Thermal analysis of diazo pigments

The differential-thermal and thermogravimetric analysis of eight derivatives of 1,4-bis-(8′-hydroxy-3′,6′-disulpho-1′-naphthyl)-benzenediamide showed that these compounds have a marked exothermic effect, with maxima in the temperature range 290–340°C. The 4-nitroaniline derivative was found to undergo a blast-like decomposition in the temperature interval 285–295°C, reflected by large steps in the TG curves. The thermal analysis of diazo pigments permits determination of their applicability at higher temperatures.