Cellulose nanofibrils extracted from the byproduct of cotton plant.

Cotton stalk bark, as the byproduct of cotton plant, was usually discarded and/or combusted, leading to waste of resources and environment pollution. How to efficiently utilize this kind of cellulosic materials is of significative to energy saving and environment protection. Herein, we report on the extraction of cellulose nanofibrils (CNF) from the cotton stalk bark for the first time by a combination of TEMPO-oxidation and mechanical disintegration method. The obtained CNF showed a yield more than 20 wt%. The morphologies, crystalline structures and thermal properties of CNF were extensively investigated by the transmission electron microscopy, scanning electron microscopy, synchrotron radiation wide-angle X-ray scattering, Fourier transform infrared spectra and differential scanning calorimetry, respectively. The results showed that the final extracted CNF have similar polymorphs with their starting materials and a significantly increased crystallinity. This work will provide a new way to utilize the cotton stalk barks.