Effects of constituents and morphology on durability of plant-based cellulosic fibers and their composites: A review on sustainable biocomposites materials

The global drive towards green materials, circularity, and sustainability that is aimed at protecting the environment against the triple planetary crisis of waste generation and pollution, climate change, and loss of biodiversity, has revolutionized the field of materials science. Hence, plant fibers are increasingly gaining prominence and attraction as durable, sustainable, and lightweight reinforcement materials for composites production. The recent increase in the use of plant fibers has been driven by the sustained global environmental campaigns as well as government regulations advocating the use of sustainable materials and practices across all sectors of the economy. However, despite the environmental, performance, and economic benefits associated with natural cellulosic fibers, their hierarchical microstructure and hydrophilic chemistry pose some challenges, such as UV degradation and hydrophilicity. This review, therefore, provides a comprehensive analysis of plant fibers’ constituents, morphology, and durability as potential sustainable alternative reinforcement materials in composite development. The review presents the limitations and innovative methods of modifying plant fibers for improved performance under moisture, UV degradation, and biodegradation challenges. The review revealed that the optimal techniques for the modification of lignocellulose fibers for effective composite performance are application-specific multi-step regimes where performance criteria are coordinated. Hence, future outlook considers the incorporation of amulti-stage hierarchical approach, predictive modeling, and design for circularity and sustainability. Also, research demand for the standardization of plant fiber treatment against water and flammability resistant are expected to advance the application of these fibers in composite development.