CHPA对PU软泡的阻燃作用及其机理研究

Studies of the Flame-retarding Effect and Mechanism of CHPA on Flexible PU Foam

本文研究了含活性氢的氯羟丙基磷酸酯(CHPA)对聚氨酯(PU)软泡的化学阻燃作用及其阻燃机理.结果表明,含12PHRCHPA的PU软泡阻燃性达到GB10800—89/I级.通过对阻燃机理的研究,可以认为,在燃烧初期PU—CHPA中的C—Cl键断裂释出HCl,HCl可与磷酸酯相互作用生成POCl_3、PCl_3和POCl_5等不燃性物,在气相起阻燃作用;在燃烧过程中,这些含P化合物在高温有氧存在下又形成具有很强脱水作用的各种形态磷酸,它们使含氧的PU软泡炭化形成阻隔燃烧的覆盖层,这些是使软泡具有较佳阻燃性的原因.

The flame-retarding effect and mechanism of chlorohydroxypropylphosphate(CHPA) containing active hydrogen on PU foam were studied. The results showed the foam containing 12 PHR CHPA hit the flame-retarding specification of GB10800-89/I. The result of the study of the flame-retarding mechanism of CHPA showed in the early stage of combustion, the C -Cl bond in PU -CHPA was broken and HC1 was released to interact with the phosphate so that incombustible compounds such as POC13, PCl3 ,POCl5 were given off to act as flame-retardants. In the very stage of combustion, under higher temperaturs the compoundes containing phosphorus reacted with oxygen to lead to the producing of varieties of phosphoric acids, whose extremely strong effect of dehydration carbonized the PU foam to form an insulation surface layer to prevent the material from further comubstion. These two aspects were the major reasons because of which the foam had a fairly good flame-retardant property.