Maleated poly(propylene carbonate) (PPC-MA)/organo-montmorillonite (OMMT) nanocomposites were first prepared via melt end-capping poly(propylene carbonate) (PPC) with maleic anhydride (MA) and melt-mixing the PPC-MA with commercial OMMT without and with hydroxyl groups in surfactants: Cloisite 20A (C20A) and Cloisite 30B (0013), respectively. Intercalated and partially delaminated morphologies were corroborated via X-ray diffraction (XRD) and transmission electron microscopy (TEM). Dynamic mechanical analysis (DMA) revealed that PPC-MA was evidently reinforced by the partially delaminated C30B platelets. From XRD patterns of statically annealed PPC-MA/ C20A and PPC-MA/C30B mixtures and Fourier transform infrared (FTIR) results of equivalent nanocomposites, partial delamination of C30B in PPC-MA was confirmed to be relevant to diffusion of PPC-MA molecular chains in C30B galleries, grafting of PPC-MA to C30B platelet surfaces and further separation of C30B platelets. (c) 2006 Elsevier Ltd. All rights reserved.