Change In The Relative Elongation Of The Propellant (Polyurethane) With Time and Temperature

Abstract

This research deals with the study of the relative elongation of solid propellant composed of ammonium perchlorate as an oxidizing agent and polyurethane as a binder, as it is one of the important and basic parameters for studying the mechanical properties of solid propellants, especially for studying the accelerated aging of this type of propellant.

The components that are subject to aging in a solid propellant rocket engine are propellant, insulator, inhibitor, ignition system, and seals. seals, insulators, and ignition systems are replaceable, the motor would be recast when the deterioration in propellant and liner are beyond specified limits due to the ageing. Therefore, it is important to study the properties of the propellant in order to estimate its service life and study the strain change, one of the parameters that clearly affects its service life. This study was conducted on a propellant with a specific chemical formula, where the strain change of this propellant was measured at different temperatures and over different periods of time using a tensile device and several furnaces for each furnace temperature. The maximum time reached was approximately 300 days, The Arrhenius model was adopted in the study