Functional copolymer/organo-silicate [N,N'-dimethyldodecyl ammonium cation surface modified montmorillonite (MMT)] layered nanocomposites have been synthesized by interlamellar complex-radical copolymerization of preintercalated maleic anhydride (MA)/organo-MMT complex as a 'nano-reactor' with n-butyl methacrylate (BMA) as an internal plasticization comonomer in the presence of radical initiator. Synthesized copolymers and their nanocomposites were investigated by dynamic mechanic analysis, X-ray diffraction, SEM, and TEM methods. It was found that nanocomposite dynamic mechanical properties strongly depend on the force of interfacial MA...organo-MMT complex formation and the amount of flexible n-butyl ester linkages. An increase in both of these parameters leads to enhanced intercalation and exfoliation in situ processes of copolymer chains and the formation of hybrid nanocomposites. (C) 2010 Wiley Periodicals, Inc. J Appl Polym Sci 118: 2904-2913, 2010