Synthesis and characterization of a novel hydroxy telechelic polyfluoroether to enhance the properties of HTPB solid propellant binders

Abstract

As the most commonly used polymer binder for solid propellants, it is of great significance to modify hydroxyl-terminated polybutadiene (HTPB) to obtain improved low-temperature behavior and mechanical properties. A novel hydroxy telechelic polyfluoroether (HTPF) was synthesized by cationic ring-opening polymerization of fluorine-containing epoxides (FPO). HTPF was introduced into HTPB polyurethane to enhance the mechanical behavior and thermodynamic properties of the elastomer. As a result, the microphase-separated structure of the polyurethane was optimized and the bonding effect with the aluminum powder became tighter. The tensile strength and elongation at break were increased by 94.69% and 197.49% after adding aluminum powder, respectively. For thermodynamic properties, the stability property in a wider temperature range was maintained up to 467.2 ℃, and the glass transition temperature (Tg) was lowered by 5.6 ℃. Therefore, block polymerization of fluorinated polyethers with HTPB proved to be a promising scheme to obtain advanced propellant binders.