INTERFACES IN POLYMERIC SYSTEMS AS STUDIED BY CASM - A NEW COMBINATION OF LOCALIZED CALORIMETRIC ANALYSIS WITH SCANNING MICROSCOPY

Unlike almost all other variants of scanning probe microscopy, scannin g thermal microscopy allows sub-surface imaging of polymers and other solids to be performed. Although on its own it provides no information that could help with chemical fingerprinting or analysis, when combin ed with a microscopic Version of modulated-temperature differential sc anning calorimetry (M-T DSC), the resulting simultaneous measurements of thermal data and spatial detail allow us to obtain useful data on t he structure of polymer blends, phase separation, and the formation of diffuse interfaces. So far, for a number of polymers, we have perform ed localised calorimetric analysis to record events such as glass tran sitions, meltings, recrystallisations and thermal decomposition within volumes of material estimated at a few tens of cubic microns. Here we review our own work only, in order to introduce the CASM technique to gether with the results of preliminary studies. As introduction we inc lude also some examples of relevant published work on polymer interfac es performed by means of the parent ''bulk'' thermal analysis techniqu e (M-T DSC): the topics covered include miscibility, shifts in glass t ransition temperature as a diffuse interface is formed, and determinat ion of weight fraction and thickness of the interface.