Effect of Acetylated SEBS/PP for Potential HVAC Cable Insulation

Blending polypropylene (PP) with thermoplastic elastomer SEBS can effectively improve the mechanical toughness of PP, thus leading to the promise of SEBS/PP as the primary insulation material for high voltage alternating current (HVAC) cables. However, the growth of electrical trees during cable operation limits the application of SEBS/PP. In this paper, acetylation reaction is used to construct acetophenone group at the end of the benzene ring on SEBS so that it has the effect of both a toughening agent and a voltage stabilizer. Then PP was melt blended with acetylated SEBS (Ac-SEBS), and the effects of Ac-SEBS on the mechanical properties, electrical tree resistance, alternating current (AC) breakdown strength, and dielectric spectrum of PP were mainly investigated with reference to PP and SEBS/PP. The results showed that Ac-SEBS with 30% content could enhance the mechanical toughness of PP and improve the electrical tree resistance and AC breakdown strength of SEBS/PP. The AC breakdown field strength of Ac-SEBS/PP reached the highest when the acetylation level was 4.6%, which was 9.2% higher than that of SEBS/PP. At this time, Ac-SEBS was also able to absorb high-energy electrons through the keto-enol interchange isomerization reaction, which inhibited the initiation and growth of electric trees and caused the development of electric dendrites in a jungle-like manner. Moreover, the dielectric loss factor of AC-SEBS/PP in power frequency is within the allowable range of industry. Therefore, Ac-SEBS/PP is expected to be applied to HVAC cables, thus further improving the efficiency of HVAC power transmission.

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Effect of Acetylated SEBS/PP for Potential HVDC Cable Insulation

Materials ◽

10.3390/ma14071596 ◽

2021 ◽

Vol 14 (7) ◽

pp. 1596

Author(s):

Peng Zhang ◽

Yongqi Zhang ◽

Xuan Wang ◽

Jiaming Yang ◽

Wenbin Han

Keyword(s):

Mechanical Properties ◽

Field Strength ◽

Thermoplastic Elastomer ◽

High Energy ◽

Thermoplastic Elastomers ◽

Electrical Strength ◽

Voltage Stabilizer ◽

Breakdown Field ◽

Cable Insulation ◽

Breakdown Field Strength

Blending thermoplastic elastomers into polypropylene (PP) can make it have great potential for high-voltage direct current (HVDC) cable insulation by improving its toughness. However, when a large amount of thermoplastic elastomer is blended, the electrical strength of PP will be decreased consequently, which cannot meet the electrical requirements of HVDC cables. To solve this problem, in this paper, the inherent structure of thermoplastic elastomer SEBS was used to construct acetophenone structural units on its benzene ring through Friedel–Crafts acylation, making it a voltage stabilizer that can enhance the electrical strength of the polymer. The DC electrical insulation properties and mechanical properties of acetylated SEBS (Ac-SEBS)/PP were investigated in this paper. The results showed that by doping 30% Ac-SEBS into PP, the acetophenone structural unit on Ac-SEBS remarkably increased the DC breakdown field strength of SEBS/PP by absorbing high-energy electrons. When the degree of acetylation reached 4.6%, the DC breakdown field strength of Ac-SEBS/ PP increased by 22.4% and was a little higher than that of PP. Ac-SEBS, with high electron affinity, is also able to reduce carrier mobility through electron capture, resulting in lower conductivity currents in SEBS/PP and suppressing space charge accumulation to a certain extent, which enhances the insulation properties. Besides, the highly flexible Ac-SEBS can maintain the toughening effect of SEBS, resulting in a remarkable increase in the tensile strength and elongation at the break of PP. Therefore, Ac-SEBS/PP blends possess excellent insulation properties and mechanical properties simultaneously, which are promising as insulation materials for HVDC cables.

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Use of Grafted Voltage Stabilizer to Enhance Dielectric Strength of Cross-Linked Polyethylene

Polymers ◽

10.3390/polym11010176 ◽

2019 ◽

Vol 11 (1) ◽

pp. 176 ◽

Cited By ~ 4

Author(s):

Wei Dong ◽

Xuan Wang ◽

Bo Tian ◽

Yuguang Liu ◽

Zaixing Jiang ◽

...

