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U.S. Department of Energy
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Reactions of PCBs and other polychlorinated aromatics with sodium and potassium salts of polyethylene glycols

Thesis/Dissertation ·
OSTI ID:5622548

Polychlorinated biphenyls (PCBs) are of major environmental and toxicological concern for several reasons. PCBs are generally water-insoluble and fat-soluble, therefore they accumulate in living tissue. A variety of toxic responses to PCBs by humans and animals has been reported. PCBs are also very resistant to thermal and chemical degradation. They are, however, easily attacked by reactive species such as alkali metals and strong bases. The high solubility of PCBs in PEGs facilitates the nucleophilic substitution of chloride by strong base in PEG solution. Chlorinated aromatic compounds undergo chlorine substitution by a variety of mechanisms. The bimolecular S/sub N/Ar mechanism is the preferred route in the presence of alkali metal hydroxides and primary alkoxides activated by cation-complexing agents such as polyethylene glycols (PEG). The chloride is preferentially displaced by the alkoxide group from a reagent comprising an alkali metal hydroxide solution in the cation-complexing alcohol. Cleavage of the ether substitutent occurs with excess alkaline PEG reagent, producing the phenoxide ion. This reaction competes with further chloride substitution on polychlorinated benzenes and biphenyls.

OSTI ID:
5622548
Country of Publication:
United States
Language:
English