THE RESISTANCE TO WEATHERING OF COTTON DUCK TREATED WITH CERTAIN COMPOUNDS OF IRON, CHROMIUM, AND COPPER

Abstract

Unbleached cotton tentage duck was impregnated with chromic oxide, copper carbonate, and ferric oxide, both singly and in mixtures, each metal being present in concentration of approximately 1% as metallic oxide, and also in the form of naphthenates in equivalent concentration. The rot resistance of the treated samples was determined by measuring the loss of breaking strength on soil burial after leaching in water and after outdoor weathering for four months. Photochemical degradation on weathering was determined by measuring the loss of breaking strength and increase in cuprammonium fluidity. The decrease in metal content on weathering was also measured.Samples treated with chromium and iron in inorganic form, used singly and together, showed no resistance to soil burial and very slight resistance when the metals were present as naphthenates. All treatments containing copper produced substantial resistance to soil burial, the mixtures producing greater resistance than the single compounds; the resistance resulting from treatment with chromium plus copper and with chromium plus copper plus iron mixtures was greater than that from the corresponding copper plus iron treatments. On the whole, the inorganic treatments produced more resistance to soil burial after leaching than the organic treatments but, after weathering, the copper alone and copper plus iron treatments produced less resistance than the corresponding naphthenate treatments.All the inorganic treatments containing chromium exerted a marked protective effect against deterioration resulting from weathering as judged by breaking strength losses and increases in cuprammonium fluidity.The naphthenate treatments containing chromium and the iron oxide and iron naphthenate treatments afforded some protection with respect to breaking strength loss but produced fluidity increases approximately the same as that of the untreated fabric. Similar results were obtained with the copper carbonate plus iron oxide treatment.The samples treated with copper carbonate and copper naphthenate showed breaking strength losses approximately the same as that of the untreated control but gave evidence of enhanced degradation as judged by the fluidity data.Losses of chromium on weathering were negligible in all cases while losses of iron ranged from zero to 34%. Complete loss of copper occurred in the copper carbonate treated sample and a slightly lower loss (85%) in the copper plus iron treated sample. In the presence of chromium and chromium plus iron, the losses of copper were reduced to 34% and 54% respectively. Similar trends were observed with the naphthenate treatments but the losses were much lower in all cases, ranging from no significant loss to a loss of 48%.