Effect of bio-scavengers on the curing behavior and bonding properties of melamine-formaldehyde resins

The effects of bio-scavengers on the formaldehyde emission, bonding strength, curing behavior, and thermal decomposition properties of MF resins for engineered flooring and adhesion for wood were investigated. Four varieties of bio-scavengers, tannin powder, wheat flour, rice husk flour, and charcoal, were added to MF resin at 5 wt.-%. To determine formaldehyde emission and bonding strength, we manufactured engineered floorings. MF-charcoal was most effective in reducing formaldehyde emission because of its porous nature, but its bonding strength was decreased. Tannin powder and wheat flour, which contain more hydroxyl groups, showed higher bonding strength and curing degree than pure MF resin did. Although the hydroxyl groups of the bio-scavengers were effective in reducing formaldehyde emission and improve bonding strength and curing degree, rice husk flour and charcoal behaved like inorganic substances, thereby disturbing the adhesion between MF resin and wood and thus reducing the bonding strength. In thermogravimetric analysis, MF-tannin showed the highest thermal stability in the low-temperature range from 100 to 300 T.