Journal of Adhesion, Vol.90, No.4, 279-295, 2014
Adhesive Properties of Medium-Density Fiberboards Fabricated with Rapeseed Flour-Based Adhesive Resins
This study examined the adhesive properties of adhesives formulated with rapeseed flour (RSF), a by-product of edible oil and bio-diesel manufacture, for medium-density fiberboards (MDFs). The RSF was hydrolyzed by sulfuric acid (AC-RSFH) and sodium hydroxide (AK-RSFH) solutions of 3%, 5%, and 7%. Phenol-formaldehyde (PF) prepolymers were prepared with formaldehyde to phenol molar ratios of 1.5, 1.8, and 2.1 (1.5-, 1.8-, and 2.1-PF). RSF-based adhesives were formulated by cross-linking 35% AC-RSFH, 35% AK-RSFH, and 30% PF prepolymers on a solid weight basis. The mechanical strength and dimensional stability of the MDFs were improved by decreasing the concentration of RSF-hydrolytic agents. The properties of the MDFs bonded with RSFH/1.8-PF resins were superior to those of RSFH/1.5- or 2.1-PF resins. These results suggest that RSF can be used as a raw material for environment-friendly adhesives used in MDF production.
Keywords:Adhesive strength;Formaldehyde emissions;Medium-density fiberboard;Phenol-formaldehyde prepolymer;Rapeseed flour