Moisture diffusion analysis and their effects on the mechanical properties of organic particle filled natural fiber reinforced hybrid polymer composites

This investigation explores the water intake characteristics of hybrid composite samples composed of Wood Dust as organic filler (WD), Prosopis Juliflora as fiber (PJF), and epoxy as matrix. The specimens underwent immersion in both distilled and seawater environments for a duration of 240 hours. The composite samples, with compositions of 10WD + 30PJF + 60 PF, 20WD + 20PJF + 60 PF, and 30WD + 10PJF + 60 PF, were subjected to moisture content measurements at different intervals. Mechanical properties were tested following ASTM standards for both dry and wet conditions. Results indicate that seawater immersion leads to higher moisture absorption compared to distilled (condensed) water, with the fiber (PJF)-rich composite (30PJF +10WD + 60 PF) exhibiting the greatest water absorption. The water absorption pattern exhibited by the hybrid composite of WD/PJF/PF does not adhere to a Fickian behavior. Tensile, flexural, and impact properties were evaluated, with the (10WD + 30PJF + 60 PF) specimen showcasing superior performance in dry conditions, boasting a tensile character of 51 MPa, flexural (bending) strength of 60 MPa, and impact value of 1.4 KJ/m². However, its strength diminishes upon exposure to distilled water and seawater. SEM analysis of fractured surfaces from seawater-exposed specimens provides additional insights. In conclusion, this study sheds light on the influence of immersion on moisture absorption and mechanical properties, emphasizing the prevalence of non-Fickian behavior and the varying performance of different compositions, with the (10WD + 30PJF + 60 PF) composition demonstrating remarkable strength under dry conditions.