The bark of the Myrcia eximia DC., tree which occurs in the Brazilian Amazon, was studied. The aim was to determine the yield of condensed tannins and their quality on formulation of natural adhesives for wood bonding. The extraction performance of tannins in water and sodium sulfite solution was compared. The tannins were characterized by Fourier transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA). Adhesives based on Myrcia eximia tannins were produced and evaluated for their physicochemical properties and shear strength in the wet and dry glue line. The extracts of Myrcia eximia bark presented 25.2% of condensed tannins in water extraction and 32.6% in sodium sulfite solution (Na₂SO₃). In these two extraction conditions, the Stiasny index values indicated that Myrcia eximia tannins can be used in wood adhesive formulations. The properties of the natural adhesives allowed for good application on wood and the glue line shear tests showed important bonding properties of the adhesive with the wood in both evaluated conditions, reaching a resistance of 5.3 MPa and 87.5% of ruptures in the wood. We conclude that Myrcia eximia bark is a source of high levels of condensed tannins with quality for application in natural adhesives.

研究了在巴西亚马逊河中生长的Myrcia eximia DC。的树皮。目的是确定缩合单宁的产率及其在天然胶粘剂配方中的质量，以用于木材粘合。比较了水和亚硫酸钠溶液中单宁的提取性能。单宁通过傅立叶变换红外光谱（FTIR）和热重分析（TGA）进行表征。生产了基于Myrcia eximia单宁的胶粘剂，并评估了其在干湿胶生产线上的理化特性和剪切强度。桃金娘科树皮提取物在水提取物中的浓缩单宁含量为25.2％，在亚硫酸钠溶液（Na ₂ SO _3中的含量为32.6％）中。）。在这两种提取条件下，Stiasny指数值表明Myrcia eximia单宁可以用于木材粘合剂配方。天然胶粘剂的性能使其可以很好地应用于木材上，胶线剪切试验表明，在两种评估条件下，胶粘剂与木材的粘合性能都很重要，达到了5.3 MPa的抵抗力和87.5％的木材断裂强度。我们得出的结论是，Myrcia eximia树皮是高浓度缩合单宁的来源，其质量可用于天然胶粘剂。