FRW Fire Retardant For Wood

The chemical treatment of wood to render it fire retardant is a very important technology for reducing the long-term costs of structures. In this paper, a new fire retardant formulation called FRW, was formed using guanylurea phosphate (GUP) and boric acid as the main fire retardant components. Comprehensive research was performed on the synthesis, the wood treating, the performance of product and the fire retardant mechanism of FRW fire retardant. The industrial processing technology for FRW fire retardant treatment was defined and fire retardant mechanism of FRW was revealed.By using the complete reaction of dicyandiamide, phosphorous acid and water at a temperature of between about 90℃and about 120℃and by using a solvent recycling process, GUP was synthesized with high mole yield (≥97%) and high purity (GUP content≥99.0%).The engineering research on the synthesis of FRW fire retardant and on the FRW treating technics of wood was successfully performed. A comprehensive evaluation of the fire properties of the product showed that FRW not only had excellent fire retardancy, but that it also had provided good smoke inhibition.Systematic research of the fire retardant mechanism of FRW on wood was carried out by CONE calorimetry, thermal analysis and by FTIR. The results showed that, except the gas diluting and matrix covering effects of the decomposition products of FRW, the strong catalytic charring effect of FRW on wood plays a major part in its fire retardant mechanism. Catalysis is important to the fire retardant mechanism of boric acid. GUP and boric acid has different activating temperatures and effects in different mechanisms that can make up for one another, therefore they have synergistic effects.FRW treatment of wood had only a minor influence on the physical properties of the treated wood. FRW treatment provided an increase in the decay protecting properties. It did not substantially influence the hygroscopicity of the treated wood. It did improve the dimensional stability of the treated wood to some extent. FRW treatment of wood had only minor influence on the mechanical and wood processing properties of the treated wood.