Polymer/montmorillonite nanocomposites were prepared. Intercalation of 2-methylaniline with aniline monomers into montmorillonite modified by cation was followed by subsequent oxidative polymerization of the monomers in the interlayer spacing. The clay was prepared by cation exchange process between sodium cation in (M-Na) and copper cation (M-Cu). We prepared a series of polymer/clay nanocomposite materials that consisted of an emeraldine base of poly(2-MA), poly(2-MA-co-ANI) and PANI by layered copper montmorillonite. All organic monomers used were first intercalated into the interlayer regions of clay hosts followed by a one-step in situ oxidative polymerization. The unique properties of the as-synthesized nanocomposites materials are investigated by electronic conductivity measurements, X-ray diffraction, FTIR spectroscopy, UV-vis spectroscopy, thermogravimetric analysis and SEM, were also studied by cyclic voltammetry which indicates the electroactive effect of nanocomposite gradually increased with aniline in the polymer chain. ; Chouli, F.; Benyoucef, A.; Yahiaoui, A.; Quijada Tomás, C.; Morallón, E. (2012). A conducting nanocomposite via intercalative polymerisation of 2-metylaniline with aniline in montmorillonite cation-exchanged. Journal of Polymer Research. 19(3):1-10. doi:10.1007/s10965-012-0003-6. ; Senia ; 1 ; 10 ; 19 ; 3