Cow blood adhesive: Characterization of physicochemical and adhesion properties

Adhesives were prepared from cow blood via alkali-modification. Their physicochemical and adhesion properties such as the degree of hydrolysis, viscosity, water solubility, curing time, and bonding strength were measured. The degree of hydrolysis increased with increasing basic pH value. The adhesive exhibited shear-thinning viscous behavior. Both viscosity and shear-thinning character showed a remarkable shift at pH 10.2 and at 50 °C. The curing time decreased with curing temperature within 60–80 °C range. The water solubility of the adhesive was the lowest when sodium silicate, the curing agent, was used during adhesive preparation at a concentration of at least 2.0% (v/v) regardless of the pH value. The adhesive bonding shear strength was independent of the pH and was comparable to that of phenol formaldehyde in the dry condition, but somewhat lower in the wet condition.