Thermal pyrolysis properties and security performance of molecular perovskite energetic crystal (C6N2H14) (NH4) (ClO4)3 (DAP-4)

Abstract

DAP-4 (C6N2H14) (NH4) (ClO4)3 has been synthesized recently as an ammonium perchlorate-based molecular perovskite energetic material with higher stability and outstanding performances. In this study, rapid thermal cracking infrared spectroscopy is applied to study the thermal pyrolysis properties and combustion process of DAP-4. Under different temperatures and pressure with a heating rate of 1000℃·s-1, the gaseous products in the rapid pyrolysis process are mainly CO, CO2, H2CO, HCN, and HCl. Above 700ºC, the pressure affects the ratio of the gas products, but the temperature does not. Based on the relative ratio of the different gas products, a thermal pyrolysis mechanism was proposed. The heat of explosion (ΔHdet), enthalpy of combustion(ΔcHθ), and standard enthalpies of formation (ΔfHθ) are determined to be -2527.39kJ·mol-1, -2492.06kJ·mol-1 and -483.96kJ·mol-1, respectively. The self-catalytic heating time is 99.5min, the temperature at the initial detection point is 280.1 ℃, and the maximum temperature rise rate is 49.1 ℃·min-1. The thermal safety experimental results showed that DAP-4 has a relatively good security performance. This study provides new insight into the mechanism of pyrolysis of DAP-4 as a potential energetic material.