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Crystal polymorphism of poly(vinylidene fluoride) blended with alkylammonium salts exhibiting different ion-dipole interaction strengths

Polymer Journal volume 55, pages 711–715 (2023)Cite this article

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Poly(vinylidene fluoride) (PVDF) is a semicrystalline polymer that exhibits complicated crystal polymorphism. PVDF mainly forms three crystalline phases, i.e., the α-, β- and γ-phases [1,2,3]. The α-phase has a trans-gauche (TGTG’) conformation, the β-phase has an all-trans (TTTT) conformation, and the γ-phase has a sequence of three trans conformers linked to a gauche (TTTGTTTG’) conformer. The β- and γ-phase crystallites exhibit electrical activity and are widely studied for industrial applications such as sensors, actuators, and transducers [4] due to their ferroelectric and piezoelectric properties [2, 5, 6]. Various processing methods have been used to control the crystal polymorphism of PVDF. For instance, the β-phase crystallites and γ-phase crystallites are obtained by melt crystallization at low temperatures below 60 °C [2] and high temperatures above 165 °C [7], respectively. β- and γ-phase crystallites are obtained from the melt crystallization process with cooling rates above 2000 K/s [8], pressures above 300 MPa [9] and share rates from 0.01 to 10 s−1 [10], and they are also obtained via the solvent casting process with specific evaporation rates [11] for polar solvents [12] and during electrospinning [13].

Extensive studies have been carried out on formation of the β- and γ-phases of PVDF crystallites in the presence of ionic salts due to the ion-dipole interactions between the ionic salts and PVDF chains [14,15,16,17]. The advantage of using ionic salts is that polar phases can be obtained by conventional melt crystallization without specific processing conditions. It is widely accepted that ion-dipole interactions promote the formation of the TTT conformation in the melt state and lead to β- and γ-phase crystallites in melt crystallization [15, 17]. Alkylammonium salts are known to efficiently induce an electrically active phase, and the strength of the ion-dipole interactions can be varied with the alkyl chain length and size of the anion structure; i.e., the ion-dipole interaction is weaker when the alkyl chain is longer and the anion structure is larger due to steric hindrance. Two crystallization mechanisms have been suggested for formation of the γ-phase crystallites during melt crystallization. One is a α-to-γ solid‒solid phase transition, i.e., α-phase crystallites formed at the early stage transition to γ-phase crystallites due to ion-dipole interactions [14]. The other is relaxation from the TTT conformation to the TTTG conformation; i.e., the TTTT conformation is relaxed to the TTTG conformation, and γ-phase crystallites exhibiting the TTTG conformation are formed. Recent time-resolved light scattering studies revealed that γ-phase crystallites were obtained through a two-stage crystallization, i.e., disordered domains were formed by the nucleation agent effect, and then γ-phase crystallites were obtained by increasing the ordering without a solid‒solid phase transition from the α-phase to the γ-phase [18]. However, the crystal polymorphism resulting from the two crystallization mechanisms has not been clarified, although it is important to understand the crystallization process to obtain the electrically active β- and γ-phases.

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References

  1. Cui Z, Hassankiadeh NT, Zhuang Y, Drioli E, Lee YM. Crystalline polymorphism in poly(vinylidenefluoride) membranes. Prog Polym Sci. 2015;51:94–126.

    Article  CAS  Google Scholar 

  2. Martins P, Lopes AC, Lanceros-Mendez S. Electroactive phases of poly(vinylidene fluoride): determination, processing and applications. Prog Polym Sci. 2014;39:683–706.

    Article  CAS  Google Scholar 

  3. Lovinger AJ. Annealing of poly (vinylidene fluoride) and formation of a fifth phase. Macromolecules. 1982;15:40–4.

    Article  CAS  Google Scholar 

  4. Zhu H. Interfacial preparation of ferroelectric polymer nanostructures for electronic applications. Polym J. 2021;53:877–86.

    Article  CAS  Google Scholar 

  5. Ruan L, Yao X, Chang Y, Zhou L, Qin G, Zhang X. Properties and applications of the beta phase poly(vinylidene fluoride). Polymers (Basel). 2018;10:228.

    Article  PubMed  Google Scholar 

  6. Tashiro K, Yamamoto H, Kummara S, Tahara D, Aoyama K, Sekiguchi H. Electric-field-induced phase transition and crystal structural change of the oriented poly(vinylidene Fluoride) β form as clarified by the in situ synchrotron wide-angle X-ray diffraction measurement. Macromolecules. 2022;55:6644–60.

