Fire-retardant additives for polymeric materials - I. Char formation from silica gel-potassium carbonate

Silica gel combined with potassium carbonate is an effective fire retardant for a wide variety of common polymers (at mass fraction of only 10% total additive) such as polypropylene, nylon, polymethylmethacrylate, poly(vinyl alcohol), cellulose, and to a lesser extent polystyrene and styrene-acrylonitrile. The peak heat release rate is reduced by up to 68% without significantly increasing the smoke or carbon monoxide levels during the combustion.