Accession Number : ADA259729


Title :   Molecular Control of Liquid Crystalline Orientation of Poly(p-phenylene- 2,6-benzobisoxazole) and Poly(p-phenylene-2,6-benzobisthiazole).


Descriptive Note : Technical rept.,


Corporate Author : MORRIS BROWN COLL ATLANTA GA DEPT OF CHEMISTRY


Personal Author(s) : Harruna, Issifu I ; Polk, Malcom B ; Khamvongsa, B ; Thuo, A ; Park, J


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a259729.pdf


Report Date : 30 Nov 1992


Pagination or Media Count : 4


Abstract : We studied the effect of molecular orientation on the transverse mechanical properties of poly(p-phenylene-2,6 benzobisoxazole) (PBO) and poly(2, 5-benzoxazole) (ABPBO). We prepared ABPBO and PBO chains with radially shaped chain orientations with respect to the anthrone nucleus. The inherent viscosity of the ABPBO in methene-sulfonic acid at 20 deg C was 0.98 dL/g. The C-13 FT NMR spectrum of the star-like polymer showed a chemical shift at 75.0 ppm (relative to TMS) corresponding to the quaternary carbon in the 9-position of the anthrone ring.... Liquid crystalline, polybenzoxazoles.


Descriptors :   *CONTROL , *LIQUIDS , *CRYSTALS , *BENZOXAZOLES , *MOLECULAR PROPERTIES , MECHANICAL PROPERTIES , CARBON , STARS , ACIDS , ANTHRONES , SULFONIC ACIDS , CHEMICAL SHIFTS , TRANSVERSE , NUCLEI , VISCOSITY , RINGS , CHAINS , ORIENTATION(DIRECTION) , POLYMERS , CHEMICALS


Subject Categories : Physical Chemistry
      Polymer Chemistry
      Crystallography
      Atomic and Molecular Physics and Spectroscopy


Distribution Statement : APPROVED FOR PUBLIC RELEASE