Accession Number:

ADA227524

Title:

Formulation of a Product Containing the Multifunctional Corrosion Inhibitor System DNBM

Descriptive Note:

Final rept. Jan 1985-Dec 1989

Corporate Author:

LOCKHEED MISSILES AND SPACE CO INC PALO ALTO CA RESEARCH AND DEVELOPMENT DIV

Personal Author(s):

Report Date:

1989-12-22

Pagination or Media Count:

74.0

Abstract:

Four quaternary ammonium salt inhibitors-DNBMdichromate, nitrite, borate, and molybdate-based on the quaternary ammonium chloride phase-change catalyst Adogen 464 were synthesized by double displacement reactions in the laboratory. The DNBM product in kilogram quantities was prepared from the equivalent methylsulfate salt to minimize chloride in the final mixture. The mixture was microencapsulated by means of emulsifying the salts in aqueous methylcellulose, followed by spray drying to remove the water phase. To render the microcapsule shells impermeable to solvents in the epoxy-polyamide test primer formulation during cure, an organosilane was applied by vapor deposition. Fumed silica was added after spray drying and before silanizing to change the form of the microcapsules from flocculated to free-flowing. The microcapsules were in the 5- to 50-um particle size range, with some 100-um particles observed. The basic capsules contained up to 78 DNBM core payload. The inhibitor, DNBM, was developed to retard corrosion fatigue and stress corrosion cracking in high-strength steels and aluminum alloys. General corrosion test results were highly favorable with regard to the absence of lifting and rusting of epoxy-coated steel panels or near the test scribles, in comparison with control coatings.

Subject Categories:

  • Properties of Metals and Alloys

Distribution Statement:

APPROVED FOR PUBLIC RELEASE