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ABSTRACTS AND REVIEWS 289 while decreasing the number of degradation products The neutral retardant increases the amount of water, furfural, 5-methyl-2-furfuraI, 5-hydroxymethyl- furfural, and the furanose derivative and either ehminates or decreases all others The basic retardant mcreases the amount of water, the furanose derivative, and both unsubstituted and substituted phenols. These treatments also affect the carbon monoxide-carbon dioxide ratio. Its value of 1 14 in basic, 0.16 in neutral, and 0.33 in untreated samples has been reported by other researchers. For a related acidic salt, the carbon monoxide- carbon dioxide ratio is 0 42 The degradation products of pure levoglucosan are similar to those of untreated cellulose. Addition of a basic salt increases the total number of gc peaks as well as the amount of the furanose derivative Acidic additives increase the amount of furanose derivative even more than basic ones and are most successful in decreas- ing the number of degradation produts. The furanose derivative degrades primarily into oxides of carbon, water, and char. Both basic and acidic additives increase the amount of water and char, which confirms SRI's earher data These findings, combined with those of the effects of additives on cellulose and levoglucosan, support the contention that the observed degradation products result from decomposition of these intermediate pyrolysis products of cellulose, and that the additional char from the retardant-treated cellulose is produced by the degradation of these products of cellulose decomposition rather than of the cellulose molecule itself. Although the Parker-Lipska model represents a significant contribution to the state of the art, i t has significant shortcomings that preclude its use for the pre- diction of ultimate improvement in fire and igmtion retardance for cellulose. The most notable failmg is its inability to predict char yields from readily charac- tenzable properties of retardant molecules. However, i t does provide some general guidance toward prescribing optimal retardance treatment. Until further major advances are made in analytical models of cellulose pyrolysis, the Parker-Lipska model will serve many useful interim purposes Woolley, W. D. and Field, P. (Joint Fire Research Organization, Boreham Wood England) "A Prehmmary Study of the Thermal Decomposition of Polyurethane Foams by Elemental Ultramicroanalysis," Joint Fire Research Organization Fire Research Note No. 880 (July 1971) Section: H Subjects: Plastics; Polyurethane foam; Pyrolysis; Analysis Authors' Summary A study of the thermal decomposition of certain rigid and flexible polyurethane foams has been undertaken by monitoring the nitrogen content of the residues
