This paper aims at making a study on the bonding properties of birch with API adhesive. A non-formaldehyde
adhesive to improve the bonding strength and water resistance of the emulsion was investigated. The adhesive was a
composite system that was formulated from polyvinyl acetate (PVAc) emulsion, PVA, isocyanate and some other
additives. In this study the effect of isocyanate at room temperature on the curing behavior of PVAc was investigated. The
research conclusion that a proper mole ratio of –NCO group and hydroxyl groups is 25/1. And the isocyanate percent have
arrived at 15%, the dry and wet shear strengths of birch is the highest. From the cost of API adhesive we choose TiO2 and
CaCO3. A XPS technique has been established to analyze structure of crosslinking in bonding interface. The experimental
results indicated that the occurrence for chemical reaction between PVAc-based API adhesive and birch wood.