Phenolic resin adhesives based on chestnut (Castanea sativa) hydrolysable tannins

Chestnut hydrolysable tannins are phenolic materials that have been considered too unreactive to compete in the phenolic resin adhesives market for exterior boards for the building industry. However, an article in 1973 describing 3 years industrial application of chestnut hydrolysable tannins during the first oil crisis indicated that this was not the case. We have extended this old work by using superior phenolic resins formulations and producing phenol–formaldehyde–chestnut tannin adhesives where a substitution of up to 80% of the phenol is possible with remarkably good results. The reactions involved were clarified by 13C NMR and MALDI-TOF mass spectrometry.