MOLECULAR BONDING AND ADHESION AT POLYMER-METAL INTERPHASES

The purpose of this review is to demonstrate that there are well estab lished molecular bonding and strong interactions between monomers or p olymers and metals. We discuss both theoretical and experimental work related to adsorption and adhesion at polymer-metal interphases. First ly, we briefly describe the fractal nature of polymer-metal interphase s, and the effect of chemisorption on fractal dimension. Secondly, we mention several theoretical studies related to the models and the conf ormation of polymer segments to metal surfaces. Recent theoretical wor k by others with molecular modeling has provided some insight about th e interfaces; however, this type of work is still at an early stage. T hirdly, we cite the experimental work by others with XPS, SERS (surfac e-enhanced Raman scattering spectroscopy), Mossbauer emission spectros copy, etc., on chemisorption, molecular bonding, redox interaction, re structuring of polar groups, and contact oxidation of polymers on meta l surfaces. Among them, SERS and XPS are capable of describing chemica l composition and conformation right at the interfaces. These results appear very valuable in understanding the formation of the architectur al framework of a functional interphase beyond the superficial blendin g. In general, some preliminary data indicate that adhesion of polymer s is greatly improved by various forms of strong interactions, e.g., c hemisorption and molecular bonding at polymer-metal interphases. Howev er, strong chemical reactions at the interphases may not be always ben eficial to adhesion and physical properties.