The Catalytic Degradation and Oxidation of Cellulose

The thermal decomposition products of cellulose treated with various organophos phorus compounds were investigated. The function of a fire retardant in cellulose is to favor the production of carbon and water rather than flammable tarry products which are formed in the thermal de gradation of untreated cellulose. Furthermore, if the oxidation of the charred residue is directed toward the production of carbon monoxide rather than carbon dioxide, it is believed that the heat produced in this reaction would not be sufficient to sustain an afterglow when the flame has been removed. A comparison was made between the amounts of char and tar produced and the efficiency of the retardant used. A correlation between the carbon monoxide-carbon dioxide ratio and the afterglow exhibited by treated cotton was made. The results obtained support the theory that fire-resistant cellulose produces less flammable tars and more carbon monoxide than untreated cellulose. However, no significant differentiation as to the relative effectiveness of the various compounds in vestigated was possible. It is suggested that further studies be completed on the various types of compounds exhibiting fire retardancy to provide a more general theory of fire-resistant cellulose. A method has been described for the determination of water and nonaqueous volatile products resulting from the pyrolysis of cotton fabric. In this procedure the nonvolatile products, the char and tar, could also be determined. The pyrolysis of seven treated samples of 8.2-oz cotton khaki cloth was studied at 200, 300, 400 and 500° C. Three of these samples were treated with fire-resistant com pounds ; the remaining four were padded with nonfire-resistant compounds. A large part of the gaseous products from the pyrolysis was found to be nonaqueous. However, the data tend to support the dehydration mechanism for the action of fire- resistance compounds on cotton fabric.