Keyword(s):

Thermal Stability ◽

Breakdown Strength ◽

Dielectric Strength ◽

Voltage Stabilizer ◽

Cross Linking ◽

Practical Application ◽

Electrical Tree ◽

Research Goal ◽

The Stability ◽

New Research

Aromatic voltage stabilizers can improve the dielectric properties of cross-linked polyethylene (XLPE); however, their poor compatibility with XLPE hinders their practical application. Improving the compatibility of aromatic voltage stabilizers with XLPE has, therefore, become a new research goal. Herein 1-(4-vinyloxy)phenylethenone (VPE) was prepared and characterized. It can be grafted onto polyethylene molecules during the cross-linking processes to promote stability of the aromatic voltage stabilizers in XLPE. Fourier transform infrared spectroscopy confirmed that VPE was successfully grafted onto XLPE, and effectively inhibited thermal migration. Thermogravimetric analysis showed that the grafted VPE/XLPE composite exhibits a better thermal stability than a VPE/PE blend composite. Evaluation of the electrical properties showed that the breakdown strength and electrical tree initiation voltage of the VPE/XLPE composite were increased by 15.5% and 39.6%, respectively, when compared to those of bare XLPE. After thermal aging, the breakdown strength and electrical tree initiation voltage of the VPE/XLPE composite were increased by 9.4% and 25.8%, respectively, in comparison to those of bare XLPE, which indicates that the grafted voltage stabilizer can effectively inhibit its migration and enhance the stability of the composite material.

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Theoretical study on the radical reaction mechanism in the cross-linking process of polyethylene

RSC Advances ◽

10.1039/c5ra16339k ◽

2015 ◽

Vol 5 (110) ◽

pp. 90343-90353 ◽

Cited By ~ 16

Author(s):

Hui Zhang ◽

Yan Shang ◽

Mingxia Li ◽

Hong Zhao ◽

Xuan Wang ◽

...

Keyword(s):

Reaction Mechanism ◽

High Voltage ◽

Theoretical Study ◽

Breakdown Strength ◽

Electrical Breakdown ◽

Radical Reaction ◽

Voltage Stabilizer ◽

Cross Linking ◽

Insulation Material ◽

Electrical Breakdown Strength

The mechanism of the valerophenone voltage stabilizer for increasing the electrical breakdown strength of cross-linked polyethylene is expected to provide reliable information to prepare insulation material for high voltage cables up to 500 kV.

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Enhanced breakdown strength and electrical tree resistance properties of MMT/SiO2 /LDPE multielement composites

Journal of Applied Polymer Science ◽

10.1002/app.47364 ◽

2019 ◽

Vol 136 (17) ◽

pp. 47364 ◽

Cited By ~ 5

Author(s):

Xiaohong Zhang ◽

Zexiang Shi ◽

Lisha Ma ◽

Junguo Gao ◽

Ning Guo

Keyword(s):

Breakdown Strength ◽

Tree Resistance ◽

Electrical Tree

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Dielectric Properties of UV Cured Thick Film Polymer Networks through High Power Xenon Flash Lamp Curing

MRS Proceedings ◽

10.1557/opl.2014.114 ◽

2014 ◽

Vol 1630 ◽

Cited By ~ 3

Author(s):

Brian C. Riggs ◽

Ravinder Elupula ◽

Venkata S. Puli ◽

Scott M. Grayson ◽

Douglas B. Chrisey

Keyword(s):

