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; A.E. CIOLINO; L.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–liquid equilibrium boundariesat 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 experimentswas from 50 to 184 ◦C. The maximum pressure was 303 bar. In all cases the overall polymerconcentration was less than or equal to 4.1 wt%. At the ranges of conditions of the experiments we havefound 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/C5ratio in the solvent mixture. (c) For ‘PE + DME + C5’, there is a substantial decrease in the CPPs with theaddition 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’.