Adhesives used for wood bonding for nonstructural applications typically contain an aqueous emulsion of poly(vinyl acetate) stabilized with poly(vinyl alcohol) and some additives. The adhesive bond derived from this class of adhesive is poor when exposed to moisture and temperature. In this context, the previous classification of wood adhesives for nonstructural applications with moisture and temperature resistance is very important to the quality and durability of adhesive joints. In this study, the influence of three wood species (Fagus sylvatica L., Mimosa scabrella Bentham and Micropholis cf. venulosa Mart. & Eichler) was studied on shear strength of adhesive joints prepared with three vinyl adhesives synthetized with different concentrations of N-butoxymethyl acrylamide (NBMA). The shear strength tests on the glue line were conducted under various conditioning cycles of adhesive joints. The results obtained shows that there are significant differences in bond strength of adhesive joints and percentage of wood failure caused by wood species and adhesive type used. The adhesives produced were classified into durability class after various conditioning treatments. Higher values of shear strength were observed on the glue joints prepared with Micropholiscf. venulosa Mart. & Eichler and Fagus sylvatica L. wood glued with adhesive AD-3. The lowest value of shear strength was observed on the glue joints prepared with Mimosa scabrella Bentham wood. Micropholis cf. venulosa Mart. & Eichler wood seems more suitable to replace Fagus sylvatica L. wood.
Glue joints; Vinylic adhesive; Shear strength
