Modulation of improved lignin structure for conversion of iron oxides on the metal artifact

This research reveals the structural analysis and antioxidant properties of unmodified ethanol organosolv lignin (AH EOL) and modified ethanol organosolv lignin (AHD EOL and AHPB EOL) upon incorporation with 1,5-dihydroxy naphthalene and p-benzoquinone, respectively. The extracted lignin derived from OPF was then evaluated with FTIR NMR, GPC, thermal analyses (TGA and DSC), solubility test, and antioxidant activity. Modified ethanol organosolv lignin incorporated with p-benzoquinone (AHPB EOL) exhibited the smallest lignin matrix, which leads to the highest water solubility and antioxidant activity compared to other ethanol organosolv lignin (EOL) samples (D% _{AHPB EOL}: 24.25 ± 0.13 % > D% _{AHD EOL}: 22.50 ± 0.16 % > D% _{AH EOL}: 20.50 ± 0.22 %). The extracted EOL samples derived from OPF were then utilized in a preliminary rust conversion study of a metal artifact, which indicated that 7 wt% AHPB EOL possessed the highest RT% with 88.81 ± 0.14 %. The XRD and surface analysis of the treated rust also showed that it had transformed the archeological rust into an amorphous phase.