P-V-T PROPERTIES OF ALTERNATING POLY(ETHYLENE-PROPYLENE) LIQUIDS

The pressure-volume-temperature (P-V-T) properties of monodisperse alt ernating poly (ethylene-propylene) (hydrogenated polyisoprene) melts o f varying molecular weights are measured at 0.1 MPa < P < 200.1 MPa, a nd 290 K < T < 510 K in a dilatometer-type apparatus. The Flory-Orwoll -Vrij (FOV), Modified Cell Model (MCM), Sanchez-Lacombe (SL), and the Statistical Associating Fluid Theory (SAFT) equations of state are fou nd to correlate the experimental data with excellent accuracy, except either at low pressures and high temperatures, or at high pressures an d low temperatures. On average, MCM and SAFT fit the data slightly bet ter than FOV and SL. The equation-of-state parameters are found to be independent of molecular weight, especially for SAFT, as required by t he theory. (C) 1994 John Wiley & Sons, Inc.