Carboxymethylation of Corncob Holocellulose and Its Influences on Paper Properties

Abstract

Corncob is an underutilized agricultural by-product. In this work, corncob was treated with sodium chlorite to remove lignin, and the resulting holocellulose was optionally modified with sodium chloroacetate under alkaline conditions for different time periods to obtain five carboxymethylated corncob holocellulose samples. The derivatization products were investigated by infrared spectroscopy, elemental analysis, carboxyl content tests, and scanning electron microscope analysis. When added at the 1% level (time of carboxymethylation 140 minutes) to an unbleached triploid Populus tomentosa Carr kraft fiber suspension and made into paper, the tensile index, burst index, and folding endurance were increased by 46.4%, 34.2%, and 397.8%, respectively. The results demonstrated that simultaneous carboxymethylation of both hemicelluloses and cellulose in corncob can be an effective approach to preparing a novel dry-strength additive for paper.