Structural and Morphological Characteristics of Polyaniline Synthesized in Pilot Scale

Abstract

AbstrAct:Polyanilines have many applications in Aerospace, especially in their doped form. Studies on their synthesis in a pilot scale can contribute to obtain products with desirable characteristics for such applications. The present study reports the chemical oxidative synthesis of polyaniline in pilot scale and different reaction times in order to determine if there are variations in the polyaniline structure, morphology and conductivity due to these synthesis conditions. It is very common to analyze these data for polymers obtained through bench scale. However, several parameters change the properties of final material in major scales, such as thermal, mechanic and diffusive variables. Therefore, the reaction time is the only variable into the 9 syntheses carried out, and polyaniline is obtained in a doped form, being dedoped with ammonium hydroxide and redoped with dodecylbenzenesulphonic acid. The doped and redoped samples were characterized by their molecular structure, thermal behavior, crystallinity and morphology. The electrical conductivity of redoped samples was determined. Some differences in the structure and morphology of doped and dedoped forms, identifying the doping structures, were reported. This paper aims to present the relationship between changes on structure and morphology of doped and undoped polyaniline obtained by the mentioned experiments. Furthermore, some addicts on conductivity are carried out. It was possible to contribute in order to obtain a more conductive polyaniline in pilot scale.

Synthesis of Polyaniline/Scarlet 3R as a Conductive Polymer

“…The signal at 9.4 • may be due to the inter-main chain distance. It was reported that PANI prepared in the presence of sodium dodecylbenzene sulfonic acid (SDBSA) as a surfactant shows no signal at 9.4 • due to a decrease in crystallinity [13]. Similarly, in this study, a decrease in crystallinity compared to the PANI prepared with no surfactant was observed, which was attributed to the presence of scarlet 3R that acted as a surfactant for the synthesis.…”

The Preparation and Characterization of Polyacrylonitrile-Polyaniline (PAN/PANI) Fibers

“…The peak at 323 nm was connected with π-π* excitation, and the peak at 618 nm was connected with the exciton excitation of the quinone rings in the PANI ( Figure 4 a). The presence of these peaks and the dark blue coloration of the solution were characteristic for the emeraldine base [ 23 ]. On the spectrum of the spinning solution containing 1 wt.% of polyacrylonitrile and polyaniline synthesized in DMF, the peak near 320 nm was more visible and shifted in towards the shorter wave ( Figure 4 b).…”

Passivation of Carbon Steel Using Intelligent Epoxy Paint

“…The reduced state of PAni is related to the conformational changes that occur in the quinoid and benzenoid rings, which are attributed to changes in the 1588 and 1165 cm −1 bands of the oxidized state of PAni, something not shown in Figure 2. In case the PAni is in the protonated state, the Raman spectrum should have a band in the region of 1300 to 1350 cm −1 , which would characterize the quinonic stretch C-N + , which is attributed to the protonated form of the PAni EP, a fact that is not observed in PAni EB film [16][17][18]. With the obtained spectra, it can be stated that the PAni EB present in the binder remains in the oxidized state.…”

“…Bands in the 1441 cm −1 region are attributed to the presence of OH groups of CEP, and to IEP samples can be associated with C-N bonds of PAni EB binder. The bands at 1603 cm −1 represent the presence of C=C bonds in CEP aromatic rings for the three samples [13,15,18].…”