Creep behavior of palm fiber reinforced epoxy composites: Experimental analysis and environmental implications

Abstract

This study investigates the combined effects of temperature and palm fiber reinforcement on the mechanical and creep behavior of epoxy-based composites. The viscoelastic response was evaluated from 20°C to 80°C, focusing on instantaneous strain, time-dependent deformation, and steady-state creep rate (min−1). The incorporation of palm fibers increased the ultimate tensile strength from approximately 20 MPa for neat epoxy to 37 MPa and 55 MPa for composites reinforced with one and two palm fiber layers, respectively. Young's modulus also increased from 3.15 GPa for neat epoxy to 3.41 GPa for the two-layer composite, indicating an improvement of about 8.3%. The results show a strong thermo-activated creep mechanism, where increasing temperature enhances molecular mobility, reduces polymer viscosity, and increases deformation in neat epoxy. In contrast, palm fiber reinforcement markedly improves the mechanical stability and creep resistance of the epoxy matrix. Under a nominal dead-weight load of 1000 g (9.81 N), the maximum creep strain decreased from approximately 0.24 for neat epoxy to 0.205 and 0.165 for the one-layer and two-layer palm fiber composites, respectively. In addition, the two-layer composite reduced the maximum creep strain by approximately 37%, 34%, and 31% under applied loads of 400 g, 600 g, and 1000 g, respectively. These improvements are attributed to efficient stress transfer, restricted polymer-chain mobility, and the reinforcing effect of the fiber network. Overall, the results demonstrate that palm fiber reinforcement enhances both mechanical performance and long-term creep resistance, making these composites suitable for lightweight structural applications under moderate thermal environments.