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I n t r o d u c t i o nThe chemical c o m p o s i t i o n of p o l y m e r surfaces is of interest because of adhesion, wetting and friction properties. A change in surface energy of the p o l y m e r indicates that a d s o r p t i o n occurs at the interface of a p o l y m e r melt and a metal substrate. W i t h c o p o l y m e r s of vinyl chloride and vinyl acetate the concentration of vinyl acetate units is higher at the surface than in the bulk of the p o i y m e r (1). In this paper these p o l y m e r -m e t a l systems are analyzed in m o r e detail, using X -r a y photoelectron s p e c t r o s c o p y (XPS), sometimes called electron s p e c t r o s c o p y for chemical analysis (ESCA). Analysis of c o m p o s i t i o n as a function of depth with the aid of argon ion etching proved to be impracticable because of degradation of the p o l y m e r and varying sputtering rates. F o r that reason we use surface reactions to distinguish groups on the surface from groups in a subsurface layer, as measured with XPS.