蜜胺-环氧树脂双层包覆聚磷酸铵及其阻燃PP的研究

针对聚磷酸铵(APP)耐水性不足、与聚丙烯(PP)等高分子材料相容性差等问题,采用甲醛-三聚氰胺(蜜胺树脂)和环氧树脂双层包覆了APP(EM-APP),采用红外、扫描电镜、热重分析、溶解度测试等方式表征了包覆效果;采用水平垂直燃烧、氧指数仪和锥形量热仪、热重-红外联用等设备考察了包覆APP用于阻燃PP的效果,探讨了阻燃机理。结果表明：包覆操作不但有效提高了APP的耐水性,且将具有成炭功能的包覆层引入到APP表面;EM-APP相较APP,800℃时残炭量提高14.2%,在聚丙烯中加入同样质量份时,前者具有更高的阻燃效率,热释放速率、总热释放量、烟释放速率和总烟释放量都明显降低;包覆改善了APP与PP的相容性;燃烧过程中包覆层起到了协同成炭的作用。

Study on ammonium polyphosphate coated with melamine-epoxy resin and its application in PP

For the problem of insufficient water resistance of ammonium polyphosphate (APP) and poor compatibility with polymer materials such as polypropylene(PP), APP (EM-APP) is coated with formaldehyde-melamine (melamine resin) and epoxy resin double layer. The coating effect was characterized by means of FT-IR, SEM, TGA and water solubility test. The effects of coating APP on flame retardant PP were investigated by means of horizontal vertical combustion, oxygen index instrument, cone calorimeter and thermo gravimetric-infrared combination, and the flame retardant mechanism was discussed.The results show that the coating operation not only improves the water resistance of APP effectively, but also introduces the coating layer with charring function to the surface of APP. Compared with APP, the residual carbon content of EM-APP increases by 14.2% at 800℃. When the same mass fraction of flame retardant is added to polypropylene, EM-APP has higher flame retardant efficiency, and its heat release rate, total heat release, smoke release rate and total smoke release were significantly reduced. The compatibility between APP and PP is improved by coating treatment. The coatings play a synergistic role in charring during combustion.