Sínteses químicas para obtenção e caracterização do polipirrol e nanofibras

Abstract

Polypyrrole (PPi) is a widely studied conductive polymer utilized in various applications due to its electrical, chemical, and biocompatible properties. Poly(vinylidene fluoride) (PVDF) and the copolymer poly(vinylidene-trifluoroethylene) (P(VDF-TrFE)) are known for their piezoelectric and dielectric properties, as well as their flexibility and ease of processing, making them suitable for electronics applications. This dissertation explores the chemical synthesis of polypyrrole (PPi) as a fundamental component in obtaining hybrid nanofibers composed of PPi/PVDF and PPi/P(VDF-TrFE). The PPi synthesis method is elaborated upon, including the chemical polymerization of pyrrole and the doping conditions used to adjust its properties. The processes for obtaining hybrid nanofibers PPi/PVDF and PPi/P(VDF-TrFE) are described, emphasizing the importance of parameter adjustments in the electrospinning process. The characterization of polypyrrole is carried out using advanced analytical techniques such as X-ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), Vibrating Sample Magnetometer (VSM), Differential Thermal Analysis (DTA), Scanning Electron Microscopy (SEM), and the nanofibers are examined through SEM. The results demonstrate the formation of well-defined nanofibers with a uniform distribution and random orientations when using polypyrrole obtained through chemical synthesis using FeCl3 as the oxidant and PTSA as the surfactant in a ratio of 1:2.5:0.2, which is crucial for the multifunctional properties of the nanofibers. Nanofibers obtained using PPi from other chemical syntheses, with variations in the oxidant, surfactant, and ratio, exhibited non-uniform distributions and random orientations, highlighting that the choice of oxidant, surfactant, and reagent ratio in the chemical synthesis of poly(pyrrole) impacts the properties of the resulting nanofibers. This study contributes to advancing the understanding of the properties and applications of hybrid nanofibers PPi/PVDF and PPi/P(VDF-TrFE), opening new perspectives for the development of biomaterials, such as conductive scaffolds for nerve regeneration. It highlights the importance of precise chemical synthesis of PPi as a key component in this context.