PULTRUDED STRUCTURAL COMPOSITES HAVING HIGH FLAMMABILITY RESISTANCE AND ELECTRICAL CONDUCTIVITY STRUCTURAL COMPOSITE MATERIALS FOR THE STS LAUNCH ENVIRONMENT

THIS INNOVATION WILL DEVELOP NONMETALLIC COMPOSITES FOR USE IN MISSILE LAUNCH FACILITIES. THE OBJECTIVE OF THIS PROJECTIS TO FORMULATE A COMPOSITE THAT (1) WILL MEET THE NASA LAUNCH ENVIRONMENT REQUIREMENTS AND (2) CAN BE PRODUCED BY THE PULTRUSION PROCESS. THROUGH AN EXTENSIVE SERIES OF TESTS ON NUMEROUS LABORATORY FABRICATED COMPOSITES, A SINGLECOMPOSITE FOR THE PHASE II PROGRAM IS DESIRED. MATERIAL PARAMETERS TO BE EXAMINED ARE: (1) HEAT RESISTANT RESINS, (2) VARIOUS FIBERS, (3) CONDUCTIVE FILLERS AND VEILS TO DISSIPATE CHARGE AND (4) ADDITIVES TO RETARD FLAME AND TO PREVENT PHOTOLYTIC DEGRADATION. AN INITIAL STUDY CHARACTERIZING NEAT RESIN POPERTIES WILL EXAMINE PROPELLANT COMPATIBILITY FLAMMABILITY AND PULTRUSION PROCESSIBILITY. AFTERWARD, SIMULATED PULTRUDED COMPOSITES WILL BE FABRICATEDUSING HIGH PRESSURE RTM PROCESSING. THIS OPERATION IS VITALTO THE SUCCESS OF THE PROGRAM SINCE IT WILL CONSERVE MATERIAL AND PROVIDE NUMEROUS COMPOSITE TEST SPECIMENS OF VARYING COMPOSITIONS. THERMOSET RESINS CONSISTING OF PHENOLIC, NOVALAC-TRIAZINE, CYANATES, BMI, AND TOUGHENED EPOXIES WILL BE EVALUATED USING S-GLASS AND KELVAR FIBERS. CONDUCTIVE FILLERS OR CARBON VEILS WILL DISSIPATE CHARGE. PRELIMINARY DESIGN CRITERIA, GALVANIC CORROSION, AND THE OVERALL ECONOMICS WILL BE EXAMINED. THIS STUDY WILL PROVIDENASA WITH VALUABLE STATE-OF-THE-ART INFORMATION ON HIGH PERFORMANCE PULTRUSIONS SUITABLE FOR LAUNCH FACILITIES.