    Article  CAS  Google Scholar 

  7. Osaki S, Ishida Y. Effects of annealing and isothermal crystallization upon crystalline forms of poly (vinylidene fluoride). J Polym Sci Polym Phys Ed. 1975;13:1071–83.

    Article  CAS  Google Scholar 

  8. Chen Y, Shen Q-D, Hu W. Primary and secondary crystallization of fast-cooled poly(vinylidene fluoride) studied by Flash DSC, wide-angle X-ray diffraction and Fourier transform infrared spectroscopy. Polym. Int. 2016;65:387–92.

    Article  CAS  Google Scholar 

  9. Hattori T, Hikosaka M, Ohigashi H. The crystallization behaviour and phase diagram of extended-chain crystals of poly(vinylidene fluoride) under high pressure. Polymer. 1996;37:85–91.

    Article  CAS  Google Scholar 

  10. Chu Z, Liu L, Liao Y, Li W, Zhao R, Ma Z, Li Y. Effects of strain rate and temperature on polymorphism in flow-induced crystallization of Poly(vinylidene fluoride). Polymer. 2020;203:122773.

    Article  CAS  Google Scholar 

  11. Horibe H, Sasaki Y, Oshiro H, Hosokawa Y, Kono A, Takahashi S. et al. Quantification of the solvent evaporation rate during the production of three PVDF crystalline structure types by solvent casting. Polym J.2013;46:104–10.

    Article  Google Scholar 

  12. Low YKA, Tan LY, Tan LP, Boey FYC, Ng KW. Increasing solvent polarity and addition of salts promote β-phase poly(vinylidene fluoride) formation. J Appl Polym Sci. 2013;128:2902–10.

    Article  CAS  Google Scholar 

  13. Asai H, Terada Y, Nakane K. Effects of the addition of protic organic solvents and the sample formation processes on the crystal structure of poly(vinylidene fluoride): detailed mechanism of promoting the formation of the β-phase. Polymer. 2022;244:124650.

    Article  CAS  Google Scholar 

  14. Li Y, Xu J-Z, Zhu L, Xu H, Pan M-W, Zhong G-J. et al. Multiple stage crystallization of gamma phase poly(vinylidene fluoride) induced by ion-dipole interaction as revealed by time-resolved FTIR and two-dimensional correlation analysis. Polymer. 2014;55:4765–75.

    Article  CAS  Google Scholar 

  15. Wu Y, Hsu SL, Honeker C, Bravet DJ, Williams DS. The role of surface charge of nucleation agents on the crystallization behavior of poly(vinylidene fluoride). J Phys Chem B. 2012;116:7379–88.

    Article  CAS  PubMed  Google Scholar 

  16. Miyashita T, Saito H. Nucleation effect of the chemical structure of alkylammonium salt on the crystallization behavior of poly(Vinylidene Fluoride). Polym Cryst. 2022;2022:1–9.

    Google Scholar 

  17. Zhu Y, Li C, Na B, Lv R, Chen B, Zhu J. Polar phase formation and competition in the melt crystallization of poly (vinylidene fluoride) containing an ionic liquid. Mater Chem Phys. 2014;144:194–8.

    Article  CAS  Google Scholar 

  18. Miyashita T, Saito H. Two-stage evolution of gamma-phase spherulites of poly (Vinylidene Fluoride) induced by alkylammonium salt. Polymers (Basel). 2022;14:3901.

    Article  CAS  PubMed  Google Scholar 

  19. Chu Z, Zhao R, Wang B, Liu L, Ma Z, Li Y. Effect of ions on the flow-induced crystallization of poly(vinylidene fluoride). Macromolecules. 2021;54:3800–9.

    Article  CAS  Google Scholar 

  20. Cai X, Lei T, Sun D, Lin L. A critical analysis of the α, β and γ phases in poly(vinylidene fluoride) using FTIR. RSC Adv. 2017;7:15382–9.

    Article  CAS  Google Scholar 

Download references

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Authors and Affiliations

  1. KF Products Department, Kureha Corporation, 3-3-2 Nihonbashi-Hamacho, Chuo-ku, Tokyo, 103-8552, Japan

    Tatsuaki Miyashita

  2. Department of Organic and Polymer Materials Chemistry, Tokyo University of Agriculture and Technology, 2-24-16 Naka-machi, Koganei-shi, Tokyo, 184-8588, Japan

    Tatsuaki Miyashita & Hiromu Saito

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Miyashita, T., Saito, H. Crystal polymorphism of poly(vinylidene fluoride) blended with alkylammonium salts exhibiting different ion-dipole interaction strengths. Polym J 55, 711–715 (2023). https://doi.org/10.1038/s41428-023-00761-0

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