Composites based on renewable materials: Polyurethane-type matrices from forest byproduct/vegetable oil and reinforced with lignocellulosic fibers

Authors

  • Elaine C. Ramires,

    1. Institute of Chemistry of São Carlos, Macromolecular Materials and Lignocellulosic Fibers Group, Center for Science and Technology of BioResources, University of São Paulo, CEP 13560-970, São Carlos, São Paulo, Brazil
    Search for more papers by this author
  • Fernando de Oliveira,

    1. Institute of Chemistry of São Carlos, Macromolecular Materials and Lignocellulosic Fibers Group, Center for Science and Technology of BioResources, University of São Paulo, CEP 13560-970, São Carlos, São Paulo, Brazil
    Search for more papers by this author
  • Elisabete Frollini

    Corresponding author
    1. Institute of Chemistry of São Carlos, Macromolecular Materials and Lignocellulosic Fibers Group, Center for Science and Technology of BioResources, University of São Paulo, CEP 13560-970, São Carlos, São Paulo, Brazil
    • Institute of Chemistry of São Carlos, Macromolecular Materials and Lignocellulosic Fibers Group, Center for Science and Technology of BioResources, University of São Paulo, CEP 13560-970, São Carlos, São Paulo, Brazil
    Search for more papers by this author

Abstract

The use of products and byproducts from the agro-industry and forest biorefinery is essential for the development of value-added and low environmental-impact materials. In this study, polyurethanes were prepared using sodium lignosulfonate (NaLS) and castor oil (CO) as reagents and were used to prepare composites reinforced with lignocellulosic fibers, namely, curaua and coir fibers (30 wt %, 3 cm length, and randomly oriented). The SEM images of fractured surfaces of the composites revealed excellent adhesion at the fiber/matrix interface of both coir and curaua composites, which probably resulted from the favorable interactions between polar groups, as well as amid low polarity domains that are present in both the matrix and the reinforcements. The composites exhibited different impact/flexural and strength/flexural moduli (NaLS/CO/Curaua = 465 Jm−1/44 MPa/2 GPa; NaLS/CO/Coir = 180 Jm−1/25 MPa/1 GPa). The higher tensile strength/aspect ratio of the curaua fibers (485 MPa/259) compared with that of the coir fibers (120 MPa/130) most likely contributes to the enhanced performance of its composite. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013

Ancillary