The net retention volumes, V-N, of n-alkanes and five polar probes are determined on cellulose acetate phthalate-polycaprolactonediol blend column by inverse gas chromatography in the temperature range 323.15-363.15 K. The dispersive surface energy, gamma(d)(S), of the blend has been calculated using the V-N values of nalkanes and the gamma(d)(S) at 333.15 K is 12.6 mJ/m(2). The gamma(d)(S) values are decreasing linearly with increase of temperature. The V-N values of the five polar solutes are used to calculate the specific component of the enthalpy of adsorption, Delta H-a(S). The Lewis acid-base parameters, K-a and K-b, are derived using Delta H-a(S) values and are found to be 0.019 and 0.403, respectively. The K-a and K-b values indicate that the blend surface contain more basic sites and interact strongly with the acidic probes. The acid-base parameters have been used to analyze the preferential interaction of the solid surface with acidic and basic probes. POLYM. ENG. SCI., 53: 1780-1785, 2013. (C) 2013 Society of Plastics Engineers