Natural fibers, sourced from renewable plant and animal origins, have garnered increasing attention due to their sustainability, biodegradability, and advantageous mechanical properties. Their performance characteristics are strongly influenced by chemical composition, crystalline structure, and environmental factors throughout growth and processing. In plant-based fibers, cellulose serves as the primary structural component, while protein-based fibers rely on complex protein chains. This structural diversity directly impacts tensile strength, elasticity, moisture absorption, and thermal stability. Despite challenges such as variability in diameter, susceptibility to moisture, and relatively low thermal degradation temperatures, targeted surface treatments and hybridization approaches can enhance fiber performance. Modifications such as acetylation, silane coupling, and plasma treatment help reduce hydrophilicity and bolster fiber-matrix adhesion in composite applications. Hybrid composites combining natural fibers with synthetic reinforcements or bio-based matrices can achieve balanced mechanical properties while reducing environmental impact. As biotechnology advances, genetically modified plants with optimized fiber properties and novel processing methods hold promise for high-value applications in automotive, construction, and packaging industries, thereby promoting broader adoption of sustainable materials.
