Development of polymer–ceramic composites for improved fire resistance

Materials that provide protection of lives and property from fire are highly desirable across many industries. Conventional polymers are generally completely consumed in a fire situation and require either halogenated additives that give off toxic and corrosive gases with large volumes of smoke or high filler loadings of non-halogen based additives in order to impart fire resistance. Attention has been shifted to the area of “ceramifiable” polymers as a means of improving passive fire protection, and silicones have been shown to possess desirable properties on firing, such as a slow burning rate without a flaming drip and low emissions of non-toxic smoke. However, the ceramic formed by firing silicones alone is very weak and powdery. Addition of certain inorganic fillers improves the strength, giving a near-net shape ceramic. The fire protection properties of silicone and silicone-based composites are investigated at temperatures up to 1100°C. The microstructure of the resultant ceramics has been studied and the mechanism for the conversion of silicone-based composites to ceramics is proposed.