Silicone vs Fluorocarbon

DATE: 5th-February-2019

When it comes to providing expert silicone solutions and rubber products, Jehbco Silicone is leading the way, growing its supply chain at a global scale. This article explores the properties of silicone rubber and how it compares to Fluorocarbon, an elastomer based on fluoro-rubber (FKM), also known as Viton (Fluoro Elastomer brand). 

Although Silicone and Fluorocarbon are quiet similar in their properties, the fluorene (trifluoropropyl) groups do provide significant variances in chemical resistance and compatibility which develops a wider range of possible applications. The following table compares the key chemical and mechanical properties of Silicone and Fluorocarbon. 

Fluorocarbon Silicone
-20° to 250° C -50° to 230° C
Excellent compression set Excellent compression set
Excellent weather resistance Excellent weather resistance
Approx. tensile strength 10 MPa Approx. tensile strength 5 MPa
Fair abrasion resistance  Poor abrasion resistance
Not compatible with: amines, oxygenated solvents, lacquer solvents Not compatible with: hydrocarbon fuels, alkalis and acids, steam over 121 °C, trichloroethylene, aromatic hydrocarbons.
Compatible with: acids, alcohols, oxygenated solvents, alkali, fuels and hydrocarbons, mineral oils,  Compatible with: oils, brake fluids, hot and cold water, salt water, high molecular weight chlorinated hydrocarbons, fire resistant hydraulic fluid, ozone.

 Silicone and Fluorocarbon have very similar temperature ratings ranges, however Silicone is generally superior for low temperature applications at -20° C. Fluorocarbon is able to withstand higher temperatures at 250° C, although Silicone with the addition of heat stabiles and fame retardants, can exceed this and provide temperature ratings of up to 300° C making it an idea for high temperature applications. 

They both share very similar abrasion resistance (fair- poor) which reduces their ability to perform well in dynamic applications and have similar ability to perform well in applications which demand durability due to their excellent compression and weather resistance. The tensile strength of Fluorocarbon is higher than Silicone at 10 MPa making it an ideal possible selection for high force and pressure applications. 

In general, Fluorocarbon due to its chemical structure is an ideal material for applications that require strong chemical compatibly with hydrocarbons, oils and fuel/petroleum. As silicone is ideal for static high-temperature sealing applications, they have poor compatibility with oils and hydrocarbons which allow fluoro-elastomers such as fluorocarbon to be the best material choice.

To discuss the ideal material for your application, please contact us