Structural and Thermal Analysis of Softwood Lignins from a Pressurized Hot Water Extraction Biorefinery Process and Modified Derivatives
In this work we have analyzed the pine and spruce softwood lignin fraction recovered from a novel pressurized hot water extraction pilot process. The lignin structure was characterized using multiple NMR techniques and the thermal properties were analyzed using thermal gravimetric analysis. Acetylat...
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| Format: | Article |
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MDPI AG
2019-01-01
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| Series: | Molecules |
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| Online Access: | http://www.mdpi.com/1420-3049/24/2/335 |
| _version_ | 1811254912276758528 |
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| author | Lucas Lagerquist Andrey Pranovich Ivan Sumerskii Sebastian von Schoultz Lari Vähäsalo Stefan Willför Patrik Eklund |
| author_facet | Lucas Lagerquist Andrey Pranovich Ivan Sumerskii Sebastian von Schoultz Lari Vähäsalo Stefan Willför Patrik Eklund |
| author_sort | Lucas Lagerquist |
| collection | DOAJ |
| description | In this work we have analyzed the pine and spruce softwood lignin fraction recovered from a novel pressurized hot water extraction pilot process. The lignin structure was characterized using multiple NMR techniques and the thermal properties were analyzed using thermal gravimetric analysis. Acetylated and selectively methylated derivatives were prepared, and their structure and properties were analyzed and compared to the unmodified lignin. The lignin had relatively high molar weight and low PDI values and even less polydisperse fractions could be obtained by fractionation based on solubility in i-PrOH. Condensation, especially at the 5-position, was detected in this sulphur-free technical lignin, which had been enriched with carbon compared to the milled wood lignin (MWL) sample of the same wood chips. An increase in phenolic and carboxylic groups was also detected, which makes the lignin accessible to chemical modification. The lignin was determined to be thermally stable up to (273–302 °C) based on its Tdst 95% value. Due to the thermal stability, low polydispersity, and possibility to tailor its chemical properties by modification of its hydroxyl groups, possible application areas for the lignin could be in polymeric blends, composites or in resins. |
| first_indexed | 2024-04-12T17:15:39Z |
| format | Article |
| id | doaj.art-315dcb45bd3c4ea1ae8772803ea01664 |
| institution | Directory Open Access Journal |
| issn | 1420-3049 |
| language | English |
| last_indexed | 2024-04-12T17:15:39Z |
| publishDate | 2019-01-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Molecules |
| spelling | doaj.art-315dcb45bd3c4ea1ae8772803ea016642022-12-22T03:23:39ZengMDPI AGMolecules1420-30492019-01-0124233510.3390/molecules24020335molecules24020335Structural and Thermal Analysis of Softwood Lignins from a Pressurized Hot Water Extraction Biorefinery Process and Modified DerivativesLucas Lagerquist0Andrey Pranovich1Ivan Sumerskii2Sebastian von Schoultz3Lari Vähäsalo4Stefan Willför5Patrik Eklund6Johan Gadolin Process Chemistry Centre, Åbo Akademi University, Biskopsgatan 8, 20500 Turku/Åbo, FinlandJohan Gadolin Process Chemistry Centre, Åbo Akademi University, Biskopsgatan 8, 20500 Turku/Åbo, FinlandDivision of Chemistry of Renewable Resources, Department of Chemistry, University of Natural Resources and Life Sciences, Konrad-Lorenz-Strasse 24, A-3430 Tulln, AustriaCH-Bioforce Oy, Ahventie 4 A 21-22, FIN-02170 Espoo, FinlandCH-Bioforce Oy, Ahventie 4 A 21-22, FIN-02170 Espoo, FinlandJohan Gadolin Process Chemistry Centre, Åbo Akademi University, Biskopsgatan 8, 20500 Turku/Åbo, FinlandJohan Gadolin Process Chemistry Centre, Åbo Akademi University, Biskopsgatan 8, 20500 Turku/Åbo, FinlandIn this work we have analyzed the pine and spruce softwood lignin fraction recovered from a novel pressurized hot water extraction pilot process. The lignin structure was characterized using multiple NMR techniques and the thermal properties were analyzed using thermal gravimetric analysis. Acetylated and selectively methylated derivatives were prepared, and their structure and properties were analyzed and compared to the unmodified lignin. The lignin had relatively high molar weight and low PDI values and even less polydisperse fractions could be obtained by fractionation based on solubility in i-PrOH. Condensation, especially at the 5-position, was detected in this sulphur-free technical lignin, which had been enriched with carbon compared to the milled wood lignin (MWL) sample of the same wood chips. An increase in phenolic and carboxylic groups was also detected, which makes the lignin accessible to chemical modification. The lignin was determined to be thermally stable up to (273–302 °C) based on its Tdst 95% value. Due to the thermal stability, low polydispersity, and possibility to tailor its chemical properties by modification of its hydroxyl groups, possible application areas for the lignin could be in polymeric blends, composites or in resins.http://www.mdpi.com/1420-3049/24/2/335lignin characterizationpressurized hot water extractionbiorefinerycondensed structuresNMR analysisthermal analysislignin modification |
| spellingShingle | Lucas Lagerquist Andrey Pranovich Ivan Sumerskii Sebastian von Schoultz Lari Vähäsalo Stefan Willför Patrik Eklund Structural and Thermal Analysis of Softwood Lignins from a Pressurized Hot Water Extraction Biorefinery Process and Modified Derivatives Molecules lignin characterization pressurized hot water extraction biorefinery condensed structures NMR analysis thermal analysis lignin modification |
| title | Structural and Thermal Analysis of Softwood Lignins from a Pressurized Hot Water Extraction Biorefinery Process and Modified Derivatives |
| title_full | Structural and Thermal Analysis of Softwood Lignins from a Pressurized Hot Water Extraction Biorefinery Process and Modified Derivatives |
| title_fullStr | Structural and Thermal Analysis of Softwood Lignins from a Pressurized Hot Water Extraction Biorefinery Process and Modified Derivatives |
| title_full_unstemmed | Structural and Thermal Analysis of Softwood Lignins from a Pressurized Hot Water Extraction Biorefinery Process and Modified Derivatives |
| title_short | Structural and Thermal Analysis of Softwood Lignins from a Pressurized Hot Water Extraction Biorefinery Process and Modified Derivatives |
| title_sort | structural and thermal analysis of softwood lignins from a pressurized hot water extraction biorefinery process and modified derivatives |
| topic | lignin characterization pressurized hot water extraction biorefinery condensed structures NMR analysis thermal analysis lignin modification |
| url | http://www.mdpi.com/1420-3049/24/2/335 |
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