scholarly journals Electrical Strength and Physicochemical Performances of HTV Silicone Rubber under Salt-Fog Environment with DC Energized

Polymers ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 324 ◽  
Author(s):  
Zhijin Zhang ◽  
Tian Liang ◽  
Chen Li ◽  
Xingliang Jiang ◽  
Jian Wu ◽  
...  
Keyword(s):  
Silicone Rubber ◽  
Electrical Strength ◽  
Dielectric Parameter ◽  
Material Degradation ◽  
Performance Loss ◽  
Static Contact ◽  
Rubber Composite ◽  
Flashover Voltage ◽  
Insulation Performance ◽  
Salt Fog

In recent years, the performances of rubber composite insulators, which operate in the coastal foggy regions, have attracted researchers’ concern because of the observation of their degradation. In this paper, salt-fog experiments with DC test voltage of high-temperature vulcanized (HTV) silicone rubber (SR) have been conducted. The electrical strength and material performances of samples with salt-fog treatment were focused on. The DC flashover voltage, hydrophobicity, scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and dielectric parameter were investigated. It was found that the samples’ performances deteriorated after salt-fog treatment. The DC flashover voltage of HTV SR decreased in the salt-fog environment. The hydrophobicity of the material deteriorated and the static contact angle (CA) became small. Under the action of electric and thermal stress, the surface of samples after salt-fog treatment became rough and porous. The absorption peak of the hydrophobic groups decreased, indicating that the molecular chain of SR material was broken, and the filler was consumed, bringing down the arc resistance of the sample. The absorption of moisture further led to insulation performance loss and then reduced the electrical strength of the material. Degradation of physicochemical properties will eventually lead to a decline in electrical strength.

scholarly journals Preparation of Bamboo-Like Carbon Nanotube Loaded Piezoresistive Polyurethane-Silicone Rubber Composite

Polymers ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 2144
Author(s):  
Mohammed Nabeel ◽  
Miklós Varga ◽  
László Kuzsela ◽  
Ádám Filep ◽  
Béla Fiser ◽  
...  
Keyword(s):  
Carbon Nanotube ◽  
Silicone Rubber ◽  
Dip Coating ◽  
Nitrogen Doped ◽  
Novel Technology ◽  
Pu Foam ◽  
Rubber Composite ◽  
Finger Touch ◽  
Human Monitoring ◽  
Strength And Durability

In this study, a novel technology is reported to prepare a piezoresistive polyurethane-silicone rubber nanocomposite. Polyurethane (PU) foam was loaded with a nitrogen-doped bamboo-shaped carbon nanotube (N-BCNT) by using dip-coating, and then, impregnated with silicone rubber. PU was used as a supporting substrate for N-BCNT, while silicone rubber was applied to fill the pores of the foam to improve recoverability, compressive strength, and durability. The composite displays good electrical conductivity, short response time, and excellent repeatability. The resistance was reduced when the amount of N-BCNT (0.43 wt %) was increased due to the expanded conductive path for electron transport. The piezoresistive composite has been successfully tested in many applications, such as human monitoring and finger touch detection.

scholarly journals Pollution Measurements to Assess the Performance of Naturally Exposed Silicone Rubber Composite Insulators

2007 ◽  
Vol 127 (9) ◽  
pp. 513-518 ◽  
Author(s):  
Igor Gutman ◽  
Håkan Wieck ◽  
Dan Windmar ◽  
Lennart Stenström ◽  
Dan Gustavsson
Keyword(s):  
Silicone Rubber ◽  
Rubber Composite

scholarly journals Thermal Decomposition and Ceramifying Process of Ceramifiable Silicone Rubber Composite with Hydrated Zinc Borate

Materials ◽  
2019 ◽  
Vol 12 (10) ◽  
pp. 1591
Author(s):  
Jiuqiang Song ◽  
Zhixiong Huang ◽  
Yan Qin ◽  
Xinyi Li
Keyword(s):  
Thermal Decomposition ◽  
Compressive Strength ◽  
Network Structure ◽  
Silicone Rubber ◽  
Bending Strength ◽  
Linear Shrinkage ◽  
Decomposition Temperature ◽  
Zinc Borate ◽  
Air Atmosphere ◽  
Rubber Composite

