Degradation of a series of fluorinated acrylates and methacrylates initiated by OH radicals at different temperatures

GARCÍA, P. LUGO; RIVELA, C. B.; GIBILISCO, R. G.; SALGADO, S.; WIESEN, P.; TERUEL, M. A.; BLANCO, M. B.

RSC Advances

RSC Advances

Año: 2020 vol. 10 p. 4264 - 4273

Rate coefficients for the gas-phase reactions of OH radicals with a series of fluorinated acrylates andmethacrylates: 2,2,2-trifluoroethylmethacrylate (k1), 1,1,1,3,3,3-hexafluoroisopropylacrylate (k2),1,1,1,3,3,3-hexafluoroisopropylmethacrylate (k3), and 2,2,2-trifluoroethylacrylate (k4) have been measuredfor the first time as a function of temperature in the range 290?308 K. The kinetic data obtained wereused to derive the following Arrhenius expressions (in units of cm3 per molecule per s): k1 ¼ (2.130.68) 1018 exp[(4745 206)/T], k2 ¼ (8.72 0.68) 1015 exp[(2166 205)/T], k3 ¼ (6.30 0.51)1017 exp[(3721 153)/T] and k4 ¼ (3.93 0.43) 1016 exp[(3140 129)/T]. The experiments wereperformed at normal atmospheric pressure in synthetic air using a 1080 L photoreactor and coupledwith FTIR analysis to monitor the decay of the substances of interest and the reference compounds. Theobtained negative temperature dependencies are in agreement with a mechanism implying an initialaddition of the OH radical to the double bond. Atmospheric implications are discussed with reference tothe rate coefficients obtained as a function of the temperature.