Influence of glutaraldehyde on the performance of a lignosulfonate/chitosan‐based medium density fiberboard adhesive

ABSTRACT A lignosulfonate/chitosan‐based medium density fiberboard (MDF) adhesive has been prepared using glutaraldehyde as crosslinking agent. Optimization of glutaraldehyde/chitosan mass ratio was carried out based on characterization details involving MDFs’ mechanical and dimensional performances analysis, Fourier transform infrared spectroscopy, thermogravimetric analysis, and X‐ray diffraction. The addition of glutaraldehyde improved the mechanical properties of the MDF significantly, while it negatively affected the dimensional properties. The MDFs using lignosulfonate/chitosan‐glutaraldehyde adhesives (LS/CS‐Glu) with glutaraldehyde/chitosan mass ratios in the range of 0.25–0.75 fulfilled the Chinese national standard for MDF. Chitosan was crosslinked with self‐polymerized glutaraldehyde through CN linkages which resulted in the reduction of the amide bonds and hydrogen bonds between chitosan and lignosulfonate. The proposed LS/CS‐Glu adhesives can be a promising candidate for traditional MDF adhesives which contain formaldehyde. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135 , 45870.