Kinetics and Products of Gas-Phase Reactions of Ozone with Methyl Methacrylate, Methyl Acrylate, and Ethyl Acrylate

Abstract

The kinetics and products of the gas-phase reactions of ozone with methyl methacrylate, methyl acrylate, and ethyl acrylate have been investigated at 760 Torr total pressure of air and 294 +/- 2 K. The rate coefficients obtained (in cm(3) molecule(-1) s(-1) units) were as follows: k(methyl methacrylate) = (6.7 +/- 0.9) x 10(-18), k(methyl acrylate) = (0.95 +/- 0.07) x 10(-18), and k(ethyl acrylate) = (1.3 +/- 0.1) x 10(-18). In addition to formaldehyde being observed as a product of the three reactions, the other major reaction products were methyl pyruvate from reaction of ozone with methyl methacrylate, methyl glyoxylate from reaction of ozone with methyl acrylate, and ethyl glyoxylate from reaction of ozone with ethyl acrylate. Possible reaction mechanisms leading to the observed products are presented and discussed.

Rate coefficients for the reactions of OH radical and ozone with a series of unsaturated esters

“…are increasing with the extent of substitution going from methyl to ethyl to propyl to butyl as: kO3_MMA < kO3_EMA < kO3_nPMA < kO3_nBMA, which could indicate that the longer length of the R group in R′C(O)OR may enhance the reactivity of C=C bond toward O3 electrophilic addition. This trend has also been found for the reaction of O3 with acrylate by Bernard et al (2010). To further estimate the reaction mechanism of O3 reaction with unsaturated esters, the reaction of MMA-D8 with O3 has also been investigated in this work.…”

“…The other measurements reported in the literature so far on the title reactions are from Grosjean et al (1993), Bernard et al (2010), Gai et al (2009) and Gaona Colmán et al Table 4, Grosjean et al (1993) and Bernard et al (2010) reported kO3_MMA = (7.5±0.9) ×10 -18 and (6.7±0.9) ×10 -18 cm -3 molecule -1 s -1 , respectively. The value obtained by Grosjean et al is 13% higher than the ones from Bernard et al and this work, these later two measurements being in excellent agreement.…”

“…Kinetic measurements of ozone reaction with unsaturated esters were performed in the 7300 L ICARE-CNRS simulation chamber at 291 ± 2 K and 760 Torr of pure air (<2% RH). The experimental set-up has been described in details previously (Bernard et al, 2010;Bernard et al, 2013), hence, only a brief description is given here. The chamber is surrounded by protection panels with two roll-up doors, which makes it easier to perform dark reaction.…”

“…Once released into the troposphere, the unsaturated esters will be subject to photodegradation mainly through reaction with OH radicals during the day-time (Blanco et al, 2009a;Blanco et al, 2006) and to a lesser extent with NO3 radicals during the nighttime (Zhou et al, 2017) and ozone during both day and night-time (Bernard et al, 2010;Gai et al, 2009;Gaona Colmán et al, 2013) and Cl atoms in certain environments such as marine area (Blanco et al, 2009b;Martin Porrero et al, 2010). Knowledge of the rate coefficients for the unsaturated esters reactions with tropospheric reactive species, as well as the degradation mechanisms are required to estimate their persistence and fate in the atmosphere.…”

Thresholds of secondary organic aerosol formation by ozonolysis of monoterpenes measured in a laminar flow aerosol reactor

“…The ICARE chamber has been described in detail elsewhere (Bernard et al, 2010), therefore, only a brief description is given here. Experiments were carried out in a 7300 L Teflon chamber in the dark at 303 72 K and 760 Torr total pressure of dry purified air ( o-29 1C of dew point).…”