No abstract

The application of differential thermal analysis (DTA) for the characterization and the investigation of the thermal degradation of synthetic textile fibers, to include polyester, nylon 6, propropylene, and polytetrafluoroethylene fibers, has been studied. The temperature range was from 50 to 650°C. using laboratory‐built DTA apparatus. Experimental considerations and techniques are discussed and such variables as sample preparation, size, cell packing, atmosphere control, and heating rate have been investigated. The conventional technique of grinding or milling DTA samples is shown to cause significant changes in certain samples, particularly in undrawn fibers. The control of sample atmosphere by dynamic gas flow through the sample cell gave peaks that were generally sharper and larger than those found when control was by gas diffusion. Data are given on the various low temperature transitions found in such fibers. Significant differences in low temperature transitions were observed between polypropylene fiber and the bulk polymer as well as between drawn and undrawn nylon 6 fibers. The interpretation of the DTA curves for the decomposition and other reactions at elevated temperatures is discussed. Nylon 6 and polypropylene showed only endothermic reactions indicative of depolymerization processes whereas other fibers showed both endothermic and exothermic reactions in the decomposition range.