TEMPO-mediated oxidation of corncob holocellulose and its influences on paper properties

In this study, the agricultural by-products of corn production (corncobs) were ground into a powder form. Then, the powder was treated with sodium chlorite to remove the lignin, and the remaining holocellulose was optionally modified with 2,2,6,6-tetramethyl-1-piperidinyloxy (TEMPO)-mediated oxidation. The resulting product was examined using an elemental analysis, along with Fourier transform infrared spectroscopy (FTIR). The effects of the oxidation time and dosages of the TEMPO on the paper’s physical properties were investigated. The results indicated that the TEMPO-mediated oxidized corncob holocellulose had the ability to improve the properties of both paper and recycled paper. When 1.0% oxidized holocellulose was used, the resulting tensile index, burst index, and folding endurance were increased by 4.16%, 8.63%, and 50.71%, respectively, compared with the control paper. The SEM analysis indicated that the bonding between fibers was improved by adding oxidized corncob holocellulose. Compared with the control paper, it was determined that the proportion of mesopore within the fibers increased and the bonding of the C–O bonds increased in the paper with the oxidized corncob holocellulose. The results of this study may potentially provide guidance for the future high value-added application of corncobs as a paper strengthening agent.