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Three-Dimensional Polybenzobisoxazoles and PolybenzobisthiazolesDue to the poor compressive strength properties of high performance liquid crystalline polymers such as polybenzobisoxazoles (PBOs) and polybenzobisthiazoles (PBTs), we have prepared homopolymers and copolymers with PBO and PBT pendant groups on a central star-like unit, 2.7-diamino-9,9'-bis(4-aminophenyl)fluorene, in order to improve upon their compressive strength properties. The fluorene moiety was prepared by the reaction of 2,7-dinitro-9-fluorene with aniline and aniline hydrochloride, followed by reduction with palladium on carbon. The central star-like unit was characterized by FTIR, FTNMR, and elemental analysis. The PBO and PBT pendant groups were synthesized by the polycondensation of 4,6-diaminoresorcinol dihydrochloride with terephthaloyl chloride and 2,5-diamino-1,4-benzendithiol dihydrochloride with terephthaloyl chloride in poly(phosphoric acid), respectively. The resulting linear polymers containing the dicarboxylic end groups were attached to the central star-like unit by refluxing with 2,7-diamino-9,9'-bis(4-aminophenyl) fluorene to give the star-like polymers. The star-like PBO and PBT were soluble in methanesulfonic acid. Further characterization of the polymers is ongoing.
Document ID
Acquisition Source
Document Type
Conference Paper
Bray, M.
(Clark-Atlanta Univ. GA United States)
Harruna, I. I.
(Clark-Atlanta Univ. GA United States)
Bota, K. B.
(Clark-Atlanta Univ. GA United States)
Date Acquired
August 17, 2013
Publication Date
January 1, 1997
Publication Information
Publication: The First National Student Conference: NASA University Research Centers at Minority Institutions
Subject Category
Chemistry And Materials (General)
Accession Number
Distribution Limits
Public Use Permitted.
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