THE EXPERIMENTAL INVESTIGATION OF MECHANICAL AND MORPHOLOGICAL PROPERTIES OF POLYSTYRENE

Microcellular foams are a group of foams which have a lot of micro cells in the size of about 10 microns. In these foams, neutral gases (Nitrogen or Carbon dioxide) are used as a foaming material. Because of their small sizes, these foams have better mechanical and physical properties (such as fatigue strength, yield strength and de-electrical and thermal properties) than non-foamed plastics. In this study, the mechanical properties of polystyrene microcellular foams have been studied. The rate of relative density, the size of the cells, the structure of the foams and yield and fatigue strength have been studied and measured. To achieve an optimal structure, the results show that temperature and time of foaming should be controlled carefully. This condition is in the temperature of about 100° c and the time of 100 second. Also, the tensile strength of the foamed sample has been reduced and the rate of energy absorption has been significantly increased.