Obtenção de estruturas de nanocompósitos poliméricos híbridos condutores

Abstract

In this work, hybrid electrical conductive nanocomposites structures with potential to be applied in conductive and electrostatic dissipative devices were obtained. Such structures were produced by combining two types of nanofiller in a matrix of thermosetting epoxy resin of diglycidyl ether of bisphenol A (DGEBA). The nanofiller were polymeric nanofibers and conductive nanofillers: multi-walled carbon nanotubes (MWCNTs) and metallic copper nanowires (CuNWs). Three different arrangements for obtaining the structures were employed and compared. The starting materials, the electrospun nanofibers and composite structures were characterized morphologically by scanning (SEM) and transmission (TEM) electron microscopy, structurally by X-ray diffraction (XRD) and infrared spectroscopy (FTIR), thermally by differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA), mechanically by mechanical tests of short duration (tensile strength and impact) and electrically by four point probe. The results showed that the production of the structures were successfully done by two routes. In the first route, the fibrous, consisting of layers of polyamide 6 (PA6) nanofibers, were sanduiched with epoxy resin loaded with MWCNT. Such structures exhibit electrical conductivities between 105-1012 (Ωcm) and, therefore, can be used as conductive and electrostatic dissipative devices. In a second route, by the electrospinning technique, nanofibers with embedded CuNWs or MWCNTs were produced. The results show that the nanofiber produced were nonconductive and therefore unsuitable for conduction or dissipation. Then, in a third route, nanofibers mats of PA6/polyaniline (PAni) blend and PA6/MWCNT nanocomposites were subjected to a treatment to promote surface adsorption of MWCNT resulting in conductive nanofibers mats. Such mats have been used for the production of structures. The structures exhibit conductivities in the range of 107 (Ωcm) and better combinations of elasticity modulus and impact resistance.