A feasible strategy for making pulp cellulose antibacterial and melt processable

Cellulose, with its abundant sources and eco-friendly properties, stands as one of the optimal alternatives to petroleum-based polymers. However, native cellulose is difficult to process thermally and lacks intrinsic antibacterial functionality. In this study, pulp cellulose was sequentially oxidized, aminated and quaternary ammonium cationic functionalized to produce a melt processable cellulose with long-lasting antibacterial function (PC-HOD-E). PC-HOD-E exhibits an onset of melt processability at 121.1 °C and enters a viscous-flow regime at 249.7 °C. After plasticization and melt processing, the material shows a high tensile modulus of 978.46 MPa but a low elongation at break (0.98%), indicating intrinsic brittleness. Blending PC-HOD-E with poly(butylene adipate-co-terephthalate) (PBAT) significantly improves toughness: at a PC-HOD-E/PBAT mass ratio of 1:9, the elongation at break reaches 795.29% with a tensile strength of 18.53 MPa. Both PC-HOD-E and its composite with PBAT exhibit long-lasting antibacterial ability, maintaining strong antimicrobial activity even after being immersion in water for 7 days. Moreover, these materials demonstrate excellent biodegradability, with PC-HOD-E exhibiting a mass loss of 61.67% after 60 days of natural degradation in soil. This work provides a promising method for developing high-performance cellulose-based plastics as alternatives to petroleum-based plastics.