Discolouration in fire retardant flexible polyurethane foams. Part I. Characterisation

Scorching of water-blown polyurethane foams is a general phenomenon usually attributed to the thermal degradation and oxidation of the foam. Scorch is more visible in the presence of some phosphorus- or halogen- containing fire retardants. Four phosphorus-containing fire retardant foams and one non-fire-retardant foam have been tested for scorching in the present study. The results showed that some fire retardants are able to accelerate the scorching process by forming by interaction with polyurethane degradation products new, easily oxydable, structures