Natural phenolic adhesives derived from Tannins and Lignin

Abstract

Natural phenolic adhesives derived from tannins and lignin are presented. The chemistry of tannins and tannin adhesives and the technology of industrial tannin adhesives are discussed and their different applications are presented. From older technology and formulations, newer concepts such as autocondensation, their formulation as nonisocyanate polyurethanes and as epoxy resins are presented. The newest reactions such as cross-linking by triethyl phosphate or by natural, nontoxic aldehydes are also briefly presented. The same methods are used to present lignin-based adhesives, with older, fairly recent, and very recent or outright new approaches and reactions to their formulation being presented.