Theoretical study of the dark-oxidation reaction mechanisms for organic polymers

To model the dark-oxidation mechanism of organic polymers, the reactions of the corresponding model compounds, including cumene, methyl 2-methylbutyrate, methyl methacrylate and methylacrylic acid, with triplet O2 molecule, have been studied by performing density functional theory calculations at the UB3LYP/6-31G(d) level. The calculated results show that these model compounds can be oxygenated by O2 via an H-abstract mechanism. The structures of initial contact charge transfer complexes, transition states, intermediates of cage-like pairs of radicals, and final hydro-peroxides involved in the reactions have been shown in details. The present results are expected to provide a general guidance for understanding the dark-oxidation mechanism of organic polymers.