Effect of bonding agent on interfacial strength of AP/T313/PBT in PBT- based composite solid propellants by molecular dynamics simulation

SW Deng and JH Wang and YW Sun and GY Luo and FC Huan and CL Mao and JG Wang, MATERIALS TODAY COMMUNICATIONS, 45, 112291 (2025).

DOI: 10.1016/j.mtcomm.2025.112291

The study of the interfacial mechanical properties of components in PBT- based composite solid propellants is crucial for optimizing propellant structure design and enhancing overall mechanical stability. In this work, molecular dynamics (MD) simulations were employed to systematically investigate the interfacial mechanical properties of a PBT (Poly(3,3-bis(azidomethyl)oxetane-co-tetrahydrofuran)) matrix, ammonium perchlorate (AP) oxidizer, and bonding agent (T313). The effects of T313 content, temperature, and strain rate on interfacial strength were examined, and the underlying molecular mechanisms contributing to mechanical performance were analyzed. Results show that when the T313 content is approximately 9 & Aring;, T313 effectively fills the voids at the PBT/AP interface and chemically reacts with the polymer molecules, forming stable chemical bonds, which significantly improve yield stress and interfacial adhesion strength. Simulations at different temperatures (253 K, 320 K, and 400 K) indicate that the material exhibits brittle deformation at low temperatures, while stronger plastic deformation occurs at higher temperatures. Uniaxial tensile test results reveal that at high strain rates (5 x10 11 s-1 to 5 x10 10 s-1), the shortened time for molecular chain rearrangement prevents timely adaptation to external stress, resulting in increased yield stress and peak strain. In contrast, at low strain rates (1 x10 10 s-1 to 1 x109 s-1), the molecular chains have sufficient time to rearrange and slide, helping to relieve chain entanglements and stress concentrations, leading to strain primarily concentrated in the PBT matrix.

Return to Publications page