Current Approaches on Natural Fiber Reinforcement Surface Treatment for Construction Material Application

Abstract

The conversion of waste into value-added products is critical to long-term sustainability as waste disposal costs, landfilling space, and climate change would be reduced. Research and production industries investigate the possible use of natural fibers as a substitute for fossil fuels. Natural fiber-reinforced polymer composites’ physical and mechanical properties can be altered by natural fiber treatment, and the treatment choice relies on the desired properties and performance. In addition to cost-profitability, environmental effects, and required performance, composites can be designed based on the product conditions. Disadvantages such as incompatibility of the hydrophilic natural fiber reinforcements with the hydrophobic polymer matrix often result in the tendency of the composite to have high moisture absorption, poor thermal stability, crystallinity, and mechanical strength. These factors critically impair the performance of the natural fibers as reinforcements in polymer composites, hence resulting in less-favourable mechanical and physical properties. Physical, chemical, and biological treatments were examined to determine their effect on the durability and thermal, physical, and mechanical properties. It was observed that plasma treatment for bamboo fibers resulted in interfibral spaces and anchoring mechanisms between the resin and fibers, leading to increased load transfer. Chemical treatment at various concentrations improved the surface smoothness. The best mechanical, physical, thermal, and chemical properties for application as reinforcement in polymer composites were obtained at 6% for alkali treatments. Enzymatic treatment showed a significant impact on the impact and flexural strength of the composites. Factors such as duration, concentration, and extent of treatment need to be established for effective treatment, as prolonged treatments may damage the NFs’ properties. This review comprehensively highlights the potential utilization of current natural fiber treatment methods for the potential of natural fibers as value-added products for construction materials, considering their economical affordability, production of lightweight materials, sustainability, utilization of readily available waste material, and nature preservation. Furthermore, the three natural fiber treatment approaches for improving fiber-matrix adhesion are discussed. The physical and mechanical properties of composites are highlighted, which aids in evaluating suitability for construction materials.