| 초록 |
Poly(p-phenylene benzobisoxazole) (PBO) has received great attention because of its fully conjugated rod-like backbone exhibiting extraordinary mechanical properties and thermal stability[1,2]. To fully exploit the mechanical properties of PBO, PBO/MWNT composites were obtained through in-situ polymerization. In order to impart chemical bonding between PBO molecules and MWNTs, MWNT were oxidized under ozone gas flow which has advantage of dry-process. The introduction of carboxylic groups to the surface of MWNT was controlled at different oxidation time. The degree of oxidation was measured by dispersion stability of MWNT in water qualitatively and by XPS quantitatively. As it is difficult to disperse MWNT in thick poly(phosphoric acid) (PPA), the modified MWNT was first dispersed in thin phosphoric acid using sonication followed by converting to PPA by dissolving additional P2O5 to prepare adequate solvent for polymerization of PBO. |
