Síntese e caracterização de blendas borracha natural/polianilina e borracha natural/polipirrol obtidas por polimerização in situ

• Ano de defesa: 2015
• Autor(a) principal: Santim, Ricardo Hidalgo [UNESP]
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Estadual Paulista (Unesp)
• Palavras-chave em Português: Polimeros condutores; Polimerização; Borracha; Latex; Ciência dos materiais; Materials science
• Link de acesso: http://hdl.handle.net/11449/126367

The polymers are generally known to be very lightweight materials, flexible and easy processing. Each year, more and more the technology area has the demand for these properties associated with adjustable electrical conductivity. From this perspective, there are studies that seek to associate intrinsically conducting polymers (ICP) with polymer matrices that has good mechanical property. Among those ICP, polypyrrole (PPy) and polyaniline (PAni) has received much attention due to easy of synthesis, high environmental stability, high conductivity (10 2 S/cm) and low cost of monomers. However, they have poor mechanical property and low solubility. An alternative to overcome these problems is to make in situ polymerization of the conductive polymer in the presence of another polymer that possesses good mechanical properties. In this way, the aim of this study was to obtain natural rubber (NR) composites with PAni and NR with PPY by in situ polymerization of aniline and pyrrole, respectively, in the natural and prevulcanized natural rubber latex. Morphological, structural, electrical, mechanical and thermal properties these samples were studied. Analysis of infrared and UV-Vis-NIR spectra showed the polyaniline and polypyrrole are in doped state. The electrical conductivity of the composites showed to be dependent on the ratio rubber/ monomer, staying in the range of 10 -14 to 10 -2 S/cm. In most cases, higher conductivity occurred when prevulcanized latex was used. The strain at break of the composites increases with decreasing rubber/monomer ratio. For the same synthesis conditions the strain at break was higher to the composites obtained from prevulcanized latex. In some polymerization condition it was evident the occurrence of encapsulation of prevulcanized rubber particles with the conducting polymers mainly to low rubber/monomer ratio