Investigation of Novel Thermosetting Copolymer-Based Monomethylolurea-Glyoxal for Wood Manufacturing.

The purpose of this investigation was to design novel alternating copolymers (monomethylolurea-glyoxal, MMU-G) as adhesives for wood manufacturing. MMU-G were synthesized under acid (pH = 5) conditions. After the 120-day storage period, the MMU-G resins were used for plywood production, which exhibited a wet shear strength of about 2.15 MPa, similar to the freshly prepared MMU-G resin. The excellent water resistance and long storage stability showed that MMU-G has particular characteristics and properties all of their own, which, in certain respects, are very different from those of urea-formaldehyde (UF) adhesives. The X-ray diffraction results showed that only a few crystallinities occurred in MMU-G resins, indicating the presence of long side chains in the MMU-G polymer structures, leading to better adhesion strength than UF resins. The structure characteristics of the MMU-G resin were studied by Fourier transform infrared and electrospray ionization mass spectrometry, and a possible molecular structure has been inferred, which is consistent with spectroscopic results.