Accelerated ultraviolet weathering investigation on micro‐/nano‐SiO ₂ filled silicone rubber composites

Abstract

This study attempts to elucidate whether the addition of micro and/or nano-silica (SiO 2) particles can enhance the resistance of pure polydimethylsiloxane against synergistic effects of UV, temperature and high-voltage stress. Four types of composites (U-SR, M-SR, MN-SR and N-SR) are fabricated by adding micro and/or nano-silica particles and then subjected to multi-stress degradation in a test chamber. Results show that there is an apparent surface discoloration in the form of yellowish pale tint and a significant resistance to hydrophobicity reduction is offered by N-SR and MN-SR followed by M-SR and U-SR. Scanning electron microscopy and surface roughness findings proclaimed that N-SR and MN-SR offer excellent resistance against filler exposure and an increase in surface roughness. There is a minor reduction in absorbance level of Si (CH 3) 2 and Si-O-Si functional groups of composites but interestingly, hydrophilic hydroxyl group absorbance level is found higher in the U-SR comparatively. Furthermore, dielectric response measurements indicate considerable sensitivity to weathering with N-SR and MN-SR giving the lowest dielectric loss. Results indicate that the addition of nano-silica to pure and micro-silica filled SR can enhance its UV weathering resistance considerably by building an effective UV shielding layer.

Effect of Ageing on the Tracking Characteristics of High-Temperature Vulcanized Silicone Rubber Hybrid Composites for High Voltage Insulation

“…In this method, the water drop was made to fall on the silicone rubber sample surface. The contact angle between the drop and the surface was measured.The contact angle greater than 90 • indicated good hydrophobicity and, less than 90 • indicated that the sample had become hydrophilic [22][23][24][25][26].…”

“…Nazir et al investigated to understand the addition of nano/micro SiO 2 particles in enhancing the UV weathering resistance of RTV silicone rubber. Nazir et al also studied the effect of different micro-fillers, like ATH, aluminum nitride (AlN) and boron nitride (BN) in improving the tracking and erosion properties of silicone rubber [22,23]. Guo, Y. et al fabricated silicone rubber with platinum/amino-silane, which enhances the tracking resistance during dry band arcing period [24].…”

Investigation of Hydrothermally Stressed Silicone Rubber/Silica Micro and Nanocomposite for the Coating High Voltage Insulation Applications

“…Yuan and co-workers studied the dielectric loss of SiR/SiO 2 composites under AC corona at different AC voltages and observed that change in dielectric loss remained under 1% after 24 days of corona aging at 3 kV [27]. Degradation of silica filled silicone rubber under accelerated ultraviolet weathering conditions has also been reported [28]. The dielectric properties of newly manufactured and 500 kV composite insulators operated shed and housing material was determined under hydrothermal conditions (20 • C, 90% humidity).…”

Multi-Stressed Nano and Micro-Silica/Silicone Rubber Composites with Improved Dielectric and High-Voltage Insulation Properties

“…Nevertheless, polymer composites offer multiple improvements over simple polymers [ 1 ]. Polymer composites have an edge over conventional polymers due to their improved stability, greater lifespan, and enhanced physical, electrical, optical, and mechanical properties [ 2 , 3 , 4 , 5 , 6 , 7 , 8 ]. The development of charge-storing devices for higher storage capability needs to meet challenging criteria such as higher dielectric permittivity, low dielectric loss, and better mechanical strength [ 9 ].…”