Impact of retting and process parameters on the physical and mechanical properties of flax fiber biobased composites
Résumé
The aim of this research was to evaluate the impact of retting and composite processing on the physico-chemical properties of flax-epoxy biobased composites. Organoleptic analysis showed that the retting time directly reduced the saturation and brightness of flax and biobased composites. The processing temperature also directly influenced the material color. SEM analysis highlighted that the fibers that have undergone the lowest retting remained in technical fiber form due to the presence of a pectin coating. By increasing the retting severity, the technical fibers appeared cleaner and more individualized, thus leading to a higher modulus with increasing retting at the expense of maximum stress and elongation. The intrinsic behavior of flax fibers provided a non-elastic mechanical behavior to biocomposite samples. Stress-strain curves revealed three different areas: at low and high deformation, the behavior was elastic, and at moderate deformation we highlighted a plastic transition. The highest processing temperature provided the best Young modulus for the biobased composites. We also noticed that the Young modulus gradually increased with retting. The effect of retting was even more pronounced by performing a modulus normalization according to the fiber volume. A 40 % improvement in modulus was observed between the lowest and highest retting tested.
Domaines
MatériauxOrigine | Fichiers produits par l'(les) auteur(s) |
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