Polymer blending is a convenient method to develop products with desirable properties. Through specific intermolecular interactions favorable polymer blending can occur, and composite materials with desirable properties can be produced. In this study we have prepared poly(ethylene oxide)lignin blends using thermal mixing. Miscible blends were observed over the entire blend ratio. A melting point depression, comparable to results obtained from phenoxy/PEO blends, and a negative deviation of T-g from the weight-average values was observed. The effect of the binary interaction parameter, chi, on T-g was analyzed. Satisfactory prediction of the T-g-composition curve was obtained, in which specific intermolecular interactions exist. FT-IR analyses revealed a strong hydrogen bond between the aromatic hydroxyl proton and the ether oxygen in PEO.