8 Surface modification of root-based fibers and their composites Ajithkumar Sitharaj and Arulmurugan Balasubramanian Department of Mechanical Engineering, KPR Institute of Engineering and Technology, Coimbatore, Tamil Nadu, India 8.1 Introduction There is a growing emphasis on the urgent need to address environmental damage, pollution, and global warming. The scientific community has devoted substantial effort to the advancement of eco-friendly and biodegradable materials, with the goal of replacing nonrenewable resources that cause environmental problems. One noteworthy type of biocomposite material is root-based fiberreinforced compo- sites (RFCs). These composites utilize plant rootbased fibers as reinforcement within a polymer matrix. RFCs present a sustainable alternative to conventional synthetic fiberreinforced composites as they are derived from invasive plant roots, which are often considered waste or byproducts of environmental management practices. By utilizing these plant roots, RFCs contribute to waste reduction, resource conservation, and environmental sustainability (Pattnaik et al., 2023; Somasundaram et al., 2022; Zhao et al., 2022). Synthetic composites, on the other hand, come with a range of hazards and limitations. They have larger carbon foot- prints and require substantial amounts of energy for fabrication. These composites typically incorporate inorganic fibers such as nylon, Kevlar, polypropylene, and glass. Moreover, the long-term sustainability of synthetic materials is endangered by fossil fuel depletion. The urgency of climate change has led to a focus on mini- mizing global warming. Developed countries pledged to restrict global temperature rise below 3  C. RFCs, unlike synthetic materials, are degradable without emitting toxic substances. It is recognized as a promising option to address environmental concerns, reduce energy consumption, and lower carbon footprints. RFCs require 16% less energy than synthetic counterparts on average (Sathishkumar et al., 2024). The worldwide market for RFCs is undergoing substantial expansion, propelled by various factors. This expansion is a segment of the broader biocomposites mar- ket, which achieved a valuation of USD 24.59 billion in 2021 and is projected to grow at a compound annual growth rate (CAGR) of 16.1% between 2022 and 2030 (Biocomposites Market Size Global Report, 20222023, 2023). Fig. 8.1 illustrates the worldwide market for natural fiber biocomposites. The growing demand for environmentally friendly materials in various industries, including automotive, con- struction, aerospace, and consumer goods, is fueling the expansion of the RFCs market. Industries in these sectors actively seek sustainable alternatives to reduce Surface Modification and Coating of Fibers, Polymers, and Composites. DOI: https://doi.org/10.1016/B978-0-443-22029-6.00008-3 © 2025 Elsevier Inc. All rights are reserved, including those for text and data mining, AI training, and similar technologies.