Compatibility and thermokinetics studies of 4-amino triazolium picrate with various polymers

Incompatibility between energetic material and polymer may result in decreased stability, accelerated aging, and undesirable explosion as a result of the thermal decomposition in polymer-based energetic formulations. This work aims to study the compatibility and kinetic parameters of binary mixture of 4-amino-1, 2, 4-triazolium picrate (4-ATPA) with several polymers including polyether (PET)-, polyester (PES)-, and hydroxyl-terminated polybutadiene (HTPB)-based polyurethanes (PUs), Estane 5703, Viton A, and poly(CTFE-VDF) (PCV) copolymer to realize the possibility in an energetic composite formulation. Compatibility was investigated through a vacuum stability test (VST) and differential scanning calorimetry (DSC) according to the guidelines STANAG 4147 as a benchmark for compatibility study. The VST measurements indicate that the 4-ATPA is chemically compatible with all PET-, PES-, HTPB-based PUs, Estane 5703, Viton A, and PCV materials. DSC results also support that the 4-ATPA has good compatibility with all kinds of the polymers. The kinetic parameters of the binary mixture were also studied by using the Ozawa, Kissinger, and isoconversional ASTM E698 methods. The activation energy values obtained the Ozawa method for the 4-ATPA/PET, 4-ATPA/PES, 4-ATPA/HTPB, 4-ATPA/Estane, 4-ATPA/Viton A, and 4-ATPA/PCV were 119.2, 129.2, 125.5, 118.9, 121.3, and 119.9 kJ mol⁻¹, respectively. These values are comparable and consistent to those obtained from the Kissinger and isoconversional ASTM E698 method for the first step of the thermal decomposition reactions.