Three different azophenols were oxidized by both the system CuCl/O2 in pyridine and electrochemically (as coherent films) on Fe and Cu anodes in water/methanol mixtures. Products of the chemical and anodic oxidative coupling process are in any case very near each other. Poly(oxy-4-phenylazo-1,2-phenylene) and its 3-allyl derivative are obtained from 4-hydroxyazobenzene (1) and 3-allyl-4-hydroxyazobenzene (2), respectively. The polymerization of 4-hydroxy-3,5-dimethylazobenzene (3) mainly proceeds through elimination of the phenylazo group and formation of poly(oxy-2,6-dimethyl-1,4-phenylene). By oxidation of 2 at Cu anodes thin, adherent films having very good protective features are obtained in short electrolysis times.
Constitution and properties of the coatings formed in situ by anodic oxidation of azophenols
1982
Abstract
Three different azophenols were oxidized by both the system CuCl/O2 in pyridine and electrochemically (as coherent films) on Fe and Cu anodes in water/methanol mixtures. Products of the chemical and anodic oxidative coupling process are in any case very near each other. Poly(oxy-4-phenylazo-1,2-phenylene) and its 3-allyl derivative are obtained from 4-hydroxyazobenzene (1) and 3-allyl-4-hydroxyazobenzene (2), respectively. The polymerization of 4-hydroxy-3,5-dimethylazobenzene (3) mainly proceeds through elimination of the phenylazo group and formation of poly(oxy-2,6-dimethyl-1,4-phenylene). By oxidation of 2 at Cu anodes thin, adherent films having very good protective features are obtained in short electrolysis times.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
