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Abstract
Ultra-thin films of a dicyanate bisphenol A prepolymer on aluminium or silicon substrates are studied as a model for an adhesive interphase. AFM shows structural details of the films with a lateral resolution from some 10 nm up to a few microns. Substrates have to be very flat in order to obtain continuous prepolymer layers. So the aluminium roughness of a few nanometers results in a discontinuous prepolymer distribution below about 10 nm thickness while the films remain intact down to 2 nm on the smoother silicon. XPS and IR spectroscopy show that the as-prepared layers do not undergo serious chemical changes or pronounced adhesive interactions. The native silicon surface is totally inert. The cyanate group is not involved at all. The native aluminium surface induces changes both in energy and orientation of the triazine rings, however. This may be considered as an indirect hint on some adhesive interaction of the cyanurate prepolymer with the aluminium substrate but the experimental facts do not explain the adhesion mechanism in detail yet.