Synthesis of Phenolformaldehyde-Lignosulfonate Adhesive for Utilization as a Wood Binder

Spent sulfite liquor (SSL) was obtained from Adamjee Paper and Board Mills, Nowshera, where different grasses (bagasse, Kaigrass and wheat straws) are being used as pulp material. Lignosulfonate (LS) was separated from SSL with the help of strong hydrochloric acid and characterized by UV and IR spectroscopy. A series of phenolformaldehyde-lignosulfonate (PF-LS) adhesive were prepared by gradual replacement of phenol (up to 70 % by weight) in the condensation reaction with formaldehyde by using alkaline medium. Various properties of the adhesive measured, indicate that phenol can be replaced by lignosulfonate up to 70 % without affecting the quality of the glue.