A Novel Methoxy-Substituted Schiff Base: Synthesis, Antioxidant Activity, and Thermal Performance in Biodiesel-Diesel Blends

Authors : Nalan Türköz Karakullukçu

Pages : 1558-1577

Doi:10.31466/kfbd.1675935

View : 83 | Download : 158

Publication Date : 2025-12-15

Article Type : Research Paper

Abstract :A condensation reaction between 5-amino-2-methylphenol and 5-methoxy-2-hydroxybenzaldehyde in methanol environment yielded a novel Schiff base, (E)-2-(((3-hydroxy-4-methylphenyl)imino)methyl)-4-methoxyphenol (HMPIM-MP). The compound\\\'s structure was validated by UV-Vis, FTIR, ¹H, and ¹³C NMR spectroscopy, and its surface properties were examined using SEM. Thermogravimetric Analysis (TGA) and Differential Scanning Calorimetry (DSC) were used to analyze thermal properties, while the 2,2-Diphenyl-1-Picrylhydrazyl (DPPH˙) radical scavenging experiment investigated free radical resistance. The chemical broke down at 263.39 °C and melted endothermically at 153.69 °C, indicating thermal stability. The IC50 value for DPPH˙ scavenging was 10.92 ± 0.80 µg/mL, similar to Trolox\\\'s 9.71 ± 0.46 µg/mL, showing strong antioxidant activity. To test cold flow characteristics, the Schiff base was added to a biodiesel-diesel combination B50D50 at 3000 ppm. Crystallization temperature dropped from –9.27 °C in the control to –12.48 °C in the Schiff base mix, according to DSC. The results show the compound\\\'s antioxidant and cold flow enhancement properties. The research suggests that tailored Schiff bases may be added to biofuels to improve fuel efficiency in a sustainable way.
Keywords : Schiff Bazı, Antioksidan Aktivite, Diferansiyel Taramalı Kalorimetri (DSC), Biyodizel, Termal Stabilite

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