Development of Epoxy Matrix Nanocomposites Reinforced with Coconut Shell Nanocellulose

As a strategy to reduce socio-environmental impacts, the incorporation of waste or natural fibers from various sources into the formulation of composites has proven to be an attractive and sustainable alternative. In the development of nanocomposites specifically, the use of coconut fiber waste at the nanoscale has been explored both for its ability to enhance the mechanical properties of materials and as a way to add value to an agro-industrial residue that would otherwise be discarded into the environment. In this context, the present work aimed to develop epoxy matrix nanocomposites using nanocellulose extracted from coconut husk fiber. The polymer matrix used was an epoxy system composed of diglycidyl ether of bisphenol A/diethylenetriamine (DGEBA/DETA), with a hardener-to-resin ratio of 16:100 (16 phr). The nanocellulose was extracted through chemical treatments of the coconut husk, using sodium hydroxide (NaOH) and sodium hypochlorite (NaClO) to remove lignin, hemicellulose, and other impurities. Subsequently, to eliminate the amorphous region of cellulose and obtain nanofibrils, the material underwent acid hydrolysis with sulfuric acid (H2SO4). The nanocomposites were prepared in an open mold by incorporating nanocellulose at weight fractions of 0, 1.25, 2.5, and 5% relative to the total mass of the epoxy system. The obtained materials were characterized through compression strength tests, Izod impact resistance, and thermal stability analysis (thermogravimetry). The results showed the influence of nanocellulose addition on the mechanical and thermal properties of the epoxy system, demonstrating the technical feasibility of applying this material as reinforcement in composites within the evaluated context.