Thermodynamic properties of the hyperbranched polymer, Boltorn H2004 (B-H2004), were investigated by inverse gas chromatography with 42 different solvents: n-alkanes (C-5-C-10), cycloalkanes (C-5-C-8), alkenes (C-5-C-8), alkynes (C-5-C-8), aromatic hydrocarbons (benzene, toluene, ethylbenzene, o-, m-, p-xylene, thiophene), alcohols (C-1-C-5), water, ethers (tetrahydrofuran (THF), methyl-tert-butylether (MTBE), diethyl-, di-n-propyl-, di-n-butyl ether), and ketones (acetone, 2-pentanone, 3-pentanone, 2-hexanone, 3-hexanone, cyclopentanone) at the temperatures from (308.15 to 348.15) K using the inverse gas chromatography (IGC). The density and thermophysical properties of polymer were described. The specific retention volume (V-g), the mass-fraction activity coefficient at infinite dilution (Omega(infinity)(13)), the Flory-Huggins interaction parameter (chi(infinity)(13)), the molar enthalpy of sorption in the polymer (Delta H-s), the partial molar excess enthalpy at infinite dilution (Delta H-1(E infinity)), the molar enthalpy of vaporization to the ideal-gas state for the pure solutes (Delta H-vap(0)), the partial molar Gibbs excess energy at infinite dilution (Delta G(1)(E,infinity)), and the solubility parameter of the polymer (delta(3)), Were calculated. The U NIFAC-FV model was used to predict the mass-fraction activity coefficient at infinite dilution for different solutes in the B-H2004 polymer. (C) 2009 Elsevier Ltd. All rights reserved