Combined Effects of Gamma and Ultraviolet Radiation Plus Heat on Fibrous Polyamides

Abstract

Several types of fibrous polyamides were exposed to gamma, ultraviolet (uv), and thermal radiation, singly and in combination, under controlled conditions. The unexposed and exposed specimens were examined by the techniques of solution viscosity, melting point, infrared (ir) spectra, uv absorption and light microscopy. Tensile strength was mea sured in some instances. The combined results give insight into the changes taking place as a result of irradiation. Most polyamides are degraded by long exposure to uv radiation. One was degraded by uv alone and not affected by gamma or heat alone. When exposed to gamma first followed by uv, the degradation was decreased. Simultaneous exposure to gamma and uv gave the same result.