High-pressure liquid/liquid equilibrium boundaries for systems containing polybutadiene and/or polyethylene and a light solvent or solvent mixture

JUAN M. MILANESIO; GUILLERMO D.B. MABE; ANDRÉS E. CIOLINO; LIDIA M. QUINZANI; MARCELO S. ZABALOY

JOURNAL OF SUPERCRITICAL FLUIDS

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2012 vol. 72 p. 333 - 339

0896-8446

In this work, we have obtained experimental cloud points, i.e., liquid/iquid equilibrium boundaries at constant composition, for the systems polybutadiene (PB) + n-pentane (C5), PB + dimethyl ether (DME) + C5, polyethylene (PE) + DME + C5, and PB + PE + DME + C5. The temperature range of the experiments was from 50 to 184 °C. The maximum pressure was 303 bar. In all cases the overall polymer concentration was less than or equal to 4.1 wt%. At the ranges of conditions of the experiments we have found the following: (a) For PB + C5, the minimum pressure required to guarantee homogeneity is 140 bar. (b) For PB + C5 + DME, the cloud point pressure (CPP) curves lie in between the CPP curves of PB + DME and PB + C5, and the maximum CPP was 226 bar. The CPP increases with the increase of the DME/C5 ratio in the solvent mixture. (c) For PE + DME + C5, there is a substantial decrease in the CPPs with the addition of C5 to the DME + C5 solvent mixture, and the maximum CPP was 303 bar. (d) The CPPs for PB + PE + DME + C5 are higher than the CPPs of PB + DME + C5 but lower than the CPPs of PE + DME + C5.