Technical Abstract: Polymer blends comprising at least one biodegradable polymer with other polymers are referred to as bioblends. Successful development of bioblends requires that the biodegradable polymers be compatible with other component polymers. One way of assessing compatibility is through the evaluation of the degree of intermolecular interactions between the component polymers. In this work, the degree of interaction in binary bioblends comprising biodegradable polycaprolactone (PCL) and polystyrene (PS) was investigated using thermogravimetric analysis (TGA), modulated differential scanning calorimetry (MDSC) and Fourier transform infrared photoacoustic spectroscopy (FTIR-PAS). The TGA studies indicated that incorporation of PCL in PS results in thermal destabilization of PCL/PS bioblends. The MDSC studies showed that some parameters favored partial miscibility of PS in PCL, while others favored immiscibility. The FTIR-PAS spectra suggested the presence of intermolecular n-pi interactions between PCL and PS and supported the results of TGA and MDSC analyses of PCL/PS bioblends.