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

摘要

We studied the effect of molecular orientation on the transverse mechanicalproperties 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.