Resumo

RAMOA, Sílvia Daniela Araújo da Silva; MERLINI, Claudia; BARRA, Guilherme Mariz de Oliveira  e  SOARES, Bluma Guenther. The preparation of montmorillonite/polypyrrole nanocomposites: the effect of surfactant incorporation on the structure and properties. Polímeros [online]. 2014, vol.24, n.spe, pp.57-62.  Epub 18-Abr-2014. ISSN 0104-1428.  https://doi.org/10.4322/polimeros.2014.051.

Montmorillonite/polypyrrole (MMT/PPy) nanocomposites were prepared by the in situ polymerization of pyrrole in the presence of clay, natural sodium bentonite, (MMT-Na⁺) in aqueous solutions with or without an anionic surfactant, sodium dodecyl sulfate (SDS), using Iron (III) chloride hexahydrate (FeCl₃.6H₂O) as oxidant. The structure and properties of the nanocomposites obtained by the in situ polymerization of pyrrole in the presence of SDS (MMT/PPy.SDS) and without surfactant (MMT/PPy) were compared and evaluated by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), thermogravimetric analysis and the four-point probe method. The XRD patterns of the MMT/PPy composites shows that the d₀₀₁ spacing in MMT (1.42 nm) was changed to higher values, indicating the intercalation of PPy on MMT for both nanocomposites. The XRD pattern, SEM and TEM images of the MMT/PPy.SDS nanocomposites confirmed that the presence of SDS in the reaction medium promoted, beyond intercalation, the partial exfoliation of the clay. The MMT/PPy.SDS nanocomposites showed electrical conductivity (9.50 S/cm) higher than the MMT/PPy nanocomposites (4.44 S/cm). The presence of the clay significantly improved the thermal stability of PPy.

Palavras-chave : Polypyrrole; montmorillonite; nanocomposites; electrical conductivity.

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