聚氨酯泡沫塑料的阻燃及热解性能

Combustibility and thermal degradation mechanism of flame retardant flexible polyurethane foam

采用热重分析仪、傅里叶变换红外光谱仪和扫描电子显微镜研究了氨基树脂型高分子膨胀阻燃剂(AIFR)阻燃软质聚氨酯泡沫塑料(FPUF)的阻燃、热解性能结果表明,w(AIFR为15%以上时,阻燃FPUF的垂燃烧性能达到美国联邦航空局颁布的条例FAR25.853的要求。AIFR阻燃FPUF热解首先发生脱磷酸、酸催化FPUF脱水和重排交联炭化反应,使其热解中间产物热稳定性增加,热失重速率降低0.144%/s,剩炭率提高10.6%,AIFR主要以凝聚相成炭作用模式起阻燃作用。残炭扫描电子显微镜照片显示,AIFR阻燃FPUF的炭层致密,空洞少;残炭的韧性好,强度较高,可阻挡燃烧过程中的热量和和气体的交换,达到阻燃目的。

This paper studied the flame retardance and thermal degradation property of flexible polyurethane foam （FPUF） modified with an amino resinous intumescent macromoleeular flame retardant （AIFR） with thermoravimetrie （TG） analyzer, Fourier transform infrared spectroscopy （FFIR） and scanning electron microscopy （SEM）. The results reveal that the flame retardant performance of the FPUF foam specimens in the vertical burn test can satisfy the requirements stipulated in the rule （FAR25.853） promulgated by the Federal Aviation Administration of the United States when the AIFR dosage is over 15% by weight. In the thermal degradation process of the AIFR retarded FPUF, dephosphorylation occurs as the initial reaction and then the resultant acid eatalyzes the dehydration of FPUF and the reactions of rearrangement, erosslinking and carbonization. As a result, the thermal stability of the intermediate resultant improves; the thermal degradation rate lowers 0.144 %/s and the earbon residue rate increases 10.6%. AIFR mainly exerts its flame retardant function in the mode of carbonization of solidification phase. The SEM mierographs of the carbon residue reveal that the AIFR retarded FPUF exhibits the features of compact intumescent charred layer and few holes inside the layer after burning. The charred layer with superior toughness and high strength can effectively block off the transfer of heat and gases during the combustion process, and thereby being able to reach the goal of flame retarding.