Novel adhesive based on black soldier fly larvae flour for particleboard production

Abstract

Protein-based adhesives are receiving considerable attention due to their potential to contribute to the development of environmentally friendly materials. Black soldier fly larvae (BSFL) can convert organic waste into high value-added products, such as proteins and fatty acids. The objective of this study is to formulate adhesives from BSFL flour and evaluate their suitability in the production of particleboards. To expose the functional groups of the proteins for reaction with the wood, denaturation strategies involving alkaline treatments were assessed. The effectiveness of these treatments was evaluated through Bradford solubility, SDS-PAGE, and FTIR analysis. Bradford analysis confirmed that the alkali treatment increased the protein solubility from 10.1 g/l for 0 M to 89.1 g/l for 1 M. FTIR analysis revealed changes in the relative intensity of bands attributable to the Amide I, II, and III regions, which are associated with the α-helix and β-sheet structures. The adhesive was applied in the manufacturing process via spraying, requiring an evaluation of the rheological properties of different formulations. Based on the rheological properties, the viscosities of 0.25 M and 1 M were measured at 0.082 Pa·s and 0.113 Pa·s, respectively, falling within the suggested range for particleboard manufacture. Subsequently, eucalyptus wood panels were manufactured using the BSFL-based adhesives, and their mechanical properties as well as water resistance were evaluated. Static bending and tensile strength perpendicular to the surface testing revealed that boards produced with BSFL adhesive exhibited mechanical values comparable to those of commercial resins. The performance of the manufactured materials was compared with the minimum standards outlined in international regulations.