Phase behaviour and thermodynamic modelling of the ternary system (carbon dioxide + ε-caprolactone + chloroform)

Abstract

The poly(ε-caprolactone) is an aliphatic polyester which has received a growing interest due its properties. Furthermore, the use of supercritical carbon dioxide is a major advance for the establishment of green polymer production processes. This advance is achieved by reducing the amount of toxic components and by the promoted separation of these components from the final product. The aim of this work was to study the high pressure phase behaviour for the ternary system involving carbon dioxide, ε-caprolactone, and chloroform, gathering crucial information to conduct polymerization reactions in supercritical medium. The experiments were executed at temperatures from (323 to 353) K, pressures from (4.68 to 21.85) MPa, and mass ratios of chloroform to ε-caprolactone of 0.5:1, 1:1 and 2:1. Phase transitions of vapour-liquid bubble point (VLE-BP), and dew point (VLE-DP) type were observed. Moreover, the experimental results were modelled using the Peng-Robinson (PR) equation of state with the Wong-Sandler (PR-WS).