UPPER-CRITICAL-SOLUTION-TEMPERATURE BEHAVIOR OF THE SYSTEM POLYSTYRENE PLUS METHYLCYCLOHEXANE - INFLUENCE OF CO2 ON THE LIQUID-LIQUID EQUILIBRIA

Experimental cloud-point data are reported for polystyrene + methylcyc lohexane systems in the vicinity of the upper critical solution temper ature (UCST). Two samples of polystyrene were used. One is nearly mono disperse with M-W = 31,600 and M-N = 29,100. The other has M-W = 250,0 00 and M-N = 64,000. Experimental pressures range from 1 MPa to 14 MPa . Experimental temperatures range from 297 K to 306 K for the lower mo lar mass polymer in methylcyclohexane and 323 K to 331 K for the highe r molar mass polymer in methylcyclohexane. The mass fractions of the p olymer range between 0.03 and 0.27 for the monodisperse sample and bet ween 0.02 and 0.14 for the other. Data are also reported on the influe nce of CO, on the phase behavior of the monodisperse sample in methylc yclohexane for two polymer mass fractions. (C) 1998 Elsevier Science B .V. All rights reserved.