Investigations of stainless steel corrosion and polyurethane-stainless steel adhesion

The high cost of maintaining naval vessels has made biocorrosion protection in the marine environment a research area of intense interest. In this dissertation the chemical mechanisms related to adhesion between Texin 985, a polyetherurethane segmented block copolymer, and 316 L stainless steel (16-18% Cr, 10-14% Ni, 2-3% Mo) are investigated using X-ray Photoelectron Spectroscopy (XPS), Static Secondary Ion Mass Spectrometry (SSIMS), and Fourier-Transform Infrared Spectroscopy (FTIR) in grazing angle mode.;The same techniques are used to characterize the steel and coating surfaces prior to adhesion, and to study the de-adhesion of the coating following a simulated marine biocorrosion experiment. Biocorrosion is simulated by exposure to glacial acetic acid, intended to model the attachment of an acetic acid producing biofilm to the surface of the coating. The FTIR results indicate that the urethane hard segment of the coating interacts with the metal oxide layer through hydrogen bonding of the amide group carbonyl. Swelling of the coating with acetic acid, and the subsequent disruption of this hydrogen bonding, is found to be the primary cause of de-adhesion.