Photothermal microscopy applied to the study of polymer composites

Abstract

It is proposed to transfer the capabilities of a high sensitivity photothermal technique, developed by the group and widely used in the study of thermal properties of ceramics, metals and glass, to the study of polymer composites. The technique uses a sensing beam for the measurement of the thermal response of the sample due to local effects induced by heating with a modulated pump laser. With a simple spatial sweep of the beams on the sample surface, information on a micrometric scale of the thermal diffusivity of the material, distribution of phases and pores is obtained. Post-process analysis allows calculating average values of relevant properties such as thermal diffusivity, degree of crystallinity and distribution of aggregates. These measurements are performed at low laser powers (of the order of micro watts) avoiding the damage of the studied samples and turning this technique into a powerful tool of non-destructive characterization.