Li Lianliang, Huang Yating, Tang Wei, Zhang Yi, Qian Lijun
School of Artificial Intelligence, Beijing Technology and Business University, Fucheng Road No. 11, Haidian District, Beijing 100048, China.
China Light Industry Engineering Technology Research Center of Advanced Flame Retardants, Fucheng Road No. 11, Haidian District, Beijing 100048, China.
Polymers (Basel). 2022 Sep 6;14(18):3722. doi: 10.3390/polym14183722.
Piperazine pyrophosphate (PAPP) combined with melamine polyphosphate (MPP) was adopted to prepare a waterborne fire retardant intumescent coating (IC) for structural steel. Silicone acrylic emulsion was used as binder. In the 2-h torch test, PAPP/MPP-IC coating presented excellent fire resistance performance. The equilibrium temperature at the backside of the steel board decreased to 170 °C with protection of MPP/PAPP-IC, compared with 326 °C of APP/PER/MEL-IC. After 72-h water immersion, MPP/PAPP-IC could still provide sufficient thermal isolation, but APP/PER/MEL-IC failed the test. The water absorption of the MPP/PAPP coating was also reduced. The thermogravimetric analysis measured that the PAPP/MPP-IC had unique initial decomposition temperature of 296 °C and higher residue of 33.8 wt%, which demonstrated better thermal stability and fire retardancy in condensed phase. In addition, Scanning Electron Microscope (SEM) images illustrated that the structure of the carbon layer formed by MPP/PAPP-IC was dense, complete and consistent, indicating the improvement of mechanical strength and thermal isolation of the char. The synergistic effect between piperazine and phosphoric acid groups in MPP/PAPP contributed to the superior flame retardancy. Consequently, MPP/PAPP-IC was much more efficient than the traditional APP/PER/MEL-IC. This work provides a novel way for designing flame retardant coatings for structural steel with excellent comprehensive performance.
采用焦磷酸哌嗪(PAPP)与三聚氰胺聚磷酸盐(MPP)制备了用于结构钢的水性膨胀型防火涂料(IC)。以有机硅丙烯酸乳液作为基料。在2小时的燃烧试验中,PAPP/MPP-IC涂层表现出优异的耐火性能。在MPP/PAPP-IC的保护下,钢板背面的平衡温度降至170℃,而APP/PER/MEL-IC的平衡温度为326℃。经过72小时的水浸后,MPP/PAPP-IC仍能提供足够的热隔离,而APP/PER/MEL-IC未能通过测试。MPP/PAPP涂层的吸水率也有所降低。热重分析测得PAPP/MPP-IC具有独特的初始分解温度296℃和较高的残炭率33.8 wt%,这表明其在凝聚相具有更好的热稳定性和阻燃性。此外,扫描电子显微镜(SEM)图像表明,MPP/PAPP-IC形成的炭层结构致密、完整且一致,表明炭层的机械强度和热隔离性能得到了改善。MPP/PAPP中哌嗪与磷酸基团之间的协同作用有助于提高阻燃性能。因此,MPP/PAPP-IC比传统的APP/PER/MEL-IC效率更高。这项工作为设计具有优异综合性能的结构钢阻燃涂料提供了一种新方法。