<![CDATA[Tannin is a derivative from organic compound from glycosides found in various plants, the most important commercial condensed tannin oblained from gymnosperms species for example Acacia mangium. Tannin is one of the adhesive materials that can have a dimensional stability of wood. Tannin contains flavonoid compounds that have hydroxyl groups that are reactive to condense against other materials as a cross-link agent, like formaldehyde, which may increase the number of polymer units of tannins, thus increasing the bonding strength of tannin based adhesives. Based on the results of physicochemical analysis of extracts (tannins) from the bark of A. mangium as a raw material for adhesives, it can be concluded that the A. mangium tannin had a higher reactivity toward formaldehyde of 96%, reactivity of tannin toward hexamefhylene tetramine of 46.18%, tannins toward ethylene glycol of 3.07% and tannins toward dimethylol urea of 183.59%. Meanwhile, the value of reactive polyphenol content determined by UV-Method showed in tannin with formaldehyde of 97.65%, tannins with hexamethylene tetramine of 46%, tannins with ethylene glycol of 2%, and tannins with dimelhylolurea of 56.26%. The resuits of gelation time (gel time) measurements fullfilled the requirements of JIS K 6833-1980 by the treatment of hexamelhylenen tetramine for variable II and III, and the treatment of ethylene glycol (variable VI). The viscosity values by the Ireatment of hexamethylenen tetramine (variable II, III, and IV), for ethylene glycol (variable II - VI) met the requirement conditions by JIS K 6833-1980. ]]>
