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Li Y, Chen H, Yan H, Xu Y, Tang J, Wang R, Yan M, Dai Y, Huang Y, Liu X. Thermal stability of levopimaric acid and its oxidation products. BMC Chem 2023; 17:118. [PMID: 37730608 PMCID: PMC10512607 DOI: 10.1186/s13065-023-01031-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2023] [Accepted: 09/03/2023] [Indexed: 09/22/2023] Open
Abstract
Biofuels are renewable alternatives to fossil fuels. Levopimaric acid‒base biofuels have attracted increasing attention. However, their stability remains a critical issue in practice. Thus, there is a strong impetus to evaluate the thermal stability of levopimaric acid. Through thermogravimetry (TG) and a custom-designed mini closed pressure vessel test (MCPVT) operating under isothermal and stepped temperature conditions, we investigated thermal oxidation characteristics of levopimaric acid under oxygen atmosphere. Thin-layer chromatography (TLC) and iodimetry were used to measure the hydrogen peroxides generated by levopimaric acid oxidation. A high pressure differential scanning calorimeter (HPDSC) was used to assess hydroperoxide thermal decomposition characteristics. Gas chromatography-mass spectrometry (GC-MS) was used to characterize the oxidation products. The thermal decomposition kinetics of levopimaric acid were thus elucidated, and a high peroxide value was detected in the levopimaric acid. The decomposition heat (QDSC) and exothermic onset temperature (Tonset) of hydroperoxides were 338.75 J g-1 and 375.37 K, respectively. Finally, levopimaric acid underwent a second-stage oxidation process at its melt point (423.15 K), resulting in complex oxidation products. Thermal oxidation of levopimaric acid could yield potential thermal hazards, indicating that antioxidants must be added during levopimaric acid application to protect against such hazardous effects.
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Affiliation(s)
- Yuanlin Li
- College of Liquor and Food Engineering, Key Laboratory of Fermentation Engineering and Biological Pharmacy of Guizhou Province, Guizhou University, Guiyang, 550025, Guizhou, China
| | - Hongqin Chen
- College of Liquor and Food Engineering, Key Laboratory of Fermentation Engineering and Biological Pharmacy of Guizhou Province, Guizhou University, Guiyang, 550025, Guizhou, China
| | - Heng Yan
- College of Liquor and Food Engineering, Key Laboratory of Fermentation Engineering and Biological Pharmacy of Guizhou Province, Guizhou University, Guiyang, 550025, Guizhou, China
| | - Yangyong Xu
- College of Liquor and Food Engineering, Key Laboratory of Fermentation Engineering and Biological Pharmacy of Guizhou Province, Guizhou University, Guiyang, 550025, Guizhou, China
| | - Jinwen Tang
- College of Liquor and Food Engineering, Key Laboratory of Fermentation Engineering and Biological Pharmacy of Guizhou Province, Guizhou University, Guiyang, 550025, Guizhou, China
| | - Runsen Wang
- College of Liquor and Food Engineering, Key Laboratory of Fermentation Engineering and Biological Pharmacy of Guizhou Province, Guizhou University, Guiyang, 550025, Guizhou, China
| | - Mengru Yan
- College of Liquor and Food Engineering, Key Laboratory of Fermentation Engineering and Biological Pharmacy of Guizhou Province, Guizhou University, Guiyang, 550025, Guizhou, China
| | - Yuqiao Dai
- Guizhou Tea Research Institute, Guiyang, 550000, Guizhou, China
| | - Yongguang Huang
- College of Liquor and Food Engineering, Key Laboratory of Fermentation Engineering and Biological Pharmacy of Guizhou Province, Guizhou University, Guiyang, 550025, Guizhou, China.
| | - Xiongmin Liu
- College of Chemistry and Chemical Engineering, Guangxi University, Nanning, 530004, Guangxi, China.
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