| Abstract:Microfibrillated cellulose (MFC) was successfully prepared by catalyst preloaded Fenton oxidation with the followed homogenization. The effects of hydrogen peroxide content, catalyst ferrous content, reaction temperature and reaction time on Fenton oxidation efficiency were discussed. The microstructure, chemical structure of the oxidized fibers and the morphology, crystal properties, thermal stable properties of MFC were characterized. The results showed that the catalyst preloaded Fenton oxidation method could significantly increase the content of carboxyl and aldehyde groups in oxidized fibers, reduce the degree of polymerization and Zeta potential, which was beneficial to increase the electrostatic repulsion between the fibers and to facilitate the subsequent homogenization treatment. Under the reaction conditions of 25% pulp consistency, 10 g dissolved pulp, 150 kg/t H2O2, 1.5 g FeSO4, pH 3, 45℃and 120 min, the contents of carboxyl group and aldehyde group in the oxidized fibers were 85.43 μmol/g and 57.32 μmol/g respectively, the degree of polymerization was 154, and the Zeta potential was -34.72 mV. The Fourier transform infrared spectroscopy (FTIR) indicated that the successful preparation of Fenton oxidized fibers, and the scanning electron microscope (SEM)、X-ray diffractometer (XRD) and thermogravimetric analyzer (TG) results indicated that the obtained MFC were uniform in size and the diameter was about 200 nm, the crystallinity was 81.35%, and the thermal stability was reduced. |