STRUCTURAL RESIN TRANSFER MOLDING OF THERMOTROPIC LIQUID CRYSTAL POLYMERS FOR SOLID ROCKET MOTOR CASE APPLICATIONS

FOSTER-MILLER PROPOSES TO DEVELOP A STRUCTURAL RESIN TRANSFER MOLDING (SRTM) PROCESS FOR THERMOTROPIC LIQUID CRYSTAL POLYMERS (TLCPS) USING INNOVATIVE PROCEEDING TECHNIQUES. DEVELOPMENT OF OUR PROPOSED PROCESSING TECHNOLOGY WILL ENABLE THE USE OF TLCPS AS MATRIX MATERIALS FOR COMPOSITES AND RESULT IN A LOW-COST, RELIABLE AUTOMATED MANUFACTURING PROCESS FOR MEDIUM TO LARGE SIZE SOLID ROCKET MOTOR (SRM) CASES. TLCPS ARE AN IDEAL RESIN MATRIX SYSTEM FOR APPLICATIONS BECAUSE OF THEIR HIGH STRENGTH, LIGHT WEIGHT, HIGH FRACTURE TOUGHNESS, THERMAL RESISTANCE, GOOD CHARRING CHARACTERISTICS AND EXCELLANT ABLATION PROPERTIES. CANDIDATE TLCPS INCLUDE VECTRA, XYDAR, AND HX4000. TLCPS CANNOT BE MELT PROCESSED FOR SRTM APPLICATIONS BECAUSE OF THEIR HIGH MELT VISCOSITY (10,000 POISE). RTM PROCESSING TYPICALLY REQUIRES VISCOSITIES OF 2 TO 6 POISE. HOWEVER, FOSTER-MILLER'S UNIQUE PROCESSING TECHNOLOGY CAN DELIVER TLCPS TO AN SRTM PROCESS AND PROVIDE COMPLETE SATURATION OF A BRAIDED PREFORM REINFORCEMENT. FOSTER-MILLER WILL DEVELOP A NOVEL SRTM MOLD TO MAKE A CYLINDRICAL SRM DEMONSTRATION ARTICLE IN PHASE I. THE MOLD WILL HAVE INNOVATIVE FILLING AND CONSOLIDATION MEANS TO PROVIDE COMPRESSIVE FORCES DURING THE COMPOSITE MOLDING PROCESS. THE COMBINATION OF SRTM MOLD DESIGN AND TLCP PROCESSING INNOVATIONS WILL ENSURE THAT THE SRM DEMONSTRATION ARTICLE HAS HIGH FIBER VOLUME (50 TO 60%) AND A LOW VOID CONTENT(<2%).