HIGH TEMPERATURE (650 DEGREES K) FILM BASED POLYBENZOXAZOLE/POLYIMIDE MICROCOMPOSITE FOR TURBINE ENGINE SUBSTRUCTURE

HIGH TEMPERATURE COMPOSITES MUST BE USED MORE EXTENSIVELY ONAIRCRAFT TURBINE ENGINES TO MEET THE HIGHER THRUST-TO-WEIGHTREQUIREMENTS ON ALL CLASSES OF NEXT GENERATION AIRCRAFT. WEPROPOSE TO PROCESS A FILM-BASED COMPOSITE OF PBO (POLY P-PHENYLENE BENZOBISOXAZOLE) AND PMR-II THAT WILL HAVE THE PROPERTIES OF HIGH PERFORMANCE CARBON COMPOSITES WITHOUT THEFABRICATION COMPLEXITY (COST) AND PROBLEMS (MICROCRACKING) ASSOCIATED WITH DISCRETE FIBER AND MATRIX COMPOSITES. OUR APPROACH IS TO INTRODUCE THE PMR-II INTO THE PBO THROUGHAN INTERPENETRATING NETWORK (IPN) PROCESS THAT ASSURES A HOMOGENEOUS MICROCOMPOSITE WHICH IS IMPERMEABLE AND IS HIGHLY RESISTANT TO DELAMINATION. WE WILL TEST THE PBO/PMR-II LAMINATE AT ROOM TEMPERATURE AND UP TO 650 DEGREES K TO VERIFY ITS HIGH TEMPERATURE PERFORMANCE. IN THE PHASE II PROGRAM, WE WILL BRING IN A TURBINE MANUFACTURER TO IDENTIFY A SUITABLE COMPONENT TO FABRICATE WITH PBO/PMR-II. SUCCESSFUL DEMONSTRATION OF THIS COMPONENTWILL BE THE PATH TO COMMERCIAL APPLICATION OF PBO/PMR-II COMPOSITES.