For the preparation oforganoclays nanocomposites, it is well established that the chemical structure of the surfactant plays a major role, enlarging the intergallery space and allowing polymer molecules to diffuse inside the clay.However, much less explored and exploited is the incorporation of reactive surfactants capable of covalently grafting to monomers and growing polymer chains.In this work, we evidence of the effect of the degree of reactivity of bio-based surfactants onto the exfoliation of montmorriilonite clay in epoxy matrix.For this purpose, 3 surfactants were prepared from a derivative of Cardanol, an meta-alkylphenol with a partially unsaturated C15 alkyl chain, incorporating reactive groups:-N(CH3)2,-NH2 or two NH2 functions.In each case, the organomodification of the clay results in a similar interlayer spacing increase.Maldi-ToF/MS was used to evidence the residual reactivity of the-NH2 and 2-NH2 surfactants after derivatization, while the-N(CH3)2 remains unreacted.Finally each organomodified clay was used for the preparation of epoxy composites.Interestingly, for the most reactive surfactant, X-Ray diffraction analysis evidenced a fully exfoliated structure while for the-NH2 terminated surfactant, a semi-exfoliation was observed and for the-N(CH3)2 terminated surfactant, a clear intercalated structure was found, thus positively answering to the question: Is the reactivity of a surfactant a benefit or a drawback to clay exfoliation mechanism in epoxy?