Self-Organization in Dilute Aqueous Solutions of Thermoresponsive Star-Shaped Six-Arm Poly-2-Alkyl-2-Oxazines and Poly-2-Alkyl-2-Oxazolines
The behavior of star-shaped six-arm poly-2-alkyl-2-oxazines and poly-2-alkyl-2-oxazolines in aqueous solutions on heating was studied by light scattering, turbidimetry and microcalorimetry. The core of stars was hexaaza [2<sub>6</sub>] orthoparacyclophane and the arms were poly-2-ethyl-2...
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MDPI AG
2021-04-01
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| Series: | Polymers |
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| Online Access: | https://www.mdpi.com/2073-4360/13/9/1429 |
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| author | Tatyana Kirila Anna Smirnova Vladimir Aseyev Andrey Tenkovtsev Heikki Tenhu Alexander Filippov |
| author_facet | Tatyana Kirila Anna Smirnova Vladimir Aseyev Andrey Tenkovtsev Heikki Tenhu Alexander Filippov |
| author_sort | Tatyana Kirila |
| collection | DOAJ |
| description | The behavior of star-shaped six-arm poly-2-alkyl-2-oxazines and poly-2-alkyl-2-oxazolines in aqueous solutions on heating was studied by light scattering, turbidimetry and microcalorimetry. The core of stars was hexaaza [2<sub>6</sub>] orthoparacyclophane and the arms were poly-2-ethyl-2-oxazine, poly-2-isopropyl-2-oxazine, poly-2-ethyl-2-oxazoline, and poly-2-isopropyl-2-oxazoline. The arm structure affects the properties of polymers already at low temperatures. Molecules and aggregates were present in solutions of poly-2-alkyl-2-oxazines, while aggregates of two types were observed in the case of poly-2-alkyl-2-oxazolines. On heating below the phase separation temperature, the characteristics of the investigated solutions did not depend practically on temperature. An increase in the dehydration degree of poly-2-alkyl-2-oxazines and poly-2-alkyl-2-oxazolines led to the formation of intermolecular hydrogen bonds, and aggregation was the dominant process near the phase separation temperature. It was shown that the characteristics of the phase transition in solutions of the studied polymer stars are determined primarily by the arm structure, while the influence of the molar mass is not so significant. In comparison with literature data, the role of the hydrophobic core structure in the formation of the properties of star-shaped polymers was analyzed. |
| first_indexed | 2024-03-10T11:50:50Z |
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| id | doaj.art-1f92ce92f4d0416582acd6e6424af4d8 |
| institution | Directory Open Access Journal |
| issn | 2073-4360 |
| language | English |
| last_indexed | 2024-03-10T11:50:50Z |
| publishDate | 2021-04-01 |
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| record_format | Article |
| series | Polymers |
| spelling | doaj.art-1f92ce92f4d0416582acd6e6424af4d82023-11-21T17:41:19ZengMDPI AGPolymers2073-43602021-04-01139142910.3390/polym13091429Self-Organization in Dilute Aqueous Solutions of Thermoresponsive Star-Shaped Six-Arm Poly-2-Alkyl-2-Oxazines and Poly-2-Alkyl-2-OxazolinesTatyana Kirila0Anna Smirnova1Vladimir Aseyev2Andrey Tenkovtsev3Heikki Tenhu4Alexander Filippov5Institute of Macromolecular Compounds of the Russian Academy of Sciences, Bolshoy pr., 31, 199004 Saint Petersburg, RussiaInstitute of Macromolecular Compounds of the Russian Academy of Sciences, Bolshoy pr., 31, 199004 Saint Petersburg, RussiaDepartment of Chemistry, University of Helsinki, 00014 Helsinki, FinlandInstitute