Decomposition of fluoroelastomer: Poly(vinylidene fluoride-ter-hexafluoropropylene-ter-tetrafluoroethylene) terpolymer in subcritical water
[Display omitted] •Poly(VDF-ter-HFP-ter-TFE) terpolymer showed little reactivity in pure subcritical water under argon.•Addition of H2O2 efficiently accelerated the decomposition of poly(VDF-ter-HFP-ter-TFE) terpolymer to F−.•The maximum yields of F− and CO2 reached both 95%: quasi-complete minerali...
Gespeichert in:
Veröffentlicht in: | European polymer journal 2017-09, Vol.94, p.322-331 |
---|---|
Hauptverfasser: | , , , , , |
Format: | Artikel |
Sprache: | eng |
Schlagworte: | |
Online-Zugang: | Volltext |
Tags: |
Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
|
Zusammenfassung: | [Display omitted]
•Poly(VDF-ter-HFP-ter-TFE) terpolymer showed little reactivity in pure subcritical water under argon.•Addition of H2O2 efficiently accelerated the decomposition of poly(VDF-ter-HFP-ter-TFE) terpolymer to F−.•The maximum yields of F− and CO2 reached both 95%: quasi-complete mineralization was achieved.•Reaction in the presence of 4.0M H2O2 and stoichiometric Ca(OH)2 at 350°C resulted in the formation of CaF2 in 84% yield.
Decomposition of poly(vinylidene fluoride-ter-hexafluoropropylene-ter-tetrafluoroethylene) terpolymer, a typical fluoroelastomer with high flexibility and high resistance to permeation of oil and excellent adhesive ability to other materials, in subcritical water (SubCW) was studied as a first example of the decomposition of the terpolymer with the aim of developing a technique to recover the fluorine element. Compared to the common fluoropolymers such as poly(vinylidene fluoride), the terpolymer was considerably stable in SubCW. 19F NMR spectral analysis of the decomposition products obtained from the reaction at 300°C was carried out to better understand the decomposition mechanism. When the reaction was performed in SubCW at 300°C for 6h under argon, only a negligible amount of F− ions (1%) was released. Addition of H2O2 into the reaction system accelerated the mineralization of the terpolymer to form F− and CO2. Apart from these major products, small amounts of malonic acid and CF3H were detected. When this polymer was heated in SubCW at 350°C with 4.0M H2O2, both the yields of F− and CO2 reached up to 95%. These features indicate a quasi-complete mineralization of the terpolymer. Furthermore, the reaction in the presence of 4.0M H2O2 and stoichiometric amount of Ca(OH)2 at 350°C for 18h resulted in the formation of pure CaF2, a raw material for hydrofluoric acid, in 84% yield. |
---|---|
ISSN: | 0014-3057 1873-1945 |
DOI: | 10.1016/j.eurpolymj.2017.05.042 |