Innovating the Future of Sustainable Immersion Cooling

Some soft plastic and elastomeric materials interact differently with esters than with hydrocarbons. These differences can lead to compatibility issues, but they can also be deliberately exploited to optimize material performance in specific applications.

NBR‑based sealing materials often shrink when exposed to hydrocarbon fluids, which can negatively affect sealing performance. In contrast, ester fluids typically cause these materials to swell. By combining hydrocarbon and ester fluids, it is possible to balance shrinkage and swelling effects and thereby tune material compatibility and sealing behavior.

This effect can also be observed in the mechanical properties of sealing materials, where fluid‑induced hardening can be balanced against softening effects. Achieving such a balance can be critical for maintaining long‑term sealing performance.

Fortunately, not all materials require this careful tuning of properties and are less sensitive to variations in fluid chemistry. Polyurethane, for example, is often regarded as relatively fluid‑tolerant and is therefore frequently recommended for applications such as cable sheathing in immersion cooling systems, where prolonged exposure to different fluid chemistries is expected.

In contrast, PU exhibits only small decreases in Shore hardness in both fluids, with very similar values, demonstrating good hardness stability and material compatibility under the tested conditions.

VISCOBASE® 11- 210 is specifically designed as an additive for immersion cooling fluids. As such, it not only has a more pronounced impact on material compatibility than ester fluids which can be used in pure form, but also significantly influences the thermal performance of the formulated coolant.

VISCOBASE® 11- 210 is particularly well suited for formulations targeting flashpoints above 200 °C and can even enhance the cooling efficiency of high‑performance synthetic base fluids. This makes it a valuable formulation component for advanced immersion cooling applications where both safety and thermal performance are critical.