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

Nalan Türköz Karakullukçu

doi:10.31466/kfbd.1675935

TR EN

Yeni Bir Metoksi-Substitue Schiff Bazı: Sentezi, Antioksidan Aktivitesi ve Biyodizel-Dizel Karışımlarında Termal Performansı

Abstract

5-amino-2-metilfenol ile 5-metoksi-2-hidroksibenzaldehit’in metanol ortamında kondenzasyon reaksiyonu sonucunda (E)-2-(((3-hidroksi-4-metilfenil)imino)metil)-4-metoksifenol (HMPIM-MP) adlı yeni bir Schiff bazı sentezlendi. Bileşiğin yapısı UV-Vis, FTIR, ¹H ve ¹³C NMR spektroskopileriyle doğrulandı ve yüzey özellikleri SEM ile incelendi. Termal özellikler Termogravimetrik Analiz (TGA) ve Diferansiyel Taramalı Kalorimetri (DSC) ile değerlendirildi; serbest radikal direnci ise 2,2-Difenil-1-Pikrilhidrazil (DPPH˙) radikal süpürme deneyiyle test edildi. Bileşik 263.39 °C’de bozunmuş ve 153.69 °C’de endotermik olarak erimiş, bu da termal kararlılığını göstermektedir. DPPH˙ süpürme için IC₅₀ değeri 10.92 ± 0.80 µg/mL olup, Trolox’un 9.71 ± 0.46 µg/mL değerine yakın bulunarak güçlü antioksidan aktivite göstermiştir. Soğuk akış özelliklerini test etmek amacıyla, Schiff bazı 3000 ppm oranında B50D50 biyodizel-dizel karışımına eklenmiştir. DSC analizine göre kristalleşme sıcaklığı kontrol grubunda –9.27 °C iken, Schiff bazı katkılı karışımda –12.48 °C’ye düşmüştür. Bu sonuçlar bileşiğin hem antioksidan özellikler hem de soğuk akış iyileştirici etkiler gösterdiğini ortaya koymaktadır. Araştırma, özel olarak tasarlanmış Schiff bazlarının biyoyakıtlara eklenerek yakıt verimliliğinin sürdürülebilir şekilde artırılabileceğini önermektedir.

Keywords

Schiff Bazı, Antioksidan Aktivite, Diferansiyel Taramalı Kalorimetri (DSC), Biyodizel, Termal Stabilite

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

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 Base, Antioxidant Activity, Differential Scanning Calorimetry (DSC), Biodiesel, Thermal Stability

References

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Details

Primary Language

English

Subjects

Physical Chemistry (Other), Renewable Energy Resources , Chemical Reaction

Journal Section

Research Article

Authors

Nalan Türköz Karakullukçu ^*
0000-0001-7774-4970
Türkiye

Publication Date

December 15, 2025

Submission Date

April 14, 2025

Acceptance Date

May 28, 2025

Published in Issue

Year 2025 Volume: 15 Number: 4

DOI

https://doi.org/10.31466/kfbd.1675935

IZ

https://izlik.org/JA87AD76AN

APA

Türköz Karakullukçu, N. (2025). A Novel Methoxy-Substituted Schiff Base: Synthesis, Antioxidant Activity, and Thermal Performance in Biodiesel-Diesel Blends. Karadeniz Fen Bilimleri Dergisi, 15(4), 1558-1577. https://doi.org/10.31466/kfbd.1675935

AMA

1.Türköz Karakullukçu N. A Novel Methoxy-Substituted Schiff Base: Synthesis, Antioxidant Activity, and Thermal Performance in Biodiesel-Diesel Blends. KFBD. 2025;15(4):1558-1577. doi:10.31466/kfbd.1675935

Chicago

Türköz Karakullukçu, Nalan. 2025. “A Novel Methoxy-Substituted Schiff Base: Synthesis, Antioxidant Activity, and Thermal Performance in Biodiesel-Diesel Blends”. Karadeniz Fen Bilimleri Dergisi 15 (4): 1558-77. https://doi.org/10.31466/kfbd.1675935.

EndNote

Türköz Karakullukçu N (December 1, 2025) A Novel Methoxy-Substituted Schiff Base: Synthesis, Antioxidant Activity, and Thermal Performance in Biodiesel-Diesel Blends. Karadeniz Fen Bilimleri Dergisi 15 4 1558–1577.

IEEE

[1]N. Türköz Karakullukçu, “A Novel Methoxy-Substituted Schiff Base: Synthesis, Antioxidant Activity, and Thermal Performance in Biodiesel-Diesel Blends”, KFBD, vol. 15, no. 4, pp. 1558–1577, Dec. 2025, doi: 10.31466/kfbd.1675935.

ISNAD

Türköz Karakullukçu, Nalan. “A Novel Methoxy-Substituted Schiff Base: Synthesis, Antioxidant Activity, and Thermal Performance in Biodiesel-Diesel Blends”. Karadeniz Fen Bilimleri Dergisi 15/4 (December 1, 2025): 1558-1577. https://doi.org/10.31466/kfbd.1675935.

JAMA

1.Türköz Karakullukçu N. A Novel Methoxy-Substituted Schiff Base: Synthesis, Antioxidant Activity, and Thermal Performance in Biodiesel-Diesel Blends. KFBD. 2025;15:1558–1577.

MLA

Türköz Karakullukçu, Nalan. “A Novel Methoxy-Substituted Schiff Base: Synthesis, Antioxidant Activity, and Thermal Performance in Biodiesel-Diesel Blends”. Karadeniz Fen Bilimleri Dergisi, vol. 15, no. 4, Dec. 2025, pp. 1558-77, doi:10.31466/kfbd.1675935.

Vancouver

1.Nalan Türköz Karakullukçu. A Novel Methoxy-Substituted Schiff Base: Synthesis, Antioxidant Activity, and Thermal Performance in Biodiesel-Diesel Blends. KFBD. 2025 Dec. 1;15(4):1558-77. doi:10.31466/kfbd.1675935

The published articles in The Black Sea Journal of Sciences are licensed under Creative Commons Attribution-NonCommercial 4.0 International

Yeni Bir Metoksi-Substitue Schiff Bazı: Sentezi, Antioksidan Aktivitesi ve Biyodizel-Dizel Karışımlarında Termal Performansı

Abstract

Keywords

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

Abstract

Keywords

References

Details

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Subjects

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Acceptance Date

Published in Issue

DOI

IZ

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