Physical Properties of Polystyrene as Influenced by Temperature

Abstract

The physical properties of plastics are markedly influenced by the ambient temperature, but comparatively few quantitative data on polystyrene have been published. The variation of flexural strength and deflection at break for compression-moulded polystyrene and for a number of other compression-moulded plastic materials at temperatures from —70° to +200° C was described by Nitsche and Salewski. Jenckel and Lagally determined the tensile strength of extruded polystyrene filaments at 30° to 60° C. The elongation at 20° to 90° C was reported for extruded and racked polystyrene foil by Müller. Since the mechanical properties of plastic materials are profoundly influenced by the methods used in preparing the test specimens, data on such properties are meaningless unless the details of preparation also are known. This paper describes variations in some of the mechanical properties of injection-moulded polystyrene over the range from —75° to +100° C. This method was chosen because injection moulding is by far the most commonly Used commercial process for the fabrication of polystyrene.