Research on the Performance of Modified Nanocrystalline Cellulose Reinforced Waterborne Epoxy Coatings

This study addresses the critical challenges of long-term protection and mechanical stability in waterborne epoxy resin (WEP) coatings by developing composite systems reinforced with modified nanocrystalline cellulose (NCC). Through surface functionalization of NCC using hexadecyltrimethoxysilane (HDTMS) and <i>N</i>-[3-(trimethoxysilyl)-propyl]-ethylenediamine (TMPEDA), we synthesized Si-NCC/WEP coatings with enhanced interfacial compatibility and tailored physicochemical properties. Comprehensive characterization via FTIR, AFM, and EIS revealed that the 1% Si-NCC/WEP coating exhibited optimal performance, achieving a 251% increase in Young's modulus (6.95 GPa vs 2.77 GPa for pure WEP) and superior corrosion resistance, as evidenced by a two-order-of-magnitude higher impedance modulus (1.55 × 10¹⁰ Ω·cm²) in neutral 3.5% NaCl solution compared to unmodified WEP. While alkaline and neutral environments demonstrated remarkable barrier stability (retaining 1.80 × 10⁷ Ω·cm² after 30 day immersion), acidic conditions (pH = 1) revealed limitations due to NCC's hydrolytic instability. This work establishes a green nanocomposite design paradigm for durable protective coatings, offering actionable insights for industrial corrosion mitigation strategies.