Abstract All-organic nanocomposites using conducting polypyrrole (PPy) nano-clips as fillers and poly(vinylidene fluoride-chlorotrifluoroethylene) (PVDF-CTFE) as the matrix are studied. The nanocomposites with a uniform microstructure were fabricated via a combination of a solution casting and a hot pressing process. Due to the uniform microstructure, the composites exhibit a single glass transition process, whose temperature decreases with increasing PPy content. The dielectric properties of the nanocomposites are systemically studied and analyzed over a wide temperature range from −60 °C to 140 °C and a broad frequency range from 100 Hz to 1 MHz. The nanocomposites have a low percolation threshold (∼7.4 wt%) and exhibit a high dielectric constant and a low dielectric loss. For the composites with 7 wt% of PPy at room temperature, the dielectric constant at 1 kHz is 23 times higher than that of the polymer matrix and the dielectric loss over a broad frequency range is less than 0.4 which is lower than the loss reported in other composites with the composition close to the percolation threshold. It is concluded that mixing PPy with P(VDF-CTFE) results in a new relaxation process that dominates the observed dielectric loss at low temperatures including room temperature. It is demonstrated that it is the DC conductivity rather than the dielectric constant that should be used to determine the percolation threshold.

中文翻译：

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使用导电聚吡咯纳米夹作为填料的全有机介电纳米复合材料

摘要 研究了以导电聚吡咯（PPy）纳米夹为填料，聚偏二氟乙烯-三氟氯乙烯（PVDF-CTFE）为基体的全有机纳米复合材料。通过溶液浇铸和热压工艺的组合制备具有均匀微观结构的纳米复合材料。由于均匀的微观结构，复合材料表现出单一的玻璃化转变过程，其温度随着 PPy 含量的增加而降低。纳米复合材料的介电性能在 -60 °C 至 140 °C 的宽温度范围和 100 Hz 至 1 MHz 的宽频率范围内进行了系统研究和分析。纳米复合材料具有低渗透阈值（~7.4 wt%），并表现出高介电常数和低介电损耗。对于室温下含有 7 wt% PPy 的复合材料，1 kHz 下的介电常数比聚合物基体的介电常数高 23 倍，并且在宽频率范围内的介电损耗小于 0.4，低于其他复合材料中报告的损耗，其成分接近渗透阈值。结论是，将 PPy 与 P(VDF-CTFE) 混合会导致新的弛豫过程，该过程在包括室温在内的低温下主导观察到的介电损耗。结果表明，应该使用直流电导率而不是介电常数来确定渗透阈值。结论是，将 PPy 与 P(VDF-CTFE) 混合会导致新的弛豫过程，该过程在包括室温在内的低温下主导观察到的介电损耗。结果表明，应该使用直流电导率而不是介电常数来确定渗透阈值。结论是，将 PPy 与 P(VDF-CTFE) 混合会导致新的弛豫过程，该过程在包括室温在内的低温下主导观察到的介电损耗。结果表明，应该使用直流电导率而不是介电常数来确定渗透阈值。