The effect of chemical modification on the strength of wood and bonded wood joints

The effect of propionic, crotonic or methacrylic anhydride (MA) modification on the lab joint strength of monomer bonded veneer strips was investigated. Lap joints were formed by hot pressing veneers of modified wood with monomer in the presence of free radical initiator and bond strength was determined on an Automatic Bonding Evaluation System tensile tester. Test results indicated that chemical treatment improved bond quality between hydrophilic wood and hydrophobic monomer. Extremely strong bonds (wet and dry conditions) formed in the case of MA modified veneer strips. In addition, the effect of chemical modification on the mechanical properties of strips was also investigated. Chemical modification had a detrimental effect on the mechanical properties.