Structure-property relationship in mechanochemically prepared polyaniline

The comparative analysis of the physicochemical properties of polyaniline prepared in the conditions of solventless mechanochemical treatment in the ball mill (PAni vertical bar(mch)) and polyaniline synthesized by the usual oxidative polymerization in the solvent (PAni vertical bar(c)) is carried out. Conductivity of PAni vertical bar(mch) substantially exceeds that of PAni vertical bar(c). As molecular weights of PAni vertical bar(mch) and PAni vertical bar(c) are comparable, the observed difference could be connected with the influence of mechanical stress which affects the polymer during its mechanochemical preparation. The increased conductivity of polyaniline obtained by post-synthesis mechanochemical treatment of PAni vertical bar(c) (PAni vertical bar(mt)) confirms such explanation. It could be concluded from the results of the structural investigations as well as of spectral and electrochemical studies that the shear stress which exerts influence on the polymer during mechanochemical synthesis or mechanochemical treatment leads to the increase of the interchain pi-pi interaction and, consequently, to the efficient improvement of conductivity. (C) 2009 Elsevier B.V. All rights reserved.