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An energetic tri-block copolymer PCL-GAP-PCL (Mn = 1794) was synthesized by a ring-opening polymerization of ε-caprolactone with glycidyl azide polymer (GAP) of low molecular weight (Mn = 1006 g/mol) as initiator, in the presence of dibutyltin dilaurate (DBTDL) as catalyst, at 100 °C in the absence of solvent. The products obtained in high yield were characterized by FTIR, gel permeation chromatography (GPC), and 1 H and 13 C NMR spectroscopy. Thermogravimetric analysis (TG) and differential scanning calorimetry (DSC) were used to study the thermal behaviour of the polymers. An advanced isoconversional method has been applied for kinetic analysis. The activation energy, calculated by the Flynn-Wall-Ozawa (FWO) and Kissinger methods, and thermal analysis revealed that the tri-block copolymer has greater thermal stability than homopolymer GAP. The results of the activation energies from the Kissinger method for the first and second steps were 180.3 kJ·mol −1 and 209.8 kJ·mol, respectively. Furthermore, for the copolymer, the activation energy versus the level of conversion was calculated by the FWO method. The glass transition temperature (Tg) for GAP was influenced by the PCL blocks; as a result the copolymer (Tg = −64 °C) showed better thermal properties than homopolymer GAP (Tg = −48 °C).

Bis (2,2-dinitropropyl) fumarate (BDNPF) as a melt cast explosive can be used alone or in combination with inert melt castable thermoplastic elastomer (TPE) diluents. In this work, the BDNPF synthesized and the structure of it were verified by IR, and 1 H-NMR spectroscopy. The thermal stability of BDNPF was studied by differential scanning calorimetery (DSC) and thermogravimetery (TG) techniques. The influence of the heating rate (5, 7, 10 and 15°C/ min) showed that with increased heating rate the decomposition temperature of the compound rose. Also, the kinetic parameters such as activation energy and frequency factor for this compound were obtained from the DSC-TGA data by non-isothermal methods proposed by ASTM E698 and Flynn-Wall-Ozawa (FWO). The critical temperatures were estimated at 241.61°C and 241.85°C for BDNPF by using ASTM and Flynn-Wall-Ozawa data, respectively.

Glycidylazide polymer (GAP) has potential interest for the development of high-performance energetic propellants. Although GAP is a well-known and promising energetic polymer, propellants based on it suffer from poor mechanical and low-temperature properties. In order to improve the mechanical and thermal properties of GAP a promising idea would be the preparation of a triblock copolymer of it with a polymer having good mechanical and thermal properties, such as polycaprolactone (PCL). In this work, we report a detailed investigation of the glass transition temperature (Tg) and viscosity of PCL-GAP-PCL samples incorporated with energetic plasticizers, BuNENA, TMETN, and BTTN. The results demonstrated that the Tg of PCL-GAP-PCL is influenced by the type of plasticizer. PCL-GAP-PCL was cured with TDI and a mixed curing system (IPDI/N100). The elastomer prepared with the mixing curing system showed excellent mechanical properties with 2.64 MPa and 138% elongation. The effects of the energetic plasticizers on the mechanical properties of the elastomer were investigated. Finally, the plasticized tri-block copolymer showed enhanced mechanical and thermal properties.