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Aging of HTPB/Al/AP Rocket Propellant Formulations Investigated by DMA Measurements
Author(s) -
Cerri Sara,
Bohn Manfred A.,
Menke Klaus,
Galfetti Luciano
Publication year - 2013
Publication title -
propellants, explosives, pyrotechnics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.56
H-Index - 65
eISSN - 1521-4087
pISSN - 0721-3115
DOI - 10.1002/prep.201200186
Subject(s) - ammonium perchlorate , propellant , materials science , rocket propellant , accelerated aging , aluminium , rocket (weapon) , composite material , dynamic mechanical analysis , chemistry , aerospace engineering , organic chemistry , engineering , polymer
Three HTPB‐based rocket propellant formulations containing ammonium perchlorate and aluminum particles, with different aluminum content and particle size, have been manufactured. The study has focused on the change of mechanical properties with aging time by using dynamic mechanical analysis (DMA). Therefore, propellant formulations underwent an accelerated aging program, in air (RH<10 %), between 60 °C and 90 °C with aging time adjusted to a thermal equivalent load of 15 to 20 years at 25 °C. DMA investigations revealed distinct changes in the shape of the loss factor curve. These curves were modeled with three exponentially modified Gaussian (EMG) functions in order to get the molecular interpretation of the involved aging phenomena by separating the binder fractions with different mobility. Aging of propellant formulations can be followed by considering only two parameters: the areas of the second and third loss factor transition peaks (A 2 , A 3 ), and the corresponding maximum temperature values of the assigned Gauss peaks ( T c 2 , T c 3 ).