Fourier-transform infra-red spectroscopy was used to study the thermal stability of silane-modified vinylmidazole copolymers on both KBr plates and copper coupons. The copolymers were synthesized by free-radical polymerization of gamma-methacryloxypropyltrimethoxysilane and N-vinylimidazole. The ability of these copolymers to inhibit the oxidation of copper at elevated temperatures was compared to that of poly(N-vinylimidazole). The silane acted as a scavenger for the water released by the imidazole ring during heating. Upon heating, the silane methoxy groups hydrolysed and condensed to form siloxane linkages.