S?ntese de nanofibras de polianilina e prepara??o do nanocomp?sito de polipropileno / polianilina

• Main Author: Ractz, Guilherme Segatt
• Other Authors: Basso, Nara Regina de Souza
• Format: Others
• Language: Portuguese
• Published: Pontif?cia Universidade Cat?lica do Rio Grande do Sul 2015
• Subjects: ENGENHARIA DE MATERIAIS; NANOTECNOLOGIA; NANOCOMP?SITOS; POLIMERIZA??O; ENGENHARIAS
• Online Access: http://tede2.pucrs.br/tede2/handle/tede/6171

Submitted by Setor de Tratamento da Informa??o - BC/PUCRS ([e-mail]) on 2015-06-24T21:45:32Z No. of bitstreams: 1 471013 - Texto Completo.pdf: 1943495 bytes, checksum: 36e051cefa7a9d47d6a0d608dff24d67 (MD5) === Made available in DSpace on 2015-06-24T21:45:32Z (GMT). No. of bitstreams: 1 471013 - Texto Completo.pdf: 1943495 bytes, checksum: 36e051cefa7a9d47d6a0d608dff24d67 (MD5) Previous issue date: 2012-07-16 === 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 10? 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. === O presente trabalho relata a s?ntese de nanofibras de polianilina (PANI) e a prepara??o de nanocomp?sitos contendo polipropileno como matriz polim?rica. Nanofibras de polianilina foram sintetizadas pelo m?todo da mistura r?pida. ?cido clor?drico e ?cido sulf?rico foram avaliados como agentes dopantes em diferentes temperaturas de rea??o: 25, 60 e 100 ?C. Nanocomp?sitos de polipropileno (PP) foram preparados adicionando-se 1 e 3% (m/m) de nanofibras de PANI por tr?s diferentes m?todos utilizados para dispersar a nanocarga na matriz polim?rica. Assim foram avaliados par?metros como a mistura direta na c?mara de fus?o, prepara??o de masterbach e pr?-dispers?o da carga em etanol. A morfologia, as propriedades el?tricas, t?rmicas e mec?nicas das nanofibras de PANI e dos nanocop?sitos preparados foram avaliados por Microscopia Eletronica de Varredura (MEV), Microscopia de For?a At?mica (AFM), An?lise Termogravim?trica (TGA), Calorimetria Diferencial Explorat?ria (DSC) e Espectroscopia de Imped?ncia El?trica (EIE). Nanofibras com morfologia mais definida foram obtidas quando foi utilizado o ?cido clor?drico como agente dopante, na temperatura de 60?C. As nanofibras preparadas por essa metodologia apresentaram resistividade el?trica na ordem de 102 ?cm e temperatura de decomposi??o pr?xima a 300?C. Imagens de AFM indicam uma boa distribui??o da carga na matriz polim?rica, independentemente do m?todo de prepara??o utilizado. Foi verificado que as propriedades t?rmicas dos nanocomp?sitos n?o foram afetadas negativamente com a adi??o das nanofibras de PANI, e foram produzidos comp?sitos com propriedades de tra??o semelhantes ? matriz de PP, com maior alongamento na ruptura e propriedades el?tricas condutoras.