Characterization and biodegradability of copper nanoparticle impregnated rice husk polyester resin nano-composites

Abstract

This research aims to synthesize, characterize, and perform a biodegradability studyof coppernanoparticle-impregnated rice husk-reinforced unsaturated polyester resin composites. The copper nanoparticles (CuNPs) were synthesized at a suitable atmospheric condition in an aqueous medium by using copper chloride dihydrate as a precursor, sodium borohydrideas a reducing agent, polyvinyl alcohol as a stabilizer, andascorbic acid. TEM, Transmission electron microscopy shows the morphology of copper nanoparticles (CuNPs) with an average particle size of 20nm. The Cu nanoparticle-impregnated rice husk composite exhibits better physical and mechanical properties. Furthermore, the rice husk fiber was also treated with different percentages (1%, 3%, and 5%) of KMnO4 solutions. The treated fibers were characterized by Fourier-transformed infrared spectroscopy (FTIR), Field emission scanning electron microscopy(FESEM), energy dispersive X-ray study, and thermogravimetric analysis. The untreated, treated,and copper nanoparticle-impregnated rice husks were fabricated with unsaturated polyester resin usingthe normal press technique in different ratios (5%, 10%, 15%, 20%, 25%, and 30%). The nature of compositematerials, mechanical properties, and biodegradability have been analyzed subsequentlyby using commonly used characterizing techniques like FTIR, FESEM, TGA, XRD,etc.The fiber reinforcement performance for UTRHC, THHC, CRHC, and CuIRHC increased by ~75%, ~134%, ~152%, and ~174% respectively. Copper nanoparticles impregnated with rice husk composite with 10% fiber loading showed better tensile strength (31.03 N/mm2) and antifungal activity (59.62%) in comparison with untreated composites. For having the large surface area and improved dispersion quality of nanoparticles (NPs) form strong interactions and microscopic inorganic networks in the nanocomposites. Therefore, the results strongly recommend that copper nanoparticles would be used as a suitable agent in rice husk fiber to increase their mechanical properties and durability. The biodegradability nature of the developed composites is inversely proportional to the percentages of copper nanoparticles impregnated with the fiber.The properties of these developed compositesimplythat the newly developed rice husk composites would be ideallycompetitive and cost-effective products for variousutilizations.