Development and Characterization of Bio-Based Basalt Fiber Reinforced Polymer Composites for Automotive Structural Applications
Thesis
The growing demand for sustainable lightweight materials in the automotive industry has increased interest in basalt fiber-reinforced polymer (BFRP) composites as eco-friendly alternatives to conventional composites. Basalt fibers (BFs) offer excellent mechanical properties, thermal stability, and environmental benefits. However, their application is often limited by weak interfacial bonding with polymer matrices due to their smooth and chemically inert surfaces. This study presents a novel nanocellulose (NC) grafting approach as the primary contribution, where cellulose nanofiber (CNF) and cellulose nanocrystal (CNC) were directly anchored onto silane-functionalized BFs before composite fabrication. Unlike conventional direct NC dispersion in epoxy, which often suffers from agglomeration and poor dispersion, the proposed grafting strategy localizes NC at the fiber–matrix interface, significantly improving load transfer and interfacial adhesion. The NC-grafted BFRP composites exhibited significant improvements in interfacial bonding, resulting in enhanced impact resistance, interlaminar shear strength, and overall mechanical performance compared with composites produced through direct NC–epoxy mixing. In addition, the grafted composites demonstrated improved resistance to moisture absorption, despite the naturally hydrophilic nature of NCs, indicating that surface immobilization of NC effectively mitigates water uptake at the interface. Surface analyses using X-ray Photoelectron Spectroscopy (XPS) and Field Emission Scanning Electron Microscopy (FE-SEM) confirmed successful grafting and improved interfacial morphology. To assess structural applicability, composite components were further evaluated through impact crushing experiments and finite element simulations using Abaqus CAE. The strong agreement between experimental and simulation results confirmed the reliability, energy absorption capability, and crashworthiness of the developed composites for lightweight automotive structures. Overall, this work demonstrates that NC grafting onto BFs is a highly effective strategy for overcoming interfacial bonding and dispersion challenges, offering a promising route toward durable and sustainable automotive composite materials.