Mechanochemical Treatment of Cellulose: A Strategy for Developing Functional Biocomposite Materials

Cellulose‐based biocomposites are attracting increasing scientific and industrial interest due to their sustainable origin, biodegradability, and potential to replace fossil‐based materials. Despite these advantages, their development is often hindered by fragmented, multistep processes that separate fiber defibrillation, activation, surface modification, and composite fabrication. This review addresses a critical literature gap by exploring mechanochemistry's multifunctional role in the integrated design of micro‐ and nanocellulose‐based composites using a solvent‐minimizing approach. A methodical literature search, covering the period from 2002 to 2025, yielded 23 relevant articles from the Web of Science, Scopus, and Google Scholar databases. Four key mechanochemical strategies emerged: (i) activation, defibrillation, and size reduction of cellulose fibers; (ii) in situ chemical functionalization; (iii) pre‐compounding with polymer matrices via solid‐state mixing; and (iv) direct biocomposite fabrication through melt blending or compression molding. Mechanochemical methods, including ball milling and high‐pressure homogenization, alter the crystalline structure and surface chemistry of cellulose, generating mechanoradicals that enable covalent modification and compatibilization without external initiators. The selected studies comprehensively evaluated how mechanochemistry influences the physicochemical, thermal, and mechanical properties of cellulose‐based biocomposites. However, the analysis also revealed a limited range of explored polymer matrices and a narrow spectrum of reported applications. Key challenges remain, such as the methodical refinement of process variables, a deeper understanding of mechanoradical behavior, extension to additional polymer materials, and quantification of environmental benefits using standardized green metrics. Overall, this review positions mechanochemistry as a promising, integrated, and environmentally responsible strategy for the scalable production of next‐generation, high‐performance biocomposites.