Core Material Breakthrough for High-End Manufacturing – FSR’s Low-Temperature Performance and 25-Year Service Life Validated
In extreme operational environments such as aero-engines, high-voltage power transmission, and deep-sea exploration, seal reliability directly determines equipment service life. A recent domestic research breakthrough in fluorosilicone rubber (FSR) low-temperature performance and lifetime prediction has passed authoritative validation, promising enhanced self-sufficiency in high-end sealing technology.
Fluorosilicone rubber, combining flexible polysiloxane backbones with chemically inert fluorine side groups, is known as the “dual champion of oil resistance and temperature extremes.” However, conventional FSR suffers from inherent low-temperature limitations (brittleness typically above -55°C) and lacks accurate lifetime prediction models under aggressive media, constraining its use in polar equipment and ultra-high-voltage transformers. In Q1 2026, a joint research team from State Grid and materials research institutes announced a significant breakthrough: by introducing flexible segments into fluorosilicone gum and surface-modifying fumed silica, they produced an FSR sealing material with dramatically improved low-temperature performance.
Test data shows the material not only retains excellent oil resistance but also achieves a significantly lower brittleness temperature, demonstrating outstanding adaptability in high-voltage transformers in frigid regions. More crucially, using the Arrhenius equation to extrapolate service life in oil-immersed transformers, the team projects a service life of up to 25 years.
This breakthrough addresses a major power industry pain point. Traditional transformer seals made of nitrile rubber or acrylate rubber, though inexpensive, tend to harden and crack under long-term oil immersion and high-temperature aging, causing oil leaks. Standard fluorocarbon rubber, while oil-resistant, has poor rebound resilience and low-temperature brittleness. FSR combines silicone rubber’s high/low-temperature resistance with fluorocarbon rubber’s oil and solvent resistance, making it an ideal sealing solution for new-generation high-voltage power equipment.
Another team focused on improving thermal aging resistance. By comparing fluorosilicone gums with different vinyl contents, researchers found that moderately increasing vinyl content and controlling molecular weight distribution significantly improves heat-air aging resistance. However, excessive vinyl content leads to higher hardness and lower elongation. By optimizing specific surface area of silica filler and combining ceria and titania as heat stabilizers, the FSR maintains high tensile strength retention after long-term use at temperatures above 200°C.
Progress in processing aids is also notable. The choice of silane coupling agent is critical. Research shows that adding γ-aminopropyltriethoxysilane to a bis-2,4-dichlorobenzoyl peroxide curing system not only improves tensile and tear strength but most significantly reduces compression set—the critical indicator of sealing material rebound resilience.
These technological advances are rapidly translating into production. In a high-tech park laboratory in East China, researchers are applying these results to seals for harmonic reducers in smart robots. As AI and robotics explode, demand for sealing materials that maintain stable friction coefficients under high-frequency vibration and lubricating oil environments is surging, moving high-end FSR from laboratories to broad industrial applications.
