Atmospheric Chemistry of CH₃O(CF₂CF₂O)_nCH₃(n= 1−3):  Kinetics and Mechanism of Oxidation Initiated by Cl Atoms and OH Radicals, IR Spectra, and Global Warming Potentials

Abstract

Smog chambers equipped with FTIR spectrometers were used to study the Cl atom and OH radical initiated oxidation of CH 3 O(CF 2 CF 2 O) n CH 3 (n ) 1-3) in 720 ( 20 Torr of air at 296 ( 3 K. Relative rate techniques were used to measure k(Clwere recorded and used to estimate halocarbon global warming potentials of 0.051, 0.058, and 0.055 (100 year time horizon, relative to CFC-11) for CH 3 OCF 2 CF 2 OCH 3 , CH 3 O(CF 2 CF 2 O) 2 CH 3 , and CH 3 O(CF 2 CF 2 O) 3 -CH 3 , respectively. Results are discussed with respect to the atmospheric chemistry of hydrofluoropolyethers (HFPEs).

Environmental risk assessment of hydrofluoropolyethers (HFPEs)

“…With respect to the gas-phase photochemistry of HFPEs, it has been recently established by limited researches [11,25,[32][33][34]. Table 4 summarizes tropospheric degradation products of some HFPEs.…”

Physical properties of four α, ω-dimethoxyfluoropolyethers

“…A new class of hydrofluoropolyethers, the a, v-dimethoxyfluoropolyethers (DM-FPEs), having the copolymeric structure CH 3 O(CF 2 C-F 2 O) n (CF 2 O) m CH 3 (where ''n'' and ''m'' are defined values), has been designed and developed by Solvay-Solexis as potential CFC replacement compounds [1][2][3][4]. They do not contain chlorine, and hence, do not contribute to the catalytic destruction of stratospheric ozone.…”

“…They do not contain chlorine, and hence, do not contribute to the catalytic destruction of stratospheric ozone. Furthermore, the incorporation of two -OCH 3 groups provides reactive sites for OH radical attack, which limits the atmospheric lifetime and hence their global warming potentials [2,[5][6][7][8]. Some papers and patents concerning the properties and the applications of DM-FPEs have been recently published [1][2][3][4]9].…”

Synthesis of α,ω-dimethoxyfluoropolyethers: reaction mechanism and kinetics

“…These chemicals are characterized by zero ozone depletion potential and by low global warming potential [1][2][3][4][5][6].…”