer is related to the release of heat, smoke and toxicant, and different parameters bring about different assessment results. In this paper, montmorillonite (MMT), aluminum hydroxide (ATH) and ammonium polyphosphate (APP) are added as flame retardants for thermal polyurethane (TPU). Static state tube furnace, steady state tube furnace and cone calorimeter are used to measure the data. Total HCN concentration is regarded as special toxicity hazard index, CO and CO2 yields are regarded as general toxicity hazard indexes. The heat release rate, average heat release rate and total heat release are regarded as heat hazard indexes. The smoke produce rate is regarded as smoke hazard. The impact of different toxic gases on the fire risk of materials in fire smoke is subdivided. Fire hazard of TPU and its nanocomposites are evaluated by analytic hierarchy process, which is used to calculate the weights of indexes. The results show that the lowest fire risk appears in the TPU with 6 wt% APP, 3 wt% ATH and 3 wt% MMT, which proves that it is feasible to reduce fire hazard of polymers from heat, smoke and toxicity simultaneously.