Ternary Phase Diagram For Polymer/ Solvent/ Supercritical-Co2 By Sanchez-Lacombe Model

Ternary phase diagrams for [polyethylene (mw—420,000, mw/mn—2.6) / n-butane/carbon dioxide], [polypropylene (mw—290,000, mw/mn—1.32)/ n-pentane/carbondioxide] and [polystyrene (mw—187,000)/ cyclohexane/ carbon dioxide] have been generated using the sanchez-lacombe (sl) lattice-fluid model. the results show that atrelatively low pressure, the ternary phase diagram has a l-l-v three-phase region bounded by two two-phase regions (l-v and l-l). at high pressure, l-l-v and l-v regions disappear and only the l-l region remains. with an increase of pressure this two-phase l-l region becomes smaller. this model can also predict transition lcst to ucst by increasing pressure. for polystyrene/ cyclohexane/ carbon dioxide mixture, the calculated results obtained using the sl-model are compared with the reported calculated results created by the perturbed hard-sphere chain model (phsc) and the reported experimental data which indicate good agreement with both the calculated results by phsc-model and experimental data.