면 린터 섬유로 제조된 카르복시메틸화 셀룰로오스 나노섬유의 특성 평가

Abstract

This study investigated the use of cotton linter fiber as a raw material for manufacturing carboxymethylated cellulose nanofiber (CM-CNF). Cotton linter mixed pulp (CLMP) and hardwood bleached kraft pulp (HwBKP) were used for preparing carboxymethlyated cellulose (CMC) based on the degree of carboxymethylation (CM) considering the dosage of sodium hydroxide: and monochloroacetic acid: low and high CMs. After CM reactions, we evaluated the fiber length and width, the degree of substitution (DS), and morphology of CM-CNF. The final CM-CNFs were prepared by grinding CMCs developed from CLMP and HwBKP for one, three, and five passes using a microgrinder, and their fiber width, low-shear viscosity, and zeta-potential were determined. CMC fibers were dissolved in water and swollen according to the degree of CM. A comparison of the properties of CMC developed from CLMP and HwBKP showed that the fiber length and width of the former was higher than those of the latter. In particular, the DS of CMC developed from CLMP was much higher than that developed from HwBKP owing to higher alpha-cellulose content;hence, the former displayed higher low-shear viscosity and lower zeta-potential than the latter. As the degree of CM increased, the fiber width and zeta-potential of the CM-CNFs decreased and their low-shear viscosity increased linearly. Therefore, cotton linter fiber with high alpha-cellulose content is a prospective material to produce highly anionic CM-CNF with considerably low-shear viscosity.