Test data show that low swell ethylene/acrylic compounds, based on AEM-DLS and AEM-LS, maintain 85-120% of their original tensile strength after aging 3,000 hours at 150[degrees]C in the GM ATF fluid and 4,000 hours in the Ford ATF fluid.
Long term aging data was obtained for both GM and Ford `factory fill' motor oils.
The volume swells of the four AEM polymers remained intermediate and consistent throughout the extended aging period.
This method establishes the upper thermal aging limits of commercially available compounds as measured at 23 [degrees] C by retention of at least 50% original elongation and tensile at break after 1,008 hours of heat aging.
Ultimate elongation was selected over other physical property measurements because of its greater sensitivity to the various effects of air oven aging on elastomers.