Abstract
The actions of heat and flame on cellulosic fibres are compared with the physical and chemical behaviour of other fibres. The combustion mechanism is discussed in terms of concerted pyrolysis and oxidative stages, which can be represented as an energy feedback system. The action of different flame retardants are seen to interfere with the system and thereby inhibit burning. The condensed-phase synergistic mechanism of phosphorus-nitrogen-containing retardants used for cotton and viscose rayon are discussed in terms of char enhancement whereas halogen-based retardants operate in the vapour phase. The latter synergistically function in the presence of antimony (III) oxide and, although lacking extreme durability, offer the advantage of conferring flame retardance to adjacent fibrous and non-fibrous materials. The effect of retardants on smoke and combustion product toxicity is also considered.