Thermal analysis of disazo pigments

Abstract

The differential-thermal and thermogravimetric analysis of eight derivatives of 1,4-bis-(5'-hydroxy-7'-sulpho-2'naphthyl).benzenediamide showed that these compounds have a marked exothermic effect, with maxima in the temperature range 280-330~ The derivative of 4-nitroaniline-2-sulphonic acid were found to undergo a blast-like decomposition in the temperature intervals 255-265 ~ and 285-290 ~ which is reflected by large steps in their TG curves.The thermal analysis of disazo pigments permits determination of their applicability at higher temperatures.This work analyses the processes occurring during the thermal decomposition of disazo pigments, derivatives of 1,4-bis-(5'-hydroxy-7'-sulpho-2'naphthyl)-benzenediamide, with the following general structural formula:

In Vitro Analysis of AHPlus and MM-Seal by ESR and Thermoanalytical Methods

“…Electron spin resonance (ESR) may be an appropriate method to investigate the materials with radical structures, having cytotoxic properties [11,12]. The thermal analysis methods have been used to obtain useful information about thermal stability of materials and also to determine the temperature ranges in which they can be used without changes in their composition, color and structural properties [13,14]. In vitro methods have been recommended by the American National Standards Institute, the American Dental Association [15] for evaluation of the cytotoxicity of endodontic materials.…”

Modification of Aspen Wood Ethanol Lignin via Azo Coupling; Promising Polymers from Renewable Plant Biomass

“…The weight loss in the EL-azo-NO 2 and SEL-azo-NO 2 samples at ~ 260°С is related to the decomposition of a nitro compounds (Simeonov et al 1990); as the temperature further increases, the azo compounds and aromatic matrix of lignin decompose, but, in general, the modi ed ethanol lignin weight loss at 350°C noticeably weakens.…”