scholarly journals Acetylated SEBS Enhanced DC Insulation Performances of Polyethylene

Polymers ◽  
2019 ◽  
Vol 11 (6) ◽  
pp. 1033 ◽  
Author(s):  
Wei Dong ◽  
Xuan Wang ◽  
Zaixing Jiang ◽  
Bo Tian ◽  
Yuguang Liu ◽  
...  
Keyword(s):  
Dielectric Properties ◽  
Field Strength ◽  
Space Charge ◽  
Aromatic Compounds ◽  
Breakdown Strength ◽  
Charge Accumulation ◽  
New Approach ◽  
Functional Units ◽  
Poly Ethylene ◽  
Accumulation Characteristics

Acetophenone can significantly improve the dielectric properties of polyethylene (PE) insulation materials. However, it easily migrates from the PE due to its poor compatibility with the material, which limits its application. In this paper, the functional units of acetophenone were modified in polystyrene-b-poly(ethylene-co-butylene)-b-polystyrene (SEBS) by an acetylation reaction, and SEBS was used as the carrier to inhibit the migration of acetophenone. The number of functional units in the acetylated SEBS (Ac-SEBS) was measured by 1H NMR and the effect of the acetylation degree of SEBS on its compatibility with PE was studied. Meanwhile, the effects of Ac-SEBS on PE’s direct current (DC) breakdown strength and space charge accumulation characteristics were investigated. It is demonstrated that Ac-SEBS can significantly improve the field strength of the DC breakdown and inhibit the accumulation of space charge in the PE matrix. This work provides a new approach for the application of aromatic compounds as voltage stabilizers in DC insulation cable materials.

scholarly journals Enhanced Insulation Performances of Crosslinked Polyethylene Modified by Chemically Grafting Chloroacetic Acid Allyl Ester

Polymers ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 592 ◽  
Author(s):  
Xin-Dong Zhao ◽  
Wei-Feng Sun ◽  
Hong Zhao
Keyword(s):  
Space Charge ◽  
Dielectric Breakdown ◽  
Breakdown Strength ◽  
Chloroacetic Acid ◽  
Dielectric Materials ◽  
Electrical Insulation ◽  
Polar Group ◽  
Charge Accumulation ◽  
Allyl Ester ◽  
Electrical Insulation Properties

Modified crosslinked polyethylene (XLPE) with appreciably enhanced DC electrical insulation properties has been developed by chemical modification of grafting chloroacetic acid allyl ester (CAAE), exploring the trapping mechanism of charge transport inhibition. The bound state traps deriving from grafted molecule are analyzed by first-principles calculations, in combination with the electrical DC conductivity and dielectric breakdown strength experiments to study the underlying mechanism of improving the electrical insulation properties. In contrast to pure XLPE, the XLPE-graft-CAAE represents significantly suppressed space charge accumulation, increased breakdown strength, and reduced conductivity. The substantial deep traps are generated in XLPE-graft-CAAE molecules by polar group of grafted CAAE and accordingly decrease charge mobility and raise charge injection barrier, consequently suppressing space charge accumulation and charge carrier transport. The well agreement of experiments and quantum mechanics calculations suggests a prospective material modification strategy for achieving high-voltage polymer dielectric materials without nanotechnology difficulties as for nanodielectrics.

scholarly journals Characterization of Polypropylene Modified by Blending Elastomer and Nano-Silica

Materials ◽  
2018 ◽  
Vol 11 (8) ◽  
pp. 1321 ◽  
Author(s):  
Xiaohong Chi ◽  
Lu Cheng ◽  
Wenfeng Liu ◽  
Xiaohong Zhang ◽  
Shengtao Li
Keyword(s):  
Dielectric Properties ◽  
Space Charge ◽  
Power Transmission ◽  
Breakdown Strength ◽  
Tensile Tests ◽  
Mechanical Analysis ◽  
Insulation Material ◽  
Nano Silica ◽  
Scanning Calorimetry ◽  
High Voltage Direct Current

Polypropylene (PP) contains promising application prospects in thermoplastic cables for high voltage direct current (HVDC) power transmission because of its outstanding thermal and dielectric properties. However, the problem of poor toughness and space charge has restricted the application of pure PP in HVDC cables. In this paper, polyolefin elastomer (POE) and nano-silica were blended thoroughly and added into a PP mixture by a melting method. Scanning electron microscopy (SEM) was employed to observe the dispersion of POE and nanoparticles. Thermal properties were characterized by differential scanning calorimetry (DSC) and dynamic mechanical analysis (DMA). Mechanical properties were evaluated by tensile tests. The elastomeric properties of composites were improved as the dispersed POE could transfer and homogenize external mechanical forces. DC breakdown results showed that the fail strength of composite with 10 phr POE and 1 phr nano-silica was obviously enhanced. The pulsed electro-acoustic (PEA) results showed that the injection and accumulation of space charge was increased by the introduction of POE, while it was restrained by the collective effect caused by nano-silica filling. X-ray diffraction (XRD) spectrograms showed that secondary ordered structures existed in the composites of PP, POE, and nano-silica, and that the ordered structure around the nanoparticles contributed to the enhancement of breakdown strength. The mechanical and dielectric properties were modified synergistically, which made the modified PP a propitious insulation material for HVDC cables.

