Síntese de nanofibras de polianilina e preparação do nanocompósito de polipropileno / polianilina

Abstract

The following paper reports the synthesis of polyaniline (PANI) nanofibers and the making of nanocomposites that have polypropylene as their polymer matrix. Polyaniline nanofibers have been synthesized by the quick-mix method. Hydrochloridric and sulfuric acids were evaluated as dopant agents in different reaction temperatures: 25, 60 and 100 °C. Polypropylene (PP) nanocomposites were prepared by adding 1 and 3% (m/m) of PANI nanofibers through three different methods utilized for dispersing the nanocharge in the polymer matrix. This way parameters such as quick-mix in the fusion chamber, masterbach prepping and pre- dispersion of the charge in ethanol were appraised. The morphology and the electric, thermic and mechanic properties of the PANI nanofibers as well as the nanocomposites prepared were evaluated by means of Scanning Electron Microscopy (SEM), Atomic Force Microscopy (AFM), Thermogravimetric Analysis (TGA), Differential Scanning Calorimetry (DSC) and Electrical Impedance Spectroscopy (EIS). Nanofibers of the upmost definition were obtained with hydrochloridric acid as the dopant agent in a temperature of 60 °C. The nanofibers prepped using this methodology presented electrical resistivity of 10² Wcm and a decomposition temperature near 300 °C. AFM pictures indicate good charge distribution in the polymer matrix regardless of the chosen preparation method. It was verified that the nanocomposites’ thermic properties were not negatively affected by the addition of PANI nanofibers and composites with similar traction properties to PP’s matrices were produced with a larger ultimate elongation and electrical conducting properties.