The compatibility of surface properties and the degree of interfacial action between filler and base directly affect the structure of their composites and make great contribution to a series of properties of composite materials. Interactions among rectorite (REC), quaternary ammonium salt and polymer are investigated via molecular simulation. Inverse gas chromatography (IGC)has been used to investigate the Surface properties of REC, organic-modified rectorite with dodecyl benzyl dimethyl ammonium bromide (12-OREC) and hexadecyl trimethyl ammonium bromide (16-OREC), and thermoplastic polyurethane (TPUR). The correlation of the surface properties and the interfacial action between REC and TPUR and the structure of composite were analyzed. The results indicate that the modification of REC lowers its Surface energy, and changes the surface from being acidic to being predominantly basic and increased the binding energy hence improving the dispersibility of 12-OREC and 16-OREC in TPUR; 12-OREC was found to be the best dispersibility in TPUR because the dispersive energy is approached to TPUR, the acid-base property is most comparable with TPUR and the binding energy between 12-OREC and TPUR is larger, which can yield higher interfacial strength. (C) 2008 Elsevier Ltd. All rights reserved.