Micro thermal analysis μTA at interphases of adhesives

The Micro Thermal Analysis μTA combines the high positioning accuracy and imaging capabilities of scanning probe microscopy with methods of thermal analysis. This thermal properties of surfaces can be acquired with a high spatial resolution. The possibilities of μTA are demonstrated by interface characterisation. Presented are measurements of local variations in the glass temperature of adhesives interphases. It was shown the influence of different adherend treatments on the building of pronounced interphases in the joint between the adherends. The local thermal analysis of the μTA is able to detect different network densities both near the adherend surface and in the bulk phase of the adhesives. In the immediate neighbourhood of the pre-treated adherend surface the glass transition temperature of an epoxy resin was 10 to 20 K higher as in a distance of about 20 μm from the adherend surface (bulk phase). The height of the glass transition temperature near the adherend surface is dependent on the pretreatment.