azo group

The FT-IR spectrum of PAZ-NT-PAZ also shows the absorption peak of the symmetrical stretching vibration of the azo group (-N=N-, 1384 [cm.sup.-1]) which confirms the existence of azo chromophores in PAZ-NT-PAZ.

In addition to that they are highly resistant to aerobic biodegradation due to the strong electron-withdrawing characteristics of the azo group. Under anaerobic conditions the degradation takes place slowly by decolorization.

An environment with low oxygen content facilitates the breakdown of the azo group links due to a reduction mechanism, which can result in the formation of colorless solutions, as demonstrated in the study by Chen et al.

Dyes containing an azo group (-N=N-) are very commonly used colorants worldwide.

In the prior works attempt insertion of azo group in phenol novolac resin at a molecular level has recently been shown to impart improvements in thermal properties, mechanical properties, flame retardance, and char yields in cured epoxy resins [23, 24].

This may be due to the production of the subsequent weak acidic intermediates as a result of degradation and cleavage of the azo group in the dye molecules [11].

Azo dyes, a large class of synthetic organic dyes that contain nitrogen as the azo group -N = N- as part of their molecular structures.

The Azo group dyes present a naphthalene ring bonded to a second benzene ring by an azo bond (N = N).

The peaks can be attributed to the reduction of the azo group. Figure 2b showed the voltammograms obtained for PY and supporting electrolyte, which showed one reduction peak.