scholarly journals Nuclear magnetic resonance in chemical structures authentication and pyrolysis oil characterization

2022 ◽  
Author(s):  
Fanxin Liu ◽  
Wujun Zeng ◽  
Yinglei Wei
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Chemical Compositions ◽  
Pyrolysis Oil ◽  
Chemical Structures ◽  
Bio Oil ◽  
Dry Heating ◽  
Oil Characterization ◽  
Spin Properties ◽  
Nuclear Magnetic

Abstract Nuclear Magnetic Resonance (NMR) involves the study of nuclei immersed in a static magnetic field and exposed to a second oscillating field. Nuclei have two properties; spin properties and charge properties. Pyrolysis oil is created by dry heating biomass in a reactor without oxygen to around 500 degrees Celsius and then cooling it. Pyrolysis oil is a type of tar that includes too much oxygen to be classified as a pure hydrocarbon. One of the most fundamental methods in synthetic chemistry is using NMR to verify chemical structure. In the literature, little attention has been paid to the application of NMR in the authentication of chemical structures. In this study, we present a use case of NMR to characterize pyrolysis oil and authenticate chemical structures. Results show that the elucidation of chemical compositions of bio-oil is essential for the optimization of its processing technology and exploration of its potential application.

scholarly journals Application of nuclear magnetic resonance (NMR) in biooil characterization and authentication of chemical structures

2021 ◽  
Author(s):  
Fanxin Liu ◽  
Wujun Zeng ◽  
Yinglei Wei ◽  
Ben Hao ◽  
Han-Quing Jiang
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Chemical Structures ◽  
Nuclear Magnetic

This article discusses the application of nuclear magnetic resonance (NMR) in biooil characterization and authentication of chemical structures.

scholarly journals Accelerated aging of bio-oil from lignin conversion in subcritical water

TAPPI Journal ◽  
2017 ◽  
Vol 16 (03) ◽  
pp. 123-141 ◽  
Author(s):  
Huyen Nguyen Lyckeskog ◽  
Cecilia Mattsson ◽  
Lars Olausson ◽  
Sven-Ingvar Andersson ◽  
Lennart Vamling ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Aging Process ◽  
Subcritical Water ◽  
Accelerated Aging ◽  
Weight Fraction ◽  
Hydrothermal Liquefaction ◽  
Bio Oil ◽  
Nuclear Magnetic

Accelerated aging of bio-oil derived from lignin was investigated at different aging temperatures (50°C and 80°C) and times (1 hour, 1 day, 1 week, and 1 month). The bio-oil used was produced by the hydrothermal liquefaction of kraft lignin, using phenol as the capping agent, and base (potassium carbonate and potassium hydroxide) and zirconium dioxide as the catalytic system in subcritical water. Elemental composition, molecular weight (by using gel permeation chromatography), and chemical composition (by using gas chromatography–mass spectrometry and 2D nuclear magnetic resonance [18.8 T, DMSO-d6]) of the bio-oil were measured to gain better understanding of the changes that occurred after being subjected to an accelerated aging process. The ligninderived hydrothermal liquefaction bio-oil was quite stable compared with biomass-pyrolysis bio-oil. The yield of the low molecular weight fraction (light oil) decreased from 64.1% to 58.1% and that of tetrahydrofuran insoluble fraction increased from 16.5% to 22.2% after aging at 80°C for 1 month. Phenol and phenolic dimers (Ar–CH2–Ar) had high reactivity compared with other aromatic substituents (i.e., methoxyl and aldehyde groups); these may participate in the polymerization/condensation reactions in the hydrothermal liquefaction bio-oil during accelerated aging. Moreover, the 2D heteronuclear single quantum coherence nuclear magnetic resonance spectra of the high molecular weight fraction (heavy oil) in the aged raw oil in the aromatic region showed that the structure of this fraction was a combination of phenol-alkyl patterns, and the guaiacol cross-peaks of Ar2, Ar5, and Ar6 after aging indicate that a new polymer was formed during the aging process.

Novel amino-containing fluorene-based bisphthalonitrile compounds with flexible group

2017 ◽  
Vol 30 (7) ◽  
pp. 767-775 ◽  
Author(s):  
An-ran Wang ◽  
Abdul Qadeer Dayo ◽  
Dan Lv ◽  
Yi-le Xu ◽  
Jun Wang ◽  
...  
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Mechanical Analysis ◽  
Proton Nuclear Magnetic Resonance ◽  
Scanning Calorimetry ◽  
Rheological Analysis ◽  
Chemical Structures ◽  
The Fourier Transform ◽  
Alkoxy Groups ◽  
Nuclear Magnetic

A series of amino-containing fluorene-based bisphthalonitrile (AFPN) monomers with alkyl or alkoxy groups were successfully produced by the reaction of 4-nitrophthalonitrile with 9, 9-bis (3-alkyl (or alkoxy)-4-aminophenyl)-2, 7-dihydroxylfluorene in the presence of potassium carbonate by a nucleophilic substitution reaction. The chemical structures of the synthesized monomers were confirmed by the Fourier transform infrared (FTIR), proton nuclear magnetic resonance, and carbon-13 nuclear magnetic resonance analyses. The synthesized monomers’ curing behaviors were evaluated by FTIR and differential scanning calorimetry, and a rheological analysis was performed to evaluate their respective processabilities. Moreover, dynamic mechanical analysis (DMA) and thermogravimetric analysis (TGA) were performed for the thermomechanical, thermal, and thermo-oxidative analyses of the polymers. The results confirmed that the newly prepared phthalonitrile (PN) monomers with alkyl or alkoxy groups exhibited a self-promoted curing behavior. The rheological analysis suggested that the processing windows of the synthesized monomers were wider than that of APFN monomer bearing no flexible group. DMA and TGA revealed that the cured polymers exhibited high glass transition temperature (358–416°C) and the char yields at 800°C under nitrogen were between 70% and 77%. Moreover, the introduction of alkyl or alkoxy groups into the PN monomers’ backbones slightly reduced the thermal stability of the resulting polymers.

Olive Oil Characterization Using High-Field Nuclear Magnetic Resonance

ChemInform ◽  
2003 ◽  
Vol 34 (36) ◽  
Author(s):  
Luisa Mannina ◽  
Cristina Calcagni ◽  
Enrico Rossi ◽  
Annalaura Segre
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Olive Oil ◽  
High Field ◽  
Oil Characterization ◽  
Nuclear Magnetic

Nuclear Magnetic Resonance Spectroscopic Analysis of Gossypol and Its Analogs in Cotton Flower Buds (Gossypium)

1978 ◽  
Vol 61 (1) ◽  
pp. 146-149
Author(s):  
Anthony C Waiss ◽  
Bock G Chan ◽  
Mabry Benson ◽  
Maurice J Lukefahr
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Spectroscopic Analysis ◽  
Internal Standard ◽  
Aromatic Proton ◽  
Flower Bud ◽  
Chemical Structures ◽  
Magnetic Resonance Spectroscopic Analysis ◽  
Proton Peak ◽  
Nuclear Magnetic

Abstract A specific nuclear magnetic resonance (NMR) method has been developed for determining gossypol and its analogs in the cotton flower bud. Gossypol and its related analogs, some of whose chemical structures have not yet been determined, can be identified by the distinctive NMR absorption of the aldehydic protons between 10.0 and 11.3 ppm. These compounds are quantitatively estimated by comparing the areas of the aldehydic proton absorptions with the aromatic proton peak (6.82 ppm) from p-dimethoxybenzene internal standard.

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