Formaldehyde-Free Alcohol-Based Wood Adhesives Prepared by ROMP: High Bonding Strength and Excellent Water Resistance

Developing novel formaldehyde-free wood adhesives with high bonding strength and stability is significant for the environment and for human health. This research developed a series of novel alcohol-based adhesives with different amounts of hydroxyl groups per repeat unit through ring opening metathesis polymerization (ROMP). P2OH exhibited a higher bonding strength than POH and P4OH owing to the strong adhesion and cohesion. In addition, the relationship between bonding strength and molecular weight was also investigated. Taking into account the chain entanglement and fluidity, P2OH₅₀₀ achieved a highest bonding strength of 5.3 MPa in bonding wood sheets, which was capable of hanging a total weight of 11 kg. Furthermore, P2OH₅₀₀ exhibited excellent solvent resistance, especially in hot water. The wood sheets retained more than 88% of the original bonding strength after soaking in water at 94 °C for 12 h. It is highly anticipated that this research will provide a new insight into designing formaldehyde-free adhesives with outstanding adhesion performances and excellent water resistance.