Phase equilibria of saturated and unsaturated polyisoprene in sub- and supercritical ethane, ethylene, propane, propylene, and dimethyl ether

Abstract

Cloud-point pressures were measured for binary sub- and supercritical fluid solutions of saturated or unsaturated polyisoprene (UPEP) in ethane, ethylene, propane, propylene, and dimethyl ether up to 150°C and 1,400 bar. The polyisoprene was hydrogenated to obtain two samples of different degrees of saturation (56% and 73%). These polymers and solvents were chosen to evaluate π-π interactions between polymer/polymer or polymer/solvent molecules. π-π interactions between polymer and solvent are found to shift the cloud-point pressures in an analogous way to those found for cross-associating polymers. Preliminary correlations using the statistical associating fluid theory (SAFT) are also included.