Depth Profiling by AFM Nanoindentations and Micro-FTIR Spectroscopy for the Study of Polymer Ageing

A method of depth profiling by AFM nanoindentations is developed for the characterisation of the heterogeneity of the mechanical properties of oxidised polymers. An increase or a decrease of the sample stiffness is measured close to the surface. A comparison with micro‐FTIR profiles and a knowledge of the photooxidation mechanism permit an interpretation of the chemical and physical changes and give new insights into the understanding of the ageing behaviour. Photooxidation profile of a TMPC film measured by AFM (•) and by micro‐FTIR (♦) after irradiation.