| The soybean meal powder was treated by microwave to prepare the soybean meal adhesive with good bonding performance. The effects of microwave power, microwave time and soybean meal powder mass fraction on the viscosity, dry shear strength and solid content of the adhesive were investigated by single factor experiment. The optimal conditions for the preparation of adhesives by microwave treatment of soybean meal powder were determined by orthogonal experiment. Fourier transform infrared spectroscopy (FT-IR) and SEM were used to investigate the effect of microwave tratment on the molecular structure and morphology of soybean protein. The results showed that the molecular structure of soybean protein was destroyed by microwave treatment of soybean meal powder, and the inner polar and non-polar groups were exposed. The exposed groups formed molecular aggregates through hydrogen bonds, electrostatic interactions, and the bonding strength increased. The optimal conditions of preparing adhesive with the microwave-treated soybean meal powder were 300 W of microwave power, 3 min of microwave time, and 25% of mass fraction of soybean meal powder. Under these conditions, the dry shear strength, viscosity and solid content of the adhesive were 1.61 MPa, 924 MPa·s and 23.05%, respectively. |
