Fluorocarbon Elastomers: A Technical Review

Abstract

Fluorocarbon elastomers were first introduced in the mid-1950s. During the past 20 years they have found wide use in a variety of applications and have established themselves as an important class of elastomers. Their success and continued growth as high performance materials is a result of their unique balance of physical properties. As a class, they are superior to most other types of elastomers in resistance to degradation at elevated temperatures and resistance to swelling in a wide variety of fluids. This superiority is evident in the ASTM D-2000 classification system where fluorocarbon elastomers normally carry the designation HK for type and class. This system specifies that fluorocarbon elastomers shall be tested for 70 hr at 482°F for resistance to degradation in hot air (the H term) and for 70 hr at 302° F (maximum allowable temperature for the fluid) in ASTM No. 3 oil for fluids resistance (the K term). Under these conditions, heat aged properties must not change more than that indicated in Table 1 while volume increase in the specified oil must not exceed 10%. These test requirements are the most severe of any elastomer described in this ASTM classification system.