Characterisation of Rice Husk Ash and Its Potential as a Reinforcement in Polymer Composites in Ebonyi State

This study characterises rice husk ash (RHA) produced from rice processing operations in Ebonyi State, South East Nigeria, and evaluates its potential as a reinforcing filler in unsaturated polyester composites. Ebonyi State is among Nigeria's principal rice-producing regions, generating substantial quantities of rice husk waste that are largely disposed of through open burning, causing environmental pollution. Rice husks are collected from processing mills in Abakaliki, incinerated at 600 and 700 degrees Celsius, and the resultant ash is characterised for particle size, morphology, and chemical composition using SEM, FTIR, and XRF. The ash is then used as a filler in unsaturated polyester resin at weight fractions of 0, 5, 10, 15, and 20 percent. Composite specimens are fabricated by hand lay-up, machined, and tested for tensile strength, flexural strength, impact strength, and water uptake. Findings indicate that RHA calcined at 700 degrees Celsius has the highest amorphous silica content and the greatest reinforcing efficiency. Mechanical properties improve up to 10 percent filler content before declining at higher loadings. Water uptake increases with filler content due to the hygroscopic nature of the ash particles. The study recommends pre-treatment of RHA with silane coupling agents to improve interfacial adhesion and mitigate water uptake. Keywords: rice husk ash, polymer composite, unsaturated polyester, mechanical properties, Ebonyi State.