Use of sustainable glucose and furfural in the synthesis of formaldehyde-free phenolic resole resins

Sustainable resol-type resins [phenol-furfural-glucose (PFuG), phenol-furfural (PFu), and phenol-glucose resins] were synthesized via alkali catalysis. The chemical structures of the PFuG resins, which had different molar ratios of glucose to furfural, were analyzed by H-1-NMR and Fourier transform infrared spectroscopy. A possible mechanism for formation of the PFuG resin was proposed. The crosslinking curing behaviors of the PFuG resins were examined by differential scanning calorimetry analysis. The performance of the PFuG resins as wood adhesives was studied. (c) 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47732.