Dielectric Constant ◽

Thick Film ◽

Breakdown Strength ◽

Shape Change ◽

Polymer Networks ◽

High Energy ◽

Flash Lamp ◽

Breakdown Field ◽

Cross Linking ◽

Xenon Flash

ABSTRACTHigh-energy flash cure lamps process thick film materials (<10 um) over large areas (<100 cm2) within milliseconds and are capable to deliver higher energy and power densities (20 J/cm2 and 20 kW/cm2) allowing for a more complete curing and elimination of flaws that would exist in conventional treatment. Click reactions are especially attractive for patterned devices as they have minimal shape change during curing and have a more predictable structure compared to free radical acrylate polymerization. Pentaerythritol tetrakis(3-mercaptopropionate) and 2,4,6-Triallyloxy-1,3,5-triazine were combined at 3:4 by weight and then spin coated on copper foil substrates. The solutions were processed both thermally and with exposure to a xenon flash bulb. Thermal treatment consisted of heating the sample at 80°C on a hot plate over night. Flash curing was accomplished using a Novacentrix Pulseforge 1300 system. The flash lamp curing fluence and intensities were varied to determine their effects on degree of cross-linking, dielectric constant, breakdown field and energy storage. The degree of cross-linking was determined through comparative FTIR studies. Dielectric constant was measured using an Agilent 4294a impedance analyzer from 100 Hz-100 MHz with a two terminal setup. Breakdown strength and energy density measurements were taken using Radiant Technology's Precision Ferroelectric tester with a 10 kV source. The printed films averaged 1-3 microns thick as observed by an SEM cross section measurement. It was found that dielectric constant varies with both treatment intensity and fluence. Energy densities were calculated using the ideal capacitor equation and ranged from 1.5-4.8 J/cm3.

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Recent Advances in the Synthesis of Polymer-Grafted Low-K and High-K Nanoparticles for Dielectric and Electronic Applications

Molecules ◽

10.3390/molecules26102942 ◽

2021 ◽

Vol 26 (10) ◽

pp. 2942

Author(s):

Bhausaheb V. Tawade ◽

Ikeoluwa E. Apata ◽

Nihar Pradhan ◽

Alamgir Karim ◽

Dharmaraj Raghavan

Keyword(s):

Energy Density ◽

Polymer Nanocomposites ◽

High Performance ◽

Breakdown Strength ◽

Polymer Nanocomposite ◽

High Energy ◽

Polymer Chains ◽

High Energy Density ◽

Grafted Nanoparticles ◽

Grafting From

The synthesis of polymer-grafted nanoparticles (PGNPs) or hairy nanoparticles (HNPs) by tethering of polymer chains to the surface of nanoparticles is an important technique to obtain nanostructured hybrid materials that have been widely used in the formulation of advanced polymer nanocomposites. Ceramic-based polymer nanocomposites integrate key attributes of polymer and ceramic nanomaterial to improve the dielectric properties such as breakdown strength, energy density and dielectric loss. This review describes the ”grafting from” and ”grafting to” approaches commonly adopted to graft polymer chains on NPs pertaining to nano-dielectrics. The article also covers various surface initiated controlled radical polymerization techniques, along with templated approaches for grafting of polymer chains onto SiO2, TiO2, BaTiO3, and Al2O3 nanomaterials. As a look towards applications, an outlook on high-performance polymer nanocomposite capacitors for the design of high energy density pulsed power thin-film capacitors is also presented.

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Application of the Gaussian Mixture Model to Classify Stages of Electrical Tree Growth in Epoxy Resin

Sensors ◽

10.3390/s21072562 ◽

2021 ◽

Vol 21 (7) ◽

pp. 2562

Author(s):

Abdullahi Abubakar Mas’ud ◽

Arunachalam Sundaram ◽

Jorge Alfredo Ardila-Rey ◽

Roger Schurch ◽

Firdaus Muhammad-Sukki ◽

...

Keyword(s):

Epoxy Resin ◽

Gaussian Mixture Model ◽

Mixture Model ◽

Tree Growth ◽

Asset Management ◽

Gaussian Mixture ◽

Growth Stages ◽

Insulation Material ◽

Electrical Tree ◽

Electrical Trees

In high-voltage (HV) insulation, electrical trees are an important degradation phenomenon strongly linked to partial discharge (PD) activity. Their initiation and development have attracted the attention of the research community and better understanding and characterization of the phenomenon are needed. They are very damaging and develop through the insulation material forming a discharge conduction path. Therefore, it is important to adequately measure and characterize tree growth before it can lead to complete failure of the system. In this paper, the Gaussian mixture model (GMM) has been applied to cluster and classify the different growth stages of electrical trees in epoxy resin insulation. First, tree growth experiments were conducted, and PD data captured from the initial to breakdown stage of the tree growth in epoxy resin insulation. Second, the GMM was applied to categorize the different electrical tree stages into clusters. The results show that PD dynamics vary with different stress voltages and tree growth stages. The electrical tree patterns with shorter breakdown times had identical clusters throughout the degradation stages. The breakdown time can be a key factor in determining the degradation levels of PD patterns emanating from trees in epoxy resin. This is important in order to determine the severity of electrical treeing degradation, and, therefore, to perform efficient asset management. The novelty of the work presented in this paper is that for the first time the GMM has been applied for electrical tree growth classification and the optimal values for the hyperparameters, i.e., the number of clusters and the appropriate covariance structure, have been determined for the different electrical tree clusters.

