Chlorinated products of plastic pyrolysis

Abstract

The formation of various chlorinated products in pyrolysis of polymers and plastics additives was studied. Formation of chlorobenzenes (in addition to the monomers) from poly(ch1orostyrene) and poly(vinylbenzy1 chloride) was observed. Hydrogen chloride is only produced from these polymers at above 600 "C when the chlorine atoms are cleaved off and abstract hydrogen. A similar process takes place in aromatic chlorine-containing dyes, in which the strong aromatic molecular structure prevents the thermal cleavage of chloroaromatic volatile products. We have observed that cupric and ferric chlorides chlorinate phenolic thermal decomposition products of plastic materials which originate either from the polymer or from the stabilizer. The highest yields of chlorophenols are obtained in pyrolysis at around 700 "C.