Investigating the use of peanut meal: a potential new resource for wood adhesives

Abstract

This study was conducted to evaluate the potential of peanut meal (PM) to produce plywood adhesives via sodium dodecyl sulfate (SDS) and ethylene glycol diglycidyl ether (EGDE) modification. Five-ply plywood specimens were fabricated to measure water resistance. The physical properties, cross section, thermal behavior, and functional groups of the resultant adhesives were characterized in detail. The results showed using SDS and EGDE in the adhesive formulation greatly improved the water resistance of the resultant adhesive by 90% and met the interior use plywood requirements. This improvement was attributed to three reasons: (1) SDS broke the structure of the PM protein and exposed inner active groups, which reacted with EGDE and formed a dense network to improve the water resistance of the resultant adhesive; (2) EGDE decreased the adhesive viscosity and led to the adhesive easily penetrating into wood and forming more interlocks; (3) the adhesive with SDS and EGDE created a smooth surface of the cured adhesive to prevent moisture intrusion. Additionally, compared with the peanut meal-based control adhesives, the viscosity of the cured adhesive was reduced by 95.8% to 24 140 mPa s, which further demonstrated that peanut meal has favorable potential as an alternative adhesive material for plywood.