The ceramifiable silicone rubber composite was prepared using hydrated zinc borate and kaolin as ceramifiable fillers. Effects of the hydrated zinc borate content and the combustion temperature on the properties of the ceramifiable silicone rubber composite were investigated. Thermal decomposition and ceramifying processes of the composite in a muffle furnace under air were also studied. The results showed that the density and the hardness of the composites increased as the content of the hydrated zinc borate increased from 0 to 30 phr. The tensile strength and elongation at break decreased. In addition, hydrated zinc borate decreased the decomposition temperature of the composite, whereas the residue weight under air atmosphere was increased. In the process of decomposition and oxidation of the ceramifiable silicone rubber composite in air, B2O3 was generated by the decomposition of zinc borate and participated in the formation of the residue network structure, which decreased the temperature of the ceramifying transition. The new phases, zinc aluminate (ZnO·Al2O3) and aluminum-rich mullite (9Al2O3·2SiO2), appeared after high-temperature thermochemical reactions. Microscopy images revealed that different structures were formed at different temperatures. The network structure of the ceramic residue became increasingly compact, and the compressive strength increased from 0.31 to 1.82 MPa with the increase of temperature from 800 to 1400 °C, which had a better protective effect on heat transfer and mass loss. The weight loss and the linear shrinkage of the ceramic residue was 37.6% and 21.9%, respectively, with the 30 phr content of hydrated zinc borate. The bending strength was improved from 0.11 to 11.58 MPa, and the compressive strength also increased from 0.03 to 1.14 MPa.

scholarly journals AC Volume Breakdown and Surface Flashover of a 4% NovecTM 4710/96% CO2 Gas Mixture Compared to CO2 in Highly Nonhomogeneous Fields

Energies ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1710 ◽  
Author(s):  
Houssem Eddine Nechmi ◽  
Mohammed El Amine Slama ◽  
Abderrahmane (Manu) Haddad ◽  
Gordon Wilson
Keyword(s):  
Electrical Strength ◽  
Gas Mixture ◽  
Nonlinear Behaviour ◽  
Co2 Gas ◽  
Surface Flashover ◽  
Surface Finishes ◽  
Needle Position ◽  
Flashover Voltage ◽  
Solid Insulator ◽  
Solid Dielectrics

AC pre-discharge currents, breakdown, and flashover voltage measurements are reported in a 10 mm needle-plane arrangement in a 4% NovecTM 4710/96% CO2 gas mixture and compared with CO2 for pressures up to 8.8 bar abs. Flashover measurements were performed on different solid dielectrics (Al2O3_filled epoxy resins, PTFE (Polytetrafluoroethylene) and PE (polyethylene)) for different roughness surface finishes. The effect of fixed conducting needles at various positions on electrical strength is reported. A strong nonlinear behaviour as function of gas pressure was observed for all the studied parameters (gas, needle position, solid insulator, insulator roughness). The non-linear behaviour is attributed to the inception and quenching of glow corona, in the interval between inception and breakdown or flashover voltages. It is found that a 4% concentration of NovecTM 4710 in CO2 has a breakdown/flashover voltage ≈ 1.14 higher than CO2. The glow corona-induced stabilization effect is seen for pressures between 2 and 5 bar abs for all the studied parameters. The peak flashover voltage and its associated pressure of the different insulators are strongly dependent on surface roughness. At 8.8 bar abs, the flashover voltage level obtained with various materials was ordered as follows: PTFE > PE-UHMW > Epoxy > HDPE(High-density polyethylene).

scholarly journals Surface Discharge Mechanism on Epoxy Resin in Electronegative Gases and Its Application

2020 ◽  
Vol 10 (19) ◽  
pp. 6673
Author(s):  
Herie Park ◽  
Dong-Young Lim ◽  
Sungwoo Bae
Keyword(s):  
Sulfur Hexafluoride ◽  
Design Method ◽  
Surface Discharge ◽  
Uniform Field ◽  
Dielectric Characteristics ◽  
Discharge Mechanism ◽  
Dry Air ◽  
Surface Flashover ◽  
Flashover Voltage ◽  
Insulation Performance

This study presents the surface discharge characteristics of insulating gases, including sulfur hexafluoride (SF6), dry air, and N2, under a non-uniform field. Surface discharge experiments were conducted, with the gas pressure ranging from 0.1 to 0.6 MPa, on samples of epoxy dielectrics under an AC voltage. The experimental results showed that the surface insulation performance significantly improved in insulating gases possessing electronegative gases, such as SF6 and dry air. Surface flashover voltages of SF6 were saturated with an increasing pressure, compared to dry air and N2. The surface discharge mechanism is proposed to explain the improvement and saturation of dielectric characteristics of the electronegative gas in complex dielectric insulations, as well as its influence on the surface flashover voltage. As an application, an insulation design method is discussed with regards to replacing SF6 gas in high-voltage power equipment based on the knowledge of the physics behind gas discharge.

Sign in / Sign up

Export Citation Format

Share Document