Influence of alkali treatment and layering pattern on the tensile and flexural properties of Palmyra palm leaf stalk fiber (PPLSF)/jute fiber polyester hybrid composites

During the current investigation, alkali treated Palmyra palm leaf stalk fiber (PPLSF) and jute fibers were chosen as reinforcement for the unsaturated polyester matrix. Layering patterns such as bi-layer (PPLSF/jute) and tri-layer (PPLSF/jute/PPLSF and jute/PPLSF/jute) were chosen, and composites were fabricated by hand layup followed by compression molding process. The tensile and flexural properties of the hybrid composites with different layering pattern were determined and compared with pure PPLSF and jute unsaturated polyester composites. It was observed that the bi-layer composites had higher tensile properties, while the tri-layer (jute/PPLSF/jute) composites had higher flexural properties in comparison with PPLSF composites. Seventeen percent improvement in tensile strength, 51% improvement in tensile modulus for bi-layer composites and 45% improvement in flexural strength, 60% improvement in flexural modulus for jute/PPLSF/jute composites were observed in comparison with the PPLSF composites. Fractographic studies on the tensile fractured surfaces were performed using scanning electron microscopy that showed the evidence of interface adhesion between the fiber and matrix.