The fire-retardant coating for wood plastic composites (WPC ) was prepared using acrylic resin as binder, ammonium polyphosphate ( APP) , melamine ( MEL) and pentaerythritol ( PER) as flame retardants. The best ratio was optimized by the method of orthogonal test and the effect of coating thickness on the retardant time was inspected, the mechanism of coating was also studied. When APP, MEL and PER mixed at a ratio of 12:7=4, the best performance with retardant time 1 500 s reaches. Although the retardant time increased with the coating thickness in quadratic curves, lots of defects such as "orange peel" , " pinhole" appeared when too thick. The WPC was protected by the char layer formed by the coating during the burning stage and finally there were only inorganic carbon skeleton and small amounts of phosphate kind material left.%以丙烯酸树脂为基体,聚磷酸铵(APP)、三聚氰胺(MEL)和季戊四醇(PER)构成的膨胀型阻燃剂为阻燃体系,制备了用于木塑复合材料表面的防火涂层.采用正交试验法优化了防火涂层的配方,考察了涂层厚度对耐燃时间的影响,研究了涂层的阻燃机理.结果表明:当APP、MEL和PER按质量比12:7:4进行复配时,阻燃效果最佳,耐燃时间达到1 500s;一定范围内,耐燃时间随涂覆质量呈二次增长,但过厚也会出现“桔皮”、“针孔”等缺陷.防火涂层通过形成致密的炭层对基材进行保护,完全燃烧后的产物主要为无机炭骨架及少量磷酸盐类物质.
展开▼
