Synthesis and physico-mechanical properties of phenol formaldehyde resin and its composites with water hyacinth and DFT study of the reaction of monomer of cellulose with sodium periodate

Environmentally sustainable polymer composites reinforced with natural fibers are rapidly expanding across a wide range of industries. The study focused on evaluating the impact of untreated and modified water hyacinth fibers when integrated into phenol formaldehyde (PF) composites. The water hyacinth plant was collected, washed, dried in bright sunlight, and ground into a fine powder. Using a sodium periodate solution, raw water hyacinth (RWH) powder was oxidized. ATR-FTIR spectroscopic analysis of RWH and oxidized water hyacinth (OWH) confirmed cellulose modification. Different fiber contents (0.1, 0.5, 1.0, 2.5, 5.0 wt%) of RWH and OWH fibers mixed with PF to form RWH-PF and OWH-PF composites via compression molding, which have been extensively evaluated in this study. Composites with 0.5 % fiber content exhibited first-rate performance in mechanical tests, particularly in tensile strength, elongation, and impact strength. Morphological analysis showed that chemical treatment with sodium periodate enhanced interfacial adhesion, resulting in better fiber-matrix bonding in OWH-PF composites than RWH-PF. Moreover, Density Functional Theory (DFT/B3LYP) calculations provided a novel, in-depth understanding of the chemical reactions and structural changes during modification. The combination of fiber treatment and comprehensive characterization of the composites' mechanical and structural properties highlights the innovative nature of this study in enhancing the performance of eco-friendly materials. • Exploring the use of water hyacinth fibers in PF resin composites, both untreated and treated with sodium periodate. • Composites with 0.5 % treated fiber content showed superior mechanical properties. • Density Functional Theory (DFT/B3LYP) calculations provided a deeper understanding of the chemical reactions with structure. • Demonstrates the potential of using water hyacinth fibers into environmentally acceptable PF-based composites.