Preparation and characterization of a water-resistant polyamide-oxidized starch-methyl methacrylate eco-friendly wood adhesive

A water-resistant polyamide-oxidized starch-methyl methacrylate (P-OS-M) adhesive with zero formaldehyde-emission was successfully synthesized, using natural corn starch, KMnO4, polyamide and methyl methacrylate as raw material, oxidant, crosslinking agent and comonomer, respectively. The P-OS-M25 adhesive synthesized with the optimal amount of methyl methacrylate (25 ml) could reach wet shear strength of 1.04 MPa, which was far greater than natural starch (NS) and oxidized starch (OS). Fourier transforms infrared spectrometer (FTIR) and X-ray diffraction (XRD) results showed that polyamide and methyl methacrylate were successfully cross-linked and copolymerized with oxidized starch. In addition, thermogravimetric analysis (TGA), rheology, scanning electron microscope (SEM) and contact angle respectively indicated that P-OS-M adhesive was suitable for wood adhesives in terms of thermal stability, viscosity, morphological and water resistence. These advantages increased the possibility of P-OS-M adhesive instead of petroleum-based wood adhesives.