Structural investigations of polyaniline prepared in the presence of dodecylbenzenesulfonic acid

Structural studies of powdered polyaniline (PANI) prepared in aqueous mediu m by the oxidative polymerization of aniline in the presence of dodecylbenz enesulfonic acid (DBSA) were performed by means of DSC and WAXS. The influe nce of the alkyl side-chains on the structure and crystallinity of the as-s ynthesized PANI-DBSA and on the structural transitions taking place in PANI upon washing and heating were investigated. It was found that DBSA induces crystallinity in the rigid matrix of PANI, and residual crystalline phases were also observed after the deprotonation of PANI-DBSA. For the first tim e, a melting peak and a relaxation transition of non-cross-linked PANI were registered.