摘要： 通过对制备防火涂料的各组分的热学性能测试,分析了膨胀型防火涂料的防火机理。研究结果表明:聚磷酸铵、三聚氰胺、季戊四醇三者分解温度范围符合膨胀炭质层的形成条件,具有很好的协调性。当温度达到220℃时,脱水催化剂聚磷酸铵首先分解释放无机酸,随着温度的逐渐升高,生成的酸与炭化剂季戊四醇发生酯化反应;在酯化反应前或酯化过程中,涂层发生软化熔融,同时发泡剂三聚氰胺受热分解产生大量不燃性气体,使软化熔融的涂层鼓泡膨胀,随着反应的不断进行,最后形成"蜂窝状"的膨胀炭质层。

关键词: 防火涂料, 防火机理, 炭质层

Abstract: By means of thermal decomposition testing of the main components in fire retardant coatings, the mechanism of intumescent coatings was analyzed. The result showed that the decomposition temperature of ammonium polyphosphate(APP), melamine(MEL)and pentaerythritol (PER) satisfied the formation of char layer and the three components exhibited a good synergy. When the temperature reached up to 220℃, ammonium polyphosphate was first decomposed and the inorganic acid was released, wherein the elevated temperature enabled an esterification reaction of the inorganic acid and PER. Before and/or during the esterification process, the coating was softened and melted, meanwhile, MEL as foaming agent produced large amount of nonflammable gases which allowed the softened and melted coating to get foam and expansion. Finally a honeycomb-like char layer was formed.

Key words: flame retardant coating, fire retardant mechanism, char layer