Development and assessment of Moringa oleifera (Sahajana) leaves filler/epoxy composites: Characterization, barrier properties and in situ determination of activation energy

Abstract This study concerns with investigation and analysis of hugely available, cost effective filler, obtained by grinding the Moringa oleifera leaves and its reinforcement in epoxy composites for semi‐structural applications. In this work, this novel filler is characterized by compositional analysis, FTIR, AFM, SEM, XRD, and TGA, along with the calculation of activation energy from two integral methods. To understand the interfacial surface chemistry of the fiber, X‐ray photoelectron spectroscopy (XPS) is also carried out. The size of filler was kept at 300 to 500 μm, and composites were prepared with five different loadings ranging from 5% to 25% using hand layup method of fabrication. The effect of varying loadings of filler on water uptake, mechanical, morphological, and thermal properties of its epoxy composites has been evaluated. Composites possess improved water resistance, tensile and flexural strengths in comparison with neat epoxy for an optimum loading of 20%, that is, 37 MPa. FWO and KAS methods are used to calculate the apparent activation energy of fillers. The apparent activation energy calculated from these methods comes to be 220 and 222 kJ/mol. The crystallinity index comes to be 55% which is comparable with other fibers. Approximately 12% increment in tensile strength and 10% in flexural strength takes place compared with neat epoxy at optimum fiber loading of 20%.