Phosphazene Elastomers for Fuel Service under Arctic Conditions *

Abstract

Polyphosphazene fluoroelastomers, developed through Government in-house and contractual efforts, exhibit good resistance to aromatic fuels as well as capability for performance at temperatures as low as −57° C. This combination of properties is necessary in fabrication of end items or components for arctic fuel handling equipment and in many other military and civilian applications. These polymers, having a C₂-C₅ [(CF₃CH₂, O)₂ PN-(HCF₂C₃F₆CH₂O)₂ PN] ***_n configuration, can contain varying degrees of unsaturation (cure sites) and fluorine content.

The inherent heat, fuel, water and low temperature properties of phosphazene rubber are compared with those of commonly used fuel resistant elastomers. These properties are also compared in a study of several structurally modified polymers containing varying amounts of fluorine. Further discussion includes results of a compounding study of two polymer types, wherein experimental design and computerized data analysis are used to ascertain the effects of various cross-linking agents and fillers.