The Damage Effects Of Ultraviolet Irradiation Environment On Organic Fibers

In order to investigate the damage effects of ultraviolet (UV) irradiation on organic fibers, UV damage effect tests were carried on polyester fibers and aramid fibers in different radiant intensity and atmosphere, respectively. The effect of UV irradiation in different conditions on mechanics and microstructure were studied for the polyester fibers and the aramid fibers, aiming to explore the influence law of UV irradiation on the organic fibers, establishing database, then guide the selection of material, forescast, life protection and lay a foundation for further study.Based on the analysis of current research worldwidely, two kinds of ultraviolet accelerated damage experiment device were developed according to the demand of experiment. UV damage effect tests in different atmosphere and different radiant intensity of ultraviolet irradiation damage experiment were finished by the equipments.Finally, the fracture tensile strength before and after the damage experiment were studied for polyester fibers and aramid fibers by the micro-mechanics test. The changes of organic function, thermodynamic properties, crystal structure and the surface micromorphology were analyzed by FTIR (FT-IR Spectromete), DTA-TG (Thermogravimetric Analysis), XRD (X-Ray Diffractomer) and SEM (Scanning electron microscope) methods. The results of tests show that under the damage experiment in different environment the fracture tensile strength of polyester fibers and aramid fibers all decrease with the increase of irradiation time, the skin layer of fibers irradiated appears different degree of damage, and the crystallinity of fibers irradiated decreases. However, the degree of damage for polyester fiber and aramid fibers is quite different. The ester bond of polyester fibers after the damage could be broken and decarbonylation could occur. Melting temperature (Tm) and the temperature of the quality loss by 10% (T10) decrease. The amide bond of aramid fibers might be broken, Tm and the temperature of the quality loss by 50% (T50) appears different degree of decrease.