Assessing the Compatibility of PAO and POE with Fluoroelastomer (FKM) for Potential EVs Application

The accelerated growth of electric vehicle (EV) powertrains has prompted the development of specialized fluids that meet stringent thermal and electrical requirements for immersion cooling systems, including interactions with non-metallic components like fluoroelastomer (FKM). This research investigates the interactions between fluoroelastomer (FKM) and two potential base fluids—polyalphaolefin (PAO4) and a polyol ester (POE)—to assess their suitability for immersion cooling applications. Immersion tests, following an adapted ASTM D7216 standard, evidenced changes in FKM’s mass, Shore A hardness, and tensile strength. Furthermore, the physical, electrical, and thermal properties of the tested fluids were analyzed before and after immersion to determine whether contact with the FKM elastomer compromised their performance. The findings of this study reveal that the fluid exerts a greater influence on the elastomer than vice versa. This study bridges a knowledge gap in regards to EV fluid development and material science, contributing to the development of durable and efficient thermal management solutions.