Enhanced Mechanical Properties of a GAP Propellant Utilizing Alcohol Amine and Its Interaction Mechanism

The introduction of aluminum (Al) powder into solid propellants often leads to the interface dewetting phenomenon, while adding bonding agents can enhance their mechanical properties. L-3, as a novel type of small-molecule alcohol amine-bonding agent, has rarely been studied regarding its interaction mechanisms with propellant components. This study focuses on L-3 and glycidyl azide polymer (GAP) propellant, exploring the regulatory effects of L-3 on GAP’s mechanical properties through stress–strain behavior and dynamic mechanical analyses. Adding 0.2% L-3 can increase GAP’s yield strength and Young’s modulus by 1.50 and 1.45 times at −40 °C, respectively. Storage modulus and loss modulus assessments indicate that L-3 enhances GAP’s stiffness while maintaining its structural integrity. Furthermore, both experimental and density functional theory studies reveal that the interaction sites are Al–O and B–F bonds, forming an Al–F chemical bond in Al/L-3. This research provides a theoretical basis for the development and application of new bonding agents.