Kinetics of the gas-phase reactions of NO3 radicals with ethyl acrylate, n-butyl acrylate, methyl methacrylate and ethyl methacrylate

The relative rate method has been used to determine the rate constants for the gas-phase reactions of NO3 radicals with a series of acrylate esters: ethyl acrylate (k1), n-butyl acrylate (k2), methyl methacrylate (k3) and ethyl methacrylate (k4) at 298 ± 1 K and 760 Torr. The obtained rate constants are k1 = (1.8 ± 0.25) × 10−16 cm3 molecule−1 s−1, k2 = (2.1 ± 0.33) × 10−16 cm3 molecule−1 s−1, k3 = (3.6 ± 1.2) × 10−15 cm3 molecule−1 s−1, k4 = (4.9 ± 1.7) × 10−15 cm3 molecule−1 s−1. The experimental rate constants are in good agreement with theoretical rate constants calculated by an algorithm of the correlation between the rate constants and the orbital energies for the reactions of unsaturated VOCs with NO3 radicals. In addition, the atmospheric lifetimes of the compound against NO3 attack are estimated and the results show that NO3 reactions contribute little to the atmospheric losses of acrylate esters except in polluted regions.