Aging behavior of Vectran fiber exposed to ultraviolet (UV) radiation was investigated. Vectran fiber was subjected to UV-accelerated degradation environment. Tensile strength of Vectran fiber was determined at room temperature using a two-parameter Weibull distribution. The average tensile strength loss was 42.75% when the irradiation time reached 186 h. The surface morphology of the degraded fiber was examined using scanning electron microscopy (SEM) and atomic force microscopy (AFM). X-ray photoelectron spectroscopy (XPS) and 13C-NMR were used to provide a molecular characterization of fibers. SEM and AFM showed that UV exposure result in microvoids on the surface of fibers. The results of the XPS and 13C-NMR indicated that the UV radiation could lead to chain scission of fiber surface layer. (C) 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012