聚磷酸铵与季戊四醇协效成炭及其对防火涂料性能的影响

Synergistic effects of ammonium polyphosphate and pentaerythritol during char formation and their effect on the fireproof performance of water-based flame retardant coatings

通过比较不同质量比的聚磷酸铵（APP）与季戊四醇（PER）混合物的理论热失重曲线和实际热失重曲线的差别,探究了两者之间的协效作用与发生的化学反应。随后以醋丙乳液为基体配制了膨胀型防火涂料,研究了APP与PER的质量比对涂料防火性能的影响,结果表明：在混合物热解过程中存在3个过程,所发生的反应为180℃～320℃时APP与PER形成磷酸酯,320℃～550℃时生成的磷酸酯脱水环化,600℃～750℃时环状结构炭化形成石墨化片段;当mAPP/mPER为3∶1时,协效作用最佳,生成炭量最多,配制的防火涂料膨胀倍率最大,防火性能最好。

The synergistic effects in ammonium polyphosphate and pentaerythritol （APP/PER） mixtures have been investigated by contrasting the experimental and the theoretical thermo-gravimetric curves of APP/PER mixtures with different ratios. Then, intumescent flame retardant coatings were prepared by combining a vinyl acetate-acrylic copolymer emulsiona matrix with the intumescent flame retardants, titanium dioxide and expandable graphite. The effect of APP/PER ratio on the performance of the coatings was investigated. The results indicated that there are three stages in the thermal degradation process of the mixtures, as follows： the initial formation of phosphocarbon- aceous esters occurring at 180- 320℃, then cyclodehydration of phosphocarbonaceous esters developing at 320- 550℃ , and finally, formation of graphite-like fragments resulting from the carbonization of the cyclic structure at 600 -750℃. The maximum synergistic effect occurred when the mass ratio of APP and PER was 3： 1, generating a maximum char yield. When the mass ratio of APP and PER was 3： 1, the coating showed optimal fire retardant performance, generating a maximum expansion rate.