A More Efficient Fenton Oxidation Method with High Shear Mixing for the Preparation of Cellulose Nanofibers. (15th June 2020) - Duan, Linjuan
Abstract: A more efficient Fenton oxidation method with high shear mixing for the preparation of cellulose nanofiber (CNF) is investigated. The Fenton reaction is the reaction between Fe 2+ and H2 O2 to produce a series of free radicals that leads to oxidation of the cellulose. With the new technology, the Fe 2+ is preloaded into the kraft pulp by a high shear refining method to realize in situ oxidation of cellulose fibers. It is found that the carbonyl content in the fibers using high shear mixing process is 149.79 μmol g −1 when the dosage of hydrogen peroxide is 0.08 g/g (weight of dry fibers), compared to the 126.40 μmol g −1 of fiber without high shearing when the dosage of hydrogen peroxide is 0.15 g/g, which indicates that the new Fe 2+ pre‐loading process has higher oxidation efficiency with lower H2 O2 consumption compared with traditional Fe 2+ preloading process. The 13 C NMR results show that the C2, C3, and C6 hydroxyl groups are oxidized to aldehyde and carboxyl groups, which is beneficial to increase the electrostatic repulsion between fibers and facilitate the subsequent homogenization treatment. The obtained CNF is uniform in size and slightly lower in thermal stability. Abstract : Cellulose nanofiber (CNF) has been widely used in numerous fields due to its distinct features. However, the preparation of CNF has some disadvantages such as high chemical consumption and low efficiency. The objective of this work is to investigate a green facile high shear mixing enhanced Fenton oxidation pretreatment method for the preparation of CNF, and this new process is feasible and has high potential in CNF industrial preparation in the future.