聚乙二醇硼酸酯在膨胀型透明防火涂料中的协效作用

Synergistic Flame-Retardant and Smoke Suppressions Effects of Polyethylene Glycol Borate in Transparent Intumescent Fire-Retardant Coatings

以酸式磷酸酯(PEA)与聚乙二醇硼酸酯(PEG-BA)为原料合成一系列不同PEG-BA含量的柔性磷酸酯(PPB),采用傅里叶变换红外光谱和核磁共振氢谱对其化学结构进行分析表征。然后将PPB应用于氨基树脂中制备膨胀型透明防火涂料。通过防火性能测试、锥形量热测试和烟密度测试等考察了PEG-BA对透明涂料的阻燃及抑烟性能的影响,并通过热重分析、扫描电镜和红外光谱对PEG-BA在涂层中的协效作用机理进行分析。结果表明,将PEG-BA引入透明防火涂料中能有效提高涂层的热稳定性、阻燃和抑烟性能。当PEA与PEG质量比为4∶1时,涂层的热释放速率、总释放热和烟密度等级最低,背部稳定温度为146℃。炭层结构分析发现,添加PEG-BA能促进涂层在燃烧过程中形成更多的P-O-C、P-O-B和B-O-C等交联结构,进而形成更加致密和热稳定的炭层结构。

A series of flexible phosphate flame retardants(PPB) with different polyethylene glycol borate(PEG-BA) contents were synthesized by the esterification of phosphate ester acid(PEA) and PEG-BA, and their structures were well characterized by FT-IR and ~1H-NMR. Then, the PPBs were applied into amino resins to prepare a series of transparent fire-retardant coatings. The effects of PEG-BA on the flame retardancy and smoke suppression properties of the transparent intumescent fire-retardant coatings were investigated by fire performance test, cone calorimeter and smoke density meter. The synergistic mechanism of PEG-BA in the coatings was also analyzed by thermogravimetric analyzer(TGA), SEM and FT-IR. The results show that the introduction of PEG-BA into transparent fire-retardant coatings can effectively improve the thermal stability, flame retardancy and smoke suppression properties of the coatings. When the mass ratio of PEA to PEG is 4∶1, the coating has the lowest heat release rate, total heat release and smoke density, and the back stable temperature of samples is 146 ℃. The char residue analysis shows that the addition of PEG-BA can promote the formation of more crosslinked structures such as P-O-C, P-O-B and B-O-C, thus forming a more compact and thermally stable char layer.