Electron paramagnetic resonance of poly(benzazole)s and conducting properties of N+-implanted poly(benzazole)s

We present electron paramagnetic resonance (EPR) studies of the magnetic de fect in poly(benzazole)s (including poly(p-phenylene benzobisthiazole) (PBZ T), poly(p-phenylene benzobisoxazole) (PBO), poly(2,5-benzoxazole) (ABPBO), PBO-ABPBO and poly(1,4-phenylene benzobisoxazole-co-dimethylene benzobisox azole) (PBO-PBOC2)) and the model compounds. Temperature dependence of the EPR spectra of poly(benzazole)s over the range 100-300 K and the effect of heat-treatment temperature on EPR parameters were also discussed. FeCl3. 6H (2)O-doped PBZT was investigated in its EPR signals. The results of analyse s of the detailed lineshapes and linewidths were discussed in terms of the soliton-antisoliton, polaron and bipolaron model of the magnetic defect. Af ter that, the conductivity studies and Raman characterization of N+-implant ed PBZT and PBO were reported. The room-temperature conductivity of these i mplanted polymers, approximately 0.1-10 S cm(-1), is significantly higher t han that of pristine polymers. It was revealed through Raman spectrum that the conductivity was attributed partially to the graphite laminar formed in the process of ion-implantation. The results of these studies contribute t oward an identification of the origin and nature of the paramagnetic center s in poly(benzazole)s and toward an understanding of the charge transport m echanism. (C) 2000 Elsevier Science Ltd. All rights reserved.