With the acceleration of the global modernization, the issue of the balancing development and environment has increasingly drawn attention. The severe environmental pollution caused by synthetic materials and polymers has led to an urgent need for green and sustainable alternatives. Natural cellulosic fibers, with their renewable, biodegradable and carbon-neutral characteristics, have emerged as environmentally friendly materials. In the development of green and sustainable composite materials to replace synthetic fibers in engineering applications, natural cellulosic fibers are the valuable resource for reinforcing polymer composites. However, up to now, there have been few comprehensive reviews on the physical and chemical, thermal, and mechanical properties of natural fiber resources. This review collected studies on the properties of natural cellulosic fibers from 2020 to 2024. It provides a comprehensive and in-depth introduction to the characteristics of these fibers, including their sources, extraction methods, chemical composition, micro-morphology, crystallinity, thermal stability, and mechanical properties, and systematically explores their great application potential in sustainable composite materials. Furthermore, the future development trends of cellulose fibers applied in the field of composite materials are also forecasted. This study aims to provide valuable insights for researchers in sustainable composite materials, thereby advancing research in the field and generating significant benefits for environmental protection and expanded material applications.
Liu et al. (2025) studied this question.