Intermolecular interactions in the blends of poly(trimethylene terephthalate)/phenoxy resin of bisphenol A prepared by melt mixing in a microcompounder were studied using Fourier transform infrared (FTIR) spectroscopy and thermal analysis. The FTIR results revealed the characteristic bands of the blend constituents along with the bands showing interassociated, self-associated, and nonassociated hydrogen bonding in the blends. It was found that the self-associated hydrogen bonds in the blends were favorable over the interassociated bonds. On the other hand, using the melting point depression, the interaction parameter of the blends was calculated to be about 0.047. The positive value of the interaction parameter and low degree of interassociated hydrogen bonding in the blends suggest the immiscibility of the blends, which is confirmed by scanning electron microscopy observations as well as dynamic mechanical analysis. However, for chemically reacted compositions, the blends were changed to homogenous systems. POLYM. ENG. SCI., 51:518-525, 2011. (C) 2010 Society of Plastics Engineers