Transparent and UV-absorbing nanocellulose films prepared by directly dissolving microwave liquefied bamboo in TBAA/DMSO co-solvent system

Bamboo is a potential resource to produce renewable materials with replacement of plastic. In this study, cellulose-rich bamboo fibers and parenchyma with partial lignin (4-10 %) retained were prepared from mi-crowave liquefaction, thereafter nanocellulose with uniform diameter (less than 10 nm) distribution were ob-tained by directly dissolving the cellulose-rich bamboo cells in TBAA/DMSO system. By solvent-casting, transparent nanocellulose films with efficient UV-absorbing ability especially the excellent UVA (82 %) and UVB (99 %) absorbing performance were fabricated. The films showed homogeneous network structure and had good tensile strength (15-25 MPa). Changes in cellulose crystallinity structure was observed during the film prepa-ration process. Results also showed that the lignin in the cellulose-rich bamboo could distribute uniformly in the nanocellulose films and had effect on the film formation, UV-absorbing ability and physical-mechanical prop-erties. Overall, microwave liquefaction coupling with TBAA/DMSO dissolving system could be selected as a facile and simple method to produce transparent nanocellulose films with UV-absorbing property.

Automated summary

A study successfully produced transparent nanocellulose films with UV-absorbing ability using microwave liquefaction and TBAA/DMSO dissolving system. The films had uniform cellulose structure and good tensile strength.