(180a) Prediction of Physical Properties of An Emerging Class of Compounds

Hydrofluoroethers (HFEs) are the primary candidate materials that will replace HFCs in industrial practice if the United States government signs legislation to reduce global climate change. The US EPA recently announced on April 24, 2009 that six compounds or classes of compounds that contribute to global climate change are human health hazards. While carbon dioxide is the largest gas of concern, hydrofluorocarbons (HFCs) are included due to their long term impacts through extended atmospheric lifetimes.

While about 50 HFEs have some physical property data available in the literature, many of these possible HFC alternatives have none. This paper uses computational chemistry to predict properties relevant for screening a larger set of these compounds for industrial use. While vapor pressures have been predicted in the past, this work is the first to estimate boiling points using quantum chemical means. Heat capacities, important for solvent re-use and for determining work requirements in compressors are also explored.

Potential environmental impacts and decision trade-offs are explored. Global warming potentials, kinetic degradation pathways, and likely end-points for removal mechanisms are detailed in the context of the pending HFC regulations.