scholarly journals Understanding Variations in the Tracking and Erosion Performance of HTV-SR-Based Composites due to AC-Stressed Aging

Polymers ◽  
2021 ◽  
Vol 13 (21) ◽  
pp. 3634
Author(s):  
Rahmat Ullah ◽  
Muhammad Akbar ◽  
Nasim Ullah ◽  
Sattam Al Otaibi ◽  
Ahmed Althobaiti
Keyword(s):  
Thermal Stability ◽  
Outdoor Environment ◽  
Shielding Effect ◽  
Nano Silica ◽  
Two Samples ◽  
Measuring Techniques ◽  
Practical Standpoint ◽  
Surface Leakage ◽  
Micro Silica ◽  
Composite Samples

Among the polymeric family, high-temperature-vulcanized silicone rubber (HTV-SR) is the most deployed material for high voltage insulation applications. However, in an outdoor environment, due to contamination and wetting-induced dry band arcing, consequently SR experiences surface tracking and erosion. From a practical standpoint, the tracking and erosion performance under multi-stress aging is required to be known. It is in that context that the present study was undertaken to measure and analyze the effect of multi-stress aging on tracking and erosion performance. Composite samples of SR having different filler concentrations of silica and alumina trihydroxide (ATH) were aged in a multi-stress chamber for a period of 5000 h, and after that their electrical tracking performance was studied. Simultaneously, unaged samples were also exposed to tracking test for comparison. To conduct this test, the inclined plane testing technique was used in accordance with IEC-60587. All samples exposed to tracking test were analyzed using different diagnostic and measuring techniques involving surface leakage current measurement, Fourier transform infrared spectroscopy (FTIR), thermal stability and hydrophobicity classification. Experimental results shown that the tracking lifetime increased through incorporation of silica and ATH fillers in the SR. Amongst all test samples, two samples designated as filled with 2% nano silica and 20% micro silica/ATH exhibited greater resistance to tracking. This was attributed to the optimum loading as well as better dispersion of the fillers in the polymer matrix. The presence of nano-silica enhanced time-to-tracking failure, owing to both improved thermal stability and enhanced shielding effect on the surface of nanocomposite insulators.

scholarly journals Effects of Micro-silica and Nano-silica on Fresh Properties of Mortar

2017 ◽  
Vol 23 (4) ◽  
Author(s):  
Leo Gu LI ◽  
Pui-Lam NG ◽  
Zhao-Hui HUANG ◽  
Jiang ZHU ◽  
Albert Kwok-Hung KWAN
Keyword(s):  
Fresh Properties ◽  
Nano Silica ◽  
Micro Silica

scholarly journals Hydrophobicity of Polyacrylate Emulsion Film Enhanced by Introduction of Nano-SiO2 and Fluorine

Polymers ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 255
Author(s):  
Tao Xu ◽  
Qiangqiang Xiao ◽  
Jiayu Chen ◽  
Li Li ◽  
Xiongjun Yang ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Photoelectron Spectroscopy ◽  
Silicon Nanoparticles ◽  
Shielding Effect ◽  
Nano Sio2 ◽  
Fluorinated Polyacrylate ◽  
Air Interface ◽  
Emulsion Film ◽  
Emulsion Films ◽  
Ultraviolet Shielding

This study proposes to utilize modified Nano-SiO2/fluorinated polyacrylate emulsion that was synthesized with a semi-continuous starved seed emulsion polymerization to improve the hydrophobicity, thermal stability, and UV-Vis absorption of polyacrylate emulsion film. To verify the proposed method, a series inspection had been conducted to investigate the features of the emulsion film. The morphological analysis indicated that Nano-SiO2 was surrounded by a silane molecule after modification, which can efficiently prevent silica nanoparticles from aggregating. Fourier transform infrared spectra confirmed that modified SiO2 and dodecafluoroheptyl methacrylate (DFMA) were successfully introduced to the copolymer latex. The particle size of latex increased with the introduction of modified Nano-SiO2 and DFMA. UV-Vis absorption spectra revealed that modified silicon nanoparticles can improve the ultraviolet shielding effect obviously. X-ray photoelectron spectroscopy illustrated that the film–air interface was richer in fluorine than film section and the glass side. The contact angle of modified Nano-SiO2/fluorinated polyacrylate emulsion containing 3 wt % DFMA was 112°, slightly lower than double that of polyacrylate emulsion, indicating composite emulsion films possess better hydrophobicity. These results suggest that introducing modified Nano-SiO2 and fluorine into polyacrylate emulsion can significantly enhance the thermal stability of emulsion films.

