Biodegradation of Polyimide-Coated Chromium Substrates

Abstract

The biodegradation of polyimide-coated chromium substrates has been investigated by electrochemical and optical techniques. All samples were sterilized prior to exposure and experiments were accomplished in either inoculated or non-inoculated (sterile conditions maintained) 0.5 M NaCl solutions. Electrochemical impedance spectra reveal that specimens exposed to inoculated solutions experience deterioration in a shorter time than samples exposed to sterile conditions. These spectra indicate deterioration of the coating and, probably, corrosion of the substrate. In addition, photographic evidence suggests that there is an effect on the polymer as a result of the presence of the microorganisms. These results strongly suggest that the polyimide- chromium system tested during this study is subject to premature breakdown in this inoculum as a result of microbial activity.