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The low temperature properties of fluorohydrocarbon elastomers (FKM) have been well documented using traditional rubber laboratory tests such as brittle point, temperature retraction, glass transition, and stiffness by Clash-berg and Gehman methods. Although these tests are considered good indicators of low temperature behavior, these techniques have not proven to be entirely accurate in predicting the low temperature sealing capability of fluoroelastomer molded products such as O-rings. The purpose of this paper is to present an overview of the low temperature properties of standard fluoroelastomers and the newer improved low temperature types, by both traditional test methods and a recently developed static O-ring testing device. Through use of this static testing apparatus, the influence of several variables are investigated, which include polymer type, compound design, seal interference, temperature, and fuel plasticization of the FKM compounds.

The automotive industry is continually seeking new elastomers capable of withstanding aggressive fluids at temperature extremes, while providing high quality at attractive costs. The challenge is formidable in view of reliability and warranty considerations, cost pressures and technology limitations. This paper presents the technical basis for a new class of specialty elastomers. DuPont has designed these elastomers to provide heat resistance that exceeds that of currently available elastomers of comparable price. The paper will discuss initial offerings in the ADVANTA™ product family. They offer a unique balance of heat resistance, oil resistance and sealing properties. Potential end-use applications include O-rings, oil seals, gaskets and custom molded sealing devices for engines, transmissions and axles. Features and benefits of selected compound formulations will be presented and benchmarked to other specialty elastomers currently used in the automotive sealing arena.

In recent years, fluoroelastomers have been used in automotive fuel systems with increasing regularity. Automotive fuels have become increasingly aggressive on fuel handling polymers. Gasolines blended with alcohols, alcohol by-products, and additives place a broader challenge on fuel handling polymers. Fluoroelastomers, especially high fluorine types, are viewed by many engineers as a method of stabilizing part performance in the face of today's ever-changing fuels. This paper will compare a traditional fluoroelastomer used in automotive fuel systems to new development fluoroelastomers that are designed to help both the end user and the rubber part manufacturer. The testing done will focus on benefits available from the new FKM polymers, such as low swell in fuel/alcohol blends, improved low temperature flexibility, and improved compression set resistance.