Unlocking the potential of peony seed meal adhesives: Multi-crosslinking and OA-POSS nanoparticle reinforcement for enhanced performance

This study introduces an innovative approach for high-performance biomass adhesives by designing and synthesizing a hydroxyl-terminated polymer (HHBP) as a central core, which is combined with polyamidoamine epichlorohydrin (PAE) as an effective cross-linking agents (PH) for peony seed meal (PSM)-based adhesives. The new type of crosslinking agent (PH) significantly increases the reactive sites with protein active groups in PSM, thereby enhancing the cross-linking density and leading to improved adhesive performance. Furthermore, the introduction of octa-aminopropyl polyhedral oligomeric silsesquioxanes (OA-POSS) further improves the adhesive's bonding strength by synergistically enhancing stress transfer efficiency and mitigating interfacial stress concentration. The optimized adhesive formulation demonstrates remarkable improvements in dry bond strength (2.59 MPa), soaked wet bond strength (1.79 MPa), and aged wet bond strength (1.05 MPa), reflecting increases of 28.8 %, 10.5 %, and 29.6 %, respectively, compared to the unmodified PSM-based adhesive. This research offers an innovative method for developing low-cost, high-performance biomass adhesives, facilitating the high-value use of PSM and supporting the advancement of the green adhesive industry.