ThermaLly processible cellulose-based bioplastics: Structure–property relationships, modification strategies, and applications

The urgent need to replace persistent petroleum-based plastics with sustainable alternatives has stimulated growing interest in cellulose, an abundant and renewable biopolymer with considerable potential for advanced materials. However, its intrinsically complex structure fundamentally limits chain mobility, creating a critical barrier to thermal processability and thus restricting its compatibility with conventional thermoplastic manufacturing. Despite extensive efforts to overcome this limitation through diverse physical and chemical strategies, a systematic and critical evaluation of these approaches remains lacking. Herein, we first elucidate the structural origins underlying the non-thermoplastic nature of cellulose, establishing a mechanistic foundation for subsequent processing strategies. We then critically assess state-of-the-art approaches for enhancing thermal processability, including physical treatments (e.g., mechanical disruption and solvent-assisted processing) and chemical modifications (e.g., dynamic covalent chemistry and conventional derivatization), with particular emphasis on their structure–property relationships, advantages, and inherent limitations. The applications of the resulting thermally processible cellulose-based bioplastics are further discussed in the context of performance requirements and practical feasibility. Finally, key challenges associated with current strategies are identified, and future directions are proposed toward the rational design of high-performance, sustainable cellulose thermoplastics. This review provides critical insights into bridging the processability gap of cellulose and aims to accelerate its development as a viable alternative to conventional plastics.