A model-free analysis of configurational properties to reduce the temperature- And pressure-dependent segmental relaxation times of polymers

The segmental relaxation time data for poly(vinyl acetate), poly(vinyl chloride), and linear and star polystyrene are analyzed using a model-free method to determine how the temperature- and pressure-dependent relaxation times, τ, scale with the relative configurational thermodynamic properties. The model-free method assumes no specific mathematical form, such as reciprocal linearity, and the configurational properties are referred to an isochronal state to eliminate the bias associated with the definition of the ideal glassy state. The scaling ability of a given configurational property is strongly material-dependent with the logarithm of τ scaling better with TS_c and H_c for poly(vinyl acetate), with TS_c, H_c, and U_c for poly(vinyl chloride), and with TS_c, H_c, and V_c for linear and star polystyrene. The choice of the isochronal reference state does not qualitatively affect the results.