Tetra ethylene, decomposition

Polyazoesters, with a DP x 10 and prepared from the reaction of AIBN with tetra-ethylene glycol, have been used to initiate the polymerization of acrylamide under conditions which allowed only a partial decomposition of the azo groups. The best results (see Table 4.8) were obtained using a precipitation polymerization in alcohol. 

As in steam cracking, a large number of by-products is produced. Some of them result from the consecutive reactions of the chlorination of vinyl chloride and of its derivatives obtained by dehydrochlorination (tri-, tetra-, pentachloroethane, perchloro-ethane, di-, trichloroethylene. perchloroethyleneX and the others from the hydrochlorination of vinyl chloride il.l-dichloroethane), while others result from decomposition reactions (acetylene, cokei or conversion of impurities initially present (hydrocarbons such as ethylene, butadiene and benzene, chlorinated derivatives such as chloroprene, methyl and ethyl Chlorides, chloroform, carbon tetrachloride, eta, and hydrogen) ... 

When our work was in progress, complex 4a was also reported to be the thermal (70 °C) decomposition product of la. The presence of dihydrogen (along with ethylene) in the gas phase was noted at the end of the reaction. This would be consistent with the formation of 3a, which was not mentioned in the publication. We therefore undertook a reinvestigation of this work. In the absence of dihydrogen, solutions of pure la are stable for extended periods at ambient temperature. Decomposition starts at around 50 60 °C and leads to a quite similar distribution of tri-, tetra- and pentanuclear cluster complexes as was found in our low temperature reactions with H2. 

Heunish analysed the thermal decomposition products of tetra-ethoxysilane (ethylsilicate) on columns comprising polypropylene glycol on silanized Chromosorb P at 40°C using a thermal conductivity detector. The main impurities in the sample were ethyl alcohol, acetaldehyde, ethylene and ethane. 

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