ABSTRACT
The development of blowing agents that exhibit lower thermal conductivity, shorter atmospheric lifetime, and less adverse effects on the atmosphere is an urgent issue. We investigated four fluorinated ethers as alternative blowing agents (1,1,2,2-tetrafluoroethyl methyl ether (HFE-254pc), 1,1,2,2-tetrafluoroethyl difluoromethyl ether (HFE-236pc) and 1,1,2,2,3,3,3-heptafluoropropyl methyl ether (HFE-347mcc)) in terms of physical properties (Table1), gaseous thermal conductivity (Table2)[2], environmental adaptability (atmospheric lifetime) [4] [5], toxicity, flammability, solubility in polyols, and thermal stability.
By using these fluorinated ethers as blowing agents, we experimentally produced rigid polyurethane foams, which all showed thermal conductivities lower than or equal to foams produced with the blowing agent alternative candidates, HFC-245fa and cyclopentane.
Included in this study are the newly discovered azeotrope or azeotrope-like of HFEs with HFC-245fa or cyclopentane.
