Mechanical Properties of HTPB Composite Propellants in the Initial Period of Service Life

 

Nikola Gligorijević

Saša Živković

Sredoje Subotić

Bojan Pavković

Momčilo Nikolić

Stevan Kozomara

Vesna Rodić

 

Uniaxial tensile tests of different composite solid rocket propellant compositions, based on hydroxyl-terminated polybutadiene (HTPB), have shown that mechanical properties extensively change after curing, up to 100% of their initial values, during the first few months. After that period, they stabilize and start to return slowly in the opposite direction. Careful measurements of these features are necessary in order to control the production quality of the propellant and for a comparison of different propellant compositions or batches. Furthermore, time distributions of the mechanical properties in the initial period after production and short-time aging should not be neglected, because they strongly affect the propellant grain structural analysis and a correct estimation of rocket motor reliability

Key words: composite rocket propellant, mechanical properties, aging, tensile strength, deformation, modulus of elasticity.