In this study, the sorption enthalpy (δHS1), sorption free energy (δG1), sorption entropy (δS1), enthalpy, and free energy at infinite dilution (δH1 and δG1) values were calculated for selected probes such as alcohols, ketones, acetates, cyclic ethers, aromatics, and alkanes in the temperature range 403-433 K for poly(methyl methacrylate) (PMMA), poly(vinyl chloride) (PVC) homopolymers, and the PVC-PMMA blend system. The values of the Flory-Huggins interaction parameters χ1(23) have been calculated in this temperature range and show the importance of specific interactions between the polymers and the solvents. The values of the polymer-polymer interaction parameters χ23(for the temperature range 403–433 K) were found to change from +3.57 to +1.16 for alcohols, from +2.99 to +0.52 for ketones, from + 1.60 to −0.48 for acetates, from +0.96 to −1.46 for cyclic ethers, from +2.66 to +0.12 for aromatics, and from +8.73 to +1.06 for alkanes.