Non-Isothermal Crystallization Behavior of Poly(vinylidene fluoride) in Dialkyl Phthalate Diluents during Thermally Induced Phase Separation Process
The non-isothermal crystallization behavior of poly(vinylidene fluoride) (PVDF) in dialkyl phthalate diluents during the thermally induced phase separation (TIPS) process was investigated by differential scanning calorimetry (DSC) at various cooling rates. Dialkyl phthalates with different alkyl cha...
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MDPI AG
2020-09-01
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| Online Access: | https://www.mdpi.com/2073-4352/10/9/782 |
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| author | Yakai Lin Yuanhui Tang Lin Wang Xiaolin Wang |
| author_facet | Yakai Lin Yuanhui Tang Lin Wang Xiaolin Wang |
| author_sort | Yakai Lin |
| collection | DOAJ |
| description | The non-isothermal crystallization behavior of poly(vinylidene fluoride) (PVDF) in dialkyl phthalate diluents during the thermally induced phase separation (TIPS) process was investigated by differential scanning calorimetry (DSC) at various cooling rates. Dialkyl phthalates with different alkyl chain-length, namely dimethyl phthalate (DMP), diethyl phthalate (DEP) and dibutyl phthalate (DBP), were used as the diluent. The effects of alkyl chain-length of dialkyl phthalate and cooling rate on the non-isothermal crystallization behavior as implied by the Avrami analysis modified by Jeziorny and Mo’s analysis were determined. The values of half-time, <inline-formula><math display="inline"><semantics><mrow><msub><mi>t</mi><mrow><mn>1</mn><mo>/</mo><mn>2</mn></mrow></msub></mrow></semantics></math></inline-formula>, and the parameters <inline-formula><math display="inline"><semantics><mrow><msub><mi>Z</mi><mi>c</mi></msub></mrow></semantics></math></inline-formula> and <inline-formula><math display="inline"><semantics><mrow><mi>F</mi><mo stretchy="false">(</mo><mi>t</mi><mo stretchy="false">)</mo></mrow></semantics></math></inline-formula>, which characterized the kinetics of non-isothermal crystallization, showed that the crystallization rate increased with the increase of the alkyl chain-length of dialkyl phthalate due to the lower compatibility between PVDF and dialkyl phthalate. Moreover, the alkyl chain-length of dialkyl phthalate also has a great impact on the compact spherulitic structure of PVDF membranes prepared from different PVDF/dialkyl phthalate blends. With the decrease of the alkyl chain-length of dialkyl phthalate, the number of spherulites increased and the size of spherulites became smaller. This research thus not only proves the effects of alkyl chain-length of dialkyl phthalate on the non-isothermal crystallization behavior of PVDF, but also provides a systematic strategy to evaluate a single diluent during the TIPS process. |
| first_indexed | 2024-03-10T16:35:36Z |
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| issn | 2073-4352 |
| language | English |
| last_indexed | 2024-03-10T16:35:36Z |
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| spelling | doaj.art-288c072bb2a94e14a206f68882eb212a2023-11-20T12:28:51ZengMDPI AGCrystals2073-43522020-09-0110978210.3390/cryst10090782Non-Isothermal Crystallization Behavior of Poly(vinylidene fluoride) in Dialkyl Phthalate Diluents during Thermally Induced Phase Separation ProcessYakai Lin0Yuanhui Tang1Lin Wang2Xiaolin Wang3Beijing Key Laboratory of Membrane Materials and Engineering, Department of Chemical Engineering, Tsinghua University, Beijing 100084, ChinaCollege of Chemistry and Environmental Engineering, China University of Mining and Technology, Beijing 100083, ChinaBeijing Key Laboratory of Membrane Materials and Engineering, Department of Chemical Engineering, Tsinghua University, Beijing 100084, ChinaBeijing Key Laboratory of Membrane Materials and Engineering, Department of Chemical Engineering, Tsinghua University, Beijing 100084, ChinaThe non-isothermal crystallization behavior of poly(vinylidene fluoride) (PVDF) in dialkyl phthalate diluents during the thermally induced phase separation (TIPS) process was investigated by differential scanning calorimetry (DSC) at various cooling rates. Dialkyl phthalates with different alkyl chain-length, namely dimethyl phthalate (DMP), diethyl phthalate (DEP) and dibutyl phthalate (DBP), were used as the diluent. The effects of alkyl chain-length of dialkyl phthalate and cooling rate on the non-isothermal crystallization behavior as implied by the Avrami analysis modified by Jeziorny and Mo’s analysis were determined. The values of half-time, <inline-formula><math display="inline"><semantics><mrow><msub><mi>t</mi><mrow><mn>1</mn><mo>/</mo><mn>2</mn></mrow></msub></mrow></semantics></math></inline-formula>, and the parameters <inline-formula><math display="inline"><semantics><mrow><msub><mi>Z</mi><mi>c</mi></msub></mrow></semantics></math></inline-formula> and <inline-formula><math display="inline"><semantics><mrow><mi>F</mi><mo stretchy="false">(</mo><mi>t</mi><mo stretchy="false">)</mo></mrow></semantics></math></inline-formula>, which characterized the kinetics of non-isothermal crystallization, showed that the crystallization rate increased with the increase of the alkyl chain-length of dialkyl phthalate due to the lower compatibility between PVDF and dialkyl phthalate. Moreover, the alkyl chain-length of dialkyl phthalate also has a great impact on the compact spherulitic structure of PVDF membranes prepared from different PVDF/dialkyl phthalate blends. With the decrease of the alkyl chain-length of dialkyl phthalate, the number of spherulites increased and the size of spherulites became smaller. This research thus not only proves the effects of alkyl chain-length of dialkyl phthalate on the non-isothermal crystallization behavior of PVDF, but also provides a systematic strategy to evaluate a single diluent during the TIPS process.https://www.mdpi.com/2073-4352/10/9/782poly(vinylidene fluoride)non-isothermal crystallization behaviordialkyl phthalatealkyl chain-lengththermally induced phase separation |
| spellingShingle | Yakai Lin Yuanhui Tang Lin Wang Xiaolin Wang Non-Isothermal Crystallization Behavior of Poly(vinylidene fluoride) in Dialkyl Phthalate Diluents during Thermally Induced Phase Separation Process Crystals poly(vinylidene fluoride) non-isothermal crystallization behavior dialkyl phthalate alkyl chain-length thermally induced phase separation |
| title | Non-Isothermal Crystallization Behavior of Poly(vinylidene fluoride) in Dialkyl Phthalate Diluents during Thermally Induced Phase Separation Process |
| title_full | Non-Isothermal Crystallization Behavior of Poly(vinylidene fluoride) in Dialkyl Phthalate Diluents during Thermally Induced Phase Separation Process |
| title_fullStr | Non-Isothermal Crystallization Behavior of Poly(vinylidene fluoride) in Dialkyl Phthalate Diluents during Thermally Induced Phase Separation Process |
| title_full_unstemmed | Non-Isothermal Crystallization Behavior of Poly(vinylidene fluoride) in Dialkyl Phthalate Diluents during Thermally Induced Phase Separation Process |
| title_short | Non-Isothermal Crystallization Behavior of Poly(vinylidene fluoride) in Dialkyl Phthalate Diluents during Thermally Induced Phase Separation Process |
| title_sort | non isothermal crystallization behavior of poly vinylidene fluoride in dialkyl phthalate diluents during thermally induced phase separation process |
| topic | poly(vinylidene fluoride) non-isothermal crystallization behavior dialkyl phthalate alkyl chain-length thermally induced phase separation |
| url | https://www.mdpi.com/2073-4352/10/9/782 |
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