ANTI-FOULING MATERIALS FOR SOUND TRANSPARENT SONAR DOMES

THE GOAL OF THIS PROGRAM IS A NON-LEACHABLE NON-TOXIC (TO PEOPLE) PERMANENT SONAR DONE ANTIFOULING TREATMENT. THIS WILL BE ACHIEVED BY GRAFTING QUAT MONOMER TO THE SUR- FACE OF THE DOME OR BY TREATMENT WITH A QUAT SILANE TO FORM AN INTERPENETRATING NETWORK ON AND JUST UNDER THE SURFACE. THERE IS EVIDENCE THAT IF THE FIRST LAYER OF FOULING CAN BE PREVENTED, THERE WILL BE NO FURTHER FOULING. TREATED SUR- FACES WILL BE EVALUATED FOR MICROFOULING RESISTANCE. MACROFOULING OF SONAR DOMES BY BARNACLES AND OTHER FORMS CAUSES DEGRADATION IN SONAR PERFORMANCE. BUTYL TIN BASED ANTIFOULANTS ARE PRESENTLY USED TO PREVENT THIS GROWTH, BUT THESE COMPOUNDS ARE TOXIC AND PRESENT A HAZARD TO NAVY PERS-ONNEL DURING INSTALLATION AND REMOVAL OF DOMES. PHASE I DEMONSTRATED THE FEASIBILITY OF ALTERNATE TREATMENT SYSTEMS BASED ON QUATERNARY AMMONIUM SILANES, QUATERNARY METHACRYLA-MIDE POLYMERS AND COPPER TANNATE USED IN CONJUNCTION WITH LOW SURFACE ENERGY TREATMENTS, INCLUDING FLUOROSILANES AND FLUOROPOLYMERS. THIS PHASE II PROGRAM WILL DEVELOP IPN (INTERPENSTRATING POLYMER NETWORK) SURFACE IMPREGNATION SYS-TEMS BASED ON THE PHASE I CONCEPT. THESE SYSTEMS WILL CON- TAIN A BIOCID(E.G. QUATERNARY AMMONIUM SILANE) TO PREVENT THE PRELIMINARY BACTERIAL BIOLAYER FROM FORMING, A LOW SUR- FACE ENERGY TREATMENT (E.G. FLUOROSILANE) TO DETER THE BIO- LAYER FROM ADHERING TO THE SURFACE, ALL IN AN IPN IMPREGNA- TION TREATMENT TO ENSURE GOOD ABRASION RESISTANCE. TEST PANELS WILL BE EVALUATED FOR RESISTANCE TO BARNACLE GROWTH BY TOTAL IMMERSION TESTING. PROMISING SYSTEMS WILL ALSO BE EVALUATED FOR THEIR EFFECT ON RUBBER TG AND ACOUSTICAL AND TENSILE PROPERTIES.