of Macromolecular Compounds of the Russian Academy of Sciences, Bolshoy pr., 31, 199004 Saint Petersburg, RussiaDepartment of Chemistry, University of Helsinki, 00014 Helsinki, FinlandInstitute of Macromolecular Compounds of the Russian Academy of Sciences, Bolshoy pr., 31, 199004 Saint Petersburg, RussiaThe behavior of star-shaped six-arm poly-2-alkyl-2-oxazines and poly-2-alkyl-2-oxazolines in aqueous solutions on heating was studied by light scattering, turbidimetry and microcalorimetry. The core of stars was hexaaza [2<sub>6</sub>] orthoparacyclophane and the arms were poly-2-ethyl-2-oxazine, poly-2-isopropyl-2-oxazine, poly-2-ethyl-2-oxazoline, and poly-2-isopropyl-2-oxazoline. The arm structure affects the properties of polymers already at low temperatures. Molecules and aggregates were present in solutions of poly-2-alkyl-2-oxazines, while aggregates of two types were observed in the case of poly-2-alkyl-2-oxazolines. On heating below the phase separation temperature, the characteristics of the investigated solutions did not depend practically on temperature. An increase in the dehydration degree of poly-2-alkyl-2-oxazines and poly-2-alkyl-2-oxazolines led to the formation of intermolecular hydrogen bonds, and aggregation was the dominant process near the phase separation temperature. It was shown that the characteristics of the phase transition in solutions of the studied polymer stars are determined primarily by the arm structure, while the influence of the molar mass is not so significant. In comparison with literature data, the role of the hydrophobic core structure in the formation of the properties of star-shaped polymers was analyzed.https://www.mdpi.com/2073-4360/13/9/1429thermoresponsive star-shaped polymerspoly-2-alkyl-2-oxazines and poly-2-alkyl-2-oxazolinesaqueous solutionslight scatteringturbidimetrymicrocalorimetry |
| spellingShingle | Tatyana Kirila Anna Smirnova Vladimir Aseyev Andrey Tenkovtsev Heikki Tenhu Alexander Filippov Self-Organization in Dilute Aqueous Solutions of Thermoresponsive Star-Shaped Six-Arm Poly-2-Alkyl-2-Oxazines and Poly-2-Alkyl-2-Oxazolines Polymers thermoresponsive star-shaped polymers poly-2-alkyl-2-oxazines and poly-2-alkyl-2-oxazolines aqueous solutions light scattering turbidimetry microcalorimetry |
| title | Self-Organization in Dilute Aqueous Solutions of Thermoresponsive Star-Shaped Six-Arm Poly-2-Alkyl-2-Oxazines and Poly-2-Alkyl-2-Oxazolines |
| title_full | Self-Organization in Dilute Aqueous Solutions of Thermoresponsive Star-Shaped Six-Arm Poly-2-Alkyl-2-Oxazines and Poly-2-Alkyl-2-Oxazolines |
| title_fullStr | Self-Organization in Dilute Aqueous Solutions of Thermoresponsive Star-Shaped Six-Arm Poly-2-Alkyl-2-Oxazines and Poly-2-Alkyl-2-Oxazolines |
| title_full_unstemmed | Self-Organization in Dilute Aqueous Solutions of Thermoresponsive Star-Shaped Six-Arm Poly-2-Alkyl-2-Oxazines and Poly-2-Alkyl-2-Oxazolines |
| title_short | Self-Organization in Dilute Aqueous Solutions of Thermoresponsive Star-Shaped Six-Arm Poly-2-Alkyl-2-Oxazines and Poly-2-Alkyl-2-Oxazolines |
| title_sort | self organization in dilute aqueous solutions of thermoresponsive star shaped six arm poly 2 alkyl 2 oxazines and poly 2 alkyl 2 oxazolines |
| topic | thermoresponsive star-shaped polymers poly-2-alkyl-2-oxazines and poly-2-alkyl-2-oxazolines aqueous solutions light scattering turbidimetry microcalorimetry |
| url | https://www.mdpi.com/2073-4360/13/9/1429 |
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