Preparation of Thermoplastic Cellulose Esters in [mTBNH][OAC] Ionic Liquid by Transesterification Reaction
The transesterification of cellulose with vinyl esters in ionic liquid media is suggested as a prospective environmentally friendly alternative to conventional esterification. In this study, various long-chain cellulose esters (laurate, myristate, palmitate, and stearate) with a degree of substituti...
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| Format: | Article |
| Language: | English |
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MDPI AG
2023-10-01
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| Series: | Polymers |
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| Online Access: | https://www.mdpi.com/2073-4360/15/19/3979 |
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| author | Elvira Tarasova Nutan Savale Illia Krasnou Marina Kudrjašova Vitalijs Rjabovs Indrek Reile Lauri Vares Heikko Kallakas Jaan Kers Andres Krumme |
| author_facet | Elvira Tarasova Nutan Savale Illia Krasnou Marina Kudrjašova Vitalijs Rjabovs Indrek Reile Lauri Vares Heikko Kallakas Jaan Kers Andres Krumme |
| author_sort | Elvira Tarasova |
| collection | DOAJ |
| description | The transesterification of cellulose with vinyl esters in ionic liquid media is suggested as a prospective environmentally friendly alternative to conventional esterification. In this study, various long-chain cellulose esters (laurate, myristate, palmitate, and stearate) with a degree of substitution (DS) up to 1.8 have been synthesized in novel distillable ionic liquid, [mTBNH][OAC]. This IL has high dissolving power towards cellulose, which can improve homogeneous transesterification. Additionally, [mTBNH][OAC] has durability towards recycling and can be regenerated and re-used again for the next cycles of esterification. DMSO is used as a co-solvent because of its ability to speed up mass transport due to lower solvent viscosity. The optimization of the reaction parameters, such as co-solvent content, temperature (20–80 °C), reaction time (1–5 h), and a molar ratio of reactants (1–5 eq. AGU) is reported. It was found that within studied reaction conditions, DS increases with increasing reaction time, temperature, and added vinyl esters. Structure analysis using FTIR, <sup>1</sup>H, and <sup>13</sup>C NMR after acylation revealed the introduction of the alkyl chains into cellulose for all studied samples. The results also suggested that the substitution order of the OH group is C7-O6 > C7-O2 > C7-O3. Unique, complex thermal and rheological investigation of the cellulose esters shows the growth of an amorphous phase upon the degree of substitution. At the same time, the homogeneous substitution of cellulose with acyl chains increases the melt viscosity of a material. Internal plasticization in cellulose esters was found to be the mechanism for the melt processing of the material. Long-chain cellulose esters show the potential to replace commonly used externally plasticized cellulose derivatives. |
| first_indexed | 2024-03-10T21:36:56Z |
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| id | doaj.art-80b1eacaecea46c8adc9be43249950d2 |
| institution | Directory Open Access Journal |
| issn | 2073-4360 |
| language | English |
| last_indexed | 2024-03-10T21:36:56Z |
| publishDate | 2023-10-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Polymers |
| spelling | doaj.art-80b1eacaecea46c8adc9be43249950d22023-11-19T14:57:12ZengMDPI AGPolymers2073-43602023-10-011519397910.3390/polym15193979Preparation of Thermoplastic Cellulose Esters in [mTBNH][OAC] Ionic Liquid by Transesterification ReactionElvira Tarasova0Nutan Savale1Illia Krasnou2Marina Kudrjašova3Vitalijs Rjabovs4Indrek Reile5Lauri Vares6Heikko Kallakas7Jaan Kers8Andres Krumme9School of Engineering, Department of Materials and Environmental Technology, Tallinn University of Technology, Ehitajate tee 5, 19086 Tallinn, EstoniaSchool of Engineering, Department of Materials and Environmental Technology, Tallinn University of Technology, Ehitajate tee 5, 19086 Tallinn, EstoniaSchool of Engineering, Department of Materials and Environmental Technology, Tallinn University