Study On Nano - Sized Aluminum Hydroxide Modified Ultra - Slender Steel Structure Fireproof Coatings

Steel structural building has been intrigued people’s interests because of its advantages of high strength, light weight, stable performance, great anti-seismic property, anti-pollutant and so on. However, as the lack of refractory property of steel, it is very valuable to study how to reduce the damage of steel structure building on fire. Fireproof coating is the most extensive, economical and effective method applied to the steel structure. Compared with thick and thin anti-fire steel structural coatings, ultra-thin anti-fire coating has finer granularity, thinner coating, less dosage, more convenient over construction, better decoration, which attracted most interests in the field of steel structure fire retardant coating.In this paper, ultra-thin fireproof coatings formulation was developed, fire detection mechanism was addressed and characterizations were made. Modified acrylic resin and an epoxy resin were physically mixed as the matrix resin. Then, the ammonium polyphosphate (dehydration catalyst), pentaerythritol (charring agent) and melamine (blowing agent) were used as intumescent flame retardant system. The optimum basic composition of each component in the sample was determined through the three factors and three levels orthogonal analysis.On the basis of the above result, the impact of nano-aluminum hydroxide on the above products was studied. Firstly, their dispersion in the paint was improved by the treatment on the surface of nano-aluminum hydroxide. Then, the influence of the nano-aluminum hydroxide on the burning time, heating rate, smoke density and other physical and chemical properties were studied. It showed that when the content of nano-aluminum hydroxide reached7%, the refractory time increased by5%to10%, and the initial combustion steel heating rate was decreased. Meanwhile, the smoke density was reduced significantly. The optimized composition meets the standards of various indoor and outdoor physical and chemical properties, corrosion resistance and aging resistance.Finally, the hazardous substances of these products were tested and the environment protection of the modified ultra-thin fireproof coatings was evaluated.