Depressurization-Induced Nucleation in the “Polylactide-Carbon Dioxide” System: Self-Similarity of the Bubble Embryos Expansion
Self-similar expansion of bubble embryos in a plasticized polymer under quasi-isothermal depressurization is examined using the experimental data on expansion rates of embryos in the CO<sub>2</sub>-plasticized <span style="font-variant: small-caps;">d</span>,<spa...
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| Format: | Article |
| Language: | English |
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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/2073-4360/13/7/1115 |
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| author | Dmitry Zimnyakov Marina Alonova Ekaterina Ushakova |
| author_facet | Dmitry Zimnyakov Marina Alonova Ekaterina Ushakova |
| author_sort | Dmitry Zimnyakov |
| collection | DOAJ |
| description | Self-similar expansion of bubble embryos in a plasticized polymer under quasi-isothermal depressurization is examined using the experimental data on expansion rates of embryos in the CO<sub>2</sub>-plasticized <span style="font-variant: small-caps;">d</span>,<span style="font-variant: small-caps;">l</span>-polylactide and modeling the results. The CO<sub>2</sub> initial pressure varied from 5 to 14 MPa, and the depressurization rate was 5 × 10<sup>−3</sup> MPa/s. The constant temperature in experiments was in a range from 310 to 338 K. The initial rate of embryos expansion varied from ≈0.1 to ≈10 µm/s, with a decrease in the current external pressure. While modeling, a non-linear behavior of CO<sub>2</sub> isotherms near the critical point was taken into account. The modeled data agree satisfactorily with the experimental results. The effect of a remarkable increase in the expansion rate at a decreasing external pressure is interpreted in terms of competing effects, including a decrease in the internal pressure, an increase in the polymer viscosity, and an increase in the embryo radius at the time of embryo formation. The vanishing probability of finding the steadily expanding embryos for external pressures around the CO<sub>2</sub> critical pressure is interpreted in terms of a joint influence of the quasi-adiabatic cooling and high compressibility of CO<sub>2</sub> in the embryos. |
| first_indexed | 2024-03-10T12:42:10Z |
| format | Article |
| id | doaj.art-04fbaf57e0a24187b4b20c6e8060e7d1 |
| institution | Directory Open Access Journal |
| issn | 2073-4360 |
| language | English |
| last_indexed | 2024-03-10T12:42:10Z |
| publishDate | 2021-04-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Polymers |
| spelling | doaj.art-04fbaf57e0a24187b4b20c6e8060e7d12023-11-21T13:44:52ZengMDPI AGPolymers2073-43602021-04-01137111510.3390/polym13071115Depressurization-Induced Nucleation in the “Polylactide-Carbon Dioxide” System: Self-Similarity of the Bubble Embryos ExpansionDmitry Zimnyakov0Marina Alonova1Ekaterina Ushakova2Physics Department, Yury Gagarin State Technical University of Saratov, 410054 Saratov, RussiaPhysics Department, Yury Gagarin State Technical University of Saratov, 410054 Saratov, RussiaPhysics Department, Yury Gagarin State Technical University of Saratov, 410054 Saratov, RussiaSelf-similar expansion of bubble embryos in a plasticized polymer under quasi-isothermal depressurization is examined using the experimental data on expansion rates of embryos in the CO<sub>2</sub>-plasticized <span style="font-variant: small-caps;">d</span>,<span style="font-variant: small-caps;">l</span>-polylactide and modeling the results. The CO<sub>2</sub> initial pressure varied from 5 to 14 MPa, and the depressurization rate was 5 × 10<sup>−3</sup> MPa/s. The constant temperature in experiments was in a range from 310 to 338 K. The initial rate of embryos expansion varied from ≈0.1 to ≈10 µm/s, with a decrease in the current external pressure. While modeling, a non-linear behavior of CO<sub>2</sub> isotherms near the critical point was taken into account. The modeled data agree satisfactorily with the experimental results. The effect of a remarkable increase in the expansion rate at a decreasing external pressure is interpreted in terms of competing effects, including a decrease in the internal pressure, an increase in the polymer viscosity, and an increase in the embryo radius at the time of embryo formation. The vanishing probability of finding the steadily expanding embryos for external pressures around the CO<sub>2</sub> critical pressure is interpreted in terms of a joint influence of the quasi-adiabatic cooling and high compressibility of CO<sub>2</sub> in the embryos.https://www.mdpi.com/2073-4360/13/7/1115<span style="font-variant: small-caps">d</span>,<span style="font-variant: small-caps">l</span>-polylactidenear-supercritical carbon dioxidedepressurizationbubble embryo expansionself-similarity |
| spellingShingle | Dmitry Zimnyakov Marina Alonova Ekaterina Ushakova Depressurization-Induced Nucleation in the “Polylactide-Carbon Dioxide” System: Self-Similarity of the Bubble Embryos Expansion Polymers <span style="font-variant: small-caps">d</span>,<span style="font-variant: small-caps">l</span>-polylactide near-supercritical carbon dioxide depressurization bubble embryo expansion self-similarity |
| title | Depressurization-Induced Nucleation in the “Polylactide-Carbon Dioxide” System: Self-Similarity of the Bubble Embryos Expansion |
| title_full | Depressurization-Induced Nucleation in the “Polylactide-Carbon Dioxide” System: Self-Similarity of the Bubble Embryos Expansion |
| title_fullStr | Depressurization-Induced Nucleation in the “Polylactide-Carbon Dioxide” System: Self-Similarity of the Bubble Embryos Expansion |
| title_full_unstemmed | Depressurization-Induced Nucleation in the “Polylactide-Carbon Dioxide” System: Self-Similarity of the Bubble Embryos Expansion |
| title_short | Depressurization-Induced Nucleation in the “Polylactide-Carbon Dioxide” System: Self-Similarity of the Bubble Embryos Expansion |
| title_sort | depressurization induced nucleation in the polylactide carbon dioxide system self similarity of the bubble embryos expansion |
| topic | <span style="font-variant: small-caps">d</span>,<span style="font-variant: small-caps">l</span>-polylactide near-supercritical carbon dioxide depressurization bubble embryo expansion self-similarity |
| url | https://www.mdpi.com/2073-4360/13/7/1115 |
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