Interfacial reactions in an interpenetrating polymer network thin film on an aluminum substrate

We have adopted the dip‐pulling method and a thinning technique to obtain interpenetrating polymer network (IPN) thin films with suitable thickness and adhesive strength on Al substrates. X‐ray photoelectron spectroscopy (XPS) and attenuated total reflection infrared spectroscopy (ATR‐FTIR) were used to study the interfacial reactions, metal transformations, and nonmetal bond types between IPN and Al. By probing the binding energy shifts of nitrogen, aluminum, and oxygen atom species at different IPN/Al interfacial layers, the reactions between the polyurethane in IPN and the OH group in aluminum substrate could be determined. Moreover, the additional structures formed by the double bond between the nitrogen and nitrogen in the NCO group in IPN suggested the existence of covalent bonding in the adhesion areas. Sufficient interfacial reactions occurring between IPN and Al effectively restricted the IPN peel off from Al substrate. Copyright © 2009 John Wiley & Sons, Ltd.