HIGH PERFORMANCE PBO (POLYBENZOBISOXAZOLE) FILM

THE ORDERED POLYMERS PBT (POLYBENZOBISTHIAZOLE) AND PBO (POLYBENZOBISOXAZOLE) BOTH HOLD PROMISE AS HIGH STRENGTH, THERMALLY STABLE, CHEMICALLY RESISTANT AND ELECTRICALLY NONCONDUCTIVE MATERIALS. WHEREAS PBT HAS ENJOYED RATHER COMPLETE INVESTIGATION AND DEVELOPMENT IN FIBER AND FILM FORM, PBO HAS NOT. PBO MAY EXCEL PBT IN THE IMPORTANT AREAS OF TRANSVERSE MECHANICAL STRENGTH, ATOMIC OXYGEN RESISTANCE, AND EASE OF SYNTHESIS. UNIAXIALLY AND BIAXIALLY ORIENTED THIN FILMS OF PBO WILL BE PRODUCED BY ADAPTION OF METHODS AND EQUIPMENT PREVIOUSLY DEMONSTRATED SUCCESSFULLY WITH PBT. RESULTING PBO FILMS WILL BE CHARACTERIZED FOR MECHANICAL, THERMAL AND HYDROLYTIC BEHAVIOR, AND WILL BE CONTRASTED WITH SIMILARLY PROCESSED PBT FILMS. A SPECIAL EFFORT WILL BE MADE TO DETERMINE WHETHER THE COMPRESSIVE OR CROSS-MACHINE-DIRECTION PROPERTIES OF PBO FILMS ARE SUPERIOR TO THOSE OF PBT.