氯羟丙基磷酸酯对软质聚氨酯泡沫阻燃的物理化学作用

应用ＳＥＭ、热分析和ＩＲ光谱等较全面地研究了ＣＨＰＡ－ＰＵ软泡燃烧的物理化学变化，结果表明该阻燃基体［－ＮＨ－ＣＯ－０－ＣＨ（ＣＨ＿２Ｃｌ）－ＣＨ＿２－０－］＿３－Ｐ＝０的热分解加速，在燃烧初期就释放出ＨＣｌ与其磷酸酯互相作用生成ＰＯＣｌ＿３、ＰＣｌ＿３、ＰＣｌ＿ｓ等不燃性化合物。证实了这些Ｐ－Ｃｌ化合物：１）挥发带走热量降低体系温度，且其散发速度比ＨＣｌ慢，可延长在燃烧区域的停滞时间，更有效地在气相起阻燃作用；２）在燃烧过程（高温区）有氧存在下，转化为各种形态的磷酸，具有强烈的脱水效能，使含氧的ＰＵ软泡表层碳化生成阻隔燃烧的覆盖层，起到固相阻燃的作用，由于这些物理化学作用使ＰＵ软泡呈现较佳的阻燃性。

Physical-chemical Effects of Chlorohydroxypropy1phosphate on Fire-resistance of Flexible Po1yurethane(PU)Foam

SEM, IR Spectra and thermal analyses were used for investigation of thephysical-chemical changes during the combustion of Chlorohydroxypropylphosphate (CHPA )-PU Flexible Foam. It was shown that the flame-retarding group-NH-CO-0-CH(CH_2Cl)-CH_2-0-]_3-P=0was decomposed so fast that in the early stage of combustion HCl wasgiven off to react with phosphate to release incombustible compounds such as POCl_3,PCl_3,PCl_5.At first they have a smaller volatizing speed than HCl and consequently a longer interval of timeto suspend in the system,so when volatized, they can act more efficiently under gas phase totake away the heat so as to lower the temperature of the material; Secondly under high tempera-tures, they react with oxygen in the environment to produce varieties of phosphoric acids, whoseextremely strong effect of dehydration carbonizes the PU Foam to form an insulation surface lay-er to prevent the material from further combustion, that is, act under solid phase.The coopera-tion of the two aspects is the major reason to give the PUF a fairly good flame-retarding effect.