Synthesis of resin from Alfa stem to applied as an adhesive corrosion-resistant coating

Abstract

The demand for eco-friendly alternatives to petrochemical-based phenolic resins has risen due to increasing concerns about climate change, environmental impact, and manufacturing costs. This study introduces a sustainable approach by partially replacing phenol with lignin, a natural polymer rich in phenolic groups, extracted from Alfa stems. Using the alkaline method, 50% of phenol was substituted with lignin to synthesize phenol–formaldehyde (PF) resins. The synthesized lignin–phenol– formaldehyde (LPF) resin was characterized to verify its chemical structure and physical properties. The resin demonstrated significant antioxidant and antibacterial activity, particularly against E. coli and P. aeruginosa gram-negative bacteria at a concentration of 20 mg/ml. Additionally, the lignin substitution provided notable advantages over conventional industrial resin formulations. The lignin’s properties closely influenced the formulation of the LPF resin, making it similar to the reference CPF resin. However, the lower intensity observed in the LPF resin suggests potential limitations in the methylol

group formation compared to the CPF resin. The antioxidant activity of LPF resin has been effectiveness in preventing cor- rosion on steel surfaces. When applied as an anti-corrosion coating and compared to industrially used CPF resins, LPF resin

demonstrates its efficacy in such applications. Also, it should be noted that the impedance modulus of the elaborated resin coating remained consistently low throughout the entire immersion period, indicating its stable performance.