Studied On The Glulam Of Room Temperature Curing MUF Resin Adhesive

This paper studied the synthesis process of the MUF resin and discussed the impact of the melamine contents on the properties of the resin. A room temperature curing MUF resin adhesive had been developed by adding one thickener referred as B whose adding content and order were also discussed. The influence of different curing agents to the bonding strength and curing process of the resin had been probed into while the mechanical properties had also been tested at the basis of the optimum amount of B component. The bonding performance of the main tree species in Northeast such as poplar, birch, ash and oak wood had been studied simultaneously so as to provide the theoretical basis and practical guidance for the wooden manufacturing technology of these trees. Finally the modern analytical methods were used such as Fourier transform infrared (FTIR), differential scanning calorimeter (DSC) to analyze the groups and structural changes, then preliminarily analyze its water resistance and curing mechanisms.Bonding strength increased and formaldehyde emission decreased with the melamine content increased. The best bonding strength was 1.09MPa when melamine content was 40%. The adding of B component could make the curing temperature of the MUF resin reach the room level and improve the water resistance at the same time. Different contents of B component influenced the bonding strength of MUF resin, the bonding strength was the best when content of B component was 5%～10%. Different curing pH influenced the bonding strength of MUF resin too and the bonding strength was better when the value was 3.0. With the different curing agents, not only the structures of cured resin or the curing effects varied, but the mechanical properties were also different. The curing time, pot life and the bonding strength of the comprehensive performance was best as formic acid acted the one component curing agent while the multi-component curing agent 1 and 3. Different tree species influenced the bonding strength of MUF resin. The dry shear strength of oak was maximum followed by ash and birch, poplar was minimum. The wet shear strength of ash was maximum, and then birch and poplar, oak was minimum. The bonding strength of MUF resin was also affected by the bonding wood surface conditions. The wet shear strength of poplar, birch, ash and oak after the surface treatment were greater than the ones had not been treated.