METHYL METHACRYLATE IN THE ATMOSPHERE: OH- AND CL-INITIATED OXIDATION IN THE GAS PHASE

Rate coefficients for the reactions of OH radicals and Cl atoms with methyl methacrylate have been determined at 298 +/- 2 K and 760 +/- 10 Torr in two different photoreactors: a 405 1 Duran glass and a 1,080 1 quartz glass reaction chamber, coupled with in situ FTIR spectroscopy. Values of k(OH) = (0.43 +/- 0.05) x 10(-10) and K-Cl = (2.86 +/- 137) x 10(-10) in units of cm(3) molecule(-1) s(-1) were obtained. Methyl pyruvate, formaldehyde and carbon monoxide were determined as products in the reaction of methyl methacrylate with OH radicals in accordance with OH radical addition to the less substituted carbon of the double bond. The atmospheric implications of the reactions have been assessed based on the calculated lifetime of methyl methacrylate.