CIBICI   14215
CENTRO DE INVESTIGACION EN BIOQUIMICA CLINICA E INMUNOLOGIA
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
PHOTODEGRADATION OF A SERIE OF FLUOROESTERS INITIATED BY OH RADICALS AT DIFFERENT TEMPERATURES
Autor/es:
GIBILISCO, R. G.; BLANCO, M. B.; LUGO, P.; SALGADO, S.; TERUEL, M. A.; RIVELA, C. B.; WIESEN, P.
Lugar:
Orléans
Reunión:
Conferencia; 11th International Conference on Chemical Kinetics; 2019
Resumen:
Fluorinated acrylates and methacrylates are unsaturated esters with a wide range of industrial applications, since they are functional monomers used for the development of a new family of fluorine-containing vinyl polymers for Hi-Tech applications.1 The atmospheric degradation of these unsaturated compounds will be initiated mainly by chemical reaction with OH and NO3 radicals and O3 molecules contributing to tropospheric ozone production and the formation of the other secondary photo-oxidants in polluted areas.The aim of this study was to determinate the rate coefficients of the following reactions:CH2=C(CH3)C(O)OCH(CF3)2 + OH Products, k1CH2=C(CH3)C(O)OCH2CF3 + OH Products, k2CH2=CHC(O)OCH2CF3 + OH Products, k3CH2=CHC(O)OCH(CF3)2 + OH Products k4The experiments were performed in the temperature range of 287-313 K and atmospheric pressure of air using a 1080 L photoreactor coupled with FTIR analysis to monitor the decay of the organics and the reference compounds. The kinetic data obtained were used to derive the following Arrhenius expressions (in units of cm3 molecule-1s-1): k1 = (4.73 ± 1.09) × 10-13 exp[(442 ± 28)/T], k2 = (1.44 ± 1.26) × 10-13 exp[(1504 ± 69)/T], k3 = (7.14 ± 1.34) × 10-13 exp[(1021± 89)/T] and k4 = (1.91 ± 0.69) × 10-17 exp[(4213 ± 579)/T].This is the first temperature dependence study of the four reactions cited above. Negative temperature dependencies of the rate constants were obtained for the four reactions studied in agreement with that an addition to the double bond as the main reaction pathways.In addition, we have estimated through the kinetic data obtained in this work, the atmospheric lifetimes of the fluorinated compounds at different temperatures and their variations with altitude.References