of Technology, Ehitajate tee 5, 19086 Tallinn, EstoniaSchool of Science, Department of Chemistry and Biotechnology, Tallinn University of Technology, Akadeemia tee 15, 12618 Tallinn, EstoniaNational Institute of Chemical Physics and Biophysics, Akadeemia tee 23, 12618 Tallinn, EstoniaNational Institute of Chemical Physics and Biophysics, Akadeemia tee 23, 12618 Tallinn, EstoniaFaculty of Science and Technology, Institute of Technology, Tartu University, Nooruse 1, 50090 Tartu, EstoniaSchool of Engineering, Department of Materials and Environmental Technology, Tallinn University of Technology, Ehitajate tee 5, 19086 Tallinn, EstoniaSchool of Engineering, Department of Materials and Environmental Technology, Tallinn University of Technology, Ehitajate tee 5, 19086 Tallinn, EstoniaSchool of Engineering, Department of Materials and Environmental Technology, Tallinn University of Technology, Ehitajate tee 5, 19086 Tallinn, EstoniaThe transesterification of cellulose with vinyl esters in ionic liquid media is suggested as a prospective environmentally friendly alternative to conventional esterification. In this study, various long-chain cellulose esters (laurate, myristate, palmitate, and stearate) with a degree of substitution (DS) up to 1.8 have been synthesized in novel distillable ionic liquid, [mTBNH][OAC]. This IL has high dissolving power towards cellulose, which can improve homogeneous transesterification. Additionally, [mTBNH][OAC] has durability towards recycling and can be regenerated and re-used again for the next cycles of esterification. DMSO is used as a co-solvent because of its ability to speed up mass transport due to lower solvent viscosity. The optimization of the reaction parameters, such as co-solvent content, temperature (20–80 °C), reaction time (1–5 h), and a molar ratio of reactants (1–5 eq. AGU) is reported. It was found that within studied reaction conditions, DS increases with increasing reaction time, temperature, and added vinyl esters. Structure analysis using FTIR, <sup>1</sup>H, and <sup>13</sup>C NMR after acylation revealed the introduction of the alkyl chains into cellulose for all studied samples. The results also suggested that the substitution order of the OH group is C7-O6 > C7-O2 > C7-O3. Unique, complex thermal and rheological investigation of the cellulose esters shows the growth of an amorphous phase upon the degree of substitution. At the same time, the homogeneous substitution of cellulose with acyl chains increases the melt viscosity of a material. Internal plasticization in cellulose esters was found to be the mechanism for the melt processing of the material. Long-chain cellulose esters show the potential to replace commonly used externally plasticized cellulose derivatives.https://www.mdpi.com/2073-4360/15/19/3979transesterificationcellulose estersmTBN superbaseionic liquidsrheologyFACE |
| spellingShingle | Elvira Tarasova Nutan Savale Illia Krasnou Marina Kudrjašova Vitalijs Rjabovs Indrek Reile Lauri Vares Heikko Kallakas Jaan Kers Andres Krumme Preparation of Thermoplastic Cellulose Esters in [mTBNH][OAC] Ionic Liquid by Transesterification Reaction Polymers transesterification cellulose esters mTBN superbase ionic liquids rheology FACE |
| title | Preparation of Thermoplastic Cellulose Esters in [mTBNH][OAC] Ionic Liquid by Transesterification Reaction |
| title_full | Preparation of Thermoplastic Cellulose Esters in [mTBNH][OAC] Ionic Liquid by Transesterification Reaction |
| title_fullStr | Preparation of Thermoplastic Cellulose Esters in [mTBNH][OAC] Ionic Liquid by Transesterification Reaction |
| title_full_unstemmed | Preparation of Thermoplastic Cellulose Esters in [mTBNH][OAC] Ionic Liquid by Transesterification Reaction |
| title_short | Preparation of Thermoplastic Cellulose Esters in [mTBNH][OAC] Ionic Liquid by Transesterification Reaction |
| title_sort | preparation of thermoplastic cellulose esters in mtbnh oac ionic liquid by transesterification reaction |
| topic | transesterification cellulose esters mTBN superbase ionic liquids rheology FACE |
| url | https://www.mdpi.com/2073-4360/15/19/3979 |
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