Mechanochemical preparation of thermoplastic cellulose oleate by ball milling

Cellulose is the most abundant natural macromolecular material, which offers a potential alternative feedstock to petroleum-based polymers. However, the large-scale and sustainable transformation of this biomass into available bio-plastics is still a challenge due to its inherent recalcitrance. Here, a sustainable esterification strategy of cellulose was developed to efficiently synthesize cellulose oleate (COE) by ball milling to endow cellulose with thermoplasticity. In this strategy, a low dosage of oleic acid (6 mol per anhydroglucose) and no solvent were used to achieve the goal during the ball-milling process. According to differential scanning calorimetry (DSC) analysis, the synthesized COEs possessed two major glass transitions at 25.6 degrees C-57.3 degrees C and 153.8 degrees C-172.5 degrees C corresponding to the motion of oleic side chains and cellulose backbones, respectively. Besides, the prepared COEs with a high degree of substitution (DS, 2.34-2.55) can be readily processed into homogeneous films with flexibility, transparency, and hydrophobicity by hot-pressing at 160 degrees C. This strategy is advantageous over traditional methods in the aspects of reduced reactant dosage, improved sustainability, and enhanced efficiency, which represents a potential green route to fabricate melt-processable cellulose esters in industry.

Automated summary

A sustainable esterification strategy was developed to synthesize cellulose oleate (COE), which can be processed into homogeneous films with flexibility, transparency, and hydrophobicity. This strategy offers advantages in terms of reduced reactant dosage, improved sustainability, and enhanced efficiency, providing a potential green route for industry manufacturing of melt-processable cellulose esters.