The analytical applications of the evolved gas analysis (EGA) performed by infrared spectroscopy, for the period extending from 2005 to 2009, are collected in this review. By this technique, the nature of volatile products released by a substance subjected to a controlled temperature program are on-line determined, with the possibility to prove a supposed reaction, either under isothermal or under heating conditions.

Evolved Gas Analysis by Infrared Spectroscopy

The applications of thermal analysis technologies in evaluating the thermal properties of energetic materials in China are briefly reviewed. They are widely adopted in the determination of thermal stability, compatibility and thermophysical constants, as well as the study of thermal decomposition kinetics, mechanism and interaction. In addition, some researches of development or innovation, including the evaluation of gas-formation reaction kinetics by using Thermo-infrared or Thermo-mass spectrometry, the evaluation of condensed-phase reaction kinetics based on monitoring the alteration of functional groups by using the Thermo-infrared spectroscopy, the examination on the mechanisms of topochemical reactions, the disclosure of the correlations between thermal properties and the combustion performances or mechanical properties, predictions of the life and low-temperature viscosity, determination of the low-temperature thermal behaviors of liquid energetic materials and TX (temperature-component content ratio) and HX (fusion heat-component content ratio) phase diagram are summarized and discussed. The future development of the thermal analyses on energetic materials is also discussed with suggestions proposed.

Review and prospect of thermal analysis technology applied to study thermal properties of energetic materials

Glycidyl azide polymer (GAP) is a promising candidate for energetic binders in future solid propellants with minimum smoke signature, reduced pollution and low sensitivity. A series of GAP-modified nitrocellulose (NC) spherical powders were prepared by an internal solution method, and its properties have been studied. SEM characterization showed that the GAP-modified NC spherical powders exhibited high roundness rate, excellent fluidity and the favorable uniformity of its corresponding propellant. XRD analyses and DSC test indicated that GAP and NC molecular chain segment had a certain degree of compatibility, and GAP molecular had desirable plasticizing effect on NC. TG–FTIR–MS coupled method revealed that GAP-modified NC spherical powders had three decomposition stages, corresponding to the decompositions of O–NO2 groups, –N3 groups and the main chains of NC and GAP, respectively. The onset decomposition temperature of GAP-modified NC spherical powders was 5.67 °C higher than that of pure NC spherical powders, which was very important for its safety performance. The NO2, CO2 and NO were detected from the gas products of first decomposition stage, while CO, H2CO2, CH4, HCN and NH3 were identified from the gas products of second decomposition stage. Finally, CO and CO2 were produced from the third decomposition stage. The thermal decomposition process of GAP-modified NC spherical powders was presented.

Fabrication and properties of glycidyl azide polymer-modified nitrocellulose spherical powders

Multistep pyrolysis behavior of core-shell type hyperbranched azide copolymer: Kinetics and reaction mechanism via experiment and simulation

In order to study the optimal ratio of the degree of bis-propargyl-succinate (BPS) cures Glycidyl azide polymer (GAP), the thermal kinetics of BPS cured system was investigated by differential scan...

Effect of different BPS concentration on the thermal decomposition and thermal stability properties of GAP curing

The whole process of the thermal decomposition of GAP was investigated by using DSC, TGA, pyrolysis-MS, TG-FTIR, insitu pyrolysis-FTIR coupling techniques. With the thermal decomposition of GAP, N2,NH3,HCN,H2CCO,CO,CO2,C2H4 and HCHO are detected in gas phase by TG-DTG-FTIR and thermolysis-MS coupling techniques. Meanwhile, the -N3 groups disappear first and form  (CH)R(NH)( imine)  in condensed phase. Kinetic parametes of decomposition were obtained and possible thermal decomposition mechanisms were suggested.

An investigation on the kinetics and mechanism of the thermal decomposition of GAP

Thermal decomposition processes of TATB and DATB were investigated by using DSC,PDSC,TG,TG-FTIR coupling technique and in-situ thermolysis rapid scan-FTIR coupling technique.Kinetic parameters of thermal decomposition were obtained,and mechanisms of thermal decomposition were presented.The results show that there exist some intermediate products in the initial thermal decomposition process of TATB and DATB,such as benzofurazan or benzofuroxan compounds.

Chen Zhi-qun

Papers

An investigation on the kinetics and mechanism of the thermal decomposition of GAP

An investigation on kinetics and mechanism of thermal decomposition for TATB and DATB