Rheo‐kinetic study of 4‐(Dimethylsilyl) butyl ferrocene‐grafted HTPB‐based composite propellant and evaluation of casting rate

Abstract

AbstractThe flow behaviour of 4‐(Dimethylsilyl) butyl ferrocene‐grafted HTPB‐based composite propellant (P01) and basic aluminized HTPB‐based propellant (P02) was investigated using shear rheometer. The experimental data were fitted to ‘power law’ for non‐Newtonian fluid flow, and the rheological parameters were expressed as consistency index (k) and pseudoplasticity index (n). For both the propellant compositions, a shear thinning nature (pseudoplasticity index; n < 1) has been observed. The study categorically showed that the incorporation of 4‐(Dimethylsilyl) butyl ferrocene‐grafted HTPB has resulted in increased consistency index (k) and yield stress as compared to HTPB based compositions. In addition, the time–temperature cure‐kinetics study suggested that the rate of curing reaction is higher with toluene diisocyanate as compared to isophorone diisocyanate and the Arrhenius activation energy (Ea) corroborated with the observed trend. Furthermore, the Haegen–Poisseuille equation modified for non‐Newtonian fluid flow has been employed to determine the theoretical casting rate for 4‐(Dimethylsilyl) butyl ferrocene‐grafted HTPB‐based composite propellant at different temperatures in a vacuum casting setup.