Abstract
Nylon-6 fibers, untreated and heat-treated at 160°C, were exposed in outdoors up to 90 days. As the exposure time increased, the tensile strength and the elongation at break decreased, whereas the density and the X-ray crystallinity of the fibers increased.
The oxidation reaction of Nylon-6 fiber caused by exposure was studied in terms of the change in the exothermic peak of differential thermal analysis (DTA) curves. It was found that this DTA method served as a very sensitive test for the oxidation of its fiber.
Electron micrographs of the surface replicas of these fibers showed that the fibrillar structure of the original fiber became obscure and the surface roughness increased with increasing exposure. The surface changes may be attributed to the fact that the water soluble products were formed by oxidative degradation and were eliminated during exposure.
