Opportunities and challenges of <i>Grewia optiva</i> (Bhimal) fiber as a sustainable resource for polymer bio-composites

Grewia optiva fiber, a lesser-known but promising lignocellulosic bioresource, holds significant potential for sustainable utilization across various industries. The current review explores the lignocellulosic smart-functional materials and implications of harnessing Grewia optiva fiber as a renewable resource. Grewia optiva fiber–derived polymer-based bio-composites exhibit a high strength-to-weight ratio and are highly recommended for various industrial applications. Moreover, it highlights the current gaps in research and identifies avenues for future investigation to optimize the utilization of its bio-composites in different industries. A systematic compilation of the research published between 1984 and March 2025, sourced from Scopus, Web of Science, and ScienceDirect, using defined inclusion and exclusion criteria, is considered in this review. Key parameters examined include the fiber’s botanical characteristics, chemical composition, extraction and surface modification methods, and its performance in mechanical, thermal, and morphological evaluations when used as polymer reinforcement. Literature showed that Grewia optiva fiber offers moderate mechanical properties, which is improved through alkali mercerization and silane coupling treatments. Despite its advantages in renewability, biodegradability, and lightweight nature, research gaps remain in large-scale processing optimization and hybrid composite design. This review identifies these gaps and provides future directions, advocating for broader geographic exploration and standardization of fiber treatment protocols.