Pyrolysis and combustion of cellulose. I. Effects of triphenyl phosphate in the presence of nitrogenous bases

The ability of selected phosphorus-containing compounds and nitrogen-containing compounds to act as flame retardants for cotton cellulose was investigated using flame tests, thermal gravimetric analysis (TGA), and differential thermal analysis (DTA). The effectiveness of the organophosphorus compounds was found to correlate with the changes which they induced in the pyrolytic degradation of the cellulose as indicated by DTA. Many of the samples containing nitrogen were found to exhibit DTA curves having pronounced exotherms. The presence of nitrogen-containing compounds in conjunction with the organophosphorus systems enhanced their ability to retard flame propagation but did not produce significant changes in the pyrolytic endotherm as observed by DTA. More conclusive evidence for a chemically based phosphorus-nitrogen synergism was obtained by the use of TGA. These data can be interpreted in terms of the phosphorus-nitrogen synergistic effects and flame retardance mechanisms which have been proposed in the literature.