In this study, a novel cellulose insulation with low dielectric constant and loss is prepared by implementing citric acid (CA) crosslinking. In the modified cellulose insulation, the existence of network structure is confirmed by X-ray photoelectron, Fourier transform infrared spectra and dispersion experiments. Moreover, the effect of different CA concentrations on the dielectric properties and other crucial properties of cellulose insulation is investigated through molecular modeling and simulation and experiments. The results show that CA crosslinking reduces the polarizability of cellulose because the hydroxyl groups on cellulose chains are consumed. Moreover, the network structure effectively hinders the motion of the cellulose chains, which further reduces the orientation polarization. The dielectric constant and loss in cellulose insulation decrease by CA crosslinking. The dielectric constant of 0.4 mol/L CA-treated cellulose decreases from 4.89 to 4.12, and the dielectric loss decreases by 32.6% at 50 Hz as compared to the unmodified cellulose insulation. When the CA is completely crosslinked, the permittivity and dielectric loss decrease with the increase in the concentration of CA. Additionally, CA crosslinking modification does not deteriorate the properties of the cellulose insulation. Thus, CA crosslinking modification can be potentially used for preparing cellulose insulation with low dielectric constant and loss.

中文翻译：

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柠檬酸交联制备具有网络结构的新型纤维素绝缘材料

在这项研究中，通过实施柠檬酸（CA）交联制备了一种具有低介电常数和损耗的新型纤维素绝缘材料。在改性纤维素绝缘材料中，通过X射线光电子、傅里叶变换红外光谱和色散实验证实了网络结构的存在。此外，通过分子建模、模拟和实验，研究了不同 CA 浓度对纤维素绝缘材料的介电特性和其他关键特性的影响。结果表明，CA 交联降低了纤维素的极化率，因为纤维素链上的羟基被消耗了。此外，网络结构有效地阻碍了纤维素链的运动，进一步降低了取向极化。CA 交联会降低纤维素绝缘材料的介电常数和损耗。0.4 mol/L CA 处理的纤维素的介电常数从 4.89 降低到 4.12，与未改性的纤维素绝缘相比，50 Hz 下的介电损耗降低了 32.6%。当 CA 完全交联时，介电常数和介电损耗随着 CA 浓度的增加而降低。此外，CA 交联改性不会降低纤维素绝缘材料的性能。因此，CA 交联改性可潜在地用于制备具有低介电常数和损耗的纤维素绝缘材料。与未改性的纤维素绝缘材料相比，在 50 Hz 时为 6%。当 CA 完全交联时，介电常数和介电损耗随着 CA 浓度的增加而降低。此外，CA 交联改性不会降低纤维素绝缘材料的性能。因此，CA 交联改性可潜在地用于制备具有低介电常数和损耗的纤维素绝缘材料。与未改性的纤维素绝缘材料相比，在 50 Hz 时为 6%。当 CA 完全交联时，介电常数和介电损耗随着 CA 浓度的增加而降低。此外，CA 交联改性不会降低纤维素绝缘材料的性能。因此，CA 交联改性可潜在地用于制备具有低介电常数和损耗的纤维素绝缘材料。