Study on Improving Low‐Temperature Mechanical Properties of Nitroguanidine Propellant by Triethanolamine

Abstract

Nitroguanidine (NQ) is one of the most popular ingredients in propellant formula, and always contributes a high weight content due to its outstanding capability in flame temperature controlling. But the mechanical properties of these NQ propellants are usually not good, especially at low temperatures. In order to improve the low‐temperature mechanical properties of the NQ propellant, triethanolamine (TEA) is used to coat NQ before propellant manufacturing. Infrared spectra show that TEA forms hydrogen bond with NQ, and the mechanical properties of the corresponding propellant at low temperatures are improved. Compared with the original NQ propellant, the anti‐impact strength, the compressive resistance and the extension strength of the modified propellant are raised by 44.6 %, 20.6 % and 7.1 % at −40°C, respectively. The low‐temperature maximum burning rate and maximum pressure of TEA‐coated NQ propellant obtained from closed bomb test are 29.6 % and 4.06 % lower than those of the original propellant, which can be attributed to the changes in the combustion process caused by TEA. No accidental combustion occurred during the entire combustion process, indicating that TEA can be considered to improve the low‐temperature mechanical properties of NQ propellant.

Effect of particle size distribution on the cryogenic mechanical properties of triple‐base propellants

“…The absorption peaks within the 3000–3500 cm −1 range were attributed to the NH 2 functional group. Remarkably, these peaks experienced splitting into at least five sub‐peaks, a phenomenon attributed to various hydrogen bonding interactions 26 . Furthermore, peaks at approximately 1394 and 1520 cm −1 corresponded to the symmetric and asymmetric stretching vibrations of the NO 2 group, respectively.…”

“…Among them, Xu et al utilized triethanolamine (TEA) for the encapsulation and modification of NQ, resulting in significant improvements in the mechanical performance of the modified propellant. 26 However, the low-temperature maximum burning rate and maximum pressure decreased by 29.6% and 4.06%, respectively. Luo et al controlled crystal morphologies in the crystallization process and contributed to the improvement of density and flowability.…”

“…Remarkably, these peaks experienced splitting into at least five sub-peaks, a phenomenon attributed to various hydrogen bonding interactions. 26 Furthermore, peaks at approximately 1394 and 1520 cm À1 corresponded to the symmetric and asymmetric stretching vibrations of the NO 2 group, respectively. Peaks at around 1630 and 1659 cm À1 indicated the stretching vibrations of the C N bond.…”

“…To address the poor mechanical performance of NQ in propellants, approaches similar to those used for RDX and HMX, such as encapsulation and modification techniques, have been employed. Among them, Xu et al utilized triethanolamine (TEA) for the encapsulation and modification of NQ, resulting in significant improvements in the mechanical performance of the modified propellant 26 . However, the low‐temperature maximum burning rate and maximum pressure decreased by 29.6% and 4.06%, respectively.…”

Modified Mechanical Strength, Thermal Decomposition, and Combustion Characteristics of Nitroguanidine Propellant with Graphene Nanosheets as Reinforcement

“…Until now, a great number of efforts have been done to solve the deficient mechanical properties of the high solid content propellant . For instance, Xu et al introduced triethanolamine (TEA) to coat NQ before propellant manufacturing and then applied the obtained NQ@TEA into the propellant to enhance the mechanical strength of the NQ propellant. It was found that the anti-impact strength, compressive resistance, and extension strength of the NQ propellant were increased by 44.6, 20.6, and 7.1% at −40 °C, respectively.…”