Synthesis and global warming potential prediction of novel hydrofluoroethers for high-resistivity engineering fluids

Despite the growing interest in eco-friendly, high-performance immersion cooling fluids, systematic studies on developing next-generation hydrofluoroether (HFE)-based engineering fluids remain in the early stage. In particular, molecular design rules for tailoring diverse thermophysical properties have not yet been fully established. In this study, novel HFE-based engineering fluids were designed and synthesized by introducing two ether linkages to modify their thermophysical properties. The molecular structures of the synthesized compounds were confirmed via gas chromatography (GC) equipped with flame ionization detection (FID), GC–field ionization time-of-flight high-resolution mass spectrometry (GC-FI-TOF HRMS), and nuclear magnetic resonance (NMR) spectroscopy. Subsequently, their physical properties—including boiling point, vapor pressure, density, viscosity, surface tension, and volume resistivity—were evaluated. The results revealed up to a 10⁴-fold increase in volume resistivity, along with tunable boiling points and viscosity, demonstrating their potential as next-generation immersion cooling fluids. Furthermore, the global warming potentials (GWPs) of the HFEs were estimated by predicting OH-radical-induced hydrogen abstraction reaction kinetics using density functional theory (DFT) at the M06-2X/6-31+G(d,p) level of theory. Based on the DFT calculations, the GWP 100/CO₂ values of HFE-TFPE and HFE-TFTF were estimated to be 161–203 and 260–295, respectively. These results suggest that introducing two ether linkages is an effective molecular design strategy for enhancing the performance of HFE-based engineering fluids while simultaneously reducing their GWPs. • Novel HFEs with two ether linkages were synthesized as engineering fluids. • Precise tunability of the physicochemical properties of novel HFEs was demonstrated • Volume resistivity exhibits a four-order-of-magnitude enhancement over commercial HFEs. • DFT calculations predict reduced GWP values for the novel HFEs compared to commercial HFEs.