The properties of a polymeric system are a consequence of the interactions that occur between the various components of these complex systems. These components may vary significantly in terms of chemical nature (e.g. organic/inorganic), physical properties (e.g. particle size, surface area, molecular weight), structural characteristics and proportion in the formulations composition. This review paper addresses the major approaches in use regarding the analysis of the interactions that occur between the polymeric system components and the use of such approaches in the interpretation of the chemical, physical and thermodynamic properties of these systems. Special attention is given to the technique of inverse gas chromatography.A case study is presented, where use was made of inverse gas chromatography to characterize thermodynamically the surface of the major components of pigmented PC/PBT blends. The concept of Lewis acidity/basicity was used in the interpretation of the intermolecular interactions nature and potential in these blends, as encountered in phase separation and phase preferences phenomena and as expressed in the morphology, the physical and the mechanical properties of these commercially important composites. #