In this paper,a low formaldehyde urea-formaldehyde resin-based intumescent fire retardant coating for steel structure was prepared.The effect of urea-formaldehyde resin content on the performance of fire retardant coating was investigated,and the fire resistance mechanism was analyzed.The results showed that the low formaldehyde urea-formaldehyde resin was prepared by adding 0.1%hydrogen peroxide at the low molar ratio of formaldehyde to urea(0.8∶1),and the formaldehyde content met the requirements of GB 18582-2020.The addition of urea-formaldehyde resin has no effect on the basic properties of the intumescent fire retardant coating for steel structure,but has a significant effect on the foaming performance and fire resistance of the coating.When the addition amount is 6%-10%,the foaming thickness of the coating is more than 3 cm,and the temperature of the back surface of the steel plate is below 300℃,the lowest is 271.9℃.In addition,pyrolysis of urea-formaldehyde resin occurs,and the molecular chain breaks to produce a large amount of flame retardant gas,forming a dense carbon layer,which plays the role of gas source and carbon source.
维普
万方数据