Effect of temperature on the rheological behavior of hydroxyl terminated polybutadiene propellant slurry

Abstract

Hydroxyl terminated polybutadine (HTPB) based composite solid propellants have gained prominence in advanced missiles and launch vehicles including the Space Shuttle's Inertial Upper Stage (IUS) motor (1). To achieve a blow‐hole free well performing casting, the knowledge of the processability characteristics and rheological behavior of the propellant slurry are of vital interest. In our earlier communication (2) we had discussed the effect of compositional aspects, namely solid loading, oxidizer particle size distribution, and aluminum content on the rheology of HTPB propellant. For an optimized solid loading with corresponding oxidizer particle size distribution and aluminium content, the effect of temperature on the processability and the pot life are studied and reported in this paper. This study establishes the fact that the HTPB slurry shows a complex rheological behavior having thixotropy and yield stress. The thixotropic index and yield stress show minimum values at an optimum temperature. This optimum temperature shifts to lower values as time elapses. Activation energies have been calculated for the cure reaction based on yield stress and viscosity. It is observed that the activation energy values reach asymptotic levels after about three hours of curative addition.

Morphology and mechanical and viscoelastic properties of natural rubber and styrene butadiene rubber latex blends

“…This is because of the increased degree of crosslinking leading to the strengthening of the 3-dimensional structure. 37 One can note that there is some difference between the tensile strength values of the gum and the films after zero prevulcanization time. The strength values of the former is lower than that of the latter.…”

On the viscosity of composite suspensions of aluminum and ammonium perchlorate particles dispersed in hydroxyl terminated polybutadiene—New empirical model

“…In the second approach, one investigates the rheological behavior of the suspension with progress of cure reaction and describes the change of viscosity as function of time, polymer composition, temperature and etc. [6][7][8][9].…”

Functionalization of terminal carbon atoms of hydroxyl terminated polybutadiene by polyazido nitrogen rich molecules

“…The binder helps the processing of the energetic materials and provides the required mechanical strengths to the final composition of the propellant (Kit and Evered 1960;Urbanski 1984;Desai et al 1996). Hydroxyl terminated polybutadiene (HTPB) is being used as binder for the modern high performance composite propellants because of its unique physico-chemical properties such as excellent flow characteristics and storage capacity compared to other known binders (Murray and Purves 1940;Meyers and Baumgarter 1973;Muthiah et al 1991). Several commercially available explosives are used with the HTPB in propellant formulation (Mathieu and Stucki 2004).…”