Novel Thermoplastic Cellulose Esters Containing Bulky Moieties and Soft Segments

It is still challenging to convert cellulose into melt-processable materials because natural cellulose, which has a strong hydrogen bonding network, degrades before melting. Herein, a series of novel cellulose-based thermoplastics were successfully designed and fabricated by a simple and efficient homogeneous esterification of cellulose in an ionic liquid. Introducing ester substituents containing both bulky moieties and soft segments can improve the mobility of the cellulose chain, and the glass transition temperatures (Tgs) appeared in the resultant cellulose esters. In particular, when the ester substituents consisted of bulky terminal moiety and soft middle segment, Tgs of the corresponding cellulose esters were relatively low (80–160 °C), indicating these cellulose materials were suitable for melt processing. Accordingly, these thermoplastic cellulose esters can be processed into transparent disks, dumbbells, fibers and flexible films by traditional injection molding, melt extrusion, and hot pressing without any external plasticizers. Therefore, this work provides a simple and engineering method to construct melt-processable bioplastics from cellulose.