Alkyl phosphonium salts are novel and unexplored modifiers for polymer based composites which can improve the clays compatibility and dispersion in the polymer matrix. These salts can enhance the thermal stability of the modified clays, which is an indispensable requirement for thermosetting composites curing and processing occurring at high temperatures. In this work, a raw bentonite was ion exchanged with tributyl(hexadecyl) phosphonium bromide and then a novel epoxy/nanoclay composite was synthesized. The curing kinetics of the nanocomposites was studied. An extensively kinetic study was performed by FT-IR analysis and models accounting for many potential reactions and diffusion restrictions were proposed. A relationship between the H-bonding interactions and the kinetics was found. Also, the effect of the modifier of bentonite was found to affect the reaction yield. (C) 2015 Elsevier B.V. All rights reserved.