The surface tensions of {iPBu-1 (M-n= 16 812 or 18 708 Da) + hydrocarbon (decane, 2,2-dimethylbutane, cyclohexane, ethylcyclohexane, toluene, p-xylene)} systems were measured at T= 298.15 K. Hydrocarbons were chosen as a model substances of gasoline and motor oils, in which the solubility of polymer was already measured in our earlier investigations. Additionally, the (solid+ liquid) phase equilibria (SLE) and (liquid + liquid) phase equilibria (LLE) of iPBu-1 with three alcohols (2-butanol, 1-hexanol and 1-octanol) were studied by a dynamic method. Alcohols as a very popular nowadays additives to the gasoline were worse solvents for the chosen polymer. From these measurements it was found that the solubility of iPBu-1 decreases as the number of carbon atoms in the solvent increases. The lower-molecular-weight iPBu-1 showed better solubility than the higher-molecular-weight iPBu-1. Moreover, the solvent activity coefficients at infinite dilution were predicted using the Flory-Huggins model. (c) 2005 Elsevier B.V. All rights reserved.