I am a mechanical engineer and I have been working with DuPont for 4 years. I am passionate about material selection!
As the world transitions towards renewable energy resources, hydrogen is becoming a popular means of storing and transporting energy. Cold or Cryogenic- highly compressed storage leads to higher on-board storage hydrogen densities, resulting in demanding material requirements for critical sealing elements.
Vespel® is an engineered polymer that is used across a wide range of applications, including several in direct hydrogen service. Polyimide parts exhibit properties that provide unique advantages over other engineered polymers and non-metallic materials. Specifically, this presentation will review how polyimide parts can create strong seals against hydrogen while maintaining lubricity and excellent wear and friction performance in the most extreme environments.
Vespel® polyimides have shown to maintain a consistent compressive modulus from room temperature to -253°C. The near- constant properties of Vespel® over this range of temperatures has proven to be critical in sealing applications in the extreme environments presented by both liquid and gaseous hydrogen.
Wear and friction tests in different environments such as vacuum, nitrogen, gaseous and liquid hydrogen will be reviewed in this presentation. For polymeric solutions, the choice of fillers and additives play an important role when determining the wear and friction performance in hydrogen environments and should be carefully considered when selecting suitable materials for the intended application. In these experiments, specific polyimide compositions have shown an exceptional friction reduction in hydrogen environments, while other ones have demonstrated a significant reduction in wear rate when exposed to such conditions.
Finally, hydrogen permeability of multiple polyimide grades had been studied and the results and significance of this property is discussed in this presentation. Certain polyimides have shown a very favorable low hydrogen permeability, and one of the longest saturation times found amongst various polymers so far.
We will be providing attendees with information on DuPont polyimides to help them feel comfortable with non-metallic material selection in the extreme conditions typically associated with hydrogen energy generation and storage.
