Studies on the structure of the aggregated state of ring-substituted polyaniline

Ring-substituted groups and doping not only have a great effect on the chain structure of polyanilines, but also on their aggregated state due to its electronic and steric effect. When steric hindrance increases, the crystallinity declines. Within the same molecular chain or between different molecular chains, the forming of hydrogen bond contributes to increasing crystallinity. From SEM and XRD experiments of polymer films it was found that the crystallinity of the ring-substituted polyanilines synthesized increases in the order of poly-o-toluidide (POT), poly-2, 5-dimethoxyaniline (PDMAn) and poly-m-chloroaniline (PmClAn). In comparison to their corresponding undoping polymers, it was concluded that proton doping of polyanilines renders their crystallinity increased. POT basically showed amorphous, while PDMAn allomorphous with low crystallinity. On the other hand, PmClAn is characterized by its molecular crystalline, being monoclinic with crystall-cell parameters of a = 0.679 nm, b = 2.304 nm, c = 0.5734 nm, alpha = 90degrees, beta = 100.9degrees, and gamma = 90degrees. By using MM+ molecular mechanics methode in HyperChem program, (HNMR)-H-1 and X-ray diffraction data were analyzed, thereby the configuration of PmClAn chain was determined and optimized, the results show that in the macromolecular chain of PmClAn the ratio of benzoid to quinoid units is 3:2..