Azo compounds (azos) are compounds bearing the functional group R-N=N-R′, about half of those commercially important azos are azo initiators which have the aliphatic organic groups or its derivatives as the attached groups. Unfortunately, the thermal decomposition of the aliphatic azos will produce nitrogen and free radicals, which can promptly decompose and releases a large amount of heat under high ambient temperature and leads to deflagration even explosion in storage, transportation or reactor. For instance, on 22 July 2011, a serious combustion accident caused by the heat accumulation from thermal decomposition of 2,2’-azobisisobutyronitrile (AIBN) occurred on a bus in Henan China killed 41 people. In July 2015, due to the runaway reaction of azos, a serious explosion accident happened in the process of shattering azos caused two casualty in Kunshan Jiangsu, China. In May 2016, a warehouse for storing azo dyes caught fire in Jiangsu, China, and the economic losses caused by this fire is about several hundred million dollars.
The purposes of the study are to character the thermal stability of azos, investigate the potential hazards for organic peroxide and finally establish an inherently safer working environment of azos in industrial progress.