The impact of fibre processing on the mechanical properties of epoxy matrix composites and wood-based particleboard reinforced with hemp (Cannabis sativa L.) fibre

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A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
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Journal of Materials Science, Volume 57
This work investigated the impact that the processing of hemp (C. sativa L.) fibre has on the mechanical properties of unidirectional fibre-reinforced epoxy resin composites loaded in axial tension, and particleboard reinforced with aligned fibre bundles applied to one surface of the panel. For this purpose, mechanically processed (decorticated) and un-processed hemp fibre bundles, obtained from retted and un-retted hemp stems, were utilised. The results clearly show the impact of fibre reinforcement in both materials. Epoxy composites reinforced with processed hemp exhibited 3.3 times greater tensile strength when compared to the un-reinforced polymer, while for the particleboards, the bending strength obtained in those reinforced with processed hemp was 1.7 times greater than the un-reinforced particleboards. Moreover, whether the fibre bundles were processed or un-processed also affected the mechanical performance, especially in the epoxy composites. For example, the un-processed fibre-reinforced epoxy composites exhibited 49% greater work of fracture than the composites reinforced with processed hemp. In the wood-based particleboards, however, the difference was not significant. Additionally, observations of the fracture zone of the specimens showed different failure characteristics depending on whether the composites were reinforced with processed or un-processed hemp. Both epoxy composites and wood-based particleboards reinforced with un-processed hemp exhibited fibre reinforcement apparently able to retain structural integrity after the composite’s failure. On the other hand, when processed hemp was used as reinforcement, fibre bundles showed a clear cut across the specimen, with the fibre-reinforcement mainly failing at the composite's fracture zone.
Funding Information: Albert Hernandez-Estrada wishes to thank the Finnish Cultural Foundation for financial support and COST Action FP1303 for supporting the STSM. Birgit Uhrlaub (HSB—City University of Applied Sciences, Bremen, Germany), and Dr Hans-Jörg Gusovius and Dr Carsten Lühr (Leibniz Institute for Agricultural Engineering and Bioeconomy ATB, Potsdam, Germany) are thanked for processing and providing the hemp. Dr Nina Graupner and Milan Kelch (HSB—City University of Applied Sciences, Bremen, Germany) are thanked for guidance in producing the epoxy composites and in testing the specimens. Niels Kühn (HSB—City University of Applied Sciences, Bremen, Germany) is thanked for the production of the 3D-printed moulds, which facilitated the production of the embeddings in polyurethane resin. Publisher Copyright: © 2021, The Author(s).
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Hernandez-Estrada , A , Müssig , J & Hughes , M 2022 , ' The impact of fibre processing on the mechanical properties of epoxy matrix composites and wood-based particleboard reinforced with hemp (Cannabis sativa L.) fibre ' , Journal of Materials Science , vol. 57 , no. 3 , pp. 1738–1754 .