RANDOM-PHASE APPROXIMATION CALCULATION OF THE SCATTERING FUNCTION FOR MULTICOMPONENT POLYMER SYSTEMS

Abstract

A method for calculating the structural factor, S(ij)(q), for multicomponent polymer systems is described using a random-phase approximation and incompressibility constraint. Also, for 4-component polymer systems, all S(ij)(q) are obtained in explicit forms. Among the many possible choices of 4-component polymer systems, we considered only two special cases: (i) a mixture of two block copolymers, (A-B)/ (C-D), and (ii) a mixture of a block copolymer and two homopolymers, (A-B,/C/D, where the diblock copolymer C-D has a chemical structure different from the diblock copolymer A-B, and the two homopolymers, C and D, have chemical structures different from the constituent blocks of the diblock copolymer A-B. The spinodal points, where all S(ij)(q) become infinite, of microphase and macrophase transitions, respectively, for the two cases are discussed in detail.