Development and evaluation of new curing agents derived from glycerol for formaldehyde-free soy-based adhesives in wood composites

Three novel curing agents (I, II, and III) were synthesized from epichlorohydrin and ammonium hydroxide. The combinations of soy flour (SF) with one of the curing agents (SF-I, SF-II, and SF-III) were investigated as adhesives for making interior plywood. Water resistance tests showed that plywood panels bonded with SF-I and SF-III adhesives met the requirements of interior plywood, whereas those bonded with SF-II did not. The modulus of rupture, modulus of elasticity, and internal bond strength of particleboard panels bonded with the SF-II adhesive all exceeded the corresponding minimum industrial requirements for M-2 grade particleboard.