Carnauba straw: Characterization and chemical treatments

Authors

  • Jéssica Emanuela Fernandes,

    1. Departamento de Química, Universidade Federal do Rio Grande do Norte, Lagoa Nova, Natal, CP1662, RN 59078-970, Brazil
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  • Tereza Neuma de Castro Dantas,

    1. Departamento de Química, Universidade Federal do Rio Grande do Norte, Lagoa Nova, Natal, CP1662, RN 59078-970, Brazil
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  • José Luís Cardozo Fonseca,

    1. Departamento de Química, Universidade Federal do Rio Grande do Norte, Lagoa Nova, Natal, CP1662, RN 59078-970, Brazil
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  • Márcia Rodrigues Pereira

    Corresponding author
    1. Departamento de Química, Universidade Federal do Rio Grande do Norte, Lagoa Nova, Natal, CP1662, RN 59078-970, Brazil
    • Departamento de Química, Universidade Federal do Rio Grande do Norte, Lagoa Nova, Natal, CP1662, RN 59078-970, Brazil
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Abstract

The influence of chemical modifications, such as dewaxing with hexane and carbon tetrachloride, and alkaline treatment, on the mechanical, thermal, and sorption properties of carnauba straw was investigated for the first time. Scanning electron microscopy showed that the solvent treatments removed the wax layer, exposing the straw fibrils. The straw water sorption capacity was very high, and the treatments turned it from Fickian to non-Fickian. The results show that the solvents used were very effective in removing the surface wax layer, whereas alkali, on the other hand, promoted a more marked change in the chemical structure of the straw. The chemical treatments demonstrated that the wax surface layer was very important in determining the final properties of this material and that its removal reduced the thermal stability and Young's modulus from 143 to 48 MPa and increased its hydrophilicity, changing the contact angle from 90 to 60°. As a result, carnauba straw is a potentially promising material to be used, for example, as a natural fiber with polymer matrices for the manufacture of low-cost, ecofriendly composite materials. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011

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