Structural and morphological characterization of poly(o-ethoxyaniline) emeraldine-salt form using FTIR, XRD, LeBail method and SEM

Abstract

The introduction of polar functional and alkyl groups into the main chain of Polyaniline (PANI) is a mechanism to obtain soluble polymers in a wider variety of organic solvents. Poly(o-ethoxyaniline) (POEA) is a derivative of PANI and its structural difference is the presence of the group (-OC2H5) in the ortho position of the carbon rings. Despite the large number of studies performed with PANI and its derivatives, there are few that focus on a structural study of these materials in doped form (ES). Poly(o-ethoxyaniline) Emeraldine-salt form (POEA-ES) was synthesized in polymerization times of 3, 24 and 48 h. Through XRD measurements were observed that different polymerization times did not cause structural changes in polymer structures. It were found in XRD patterns peaks at 2θ = 8°, 12°, 16°, 24°, 26°, 38°, 44° and 52°. Crystallinity percentage was calculated using the Peak Fitting Module Program and showed that POEA-ES has around 39% of crystallinity. FTIR analysis allowed to identify characteristic absorption bands in the structure of POEA-ES. By Scanning Electron Microscopy (SEM) it was observed micrometric particles of varying sizes, with morphologies similar to interconnected vesicular microspheres. Through LeBail Method, it was observed that crystallites of POEA-ES are present in the order of 26 Å. It was found a conductivity value of 0.3 × '10 POT. -7' S/cm for POEA-ES.