Evaluation of Mechanical Properties of Acacia-Jute-Sisal-Glassfibrereinforced Composite

2015 ◽  
Vol 813-814 ◽  
pp. 51-56 ◽  
Author(s):  
C. Elanchezhian ◽  
B. Vijaya Ramnath ◽  
V. Ramanan ◽  
R. Saisundararam ◽  
C.S. Siddarth
Keyword(s):  
Impact Test ◽  
Weight Ratio ◽  
High Strength ◽  
Light Weight ◽  
Compression Moulding ◽  
Environment Friendly ◽  
Two Samples ◽  
Automobile Components ◽  
Maximum Content ◽  
Composite Samples

Now-a-days traditional materials are replacing the natural fibres in automobile components like dashboards, seat-backs and interior trims due to its properties like light weight, environment friendly, good stiffness and high strength to weight ratio . In the study three different continuous fibres, Acacia, Jute and Sisal were mixed in varying proportion with GFRP and epoxy resin on a determined ratio basis to get three different composite samples. These fibres were alkaline treated and moulded using compression moulding and hand lay-up technique. These samples were tested for their Tensile and Impact strengths to find the specimen with higher strength. Scanning Electron Microscope (SEM) test was also conducted to study the structure of all three specimens after tensile test. The study concludes that the sample ‘A’ which has maximum content of sisal has higher tensile strength than other two samples. Similarly impact test concludes that specimen ‘B’ and ‘C’ which has maximum content of Jute and Acacia has equal and higher strength.

scholarly journals Experimental Study on the Mechanical Properties of Concrete using Micro Silica and Nano Silica - A Step Towards Sustainability

2016 ◽  
Vol V5 (11) ◽  
Author(s):  
Myriam Marie Delcasse ◽  
Nirmith .S. Kumar,Ashwith .S. ◽  
Nikethan .M.S. ◽  
Sunil Kumar .S. Nayak ◽  
Keyword(s):  
Mechanical Properties ◽  
Experimental Study ◽  
Nano Silica ◽  
Micro Silica

scholarly journals Thermal stability and gaseous exhaust products of bovine leather for firefighter boots

2019 ◽  
Vol 68 (1) ◽  
pp. 16-19
Author(s):  
Sandra Flinčec Grgac ◽  
Franka Žuvela Bošnjak ◽  
Boris Valečić ◽  
Jadranka Akalović
Keyword(s):  
Thermal Stability ◽  
Thermogravimetric Analysis ◽  
Fire Resistance ◽  
Direct Contact ◽  
Degradation Products ◽  
Flame Spreading ◽  
Gaseous Products ◽  
Heat Degradation ◽  
Two Samples ◽  
Artificial Surface

This paper aims to investigate fire resistance properties of two samples of fireproof bovine leather; both with smooth and perforated brushed surfaces. Apart from flammability and flame spreading, an important property is heat resistance and the development of gaseous products that occur during heat degradation. For the purpose of characterizing those properties, cowhide leather samples were exposed to thermogravimetric analysis (TGA) of monitoring gaseous degradation products (TG-IR) during decomposition. Considering the results of fire resistance, it can be concluded that tested samples of smooth bovine leather show satisfactory stability to the influence of flame and heat, while perforated brushed fireproof leather with artificial surface was partially pouched and gathered in the area of direct contact with flame. Both samples show similar behavior during TGA, but differences have been observed in the analysis of gaseous degradation products.

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