Photolysis of dimethyl carbonate

Abstract

The gas-phase photolysis of dimethyl carbonate (DMC) has been studied in the temperature range 41-93°C. Methoxyl and methyl radicals are generated in this photolysis and their reactions have been studied. Arrhenius parameters have been measured for the following reactions : log A(mo1e-1 cm3 sec-1) E(kca1 mole-1) CH30 + DMC +CH30H + R 10-75 5.9 CH3+DMC +CH4+R 10.19 7-4 CH3+CH30 +CH4+CH20 13-38 0A value of 1014.13(mole-l c m 3 sec-1) at 41°C has been obtained for the auto-disproportionation of methoxyl radicals : X H 3 0 +CH30H+ CH20Using this velocity constant a value of ca. 67 has been deduced for the disproportionation ratio of methoxyl radicals, A(CH30, CH3O).

Mn2(CO)10‐Visible Light Photomediated, Controlled Radical Polymerization of Main Chain Fluorinated Monomers and Synthesis of Block Copolymers Thereof

“…DMC is stable to pyrolysis and photolysis up to 350 • C [118], but gas phase irradiation with high power Hg UV lamps induces some acetone promoted [119] decomposition at T > 150-200 • C [120], while methyl and methoxy radicals form in the presence of nitric oxide [121]. Liquid phase DMC UV-photolysis with H 2 O 2 [122], NO, NO 2 [123] or t butylperoxide [124], additives occurs with H abstraction and formation of CH 3 O CO O CH 2…”

An experimental and modeling study of the ignition of dimethyl carbonate in shock tubes and rapid compression machine

“…Dimethyl carbonate (CH 3 O(C = O)OCH 3 , DMC), a non-toxic and Q2 2 non-corrosive carbonate ester with no C-C bonds and containing 3 53% oxygen by weight, has been identified as a suitable fuel com- 4 pound to be added to diesel fuel to reduce PM emissions without 5 affecting NO X emissions [e.g., 1 ]. Even though it is 100% miscible 6 with diesel fuel, it must be used as a blended fuel in diesel en- 7 gines due to its low cetane number (35)(36), low calorific value 8 (15.78 MJ/kg), and high latent heat of evaporation (369 kJ/kg) [2,3] . 9 To contribute to the development of detailed chemical kinetic 10 models to describe the combustion characteristics of DMC, a thor- 11 ough understanding of its combustion chemistry is needed.…”

Towards a Micro-Kinetic Model of Li-Ion Battery Thermal Runaway - Reaction Network Analysis of Dimethyl Carbonate Thermal Decomposition

“…Similarly, Thynne and Gray [30] report that the decomposition of DMC in the gas phase over the temperature range of 150 • C to 240 • C occurs with an activation barrier of 15 kcal mol −1 . Thynne and co-authors further report that the methyl radical-sensitised decomposition of DMC has an activation barrier of 7.4 kcal mol −1 to 8.9 kcal mol −1 [30,31]. Products of DMC decomposition by photolysis include methanol (CH 3 OH), carbon monoxide, carbon dioxide, methane (CH 4 ), dimethyl ether (CH 3 OCH 3 ), methyl ethyl ether (CH 3 OCH 2 CH 3 ), and traces of methyl formate (HC(O)OCH 3 ).…”

“…The possible primary thermal decomposition reactions of DMC are listed in (R1) to (R8) [29,31,35]. The bond fission reaction (R2), (R5) and (R6) and ultimately lead to CH 3 , CO 2 , CH 2 O, and H at high temperatures [35].…”