Effect of surface-modified cellulose nanofibrilwith cationic polyelectrolyte on drainage and strength of paper

Abstract

In this study, we evaluated the effect of the surface-modified cellulose nanofibril (CNF) on the strength, drainage, and retention of the specialty paper made from cotton lint mixed pulp (CLMP). The surface modification of CNF was conducted via enzymatic hydrolysis and homogenization using cationic polyacrylamide (C-PAM) to yield enzyme (EN)-CNF. C-PAM was added into a 0.5% CNF slurry for 5 min at 600 rpm. After performing surface modification, the viscosity, particle size, and fiber width of the unmodified and surface-modified CNFs were measured. Further, handsheets were produced by adding CNF or EN-CNF into the CLMP furnish. The drainage rate and chemical oxygen demand of the CLMP furnish were determined to evaluate the effect of surface modification on the drainability and retention in the wet-end part. There were no significant differences in terms of the viscosity, particle size, and fiber width when comparing unmodified and surface-modified CNFs. The surface-modified CNF handsheets exhibited higher tensile strength and folding endurance when compared with those exhibited by the unmodified CNF handsheets. Additionally, surface modification increased the drainage rate and decreased the COD of the CLMP furnish. Therefore, the surface modification of CNF positively affected the specialty paper in terms of strength, drainage, and retention. ? 2019 Korean Technical Assoc. of the Pulp and Paper Industry. All rights reserved.