Juan Pereira-Rojas, Nelson Barrios, Álvaro Javier Patiño-Agudelo, Orlando J. Rojas, María Soledad Peresin, Daniel Saloni
The integration of cellulose into thermoplastic and polymer matrices for fused deposition modeling (FDM) represents a transformative approach to sustainable, high-performance additive manufacturing. This review systematically examines chemical functionalization strategies that enhance the compatibility, printability, and structural integrity of cellulose-based composites. Functionalization approaches, including etherification, esterification, oxidation, silanization, acylation, and grafting, are critically evaluated with respect to their effects on thermal stability and mechanical reinforcement. Comparative assessments indicate that controlled substitution levels and grafting densities promote improved dispersion, enabling the fabrication of dimensionally stable filaments within the narrow processing window of FDM. Particular attention is devoted to the relationship between chemical modification and cellulose reactivity, as well as emerging pathways aimed at reducing dependence on conventional thermoplastic matrices. The discussion further addresses opportunities for all-cellulose composites, the need for standardized modification protocols, and the scalability of functionalized systems. Collectively, these insights provide a framework for the rational design of chemically tailored, recyclable cellulose-based filaments that combine environmental benefits with advanced performance, thereby advancing the role of bio-based materials in next-generation FDM technologies.