X-ray induced degradation of regenerated cellulose membrane films

Abstract

Polymeric membranes are often exposed to degrading conditions that may compromise their performance before or during their application. In particular, membranes used in hemodialysis require sterilization by irradiation with high energy radiation. The X-ray induced degradation of regenerated cellulose membranes (Cuprophan film) has been investigated by infrared, ultraviolet/visible and electron spin resonance spectroscopies. The infrared spectra show a change in the intensity of several bands associated with the glucose ring. A new band appears at 1724 cm −1, whose intensity increases with X-ray exposure time. The UV/visible spectra show bands at 200 and 260 nm, whose intensity increases with X-ray irradiation time. The ESR spectrum of Cuprophan membranes is a seven-line spectrum composed of the overlapping of at least two triplet and one doublet signal, indicating the presence of several types of free radicals in the irradiated membranes.