Résumé
This study aims to investigate the reinforcement potential of flax shives (FS) in thermoplasticcomposites. The influence of FS initial granulometry on the microstructure of the composites and theirtensile properties is studied. Various FS granulometries were prepared. Polypropylene (PP) compositesreinforced with 10% to 40%wt. of FS for each granulometry were manufactured using twin-screwextrusion and injection-moulding processes with Maleic Anhydride Polypropylene (MAPP) as acompatibilizer. Microstructural analysis was carried out using 2D scanner after fibre extraction and Xraytomography on composites. The 3D microstructural parameters were used to model the elasticproperties of the composite using Mori-Tanaka model. Our results revealed that FS-200-315 achievedmaximum aspect ratio after processing, with granulometry deviations reducing aspect ratio.Additionally, medium size particles tend to be more oriented toward the injection flow compared tolarger particles. These findings are consistent with the tensile properties of the composites. PPcomposites reinforced with FS-200-315 exhibit a 20% and 25% increase in Young’s modulus andultimate tensile strength, respectively, compared to those reinforced with FS-800-1600. The Mori-Tanaka model shows that there is a variation in the back-calculated FS Young’s modulus as a functionof granulometry, within a range between 14 and 28 GPa.