In this study, aramid fiber-reinforced polymer (AFRP) composites were prepared and then postcured under specific heating/cooling rates. By dynamic mechanical analysis, the viscoelastic properties of the AFRP composites at elevated temperatures and under various frequencies were determined. Thermomechanical analysis (TMA), in the modes of creep-recovery and stress–relaxation tests, was also performed. Furthermore, differential scanning calorimetry was also used, and the decomposition of the AFRP composites, aramid fibers, and pure postcured epoxy, in two different atmospheres, namely, air atmosphere and nitrogen (N 2 ) atmosphere, was explored by the thermogravimetric analysis (TGA). From this point of view, the aramid fibers showed remarkably thermal resistance, in N 2 atmosphere, and the volume fraction of fibers (Φ f ) was calculated to be Φ f = 51%. In the TGA experiments, the postcured AFRP composites showed very good thermal resistance, both in air and N 2 atmosphere, and this characteristic in conjunction with their relatively high T g , which is in the range of 85–95°C, depending on the frequency and the determination method, classifies these composites as potential materials in applications where the resistance in high temperatures is a required characteristic.

中文翻译：

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后固化芳纶纤维/环氧树脂复合材料的热分析

在这项研究中，制备了芳纶纤维增强聚合物 (AFRP) 复合材料，然后在特定的加热/冷却速率下进行后固化。通过动态力学分析，确定了 AFRP 复合材料在高温和不同频率下的粘弹性。还进行了蠕变恢复和应力松弛测试模式下的热机械分析 (TMA)。此外，还使用了差示扫描量热法，并通过热重分析（TGA）探索了 AFRP 复合材料、芳纶纤维和纯后固化环氧树脂在两种不同的气氛中的分解，即空气气氛和氮气 (N 2 ) 气氛。 ）。从这个角度来看，芳纶纤维表现出显着的耐热性，在 N 2 气氛中，纤维的体积分数（Φ f ）计算为Φ f = 51%。在 TGA 实验中，后固化的 AFRP 复合材料在空气和 N 2 气氛中都显示出非常好的耐热性，并且这一特性与其相对较高的 T g 相结合，在 85-95°C 的范围内，具体取决于频率和测定方法，将这些复合材料归类为在需要耐高温特性的应用中的潜在材料。