The decomposition of functional fluoropolymers poly[vinylidene fluoride-co-2-(trifluoromethyl) acrylic acid] copolymers, [poly(VDF-co-MAF)], in superheated water was investigated as the first example of the decomposition of these copolymers aimed at recycling the fluorine element. Such statistical copolymers were prepared from the conventional radical copolymerization of VDF and MAF in two different feed molar ratios leading to different VDF/MAF molar ratios (90/10 and 58/42 molar percentages). Their degradation was achieved in the presence of two oxidizing agents. By the use of KMnO₄ (25–158 mM), these poly(VDF-co-MAF) copolymers efficiently generated F^– ions and resulted in low total organic carbon (TOC) content in the reaction solutions. Specifically, when the copolymer containing a 90 mol % VDF was treated with aqueous KMnO₄ (158 mM) at 250 °C for 6 h, the F^– yield reached 83% and the remaining amount of TOC decreased to 4% of the carbon atom amount in the initial copolymer. Likewise, for the same treatment of the other copolymer (58 mol % VDF), the F^– yield reached 90% while the remaining TOC ratio was 4%. Compared to KMnO₄, H₂O₂ induced a lower copolymer mineralization. Adding Ca(OH)₂ to the solutions from superheated water treatment with KMnO₄ and a subsequent washing procedure gave pure CaF₂.

中文翻译：

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聚[偏二氟乙烯-co-2-(三氟甲基)丙烯酸]共聚物在过热水中的氧化矿化

功能性含氟聚合物聚[偏二氟乙烯-co -2-(三氟甲基)丙烯酸]共聚物[聚(VDF- co -MAF)]在过热水中的分解作为这些共聚物分解的第一个例子进行了研究，旨在回收氟元素。此类统计共聚物由 VDF 和 MAF 在两种不同的进料摩尔比下的常规自由基共聚制备，导致不同的 VDF/MAF 摩尔比（90/10 和 58/42 摩尔百分比）。它们的降解是在两种氧化剂存在下实现的。通过使用 KMnO ₄ (25–158 mM)，这些聚 (VDF- co -MAF) 共聚物有效地产生了 F ^–离子并导致反应溶液中的总有机碳 (TOC) 含量低。具体而言，当含有 90 mol % VDF 的共聚物在 250 °C 下用 KMnO _{4 (158 mM) 水溶液处理 6 h 时，F} ^–收率达到 83%，TOC 的剩余量减少到碳原子的 4%初始共聚物中的量。同样，对于另一种共聚物（58 mol% VDF）进行相同处理，F-^产率达到 90%，而剩余的 TOC 比率为 4%。与KMnO ₄相比，H ₂ O ₂诱导了较低的共聚物矿化。_{在 KMnO 4}过热水处理溶液中添加 Ca(OH) ₂并且随后的洗涤程序得到纯CaF ₂。