Acetosolv pine lignin as copolymer in resins for manufacture of exterior grade plywoods

Plywood boards were prepared from pine and eucalyptus woods using resins obtained by copolymerization of phenol, formaldehyde and pre-methylolated acetosolv pine lignin. The influence of the lignin:phenol, formaldehyde:phenol and soda:phenol ratios on the properties of the resins and the quality of the boards was determined. Several formulations produced resins with knife-test results better than those obtained with a commercial phenol–formaldehyde resin.