Experimental and numerical analysis of natural fillers loaded and E-glass reinforced epoxy sandwich composites

Natural fibers play a crucial role in sandwich composites due to their biodegradability, ease of manufacturing, and ability to reduce pollution. The research aims to develop new biodegradable polymer composites using pine tree leaves (PTL) fillers loaded with epoxy through hand layup technique with different wt. % of PTL fillers. The molded composites were characterized to analyze the crystal size and plane orientations, surface morphology, thermal resistance, and presence of elemental compositions in the PTL filler-loaded epoxy composites through X-ray diffraction (XRD), Field emission scanning electron microscope (FESEM), Energy dispersive analysis (EDX), Differential scanning calorimetry (DSC), and Thermogravimetric analysis (TGA). The 40 wt % of PTL epoxy composites showed a maximum tensile strength of 32 ± 0.5 MPa, a compressive strength of 15 ± 0.5 MPa, a flexural strength of 55 ± 0.5 MPa, and a Shore D hardness of 73 ± 0.5 SHN. The mechanical strength of 40 wt% PTL fillers loaded epoxy composite was enhanced by adding a single and double layer of E-glass fiber on the bottom and top of the PTL fillers loaded epoxy composite, achieving a maximum tensile strength of 76 ± 0.5 MPa. The 40 wt% PTL fillers loaded double E-glass fiber on the bottom and top of the PTL fillers loaded epoxy sandwich composite attained the maximum tensile strength of 156 ± 0.5 MPa, compressive strength of 29 ± 0.5 MPa, flexural strength of 220 ± 0.5 MPa, and Shore D hardness of 79 ± 0.5 SHN. The PTL fillers loaded and reinforced double E-glass fiber epoxy sandwich composite would be used in low-strength structural applications.