The Effect of Carboxymethyl Cellulose Addition on the Properties of Starch-based Wood Adhesive

Starch adhesive was prepared utilizing corn starch, polyvinyl alcohol, and borax as raw materials. A certain amount of water-soluble carboxymethyl cellulose (CMC) was added in the preparation process, and a certain percentage of polymethylene polyphenylene isocyanate pre-polymer as cross-linking agent was used to improve its water resistance. To evaluate the water resistance, three-layer plywood was fabricated by hot pressing, and bonding strength was measured using a mechanical testing machine according to the National Standard of the People’s Republic of China GB/T 17657-2013. Differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and scanning electron microscopy (SEM) were used to characterize curing of the adhesion. The results showed that the initial viscosity, solids content, and bonding strength of the starch adhesive, as well as the interface compatibility between starch adhesive and pre-polymer, were all improved. The curing temperature of the adhesive decreased, and the optimal addition of CMC was 0.375%.