THERMAL-DECOMPOSITION OF PAN, PPN AND VINYL-PAN

The gas phase thermal decomposition rates of the C1 and C2-substituted peroxyacyl nitrates (RC(O)OONO2), PAN (R = CH3), PPN (R = C2H5) and v inyl-PAN (R = CH2 = CH-) have been measured at ambient temperature (28 8 - 299 K) and 1 atm. of air. Our results for PAN (k = A exp (-E(a)/RT ), log10 (A, s-1) = 16.2 +/- 1.6, E(a) = 26.9 +/- 2.1 kcal/mol, k298 = 3.0 x 10(-4) s-1) are consistent with literature data. Thermal decomp osition rates for PPN and vinyl-PAN are similar to that for PAN, with k298 = 3.0 x 10(-4) s-1 for PAN, 3.4 x 10(-4) s-1 for PPN and 3.0 x 10 (-4) s-1 for vinyl-PAN. Implications for the atmospheric persistence o f PPN and vinyl-PAN as compared to that of PAN are briefly discussed.