STATISTICAL THERMODYNAMICS OF POLYDISPERSE POLYMER MIXTURES

A statistical thermodynamics theory of polydisperse polymer blends bas ed on a lattice model description of a fluid is formulated. Characteri zation of a binary polydisperse polymer mixture requires a knowledge o f the pure polymer system and the interaction energy. It is assumed th at the intrinsic and interactive properties of polymer (for example, T , P*, rho*, and epsilon(ij)*) are independent of molecular size. Ther modynamic properties of ternary and higher order mixtures are complete ly defined in terms of the pure fluid polymer parameters and the binar y interaction energies. Thermodynamic stability criteria for the phase transitions of a binary mixture are shown. The binodal and spinodal o f general binary systems and of special binary systems are discussed.