Enhancing polyvinyl acetate adhesion via atmospheric pressure plasma treatment of bamboo (Bambusa spinosa Roxb.)

Green materials, such as lumber, have played a vital role in the construction industry. However, global demand for lumber exceeds supply, which is driving interest in alternative materials such as engineered bamboo products. The performance of engineered bamboo is highly dependent on the strength of the adhesive used. As the industry shifts toward environmentally friendly adhesives, polyvinyl acetate (PVAc) has emerged as a candidate for bamboo adhesives. However, PVAc is known to a have lower strength than formaldehyde-based adhesives. To address this, we explored the enhancement of PVAc adhesion by pretreating the bamboo surface with a custom-built atmospheric pressure plasma jet. A significant increase in shear strength of up to 55 % was realized when the bamboo surface was treated with plasma. We attributed this to an increase in the surface free energy of bamboo, particularly the polar component. The treatment enhanced the affinity for PVAc, enabling stronger adhesion strength. The fast and relatively inexpensive atmospheric pressure plasma treatment technique offers a promising solution to improve the performance of engineered bamboo and to advance the development of more sustainable construction materials. • A custom-built plasma system was able to modify bamboo slat surfaces. • Argon with air plasma induced full surface wetting after 60 s treatment. • 55 % increase in bond shear strength using polyvinyl acetate was achieved when bamboo is treated with argon and air plasma.