氯羟丙基磷酸酯对软质聚氨酯泡沫阻燃机理的研究

Abstract

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。此P/Cl化合物一方面因其散发速度比HCl慢，而延长在燃烧区域的停滞时间，更有效地在气相起阻燃作用；另一方面，在高温有氧存在下，与氧作用生成各种形态的磷酸，其强烈的脱水作用使含氧的Puf在层碳化而生成阻隔燃烧的覆盖层，起到固相阻燃的作用。二者的协同是使软质Puf呈较佳阻燃效应的原因。

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.