OXIDATION OF ULTRAHIGH MOLECULAR-WEIGHT POLYETHYLENE CHARACTERIZED BYFOURIER-TRANSFORM INFRARED SPECTROMETRY

The effects of processing conditions, sterilization treatment, aging t ime, and poststerilization aging environment on the oxidation behavior of ultrahigh molecular weight polyethylene (UHMWPE) are examined. Oxi dation is monitored by observing changes in the carbonyl peak appearin g in Fourier Transform Infrared Spectrometry (FTIR) and is found to be relatively insensitive to processing conditions but strongly influenc ed by sterilization treatments and aging parameters. Oxygen uptake by UHMWPE increases as a result of gamma or electron beam irradiation and continues to rise during subsequent aging at a rate influenced by the aging environment. A hydrogen peroxide ambient causes more severe oxi dation than either air or hyaluronic acid. Control (unsterilized) samp les and those sterilized in ethylene oxide are resistant to oxidation under all conditions except hydrogen peroxide aging. (C) 1997 John Wil ey & Sons, Inc.