Atmospheric chemistry of HCF2O(CF2CF2O)xCF2H (x=2-4): kinetics and mechanisms of the chlorine-atom-initiated oxidation.
Smog chamber/FTIR techniques were used to measure k(Cl+HCF(2)O(CF(2)CF(2)O)(x)CF(2)H)=(5.3±1.5)×10(-17) cm(3) molecule(-1) s(-1) in 700 Torr of N(2)/O(2) diluent at 296±1 K. The Cl-initiated atmospheric oxidation of HCF(2)O(CF(2)CF(2)O)(x)CF(2)H, x=2,3 and 4, gave COF(2) in molar yields of (593±41)%, (758±71)% and (939±73)%, respectively, with no other observable carbon-containing products (i.e., essentially complete conversion of the hydrofluoropolyethers into COF(2)). Quantitative infrared spectra for HCF(2)O(CF(2)CF(2)O)(x)CF(2)H (x=2-4) were recorded and used to estimate the radiative efficiencies of the title compounds (1.07, 1.33, and 1.36 W m(-2) ppb(-1)). Global warming potentials (100 year time horizon) of 3870, 4730 and 5060 were estimated for HCF(2)O(CF(2)CF(2)O)(x)CF(2)H, x=2, 3 and 4, respectively. The results are discussed with respect to the atmospheric chemistry and environmental impact of hydrofluoropolyethers.
Sulbaek Andersen
Mads P
MP
Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Stop 183-901, Pasadena, CA 91109, USA. mads@sulbaek.dk
Andersen
Vibeke F
VF
Nielsen
Ole J
OJ
Sander
Stanley P
SP
Wallington
Timothy J
TJ