滑石粉在膨胀型透明防火涂料中的协效阻燃和抑烟作用

Synergistic effect of talc on flame retardancy and smoke suppression properties of transparent intumescent fire-retardant coatings

为了提高透明防火涂料的阻燃和抑烟性能,将滑石粉(talc)与柔性磷酸酯(PPB)反应制备一系列新型磷酸酯接枝滑石粉阻燃剂(TPPBs),再将其与甲醚化三聚氰胺甲醛树脂(MF)复配制备透明防火涂料,并对涂层的防火性能、热稳定性、生烟特性及炭层结构进行表征。研究结果表明:滑石粉均匀分布在基材树脂中能使涂层保持较高的透明性,并有效增强防火涂料的热稳定性、阻燃和抑烟性能;PPB与talc以质量比95?5复配所制备的涂层表现出最优异的阻燃和抑烟性能,其火焰传播比值和烟密度等级最低,分别为3.1和6.2%;滑石粉的加入能增强磷酸酯的交联反应,形成更多富含磷交联结构和芳香结构以提高涂层的热稳定性和成炭量,并生成更加致密和稳定的膨胀炭层,达到较好的协效阻燃和抑烟效果。

In order to improve the flame retardancy and smoke suppression properties of transparent intumescent fire-retardant coatings,a series of polyphosphate-modified talc(TPPBs)were synthesized by the reaction of flexible polyphosphate flame retardant(PPB)and different contents of talc.Then,the obtained TPPBs were mixed with melamine formaldehyde resin(MF)to prepare transparent intumescent fire-retardant coatings.The flame retardancy,thermal stability,smoke suppression properties and char structures of the coatings were intensively investigated.The results show that the uniform dispersion of talc can achieve a high level of transparency in the coatings,and greatly enhance the thermal stability,flame retardancy and smoke suppression properties of the coatings.When the mass ratio of PPB and talc is 95?5,the obtained MTPPB3 coating exhibits the best flame retardancy and smoke suppression properties among the samples,presenting the lowest flame spread rating of 3.1 and smoke density rating of 6.2%.The addition of talc can promote to form more phosphorus-rich crosslinking structures and aromatic structures in the condensed phase that produce a more compact and thermally stable char layer against the fire,thus exhibiting excellent synergistic flame-retardant and smoke suppression effects.