Investigation of 9000 hours multi-stress aging effects on High-Temperature Vulcanized Silicone Rubber with silica (nano/micro) filler hybrid composite insulator

Abstract

Degradation in the polymeric insulators is caused due to the environmental stresses. The main aim of this paper is to explore the improved aging characteristics of hybrid samples by adding nano/micro silica in High Temperature Vulcanized Silicone Rubber (HTV-SiR) under long term accelerated aging conditions for 9000 hours. As HTV-SiR is unable to sustain environmental stresses for a long time, thus a long term accelerated aging behavior is an important phenomenon to be considered for field application. The aging characteristics of nano/micro filled HTV-SiR are analyzed by using techniques such as Scanning Electron Microscopy (SEM), Leakage Current (LC), Fourier Transform Infrared Microscopy (FTIR), Hydrophobicity Classification (HC), and breakdown strength for the aging time of 9000 hours. FTIR and leakage currents are measured after every cycle. All the co-filled samples revealed escalated aging characteristics as compared to the neat sample except the SN8 sample (8% nano-silica+20% micro-silica) after 9000 hours of aging. The highest loading of 6% and 8% nano-silica with 20% micro-silica do not contribute to the improved performance when compared with the neat and hybrid samples. However, from the critical experimental analysis, it is deduced that SN2 sample (2% nano-silica+20% micro-silica) is highly resistant to the long term accelerated aging conditions. SN2 has no cracks, lower loss percentages in the important FTIR absorption peaks, higher breakdown strength and superior HC after aging as compared to the unfilled and hybrid samples.

Enhanced Hydrofobicity of Polymers for Personal Protective Equipment Achieved by Chemical and Physical Modification

“…The bands correspond to asymmetric stretching vibrations of the Si–O group, which confirms the structure of the main chain of the MVQ macroparticle. An intensive and sharp band of deformation vibrations at the wave number of 1258 cm −1 is typical of the Si–CH 3 group [ 47 , 48 , 49 , 50 ]. The strong and sharp band also confirms the presence of C–Si–C groups at the wavenumber of 785 cm −1 and a medium-intensity doublet in the wavenumber range between 700 and 660 cm −1 .…”

Surface Recovery Investigation of Silicone Rubber Composites for Outdoor Electrical Insulation under Accelerated Temperature and Humidity

“…The FTIR spectroscopy technique was used to analyze the internal chemical changes of nSir, SNC 2.5% SiO 2 , SMC 15% SiO 2 , SMC 15% ATH and SMNC 10% ATH 2% SiO 2 . After each cycle, all the samples were analyzed in absorption form [ 31 ]. The important functional groups of silicone rubber and their respective wavenumbers are given in Table 3 .…”

“…After each cycle, all the samples were analyzed in absorption form [31]. The important functional groups of silicone rubber and their respective wavenumbers are given in Table 3.…”

Effects of processing parameters on the leakage current of silicone rubber insulator

“…During IPT, the polymer experiences chain scissoring or even further crosslinking due to oxidation, hydrolysis, hydrosilylation or pyrolysis, causing the absorbance peak of the SiR functional group to reduce. Adding filler helps in increasing the materials resistibility against aging as the linking between the base polymer matrix and filler can results in the alterations of the bulk properties of the composite insulating materials [32], [33]. Hence, it can be inferred that the chosen processing parameters in samples 1, 3, and 4 might not be optimal for achieving proper filler dispersion, resulting in reduced functional groups and accelerated aging of the samples.…”