PHASE-EQUILIBRIA OF POLYPROPYLENE WITH COMPRESSED PROPANE AND RELATEDSYSTEMS .2. FLUID-PHASE EQUILIBRIA OF POLYPROPYLENE WITH PROPANE CONTAINING ALCOHOLS AS COSOLVENTS AND OF SOME OTHER BRANCHED POLYOLEFINS WITH PROPANE

The phase equilibrium measurements for the pseudobinary supercritical polypropylene-propane system reported in the previous paper are extend ed to include pseudoternary systems where a polar cosolvent, in this c ase a low molecular weight alcohol, has been added. The cloud-point is opleths near the critical composition show the range of behavior to be expected as the type V pseudobinary system, polypropylene-propane, de scribed in the previous paper, is transformed into the type IV pseudob inary system polypropylene-alcohol. This type of system contains an ad ditional critical locus with upper critical solution temperatures (UCS Ts) emanating from an upper critical end point (UCEP). The pseudoterna ry systems polypropylene-propane-alcohol possess in most cases a merge d critical locus which contains a set of UCSTs and lower critical solu tion temperatures (LCSTs) and which does not touch the vapor pressure curve of the solvent. The phase equilibrium measurements of the system polypropylene-propane were also extended to include some polymers and copolymers which vary in branch length and frequency. The cloud-point pressures of these systems correlate with the wt % carbon in the bran ches but not with the branch frequency.