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Enhanced dielectric properties and thermostability in polyimide composites with core-shell structured polyimide@BaTiO3 nanoparticles

High Performance Polymers ◽

10.1177/0954008321993526 ◽

2021 ◽

pp. 095400832199352

Author(s):

Wei Deng ◽

Guanguan Ren ◽

Wenqi Wang ◽

Weiwei Cui ◽

Wenjun Luo

Keyword(s):

Dielectric Constant ◽

Dielectric Loss ◽

Energy Density ◽

Breakdown Strength ◽

In Situ Polymerization ◽

Dielectric Materials ◽

High Energy ◽

Amic Acid ◽

High Energy Density ◽

Core Shell

Polymer composites with high dielectric constant and thermal stability have shown great potential applications in the fields relating to the energy storage. Herein, core-shell structured polyimide@BaTiO3 (PI@BT) nanoparticles were fabricated via in-situ polymerization of poly(amic acid) (PAA) and the following thermal imidization, then utilized as fillers to prepare PI composites. Increased dielectric constant with suppressed dielectric loss, and enhanced energy density as well as heat resistance were simultaneously realized due to the presence of PI shell between BT nanoparticles and PI matrix. The dielectric constant of PI@BT/PI composites with 55 wt% fillers increased to 15.0 at 100 Hz, while the dielectric loss kept at low value of 0.0034, companied by a high energy density of 1.32 J·cm−3, which was 2.09 times higher than the pristine PI. Moreover, the temperature at 10 wt% weight loss reached 619°C, demonstrating the excellent thermostability of PI@BT/PI composites. In addition, PI@BT/PI composites exhibited improved breakdown strength and toughness as compared with the BT/PI composites due to the well dispersion of PI@BT nanofillers and the improved interfacial interactions between nanofillers and polymer matrix. These results provide useful information for the structural design of high-temperature dielectric materials.

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Temperature Dependence of Mechanical, Electrical Properties and Crystal Structure of Polyethylene Blends for Cable Insulation

Materials ◽

10.3390/ma11101922 ◽

2018 ◽

Vol 11 (10) ◽

pp. 1922 ◽

Cited By ~ 11

Author(s):

Lunzhi Li ◽

Lisheng Zhong ◽

Kai Zhang ◽

Jinghui Gao ◽

Man Xu

Keyword(s):

High Temperature ◽

Electrical Properties ◽

Temperature Dependence ◽

Elevated Temperatures ◽

Breakdown Strength ◽

Temperature Stability ◽

Xrd Analysis ◽

Insulation Material ◽

Cable Insulation ◽

Polyethylene Blends

There is a long-standing puzzle concerning whether polyethylene blends are a suitable substitution for cable-insulation-used crosslinking polyethylene (XLPE) especially at elevated temperatures. In this paper, we investigate temperature dependence of mechanical, electrical properties of blends with 70 wt % linear low density polyethylene (LLDPE) and 30 wt % high density polyethylene (HDPE) (abbreviated as 70 L-30 H). Our results show that the dielectric loss of 70 L-30 H is about an order of magnitude lower than XLPE, and the AC breakdown strength is 22% higher than XLPE at 90 °C. Moreover, the dynamic mechanical thermal analysis (DMA) measurement and hot set tests suggest that the blends shows optimal mechanical properties especially at high temperature with considerable temperature stability. Further scanning electron microscope (SEM) observation and X-ray diffraction (XRD) analysis uncover the reason for the excellent high temperature performance and temperature stability, which can be ascribed to the uniform fine-spherulite structure in 70 L-30 H blends with high crystallinity sustaining at high temperature. Therefore, our findings may enable the potential application of the blends as cable insulation material with higher thermal-endurance ability.

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