An Analytical Equation of State for Molten Polymers

An analytical equation of state (EOS) developed by Ihm-Song-Mason (ISM) has been applied tocalculate some thermophysical properties of molten polymers including Poly (1-octene) (PO), Poly (vinylmethyl ether) (PVME), Poly (vinyl chloride) (PVC), and Poly (styrene) (PS). Three temperature-dependentparameters of the ISM EOS have been determined based on the alternative scaling constants, dispersiveenergy parameters between segments/monomers (ε) and segment diameter (σ). The ability of the proposedEOS has been checked by comparing the results with 547 literature data points for the specific volumes overtemperature from 311-557 K and pressure ranging from 0.1 up to 200 MPa. The average absolute deviation(AAD) of the calculated specific volumes from literature data was found to be 0.47%. The isothermalcompressibility coefficients, κT have also been predicted using ISM EOS. From 188 data points examined,the AAD of estimated κT was equal to 7.75%. Our calculations on the volumetric and thermodynamicproperties of studied polymers reproduce the literature data with reasonably good accuracy.