POLYMER COMPOSITES REINFORCEMENT WITH MORINGA OLEIFERA PLANT FIBERS

Abstract

Recent technical and economic advancements are inspiring academics and scientists to investigate unique substances that can be used in advanced applications while yet being sustainable and eco-friendly. Natural fibres strengthened in diverse polymeric matrices are becoming more and more well-liked as a substitute for synthetic fibres in composites in this decade because of their outstanding mechanical and thermal properties. Traditional lignocellulosic natural fibres like bagasse, wheat straw, jute, sisal, coir, ramie, kenaf, hemp, banana, pineapple, and flax have been broadly used as strengthening material in different polymer composites due to their recyclability, availability, lightweight nature, and enhanced mechanical properties. The key issues are the hydrophilic inclination of these lignocellulosic natural fibres and their ineffective interaction with the hydrophobic polymeric material. The recommended method for hemicellulose and lignin breakdown by alkylation is to improve the adhesion between the polymer matrix and these fibres. Numerous strengthening composite materials employ epoxy resin and PVA as the polymers due to their outstanding characteristics, such as elevated temperature endurance and resilience to chemicals and corrosion. As investigators look for innovative fibres to strengthen polymer matrixes, many unique fibres have been tested as reinforced stages in epoxy resin for a range of applications. Alkali treatment is mostly used to improve the compatibility and interaction between the fibre and matrix. The current study examines and analyses the widely accessible, economically advantageous filler made from Moringa Oleifera (MO) leaf and seed and it’s reinforcement in epoxy composites used for semi-structural purposes. Compositional analysis, FTIR, AFM, SEM, XRD, TGA, and the estimation of activation energy using two integral approaches are all used in this study to evaluate the novel filler. X-ray photoelectron spectroscopy (XPS) is also used to comprehend the interfacial surface chemical properties of the fibre. The hand layup methodology of preparation was used to make composites with five distinct loadings varying from 5 wt. % to 25 wt. % while maintaining a filler size of 300-500 μm. Its epoxy composites' water absorption, mechanical, morphological, and thermal characteristics have been assessed in relation to the impact of different filler loadings. For a 20 wt. % maximum capacity of 37 MPa, composites are stronger in terms of tensile, flexural, and water resistance than pure epoxy. We estimate the apparent activation energy of fillers using the FWO and KAS techniques. These approaches yield apparent activation energies of 220 and 222 kJ/mol respectively. The final result is a 55% crystallinity index, which is identical to other fibres. At an appropriate fibre concentration of 20 wt. %, there is a 12% increase in tensile strength and a 10% increase in flexural strength when compared to pure epoxy. The increasing use of composite components in various engineering disciplines necessitates detailed comprehension of their operation. When subjected to adverse environmental circumstances, such as variable humid surroundings and UV radiations, the structural and mechanical characteristics of the composites can deteriorate. Additionally, using these composite materials for structural applications such as rooftop buildings or household properties may reduce lifespan. In this study, the static and dynamic mechanical properties and the stability of novel lignocellulosic moringa husk fibre-based epoxy composites exposed to various environmental factors were assessed. These harsh conditions were picked to imitate those encountered outside and influence the longevity of these composites. The obtained fibre from the husk was examined for its physiological, structural, and thermal characteristics. Using the Broido, Kissinger, Flynn-Wall-Ozawa (FWO), Coats- Redfern and Kissinger-Akahira-Sunose (KAS) isoconventional models, the thermal degradation kinetics of the fibres were investigated. KAS method results in the best-fitted curve and shows maximum activation energy of 175.13 KJ/mol. After husk fibre assessment, composite materials were fabricated using a Hand layup method, and their static and dynamic mechanical properties, water uptake rate, and contact angle analysis with surface energy behavior under various environmental ageing circumstances were studied. In comparison to the composites "as developed," the findings indicate that the mechanical characteristics of husk fibre-based epoxy composites are significantly reduced by humidity and UV ageing. Overall, the development of thermoset composites for structural applications can utilize husk fibre. Furthermore, after curing the water and UV-aged composites, qualities can be recovered. Moringa oleifera seed filler (MOSF) is among the few newly known novel fibre-rich in cellulose and meagerly used in commercial industries. This research article used a broad characterization of 2,2,6,6-tetramethyl-1-piperidinyloxy (TEMPO)-modified Moringa Oleifera cellulosic nanofiller (TMCF)/epoxy composites to verify its potential as a feasible substitute for synthetic fibres in polymer composites. Composites were fabricated at a fixed filler size of 200 nm with a loading of 15 wt. % untreated and alkali-treated composites through the two processes: hand lay-up followed by autoclave curing. The interfacial surface compatibility of the cellulosic nano-fillers/epoxy composite was analyzed through X-ray Photoelectron spectroscopy. The other properties, such as water uptake rate, static and dynamic mechanical properties and thermal stability, have been studied for untreated and treated composites.Composites with 5 wt. % alkali treatment TMCF loading possesses superior water resistance, interfacial surface chemistry, and mechanical property compared to autoclaved epoxy and the untreated composite. Four isoconversional methods, Friedman, Coats-Redfern, Broido, and Kissinger, were utilized to investigate the degradation behavior and kinetic parameters like activation energy of composites. Composites that have been 5 wt. % mercerized exhibit greater thermal resilience and activation energy of 250 kJ/mol, which is 20% greater than the untreated sample. This study validates the 5 wt. % alkali treated TMCF as a novel sustainable and bio-reinforcement in polymer composite for semi-structural applications. As a viable strengthening material in the (Polyvinyl alcohol) PVA composite, MOSF's surface chemical modification, characterization, biodegradability, and barrier characteristics are also important. At ambient temperature, film-forming suspensions were cast with various alkali and acid ratios. Analysis was done on the compositional, physiological, mechanical, biodegradability, and barrier characteristics of the produced film as a result of surface changes. The functional content, development, and surface morphology of the film were described using Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), and atomic force microscopy (AFM) techniques. Tensile strength (33.69 MPa) and flexural strength (56.612 MPa), which were comparable to the widely used LDPE and HDPE packaging films, were greatly increased by the 5 wt.% acid treatment of the film. Composite films could preserve content and homogeneity while also absorbing moisture. The applicability of composite film for diverse packaging applications was demonstrated by its lower water vapour permeability (1.42 x 10 -10 g. s-1 m -1 Pa -1), and superior biodegradability.