Shock compressibility of polystyrene of variable initial density

The dynamic compressibility of polystyrene C₆H₅-CH-CH₂]_n with initial densities of 1.0, 0.7, 0.5, and 0.3 g/cm³ has been investigated at pressures of 200–400 kbars. The D–₀ (wave velocity-initial density) relations are presented for specimens of normal and reduced density tested under identical conditions. Wave velocity-particle velocity relations are given for polystyrene of normal and reduced density together with the shock Hugoniots. The simplest equation of state satisfactorily describing the entire set of experimental data is selected.