文献类型：期刊文献

英文题名：LIQUID-LIQUID EQUILIBRIA FOR SOLUTIONS OF POLYDISPERSE POLYMERS - CONTINUOUS THERMODYNAMICS FOR THE LATTICE FLUID MODEL

作者：Hu, Ying[1]; Ying, Xugen[1]; Wu, D.T.[1]; Prausnitz, J.M.[1]

机构：[1]LAWRENCE BERKELEY LAB,DEPT CHEM ENGN,DIV CHEM SCI,BERKELEY,CA 94720;[2]E CHINA UNIV SCI & TECHNOL,THERMODYNAM RES LAB,SHANGHAI 200237,PEOPLES R CHINA;[3]DUPONT CO INC,MARSHALL LAB,PHILADELPHIA,PA 19146

年份：1994

卷号：98

起止页码：113

外文期刊名：FLUID PHASE EQUILIBRIA

收录：;EI(收录号：1994122407648);WOS:【SCI-EXPANDED(收录号:WOS:A1994PB47100009)】；

语种：英文

外文关键词：THEORY; POLYMER SOLUTIONS; POLYDISPERSE POLYMERS; CONTINUOUS THERMODYNAMICS; LATTICE FLUID MODEL

摘要：A continuous-thermodynamics framework is presented for phase equilibrium calculations for solutions of polydisperse polymers using a lattice-fluid model. A two-step process is designed to form a real solution containing a solvent and a polydisperse polymer solute at fixed temperature and pressure. In the first step, close-packed pure components are mixed to form a close-packed polymer solution. In the second step, the close-packed mixture, considered to be a pseudo-pure substance, is mixed with holes to form a real polymer solution whose volume depends on temperature and pressure. The simplified Freed model developed previously is adopted for both steps. Besides pure-component parameters, the theory uses a binary size parameter c(r) and a binary energy parameter epsilon12; these binary parameters may be temperature-dependent, The functional approach is adopted to derive expressions for chemical potentials, spinodals and critical points. Computation procedures are established for cloud-point-curve, shadow-curve, spinodal and critical-point calculations for polymer solutions using either a standard distribution or an arbitrary distribution for the polymer molar masses or chain lengths. Calculations are shown for the effect of polydispersity on upper critical solution temperature (UCST), lower critical solution temperature (LCST) and hour-glass-shaped phase behavior for the system acetone-polydisperse polystyrene.