Effects of phosphorus-containing flame retardants on pyrolysis of cotton cellulose

Unmodified cotton and cottons finished with high levels of seven different phosphorus‐containing flame retardants were pyrolyzed in a temperature‐programmed solid probe of a mass spectrometer, and mass spectra were recorded continuously throughout the pyrolyses. The spectra at the maximum rates of volatiles evolution during the pyrolyses were analyzed to determine relative amounts of water, carbon monoxide, carbon dioxide, furfural, furyl hydroxymethyl ketone, hydroxymethylfurfural, levoglucosan, and 1,6‐anhydro‐β‐glucofuranose. These volatile materials accounted for 64% to 90% of the total ionization in the spectra. The flame retardants increased the fractions of nonfuel volatiles (water and carbon dioxide) and decreased those of anhydroglucoses, but had less effect on the carbon monoxide and furan derivatives. The flame retardant fabrics differed greatly in the fractions of anhydroglucoses (from 1% to 23%) and water (from 19% to 57%) in their pyrolysis products. These results indicate that mechanisms of flame retardant action differ among phosphorus‐containing finishes.