The interadtion with chloroform of crystalline poly(ethylene oxide) (PEO) and its blends with amorphous poly(methacrylate) (PMA), poly(methyl methacrylate) (PMMA), poly(butyl acrylate) (PBA), and poly(butyl methacrylate) (PBMA) was investigated using the static discrete sorption method. Calculations of the Gibbs mixing energy were carried out with allowance made for the degree of crystallinity of blends determined from X-ray diffraction data. The Gibbs energy of mixing with chloroform changes in the following order: PEO > PEO-PMA > PEO-PMMA > PEO-PBA = PEO-PBMA. The energies of mixing of crystalline PEO with amorphous polymers were calculated from the obtained Gibbs energies of mixing with chloroform. These energies fall in the range from -2.3 to -4.4 kJ/kg depending on the structure of the poly(acrylates).