Reaction of polyphenols with formaldehyde

Abstract

Abstract The reaction of wattle and mangrove polyphenols with formaldehyde was studied at various pH and under different conditions of temperature and time. The reactivity was greater at pH 8 than at pH 1 and least at pH 4–5. The initial fast stage in the reaction was followed by a slow stage. The formaldehyde uptake at pH 8 and 100° in 3 h. was determined for several polyphenols; it gave a better indication of the efficiency of a polyphenol as an adhesive than did the determination of Stiasny polyphenols. The reasons for the different behaviour of polyphenols as adhesives are discussed.