Combustion Inhibition of Cellulose by Powders - Preliminary Data and Hypotheses

Small-scale qualitative tests were used to screen 185 inorganic powders for flame and inhibiting effects upon cellulose. Nearly half of the compounds inhibited smoldering. These were limited to inorganic salts whose anions include boron, phosphorus, sulfur or halogen. Over half the compounds inhibited flaming, and about one-third inhibited both flaming and smoldering. Differences were found between the actions of the powders and of similar retardants used in other forms and conditions. An appendix is included reporting the effects of alkali metal halides on the pyrolysis of cellulose. Implications of the results to the inhibitors are discussed.