摘要
【目的】利用可膨胀石墨(EG)增强膨胀型钢结构防火涂料的防火性能和耐盐雾性。【方法】利用锥形量热仪、热重分析仪、中性盐雾试验等分析了EG对膨胀型防火涂料防火性能和耐盐雾性的影响。【结果】添加EG可以有效增强涂层防火和抑烟性能,添加1.67%(质量分数)EG后涂层的峰值热释放速率和峰值生烟速率分别低至96.0 kW/m^(2)和0.021 m^(2)/s、700℃时的残炭率提升至28.3%,这主要是因为EG在燃烧过程中可形成“蠕虫状”结构增强膨胀炭层的致密性从而更有效地阻隔热量和物质传递。盐雾试验表明,中性盐雾作用会破坏涂层结构的完整性,导致涂层热释放速率和生烟量增大,而添加EG可以在一定程度上延缓盐雾对涂层的老化并使涂层老化后仍保持较低的热释放速率、生烟量以及较好的炭层稳定性,其中添加EG的涂层在700℃时的残炭率较未添加EG的涂层提升15.4%。【结论】EG作为膨胀型钢结构防火涂料的协效剂可以显著提高涂层防火性能和耐盐雾性。
[Objective]To enhance the fire resistance and salt spray resistance of intumescent fire-retardant coatings for steel structures using expandable graphite(EG)as a synergist.[Methods]The effects and mechanisms of EG on the fire resistance and salt spray resistance were investigated using cone calorimetry,thermogravimetric analysis(TGA),and neutral salt spray testing.[Results]The addition of EG could effectively enhance the coating′s fire resistance and smoke suppression properties.The peak heat release rate and the peak smoke generation rate of the coating after the addition of 1.67%(mass fraction)of EG were as low as 96.0 kW/m^(2)and 0.021 m^(2)/s,respectively.The residual carbon rate at 700℃was increased to 28.3%.This enhancement was primarily attributed to the formation of worm-like structures by EG during the combustion process,which reinforced the denseness of the expanded carbon layer to block the heat and material transfer more effectively.Salt spray tests revealed that exposure to a neutral salt spray environment could damage the structural integrity of the coating,leading to an increase in the heat release rate and smoke production.However,the addition of EG could delay the coating′s aging process induced by salt spray to a certain extent.Consequently,even after aging,EG-modified coatings maintained lower heat release,reduced smoke production,and superior carbon layer stability compared to unmodified coatings.Notably,the residual carbon rate at 700℃for the aged EG-modified coating was 15.4%higher than that of the aged coating without EG.[Conclusion]EG as a synergist of intumescent steel structure fire-retardant coatings could significantly improve the fire resistance and salt spray resistance of the coating.
作者
赵致景
黄丹蓉
张琦
颜龙
ZHAO Zhijing;HUANG Danrong;ZHANG Qi;YAN Long(Institute of Disaster Prevention Science and Safety Technology,Central South University,Changsha 410075,China;Power China Ninth Engineering Bureau Co.,Ltd.,Guiyang 550000,China)
出处
《涂料工业》
北大核心
2026年第1期1-6,共6页
Paint & Coatings Industry
基金
国家自然科学基金项目(52276143)
贵州省科技计划项目(黔科合支撑[2024]一般134)。
关键词
膨胀型防火涂料
钢结构
可膨胀石墨
防火性能
抑烟性能
耐盐雾性
intumescent fire-retardant coatings
steel structure
expandable graphite
fire resistance
smoke suppression
salt spray resistance
