Studies on the Thermal Behavior of Polyamides

I. Determination of the Extent of the Degradation of Polyamide Fibers on Thermal Oxidation

Abstract

The deterioration of the mechanical properties of polyhexamethyleneadipamide fibers was studied and its relation to their DTA curves, UV spectra, oxygen absorption and the change of their molecular weights was investigated.
It was found that the height of exothermic peak of DTA curves around 240°C showed a good correlation with the maintenance of tensile strength of the fibers and the optical density at 290mμ in 60% sulfuric acid showed the same correlation.
These experimental results suggest that DTA and UV spectra are suitable methods for the determination of the extent of the degradation of polyamide fibers on thermal oxidation, especially suitable for the estimation of the effects of stabllizers in polyamide fibers.