The three-component blends composed of multiwall nanotubes (MWNT), bromine and polyphenylacetylene (PPA) were prepared by using two different procedures, e.g., mixing mechanically bromine absorbed MWNT with PPA and blending MWNT with PPA in organic solvents followed by absorbing bromine. The blends showed electrical conductivity of about 10 S/m, approaching to that of bromine doped MWNT. By using UV-Vis spectra, X-ray spectroscopy (XPS), and scanning electron microscope (SEM), the interaction among MWNT, bromine and PPA was investigated, and the influence of individual conductive units on the conductivity of the blends was also studied. The results indicated that the lower content of MWNT in the blends resulted in the transfer of bromine from PPA to MWNT, further bringing about the decrease of the conductivity, whereas higher content of MWNT could greatly enhance the conductivity.

Key words: MWNTs, bromine, polyphenylacetylene, the transfer of bromine, conductive unit