CRITICAL-POINTS OF MIXTURES OF ETHYLENE AND POLYETHYLENE WAX UNDER HIGH-PRESSURE

Critical points of systems of ethylene with different polyethylene wax mixtures have been measured in the temperature range 413 to 513 K and at pressures up to 93 MPa. The results show a distinct influence of t he polydispersity of the polyethylene wax on the critical point. A met hodology for evaluating critical points of mixtures of ethylene and po lydisperse polyethylene wax with a cubic equation of state and the Won g-Sandler mixing rule is proposed. We find that this method is able to predict critical points with good accuracy over a wide range of polyd ispersity. For industrial calculations it is advantageous to have a si mple model with a limited number of parameters. This method applicates simple cubic equations of state to mixtures under high pressure. (C) 1998 Elsevier Science B.V. All rights reserved.