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

JUAN MANUEL MILANESIO; GUILLERMO DOMINGO MABE; ANDRES CIOLINO; LIDIA MARÍA QUINZANI; MARCELO SANTIAGO ZABALOY

JOURNAL OF SUPERCRITICAL FLUIDS

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2012

0896-8446

In this work, we have obtained experimental cloud points, i.e., liquid-liquid 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´.