In this work, we present a theoretical discussion regarding the Flory-Huggins chi interaction parameter for 11 random copolymer-solvent systems along with their corresponding polymer pairs. Copolymers studied are poly(acrylonitrile-co-butadiene) in acetonitrile, poly(styrene-co-acrylonitrile) in 1,2-dichloroethane, poly (acrylonitrile-cobutadiene) in hexane, and poly(acrylonitrile-co-butadiene) in pentane. For ternary systems, the results are expressed in terms of chi(1,23), which is reduced to the classical Flory-Huggins chi(12) interaction parameter in case of binary mixtures. The data on chi(1,23) may be used for an approximate estimation of the chi'(23), interaction parameter for the limiting case of zero solvent concentration. For this purpose, at the end of each subsection of tables, the limiting value Of x(1,23)(infinity) is given. The limiting values of phi(infinity)(2), p(3)(infinity), and chi'(23) also appear at the end of each table. It should be noted that these values are obtained by the graphical extrapolation of data to zero concentration of solvent. (c) 2006 Wiley Periodicals, Inc.