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Proton, Thermal and Mechanical Relaxation Characteristics of De-fatted Date-Pits as a Function of Temperature
Authors: Maha Al-Khalili,
Identifier: CSBE21927
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Published in: CSBE-SCGAB Technical Conferences » 5th CIGR and AGM Quebec City 2021 » Regular Sessions
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Description: Thermal (Differential Scanning Calorimetry, DSC), Proton (Low-Frequency Nuclear Magnetic Resonance, LF-NMR), and mechanical (Differential Mechanical Thermal Analysis, DMTA) relaxations were measured for defatted date-pits as a function of temperature. DSC showed three types of relaxations, lower one structural change (i.e. -5oC), followed by glass transition (i.e. 136oC) and solids melting-decomposition (i.e. 171oC). LF-NMR showed three pools of protons, rigid, semi-rigid and mobile. Rigid protons showed two types of relaxations, first one low temperature increase (-80 to -40oC), plateau region (-60 to -40oC) and second one peak at 120oC, and semi-rigid showed maximum peak at -5oC and minimum peak at 150oC. Mobile protons showed low relaxation (-80 to -40oC), a maximum peak at 70oC and a minimum peak at 130oC. The maximum peak (i.e. -5oC) of semi-rigid protons was similar to the DSC structural change, while the maximum peak of rigid protons (120oC) was similar to DSC glass transition (i.e. 136oC). The minimum peak of the semi-rigid protons (i.e. 150oC) was similar to the solids melting-decomposition (171oC). DMTA showed five regions of mechanical relaxations, glassy region (i.e. onset at 32oC), glass transition (i.e. 32-85 or 87oC), first reaction region with a plateau or peak (85-140oC), second reaction region (87-174oC), and softening or decomposition region (223 or 242oC). Mechanical glass showed completely different relaxation as compared to the protons and thermal transitions. This study showed that LF-NMR, DSC and DMTA could be used to explore the relaxations of a material at nano, micro and macro levels.
Keywords: Glass transition, phase change, structure, proton mobility, molecular stability, date-pits, fibers
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Date: 2021-06-11
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Conference name: 5th CIGR International Conference and CSBE-SCGAB AGM 2021, Quebec City,QC, 11-14 May 2021.
Session name: Food 5 - Processing & Quality
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Type: Text.Abstract
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Publication type: Presentation
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Coverage: Oman
Language 1: en
Language 2:
Rights: Canadian Society for Bioengineering
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DOI:
Description: Thermal (Differential Scanning Calorimetry, DSC), Proton (Low-Frequency Nuclear Magnetic Resonance, LF-NMR), and mechanical (Differential Mechanical Thermal Analysis, DMTA) relaxations were measured for defatted date-pits as a function of temperature. DSC showed three types of relaxations, lower one structural change (i.e. -5oC), followed by glass transition (i.e. 136oC) and solids melting-decomposition (i.e. 171oC). LF-NMR showed three pools of protons, rigid, semi-rigid and mobile. Rigid protons showed two types of relaxations, first one low temperature increase (-80 to -40oC), plateau region (-60 to -40oC) and second one peak at 120oC, and semi-rigid showed maximum peak at -5oC and minimum peak at 150oC. Mobile protons showed low relaxation (-80 to -40oC), a maximum peak at 70oC and a minimum peak at 130oC. The maximum peak (i.e. -5oC) of semi-rigid protons was similar to the DSC structural change, while the maximum peak of rigid protons (120oC) was similar to DSC glass transition (i.e. 136oC). The minimum peak of the semi-rigid protons (i.e. 150oC) was similar to the solids melting-decomposition (171oC). DMTA showed five regions of mechanical relaxations, glassy region (i.e. onset at 32oC), glass transition (i.e. 32-85 or 87oC), first reaction region with a plateau or peak (85-140oC), second reaction region (87-174oC), and softening or decomposition region (223 or 242oC). Mechanical glass showed completely different relaxation as compared to the protons and thermal transitions. This study showed that LF-NMR, DSC and DMTA could be used to explore the relaxations of a material at nano, micro and macro levels.
Keywords: Glass transition, phase change, structure, proton mobility, molecular stability, date-pits, fibers
Résumé:
Mots-clés:
Citation:
Volume:
Issue:
Pages -
Contributor:
Date: 2021-06-11
Technical field:
Conference name: 5th CIGR International Conference and CSBE-SCGAB AGM 2021, Quebec City,QC, 11-14 May 2021.
Session name: Food 5 - Processing & Quality
Other information:
Type: Text.Abstract
Format:
Publication type: Presentation
Source:
Relation:
Coverage: Oman
Language 1: en
Language 2:
Rights: Canadian Society for Bioengineering
Notes:
Other files:
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