Improving the wet adhesive bonding of bamboo urea‐formaldehyde adhesive using styrene acrylate by controlling monomer ratios

Abstract

The utilization of bamboo resources can significantly alleviate the wood shortage and facilitate CO2 neutralization. However, the adhesive bonding performance of bamboo is not ideal, which greatly limits its application. Therefore, the biggest challenge is to explore a simple and effective method to enhance the bonding between bamboo and adhesive. In this study, we synthesized three butyl acrylate‐styrene (BS) emulsions with different monomer ratios and incorporated them into urea‐formaldehyde (UF) resins to prepare butyl acrylate‐styrene modified urea‐formaldehyde (BUF) adhesives. Results show that BS emulsion not only prolongs the workability time of UF adhesives (95 s–108 s), but also reduces the free formaldehyde content (0.38%–0.26%). Specifically, BS emulsion with the highest hard/soft monomer ratio makes BUF adhesive the lowest activation energy, showing the accelerated curing reaction. Specifically, the prepared laminated bamboo‐veneer lumber (LBVL) exhibits the best wet‐bonding strength and meets the Chinese National Standard, suggesting that BS emulsion with a higher hard/soft monomer ratio can enhance bonding performance. Thus, this efficient method can not only enhance various adhesive properties, but also improves the bonding performance on LVBL, which can greatly ease the shortage of wood resources and speed up the development of the bamboo industry.