Adhesive and curing properties of chicken feather/blood-based adhesives for the fabrication of medium-density fiberboards

This study was conducted to investigate the adhesive properties of chicken feather (CF)-based adhesives for wood-based panels. CF was hydrolysed in sodium hydroxide solutions of 5%, 7.5% and 10% (CF-AK). Chicken blood (CB) hydrolysed in sulfuric acid solution of 5% (CB-AC) was used as a hardener. The adhesives were formulated by crosslinking 60% CF-AK, 10% CB-AC and 30% formaldehyde-based crosslinking agents (formalin, melamine-urea-formaldehyde and phenol-formaldehyde prepolymers) on a solid weight basis. The CF-based adhesives were very viscous at room temperature, but the viscosity at 50 °C ranged from 300 to 600 mPa·s resulting in a sprayable adhesive. From the DSC analysis, the use of CF-AK-10% in the CF-based adhesives need longer curing time compared with that of CF-AK-5%. Most mechanical strength properties and dimensional stability of MDF bonded with CF-based adhesives were similar to those of commercial urea-formaldehyde (UF) resin. However, internal bonding strength of most MDF bonded with CF-based adhesives was higher than that with the UF resin. Most adhesive properties of the MDF manufactured with the new CF adhesive met the Korean Standard requirements for interior MDF. These results suggest that CF and/or CB can be used as raw materials for environment-friendly adhesives for producing wood panels.