A new adhesive from waste wool protein hydrolysate

Abstract

This study aimed to produce a new non-toxic adhesive system consisting of wool-hydrolysed (WH) and a commercial wet-strength agent for paper (Kymene® 557H) which is an aqueous solution of cationic polyamidoamine-epichlorohydrin (PAE) resins. The WH mixed with Kymene (WH-K) and used as an adhesive for bonding pine veneer. Rheology aspects of the blends measured in different WH-K weight ratios and the effect of reaction time on the lap-shear strengths of wood composites bonded with WH-K adhesives were evaluated. The physicochemical properties of the newly developed wood adhesive system were characterised using FTIR, DSC and TGA. Wood composites bonded with WH-K adhesive had shear strengths comparable to or higher than those bonded with commercial phenol-formaldehyde resins. Wood composites bonded with the new adhesive system demonstrated high water resistance and retained relatively high strength even after treated with boiling water. The new adhesive system is non-toxic, free from formaldehyde and friendly to use for diverse applications. Thus, we anticipate that this new adhesive system will be potential candidate for bio-composites and packaging applications.