Accession Number:

AD0843056

Title:

Microscopic and Microchemical Study of Aged Solid Propellant Grains

Descriptive Note:

Final technical rept. 18 Jul 1966-17 Jul 1968

Corporate Author:

AEROJET-GENERAL CORP SACRAMENTO CA RESEARCH AND TECHNOLOGY DEPT

Personal Author(s):

• Di Milo, Anthony J.
• Moe, Henry
• McGurk, James L.

Report Date:

1968-11-01

Pagination or Media Count:

81.0

Abstract:

Microscopic examination of thin sections of aged polyurethane propellant from a field aged Polaris motor revealed the presence of high refractive index reaction sites surrounding aluminum particles. Chemical analyses of these sites revealed them to be composed of polyurethane binder. Color sites in a Hawk field aged motor were found by microscopic examination and chemical analysis of these sites showed them to be due to the presence of iron in different oxidation states. The source of the iron is the iron acetylacetonate used as a curing catalyst. Model propellant grains were made to simulate conditions for the generation of reaction sites and the formation and growth of the sites were followed by mapping. Correlation of reaction site formation with mechanical properties of the propellant was unsuccessful because the propellants available for study up to 7 years old showed no real loss of mechanical and ballistic capability. The reaction sites portend changes which will occur over a period of time not now available for study. The chemical mechanism of the aging was defined and expressed by chemical equations.

Descriptors:

• *CHEMICAL ANALYSIS
• ALUMINUM
• ALUMINUM COMPOUNDS
• CHEMICAL REACTIONS
• GRAIN SIZE
• IRON
• ISOCYANATES
• KETONES
• MECHANICAL PROPERTIES
• PERCHLORATES
• REFRACTIVE INDEX
• ROCKET PROPELLANT GRAINS
• SOLID ROCKET PROPELLANT BINDERS
• STABILIZATION
• VISUAL INSPECTION

Subject Categories:

• Physical Chemistry
• Solid Rocket Propellants

Distribution Statement:

APPROVED FOR PUBLIC RELEASE