ADSORPTION OF MIGRATING CHEMICAL SPECIES BY COMPOSITE POLYMER COATINGS

THE INTEGRITY OF THE MOTOR CASING INSULATION/SOLID PROPELLANT BOND INTERFACE IS INFLUENCED BY THE MIGRATION OF VOLATILE CHEMICAL COMPOUNDS ACROSS THE INTERFACE. LINERS ARE PRESENTLY USED TO INHIBIT MOISTURE MIGRATION. THE PROPOSED PROGRAM ADDRESSES THE PROBLEM OF PROVIDING A PROTECTIVE COATING TO ELIMINATE THE MIGRATION OF VOLATILE CHEMICALS EXUDED FROM THE INSULATION DURING VULCANIZATION. THE PROPOSED WORK INVOLVES THE DEVELOPMENT OF A COMPOSITE COATING CONSISTING OF A PERMEABLE BINDER INCORPORATING UNIFORMLY DISPERSED, POWERED SURFACE ACTIVE ADSORBENTS, SUCH AS SILICA GEL ACTIVATED CARBON AND/OR MOLECULAR SIEVES. TWO APPROACHES WILL BE EVALUATED FOR THE PERMEABLE BINDER; ONE INVOLVES A MICROPOROUS NYLON MEMBRANE AND THE OTHER INVOLVES A FELTED POROUS SHEET. THE COMPOSITE COATING WOULD ALLOW THE MIGRATING SPOECIES TO PASS THROUGH THE PERMEABLE MATRIX AND BE RAPIDLY AND COMPLETELY ADSORBED BY SURFACE ACTIVE AGENTS. THE OBJECTIVE OF THE PHASE I PROGRAM WOULD BE TO DETERMINE THE FEASIBILITY OF USING THESE COMPOSITE COATINGS TO INHIBIT THE MIGRATION OF THE VULCANIZATION BY-PRODUCTS. SMALL FLAT SHEET COATINGS WILL BE FABRICATED AND CHARACTERIZED WITH RESPECT TO THEIR ADSORPTIVE CAPACITY FOR THE BY-PRODUCTS. THEY WILL ALSO BE EVALUATED FOR THEIR EASE IN MANUFACTURING AND APPLICATION.