1 ,2,4-Trichlorobenzene, thermal decomposition

In 1953, recycling efforts for these waste isomers began, and thermal decomposition of these residues led to integration of several process steps (see figure). Thermal decomposition of the HCH isomers led to a 75% yield of 1,2,4-trichlorobenzene, which opened the process for production of 2,5-dichlorophenol and the corresponding bro-mination product. In addition to 2,5-dichloro-4-bromo-phenol production, the recycled trichlorobenzene was converted to 1,2,4,5-tetrachlorobenzene which could then be converted to 2,4,5-trichlorophenoxyacetic acid. 

One of the main functions of a metallic catalyst during autoxidation is believed to be promoting the breakdown of hydroperoxides to free radicals, thus continuing chain reactions (8). Thus, thermal decomposition of tert-butyl hydroperoxide was carried out in trichlorobenzene in the presence of the metal stearates. The results obtained are shown in Figure 3. It is difficult to correlate the catalytic activity of the metal stearates in the polymer oxidation with that of the decomposition of tert-butyl hydroperoxide in solution. 

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