氯羟丙基磷酸酯对软质聚氨酯泡沫阻燃机理的研究

采用含活性氢的氯羟丙基磷酸酯（ＣＨＰＡ）参与ＰＵ发泡配方中的异氰酸酯反应，使生成的软质聚氨酯泡沫（软ＰＵＦ）分子含阻燃元素Ｃｌ、Ｐ而实现其阻燃化。研究结果表明，含１２ｐｈｒＣＨＰＡ的软质ＰＵＦ的阻燃性能可达ＧＢ１０８００－８９／Ｉ级。着重研究了ＣＨＰＡ对软质ＰＵＦ的阻燃机理，提出燃烧初期ＰＵＦ／ＣＨＰＡ中的Ｃ－Ｃｌ键断裂，释放出ＨＣｌ与磷酸酯作用，生成ＰＯＣｌ３、ＰＣｌ３、ＰＣｌ５等不燃性化合物。

STUDIES OF FLAME-RETARDING MECHANISM OF CHPA ON FLEXIBLE PU FOAM

In the foaming of PU,chlorohydroxypropylphosphate(CHPA) was used to react with the isocyanate to participate the foaming recipe so that fire-extinguishing elements such as P,Cl was made to join in the molecular chain of PU to make the foam flame-retarding.It was studied to show that the flame-retarding effect of the flexible PUF containing 12 phr CHPA hit the specification of GB-10800-89/I.In this paper,the flame-retarding mechanism is investigated to show that in the early stage of the combustion,C-Cl bond in PU-CHPA is broken and HCl is given off to interact with the phosphate so that incombustible compounds such as POCl_3 PCl_3,PCl_3 are released.On the one hand,they have a smaller volatizing speed than HCl and consequently a longer interval of time to suspend in the material,so they can act more efficiently under gas phase;on the other hand,under high temperatures,they react with oxygen in the enviroment to produce varieties of phosphoric acids whose extremelt strong effect of dehydration carbonizes the PU foam to form an insulation surface layer to prevent the material from further combustion,that is,act under solid phase.The cooperation of the two aspects is the major reason to give the PUF a fairly good flame-retarding effect.