Preparation Of Water-borne Silicone-acrylate Resin Superthin Intumescent Fire Resisting Coating For Steel Structure

Nowadays, steel structure has been used in skyscraper widely. However, the critical temperature of steel's machanical property is 540℃. When fire hazard happens, the temperature of steel will rise to critical temperature in only about a quarter hour, inducing the break down of building which carrying capacity has been destroyed severely. Leads to damage of personal casualty and economical loss. When water-borne silicone-acrylate resin superthin intumescent fire resisting coating for steel structure meets the fire or high temperature, the decompose production of dehydrating-charring agent ammonium polyphosphate occurs esterification reaction with charring agent pentaerythritol generate phosphate. Along with the melting of coating system, the system occurs intumescence with the action of gas which is emitted by gasifying agent melamine. Consequently, phosphate continues dehydrating and charring, forming a low heat conductivity multihole charring layer. This charring layer could obstruct heat, delay the temperature rise of steel structure. Thus, buildings have been protected.This article studied the mechanism of associated action in water-borne silicone-acrylate resin superthin intumescent fire resisting coating for steel structure and the influence rules of each component in coating which effected to the fire resisting performance. Firstly, the fire resisting performance of water-borne silicone-acrylate resin, acrylic emulsion, styrene-acrylic emulsion were compared by using phenomenon analysis and thermogravimetric analysis. The results showed water-borne silicone-acrylate resin had the better fire resisting performance. Secondly, the influence on fire resisting performance of each element was investigated by orthogonal design, and it was found that the optimum composition of water-borne silicone-acrylate resin, ammonium polyphosphate, melamine, pentaerythritol in fire resisting coating is 6:6:4:3. In this condition, the fire resisting limit time is 78 minutes. Subsequently, titanium dioxide was added in coating as pigment in order to research the effect to fire resisting performance. It was found that,...