EQUATIONS OF STATE AND PREDICTIONS OF MISCIBILITY FOR HYDROCARBON POLYMERS

The pressure-volume-temperature properties of a number of hydrocarbon polymers, including a series of ethylene-propylene copolymers, have been measured. These data, in the melt state, have been fit to equations of state. The characteristic parameters from the equations of state are related to thermodynamic properties of the polymers and have been correlated with their structure. The pure component data have been used to make predictions about the miscibility of the polymers with each other. It was found that, even in these nonpolar materials the enthalpy of mixing should dominate the behavior. The ethylene-propylene copolymers are predicted to be miscible for less than 15% differences in monomer contents at molecular weights of 10(5).