Synthesis of Grafting Itaconic Acid to Starch-Based Wood Adhesive for Curing at Room Temperature

摘要

A new biodegradable, renewable, and environmentally friendly starch-based wood adhesive that can be used at room temperature was synthesized by grafting of itaconic acid (IA) monomer onto cassava starch. When the addition of IA was 5% (starch basis), we can obtain the optimal mechanical properties of 15.38 MPa in dry state and 4.56 MPa in wet state. Compared with unmodified starch adhesive, the shear strength of grafted starch adhesive improved by 43.6% in dry state and 93.2% in wet state, respectively. The improved performance of the grafted starch-based wood adhesive was characterized by the measurement of viscosity and solid content, Fourier-transform infrared (FTIR), Thermogravimetry (TGA), X-ray diffraction (XRD) and scanning electron microscopy analyses (SEM). The results showed that there was a new characteristic peak of ester at 1700 cm(-1)in the infrared spectrogram, which indicated the successful grafting of IA onto starch. After grafting modification, the storage stability and thermal stability of starch adhesive were improved. From SEM images and XRD patterns, we can witness that the morphology and crystallinity of starch particles were changed, which as a supplement of FTIR, confirmed the improvement of bonding strength and water resistance of the adhesive.