Thermodynamics of polymer/diluent systems for thermally induced phase separation: 1. Determination of equation of state parameters

The parameters for Flory's equation of state adapted to polymer/oligomer systems were determined to estimate the thermodynamic properties of isotactic polypropylene/diluent systems undergoing thermally induced phase separation. Three kinds of diluents were covered: n-alkanes, n-fatty acids and n,n-bis (2-hydroxyethyl) tallowamine. Reduced volumes and temperatures were determined by measuring the volumetric properties, characteristic pressures were determined by measuring the vapour pressures, and exchange interaction parameters were determined by measuring the heat of mixing for analogous systems of small molecules. The exchange interactional parameters obtained from analogous systems were extrapolated to polymeric systems by using a series of analogous molecules for isotactic polypropylene. The equation of state parameters determined in this study were proved reliable for the thermodynamic analyses covered in other papers in this series.