Abstract
Expanded polystyrene (EPS) is a commonly used polymer in the packaging industry and for the thermal insulation of buildings. It has poor mechanical properties which limit its application in some areas. A heat treatment was carried out on a sample of EPS, in order to improve its mechanical properties. The treatment consists of operations that combine the heating and cooling of the material. It is executed to improve the characteristics of the treated polymer and make it more favourable for use in new applications. In the case of EPS, this process changes the behaviour of the polymer in a beneficial manner and maximizes its density and hardness. Indeed, the treated version shows interesting mechanical, tribological and hygroscopic properties. This improvement was obtained mainly due to the morphological modification of the structure of EPS. Indeed, heat treatment leads to the creation of a polystyrene crust which covers every EPS bead. This crust protects the cell structure of each bead against stretching and supports most of the load applied to the treated version of EPS. Thus, the treated EPS can be used not only for packaging and thermal insulation but also for more structural applications.