17. Mineral Filler Fire Retardants

Mineral filler fire retardants are one of the most important classes of fire retardant, and one of the most important classes of polymer additives. In addition to reducing the flammability of the polymer to within acceptable limits, they can also provide structural integrity and reinforcement to the polymer composite. Mineral filler fire retardants operate through endothermic decomposition with the release of an inert gas or vapor. Four fire retardant effects have been quantified: heat capacity of the filler, decomposition endotherm, heat capacity of the gas or vapor, and heat capacity of the residue. In specific fire scenarios, other factors, such as shielding from radiant heat, may also play a critical role. Unfortunately, the screening techniques for assessment of fire retardant performance do not adequately capture real fire behavior. The common techniques, and their deficiencies, in relation to mineral filler fire retardants are reviewed.