'New tailor-made biopolymers produced from lignocellulosic sugars waste for highly demanding fire-resistant applications'

TECHNICAL ARTICLE
Biocomposite from polylactic acid and lignocellulosic fibers: Structure property correlations

Abstract

PLA biocomposites were prepared using three corn cob fractions and a wood fiber as reference. The composites were characterized by tensile testing, scanning electron microscopy (SEM) and polarization optical microscopy (POM). Micromechanical deformation processes were followed by acoustic emission measurements. The different strength of the components was proved by direct measurements. Two consecutive micromechanical deformation processes were detected in composites containing the heavy fraction of corncob, which were assigned to the fracture of soft and hard particles, respectively. The fracture of soft particles does not result in the failure of the composites that is initiated either by the fracture of hard particles or by matrix cracking. Very large particles debond easily from the matrix resulting in catastrophic failure at very low stresses. At sufficiently large shear stresses large particles break easily during compounding, thus reinforcement depending on interfacial adhesion was practically the same in all composites irrespectively of initial fiber characteristics.

Highlights

► PLA/corn cob composites were prepared from agricultural waste.
► The different strength of the components was proved by direct measurements.
► Two consecutive micromechanical deformation processes were detected in composites containing the hard fraction of corn cob.
► At sufficiently large shear stresses large soft particles break easily during compounding.
► The final properties depend unambiguously on the micromechanical deformations.

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This project has received funding from the European Unionís Seventh Framework Programme for research, technological development and demonstration