Characterization on the Copolymerization Resin between Bayberry (Myrica rubra) Tannin and Pre-Polymers of Conventional Urea–Formaldehyde Resin

By focusing on the disadvantages of weak water resistance and high formaldehyde emission urea–formaldehyde resin (UF), this research provides a new method to overcome these shortages UF by using tannin for partial substitution urea. Furthermore, plasma pretreatment wood was introduced strengthen bonding performance plywood. The investigation chemical structure tannin–urea–formaldehyde (TUF) were performed with Fourier transform infrared spectroscopy (FT-IR) solid-state 13C nuclear magnetic resonance (13C NMR). results investigations confirmed joining into structure, which may enhance structural rigidity TUF adhesives improve hydrolysis stability. Then, thermal resins tested differential scanning calorimetry (DSC) thermogravimetric (TG) analysis. DSC indicated that curing temperature did not change significantly. However, TG analysis showed stability considerably improved. In test, revealed an excellent resistance, comparable can fulfill standard requirement plywood (Type II according Norm GB/T 17657-2013). It is interesting shear strength specimens, bonded TUF6 resin, after low-pressure cold equipment (CLP plasma) jet type atmospheric low-temperature (JTLP treatment, reached 0.80 MPa 0.85 MPa, respectively, being soaked in boiling 3 h. addition, most samples exhibited lower emission, especially those prepared at 70 °C 1.5 h, amount could be reduced approximately 39%.