Equation of state for polymers based on glass transition data

摘要

This paper addresses a method for predicting the participating constants in equation of state (EOS) for compressed polymeric fluids using two scaling constants, the surface tension γ_g and the molar density ρ_g, both at the glass transition point. The theoretical EOS undertaken is the one attributed to Tao and Mason. The second virial coefficients are calculated from a two-parameter corresponding states correlation, which is constructed with two constants as scaling parameters, i.e., the surface tension γ_g and the molar density ρ_g. This new correlation has been applied to the Tao-Mason (TM) EOS to predict the volumetric behavior of several polymer melts. The operating temperature range is from 291.25 to 603.4 K and pressures of up to 202.5 MPa. A collection of 516 data points has been examined for the aforementioned polymers. The average absolute deviation between the calculated densities and the experimental ones is of the order of 0.44%.