聚氨酯软质泡沫制品阻燃性能检测分析

The combustion characteristics, cell structure of flexible polyurethane (PU)foam were tested by limit oxygen index tester, vertical burning tester and SEM, and fire grade classified by 7.1.4 and 8.1.4 of GB 50826 Technical code for construction of electromagnetic wave anechoic enclosure. The relationship between different combustion characteristics of PU was studied. The applicability of the burning test method was discussed. The results show that the lower limit oxygen index(LOI), the more difficult the PU foam is to extinguish after being ignited in the air, and the less mass remains. The PU foam with high density and high LOI was tested by vertical burning, the specimen was extinguished after the burner was removed. There is no significant correlation between oxygen index and vertical combustion height (flame height). The judgement results of flexible PU foam according to requirement in absorbing material show that unqualified flame height of vertical combustion is the main reason for the unqualified flame retardant performance. Due to the open-cell structure of flexible PU foam and the characteristics of vertical burning test method, the evaluation method of vertical burning performance of flexible PU foam using GB/T 8333-2012 is debatable.