Synthesis Process Optimization of Polyimide Nanocomposite Multilayer Films, Their Dielectric Properties, and Modeling

Polymer nanocomposite-based dielectric materials are playing a vital role in the area of electrical insulation research and developments. The nanoparticle dispersion and interface region are the crucial parts of these developments. This chapter begins with the description of physical properties and their derived nanoparticles of polyimide (PI) films. Then, the detailed synthesis process of PI/nanocomposite multilayer film and its optimization is discussed in this chapter. Several factors in the synthesis process, which can influence the quality of the film, are discussed. After synthesis, the dielectric properties such as space charge were measured, and the results are compared with single and multilayer PI/nanocomposite films. Simulations and modeling help to shed light on the experimental results and create an understanding of polymer nanocomposite properties. Therefore, the PI/nanocomposite multilayer 3D model based on boundary conditions obtained from SEM/TEM images of synthesized samples was also constructed and simulated in COMSOL multiphysics software. The nanoparticle agglomeration and the impact of nanoparticle dispersion on the electrical properties of the material are described in detail in this model. The results demonstrate that the nanoparticle dispersion is improved by using a thin layer of PI/nanocomposite on PI film. As a result, fewer space charges and low electric fields are observed in multilayer films

Heating Effects on Structural and Electrical Properties of Polyetherimide

Abstract: Problem statement: Polyetherimide (PEI) has several uses such as electrical insulation. It can undergo different constraints like heat or high voltage which influence its performances as insulator. In this study, the effects of heating on structural and electrical properties of polyetherimide (Ultem 1000) are studied. Approach: PEI samples were heated at different temperatures below the glass transition temperature (175, 190 and 205°C). Different complementary techniques were used to investigate structural alterations and dielectric relaxations. These are infrared (IR) spectroscopy, Differential Scanning Calorimetry (DSC), Thermally Stimulated Depolarisation Current (TSDC) technique and Dielectric Spectroscopy (DS). Results: Physical ageing was revealed in heated samples by DSC analysis. DS and TSDC results have shown that dipolar relaxations are affected by heating. The amount of relaxing dipoles decreases when the material is heated at 190°C. Conclusion/Recommendations: The heating of polyetherimide at 190°C leads to a stabilisation of charges in deeper energetic levels which influences the insulating character of the material

Review of space charge measurements in high voltage DC extruded cables by the thermal step method

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Recent Advances in Calculating Space Charge Distribution by Processing the Signals Obtained Using the Thermal Step Method

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Space Charge Measurements under Applied dc Field by The Thermal Step Method

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Dernières avancées de la méthode de l'onde thermique

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Space Charge Measurements in ac-Poled XLPE for High Voltage Cables

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Space Charge Measurements in ac-Poled XLPE for High Voltage Cables

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Space Charge Measurements on Power Cable Length

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