为了提高水性膨胀型钢结构防火涂料的耐火性能，探究了水性成膜物质和各原料用量对耐火性能的影响。以低活性端氨基聚醚为关键原料，合成了非离子型水性聚脲，并以合成的水性聚脲为成膜物质制备了水性聚脲基膨胀型钢结构防火涂料。采用《超薄型钢结构防火涂料防火性能快速测试方法》对小试配方进行快速筛选，考察了水性聚脲、钛白粉和陶瓷纤维的添加量对其耐火性能的影响。结果表明：以水性聚脲 B为成膜物质，当水性聚脲添加量 20%、钛白粉添加量 16%、陶瓷纤维添加量 1. 0%时，制备得到的膨胀型钢结构防火涂料耐火性能最佳。对优选配方按照 GB 14907— 2018《钢结构防火涂料》进行耐火性能测试，耐火性能为 1. 27 h/1. 43 mm、1. 68 h/2. 05 mm和 2. 02 h/2. 79 mm，耐火性能较高。

In order to improve the fire resistance of water-based intumescent fireproof coatings for steel structures, the effects of the types of water-based film-forming substances and the amount of each raw material on the fire resistance were explored in this paper. The non-ionic water-based polyurea was synthesized using low-activity amino terminated polyether as the key raw material. And the waterborne polyurea-based intumescent fire retardant?coating for?steel structure was prepared by using the synthetic waterborne polyurea as film-forming substance. The "Rapid Test Method for Fire Resistance of Ultra-thin Steel Structure Fire Retardant Coatings" was used to quickly screen the small test formulations, and the effects of the additions of water-based polyurea, titanium dioxide and ceramic fiber on their fire resistance were investigated. The results show that when the water-based polyurea B was used as the film-forming material, when the water-based polyurea addition amount was 20%, the titanium dioxide addition amount was 16%, and the ceramic fiber addition amount was 1.0%, the prepared intumescent fireproof coating for steel structure had the best fire resistance. The fire resistance of the optimized formula was tested according to GB 14907-2018 Fire retardant Coatings for Steel Structure. The fire resistance was 1.27h/1.43mm, 1.68h/2.05mm and 2.02h/2.79mm, which showed high fire resistance.