Experimental characterization and theoretical modeling of the infrared-optical properties and the thermal conductivity of foams

In order to understand and improve the thermal insulation performance of cellular polymeric foams, two different polymers and corresponding foams, extruded polystyrene foam (XPS) and Polyurethane foam (PUR) were selected and thoroughly characterized at ZAE Bayern. At first radiative properties, cell morphology and thermal conductivity were characterized. The measured results were then compared to the theoretical model developed at ZAE Bayern. The validated model allows then the prediction of the insulation performance of an arbitrary XPS or PUR foam with given density and geometrical structure. It also allows defining the optimal structure (resin, cell morphology, density) to achieve the desired thermal conductivity.