Journal of Applied Polymer Science · 2004 · 196 citations · 5 references
Natural SciencesMaterials EngineeringMaterials ScienceMechanical Behavior Of MaterialsPolymer EngineeringPolymer MaterialsComposite MaterialsComposites ManufacturingFiber PropertiesFiber-reinforced CompositesPolymer CompositesPolymer-matrix CompositesEpoxy ResinsFilament WindingFlax FibersGlass Fiber Reinforced CompositesGlass Fiber Reinforced PolymersHemp FibersNatural Fiber CompositesUnidirectional Composites
Natural fiber reinforced polymers are being explored to replace glass fiber in automotive applications, demanding higher fiber properties, adhesion, and quality assurance. The study aims to enhance epoxy and polypropylene composite performance by mercerizing flax and hemp fibers and applying an MAH‑PP coupling agent. Researchers varied mercerization conditions (NaOH concentration, temperature, time) and applied tensile stress to hemp fibers, fabricated unidirectional EP composites via filament winding and PP composites via film‑stacking, and evaluated the resulting fiber and composite structures and properties. Appropriate mercerization parameters allow broad control of fiber mechanical properties, and the resulting hemp‑ and flax‑based PP composites exhibit distinct macromechanical behaviors depending on mercerization and MAH‑PP treatment. © 2004 Wiley Periodicals, Inc., J Appl Polym Sci 93: 2150–2156.
Abstract In some technical areas, mainly in the automotive industry, glass fiber reinforced polymers are intended to be replaced by natural fiber reinforced polymer systems. Therefore, higher requirements will be imposed to the physical fiber properties, fiber‐matrix adhesion, and the quality assurance. To improve the properties of epoxy resins (EP) and polypropylene (PP) composites, flax and hemp fibers were modified by mercerization and MAH‐PP coupling agent was used for preparing the PP composites. The effects of different mercerization parameters such as concentration of alkali (NaOH), temperature, and duration time along with tensile stress applied to the fibers on the structure and properties of hemp fibers were studied and judged via the cellulose I–II lattice conversion. It was observed that the mechanical properties of the fibers can be controlled in a broad range by using appropriate mercerization parameters. Unidirectional EP composites were manufactured by the filament winding technique; at the PP matrix material, a combination with a film‐stacking technique was used. The influence of mercerization parameters on the properties of EP composites was studied with hemp yarn as an example. Different macromechanical effects are shown at hemp‐ and flax‐PP model composites with mercerized, MAH‐PP‐treated, or MAH‐PP‐treated mercerized yarns. The composites' properties were verified by tensile and flexural tests. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 2150–2156, 2004
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