This invention discloses a reusable,
dopamine /
tannic acid synergistic modified
natural rubber latex
adhesive and its preparation method, belonging to the field of green bio-based
adhesive technology. The
adhesive uses
natural rubber latex as the main film-forming matrix,
dopamine or
dopamine hydrochloride as the biomimetic adhesion component, and
tannic acid as the natural
polyphenol reinforcing component. Under the action of a weakly alkaline buffer
system and an oxidant, dopamine undergoes oxidative
polymerization and forms a
polyphenol composite network with
tannic acid, thereby improving the
interfacial bonding force,
cohesive strength, and
environmental stability of the
natural rubber latex layer. Experimental results show that the initial lap
shear strength of the adhesive obtained by synergistic modification of 25% solids content
natural rubber latex, dopamine
hydrochloride, and tannic acid can reach 1.557 MPa, which is about 95.1% higher than that of pure
natural rubber latex adhesive; after two repeated hot-press bondings, the
shear strength still reaches 0.751 MPa. After soaking in water at 25 ℃ for 24 h, treating with water at 63 ℃ for 3 h, and soaking in
anhydrous ethanol for 24 h, the lap
shear strength remained at approximately 0.808 MPa, 0.769 MPa, and 0.719 MPa, respectively. This adhesive has a simple preparation process, primarily using water as the dispersion medium, requiring no additional
formaldehyde crosslinking agents or organic solvents. It is suitable for bonding
wood processing,
furniture manufacturing, packaging materials, and other
cellulose-based materials.