Dielectric properties and effect of electrical aging on space charge accumulation in polyimide/TiO2 nanocomposite films

2010 ◽  
Vol 108 (9) ◽  
pp. 094113 ◽  
Author(s):  
Jun-Wei Zha ◽  
Zhi-Min Dang ◽  
Hong-Tao Song ◽  
Yi Yin ◽  
George Chen
Keyword(s):  
Dielectric Properties ◽  
Space Charge ◽  
Nanocomposite Films ◽  
Charge Accumulation ◽  
Electrical Aging

HVDC Cable Accessory Insulation

2017 ◽  
pp. 160-193
Keyword(s):  
Dielectric Properties ◽  
Space Charge ◽  
High Power ◽  
Nanosized Particles ◽  
Charge Accumulation ◽  
Long Distance ◽  
Ethylene Propylene ◽  
Interface Charge ◽  
Direct Fluorination ◽  
Ethylene Propylene Diene Terpolymer

HVDC cables have shown great advantages for long-distance, high-power underground or underwater transmission. The performance of cable accessories, as an essential part of the HVDC networks, is a great concern to the reliability of the system. However, Cable accessories made of ethylene-propylene-diene terpolymer (EPDM), which are considered to be the weakest part of HVDC cable system, have to face the problem of space charge accumulation. Nanosized particles have been proved as an effective method to suppress the space charge accumulation in dielectric composites. This chapter presents a study aimed at clarifying the effect of nanoparticles and direct-fluorination on space charge behaviors for HVDC cable accessory insulation. Obtained results show that the dielectric properties and DC conduction for HVDC cable accessory insulation are significantly influenced and the interface charge density can be effectively suppressed by doped fillers.

Space Charge Accumulation Characteristics in Fluorinated Insulating Material under DC High Stress

2018 ◽  
Vol 138 (4) ◽  
pp. 163-170 ◽  
Author(s):  
Takahiro Nagase ◽  
Shugo Yoshida ◽  
Takuma Mori ◽  
Hiroaki Miyake ◽  
Kimio Hijikata ◽  
...  
Keyword(s):  
Space Charge ◽  
High Stress ◽  
Charge Accumulation ◽  
Insulating Material ◽  
Accumulation Characteristics

scholarly journals Dielectric and Thermal Conductivity of Epoxy Resin Impregnated Nano-h-BN Modified Insulating Paper

Polymers ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 1359 ◽  
Author(s):  
Hongda Yang ◽  
Qingguo Chen ◽  
Xinyu Wang ◽  
Minghe Chi ◽  
Heqian Liu ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Dielectric Properties ◽  
Space Charge ◽  
Epoxy Resin ◽  
Direct Current ◽  
Heat Conductivity ◽  
Power Transmission ◽  
Breakdown Strength ◽  
Hexagonal Boron Nitride ◽  
Insulating Paper

Epoxy resin-impregnated insulation paper (RIP) composites are used as the inner insulation of dry condenser bushing in the ultra-high voltage direct current (UHVDC) power transmission system. To improve the dielectric properties and heat conductivity of RIP, hexagonal boron nitride (h-BN) nano-flakes are added to the insulation paper at concentrations of 0–50 wt % before impregnation with pure epoxy resin. X-ray diffraction (XRD), scanning electron microscopy (SEM) observations, thermal conductivity as well as the typical dielectric properties of direct current (DC) volume conductivity. DC breakdown strength and space charge characteristics were obtained. The maximum of nano-h-BN modified heat conductivity reach 0.478 W/(m·K), increased by 139% compared with unmodified RIP. The DC breakdown electric field strength of the nano-h-BN modified RIP does not reduce much. The conductivity of nano-h-BN modified is less sensitive to temperature. As well, the space charge is suppressed when the content is 50 wt %. Therefore, the nano-h-BN modified RIP is potentially useful in practical dry DC bushing application.

scholarly journals Enhanced dielectric properties due to space charge-induced interfacial polarization in multilayer polymer films

2017 ◽  
Vol 5 (39) ◽  
pp. 10417-10426 ◽  
Author(s):  
Xinyue Chen ◽  
Jung-Kai Tseng ◽  
Imre Treufeld ◽  
Matthew Mackey ◽  
Donald E. Schuele ◽  
...  
Keyword(s):  
Dielectric Properties ◽  
Space Charge ◽  
Polymer Films ◽  
Breakdown Strength ◽  
Interfacial Polarization ◽  
Electrical Insulation ◽  
Space Charges

Interfacial polarization due to space charges enhances electrical insulation and thus breakdown strength for multilayer polymer films.

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