Constructing lignin functional coatings for intelligent protection through interface engineering technology: exhibiting excellent anti‐corrosion and weather resistance

Abstract Combining conventional waterborne epoxy coatings (WEP) with specific functionalities is essential to increase their service life. However, designing multifunctional protective coatings with tunable interfaces to improve their corrosion and weather resistance remains challenging. In this study, based on intermolecular forces between quaternized lignosulfonate (QLS) and tertbutyl titanate, we prepared QLS‐TiO 2 nanocomposite with structural regularity and strong chemical bonding by a simple one‐pot method. It was further used for doped modified WEP to prepare a high‐performance QLS‐TiO 2 /WEP coating. The results showed that QLS‐TiO 2 can effectively scavenge radicals, absorb and reflect strong ultraviolet rays, and exhibit high dispersibility and interfacial compatibility in the epoxy matrix. Consequently, QLS‐TiO 2 /WEP coating demonstrated excellent weathering resistance, with the polymer chain segments within the coatings remaining intact after 240 h of accelerated aging test. Furthermore, QLS‐TiO 2 exhibited chemical stability and impressive anti‐corrosion properties. Its incorporation into epoxy coatings effectively prolonged the corrosion pathway. Therefore, QLS‐TiO 2 /WEP demonstrated excellent anti‐corrosion performance in high salt, acid, and alkali. Especially under acidic conditions, its | Z | 10 mHz was 5.810 × 10 7 Ω cm 2 , which improved three orders of magnitude compared with WEP (3.688 × 10 4 Ω cm 2 ). This study innovates the design concept of high‐performance biomass functional waterborne epoxy anti‐corrosion coating and is conducive to the high‐value utilization of biomass.