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

RSC Advances ◽  
2015 ◽  
Vol 5 (110) ◽  
pp. 90343-90353 ◽  
Author(s):  
Hui Zhang ◽  
Yan Shang ◽  
Mingxia Li ◽  
Hong Zhao ◽  
Xuan Wang ◽  
...  

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.

RSC Advances ◽  
2016 ◽  
Vol 6 (112) ◽  
pp. 110831-110839 ◽  
Author(s):  
Hui Zhang ◽  
Yan Shang ◽  
Mingxia Li ◽  
Hong Zhao ◽  
Xuan Wang ◽  
...  

The grafting of the valerophenone as voltage stabilizer to the polyethylene molecule chain is possible in the UV radiation cross linking process. This is useful for preparing insulation cables of high voltage up to 500 kV in real application.


Materials ◽  
2019 ◽  
Vol 12 (21) ◽  
pp. 3562 ◽  
Author(s):  
Chang Liu ◽  
Yiwen Xu ◽  
Daoguang Bi ◽  
Bing Luo ◽  
Fuzeng Zhang ◽  
...  

AlN nanoparticles were added into commercial high-temperature-vulcanized silicon rubber composites, which were designed for high-voltage outdoor insulator applications. The composites were systematically studied with respect to their mechanical, electrical, and thermal properties. The thermal conductivity was found to increase greatly (>100%) even at low fractions of the AlN fillers. The electrical breakdown strength of the composites was not considerably affected by the AlN filler, while the dielectric constants and dielectric loss were found to be increased with AlN filler ratios. At higher doping levels above 5 wt% (~2.5 vol%), electrical tracking performance was improved. The AlN filler increased the tensile strength as well as the hardness of the composites, and decreased their flexibility. The hydrophobic properties of the composites were also studied through the measurements of temperature-dependent contact angle. It was shown that at a doping level of 1 wt%, a maximum contact angle was observed around 108°. Theoretical models were used to explain and understand the measurement results. Our results show that the AlN nanofillers are helpful in improving the overall performances of silicon rubber composite insulators.


RSC Advances ◽  
2016 ◽  
Vol 6 (14) ◽  
pp. 11618-11630 ◽  
Author(s):  
Hui Zhang ◽  
Yan Shang ◽  
Hong Zhao ◽  
Xuan Wang ◽  
Baozhong Han ◽  
...  

The mechanism of benzil-like voltage stabilizers with the tailored side-chain architecture for enhanced dielectric electrical breakdown strength of cross-linked polyethylene at the atomic and molecular levels has been investigated.


Author(s):  
Rebecca Hollertz ◽  
Lars Wågberg ◽  
Claire Pitois

<p>The dielectric properties of the electrical insulation material have a significant influence on the performance and reliability of components in electrical equipment. The influence of the chemistry and electronic structure of the different constituents of the kraft pulp (used in electrical insulation) on some dielectric properties is discussed in this paper. The studies and mechanisms discussed indicate that the presence of different wood polymers (cellulose, hemicellulose and lignin), have different effects on dielectric properties (static electrification and high frequency response). Our results show that the dielectric response of lignin is different compared with the response of hemicellulose and cellulose and this is also expected from the chemical structure of the different components. The lignin molecule has a higher polarizability at frequencies of significance for streamer inception and propagation. With spectroscopic ellipsometry measurements it has also been shown that the energy for electronic transitions in this spectral region is lower for lignin. The results also clearly indicate that the role of cellulose, lignin and hemicellulose should be further investigated for improving electrical breakdown strength of paper based insulation materials.</p>


2021 ◽  
Vol 130 (14) ◽  
pp. 144101
Author(s):  
Jeffrey X. Zheng ◽  
Dixiong Wang ◽  
Pariasadat Musavigharavi ◽  
Merrilyn Mercy Adzo Fiagbenu ◽  
Deep Jariwala ◽  
...  

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