CONTINUOUS THERMODYNAMICS FOR POLYMER SOLUTIONS I.CLOSE-PACKED LATTICE MODEL  

作　　者：胡英 英徐根 D.T.Wu J.M.Prausnitz 

机构地区：[1]Marshall Laboratory,E.I.Du Pont de Nemours & Company Philadelphia,PA 19146,USA [2]Department of Chemical Engineering,University of California,Berkeley Berkeley,CA 94720,USA

出　　处：《Chinese Journal of Chemical Engineering》1994年第3期4-18,共15页中国化学工程学报（英文版）

摘　　要：using close-packed lattice models,a continuous thermodynamic framework is presented forphase-equilibrium calculations for binary solutions with a polydisperse polymer solute.An expressionfor the Helmholtz function of mixing is based on the revised Freed model developed previously.Asize parameter c_r and an energy parameter ε are used;the former can be temperature dependent,while the latter can depend on both temperature and chain-length of the polymer.The discretemulticomponent approach is adopted to derive expressions for chemical potentials,spinodals and criti-cal points.The continuous distribution function is then used in calculations of moments occurring inthose expressions.Computation programs are established for cloud-point-curve,shadow-curve,spinodal and critical-point calculations for polymer solutions with standard distribution or arbitrarydistribution of polymer.In the latter case,the derivative method developed previously is applied.lllustrations for phase-equilibrium calculations areUsing close-packed lattice models, a continuous thermodynamic framework is presented for phase-equilibrium calculations for binary solutions with a poJydisperse polymer solute. An expression for the Helmholtz function of mixing is based on the revised Freed model developed previously. A size parameter cr and an energy parameter ε are used; the former can be temperature dependent, while the latter can depend on both temperature and chain-length of the polymer. The discrete multicomponent approach is adopted to derive expressions for chemical potentials, spinodals and critical points. The continuous distribution function is then used in calculations of moments occurring in those expressions. Computation programs are established for cloud-point-curve, shadow-curve, spinodal and critical-point calculations for polymer solutions with standard distribution or arbitrary distribution of polymer. In the latter case, the derivative method developed previously is applied. Illustrations for phase-equilibrium calculations are shown for cyclohexane-polydisperse polystyrene systems. Satisfactory results obtained indicate the effectiveness of the proposed framework and the computation procedures.

关 键 词：continuous thermodynamics polymer solution POLYDISPERSITY lattice model CLOUD-POINT CURVE SHADOW CURVE SPINODAL critical point 

分 类 号：O631.4[理学—高分子化学]