Quaternized chitosan/sodium alginate functionalized halloysite for melamine formaldehyde resin impregnated paper: synergistic toughening and antibacterial properties development.

Melamine formaldehyde (MF) resin is a widely used decorated material, but its inherent brittleness limits broader applications. In this study, a novel bio-based nanomaterial (AQ@HNTs) was fabricated via a layer-by-layer self-assembly of quaternized chitosan and sodium alginate onto halloysite nanotubes (HNTs), providing a green and efficient strategy for natural nanotube surface modification. The resulting AQ@HNTs were incorporated into MF resin to synergistically enhance its toughness and antibacterial properties without affecting its curing behavior at 120 °C. Comprehensive characterization of AQ@HNTs was performed using Fourier transform infrared spectroscopy (FTIR), Zeta potential analysis, thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and transmission electron microscopy (TEM). The mechanical and antibacterial performance of the resulting MF-AQH resin-impregnated paper was evaluated for mechanical properties, antibacterial performance, and crack resistance through dynamic mechanical analysis (DMA), mechanical testing, antibacterial assays, and crack resistance tests. The paper impregnated with 5 wt% AQ@HNTs exhibited significantly improved mechanical properties, with tensile strength, elongation at break, and elastic modulus increasing by 78.11 %, 39.66 %, and 27.61 %, respectively. Additionally, it demonstrated strong antibacterial activity against Escherichia coli and Staphylococcus aureus, with inhibition zones of 21.97 ± 0.57 mm and 32.19 ± 0.37 mm, and bacterial survival rates reduced to 17.99 % and 11.52 %, respectively. This work highlights a dual-functional approach combining structural reinforcement and antimicrobial activity through an innovative bio-based modification strategy, offering a promising solution for high-performance MF resin in interior decoration applications.