Bonding strengths of poly(vinyl acetate), Desmodur-VTKA, phenol–formaldehyde and urea–formaldehyde adhesives in wood materials impregnated with Vacsol Azure

Abstract

This study has been performed to determine the impacts of Vacsol Azure (VA) on the bonding strength of poly(vinyl acetate) (PVAc), Desmodur-VTKA (D-VTKA), urea–formaldehyde (UF) and phenol–formaldehyde (PF) adhesives on some impregnated wood materials. To this end, the test samples prepared from Oriental beech ( Fagus orientalis Lipsky), European oak ( Quercus petraea Liebl.), Scotch pine ( Pinus sylvestris Lipsky), European linden ( Tilia cordata) and Lombardy poplar ( Populus nigra Lipsky) woods materials were treated with Vacsol Azure by the Vac–Vac double vacuum impregnation process of ASTM D 1413 standards and directions of the manufacturer. After impregnation, bonding strength test (based on BS EN 205) was applied on both sanded connection surfaces jointed by PVAc, D-VTKA, UF and PF adhesives. Consequently, in the interaction of the impregnated wood materials and adhesive types, the highest bonding strength was obtained in Oriental beech + PVAc (9.707 N mm −2) and the lowest was obtained in Lombardy poplar + UF (3.758 N mm −2). In consequence, in the massive constructions and furniture elements that the bonding strength after the impregnation with Vacsol Azure is of great concern, bonding with PVAc of Oriental beech wood materials could be recommended.