A Review of Fire Retardants for Commercially Important Polyurethane Foams

Abstract

The review covers various additive and reactive fire retardants used to render flexible and rigid polyurethane foams fire retardant. Literature sources are mostly from technical publications, patents, books and handbooks since 1962. Various fire retardants such as phosphorus-containing compounds, halogen-containing compounds, nitrogen-containing additives, silicone-containing products and miscellaneous organic and inorganic additives have been used to render polyurethane foams fire retardant. Some heat-resistant groups such as carbodiimide, isocyanurate and nitrogen-containing heterocycles formed with polyurethane foams also render polyurethane foams fire retardant. Fire-retardant additives reduce the flammability of polyurethane foams significantly with some degradation in physical and mechanical properties. It is concluded that a wide range of fire-retardant additives are available for polyurethane foams; however, most of the fire retardants degrade the physical and mechanical characteristics up to certain extent with significant improvement in the fire retardancy of polyurethane foams.

Keywords: Polyurethane foams, flammability, phosphorus-containing fire retardants, halogen-containing fire retardants, carbodiimide, isocyanurate