Fluoropolymers are fluorinated polymers that are highly attracted to industries due to their high chemical, thermal and mechanical resistance. Among them, fluorinated ethylene propylene copolymers (FEP) include very prominent Teflon™ commercial resins. Easy processability and low cost have contributed to FEP involving many interesting applications. In this sense, the extruded samples of fluorinated ethylene-propylene copolymer (FEP), thermally degraded at different temperatures and times were studied to assess the influence of degradation on their properties. After degradation, the samples were characterized by differential scanning calorimetry (DSC) thermogravimetric analysis (TGA) and Fourier transform infrared spectroscopy (FTIR) techniques and their morphology was evaluated through the atomic force microscopy (AFM). The results obtained through TGA revealed that the samples maintained two stages of decomposition at all degradation temperatures. No significant changes were observed in the spectra obtained by FTIR analysis. The analyses through AFM showed an increase in the surface irregularity of the polymer. In this way, it was possible to evaluate the different physical and structural changes of FEP in different times and temperatures of degradation without loss of the functional group. In general, the physical and structural properties of FEP were affected with the degradations performed without loss of functional group. The most affected properties were the crystallinity and morphology of the polymer, which could be evaluated by DSC and AFM techniques. Thus, this work showed the importance of the study of FEP properties, giving the industries greater support regarding the evaluation of degradability of the material after processing and under certain applications.

Graphical abstract

中文翻译：

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含氟乙烯-丙烯共聚物热降解及其对共聚物物理和结构性能的影响

含氟聚合物是一种氟化聚合物，由于其高耐化学性、耐热性和耐机械性而深受工业界的青睐。其中，氟化乙烯丙烯共聚物 (FEP) 包括非常突出的 Teflon™ 商用树脂。易加工性和低成本促成了 FEP 涉及许多有趣的应用。从这个意义上讲，研究了在不同温度和时间下热降解的氟化乙烯-丙烯共聚物 (FEP) 挤出样品，以评估降解对其性能的影响。降解后，通过差示扫描量热法 (DSC) 热重分析 (TGA) 和傅里叶变换红外光谱 (FTIR) 技术对样品进行表征，并通过原子力显微镜 (AFM) 评估其形态。通过 TGA 获得的结果表明，样品在所有降解温度下都保持了两个分解阶段。在通过 FTIR 分析获得的光谱中没有观察到显着变化。通过 AFM 的分析表明聚合物的表面不规则性增加。通过这种方式，可以评估 FEP 在不同时间和温度下的不同物理和结构变化，而不会损失官能团。一般来说，FEP 的物理和结构特性会受到在不损失官能团的情况下进行的降解的影响。受影响最大的性能是聚合物的结晶度和形态，这可以通过 DSC 和 AFM 技术进行评估。因此，这项工作表明了研究 FEP 特性的重要性，

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