Amylopectin (AP), a potato-starch-based polymer with a molecular weight of 6,000,000 g/mol, was blended with poly(epsilon-caprolactone) (PCL) and characterized with inverse gas chromatography (IGC), differential scanning calorimetry (DSC), and X-ray diffraction (XRD). Five different compositions of AP-PCL blends ranging from 0 to 100% AP were studied over a wide range of temperatures (80-260 degrees C). Nineteen solutes (solvents) were injected onto five chromatographic columns containing the AP-PCL blends. These solutes probed the dispersive, dipole-dipole, and hydrogen-bonding interactions, acid-base characteristics, wettability, and water uptake of the AP-PCL blends. Retention diagrams of these solutes in a temperature range of 80-260 degrees C revealed two zones: crystalline and amorphous. The glass-transition temperature (T-g) and melting temperature (T-ni) of the blends were measured with these zones. The two zones were used to calculate the degree of crystallinity of pure AP and its blends below T which ranged from 85% at 104 C to 0% at T-m. IGC complemented the DSC method for obtaining the T-g and T-m values of the pure AP and AP-PCL blends. These values were unexpectedly elevated for the blends over that of pure AP and ranged from 105 to 152 C for T-g and from 166 to 210 C for T-g. The T-m values agreed well with the XRD analysis data. This elevation in the T-g and T-m values may have been due to the change in the heat capacity at Tg and the dependence of T-g on various variables, including the molecular weight and the blend composition. Polymer blend/solvent interaction parameters were measured with a variety of solutes over a wide range of temperatures and determined the solubility of the blends in the solutes. We were also able to determine the blend compatibility over a wide range of temperatures and weight fractions. The polymer-polymer interaction coefficient and interaction energy parameter agreed well on the partial miscibility of the two polymers. The dispersive component of the surface energy of the AP-PCL blends was measured with alkanes and ranged from 16.09 mJ/m(2) for pure AP to 38.26 mJ/m(2) when AP was mixed with PCL in a 50/50% ratio. This revealed an increase in the surface energy of AP when PCL was added. (c) 2006 Wiley Periodicals, Inc.