Synthesis, characterization and electrical properties of poly[bis-(2-aminophenyl)disulfide] and poly[bis-(2-aminophenyl)diselenide]: Part II. XPS, ESR, SEM and conductivity study

Poly[bis(2-aminophenyl)disulfide] (DSDA) and poly[bis(2-aminophenyl)diselenide] (DSeDA) were synthesized by monomer oxidation with ammonium persulphate at different polymerization times, in 0.5 M H2SO4 and 1 M HCl media. X-ray photoelectron spectroscopy (XPS) analysis of DSDA shows similar percentage of imine and amine groups in the polymer, like emeraldine. DSeDA shows different percentages of imine and amine groups, which corresponds to a state different of emeraldine. When the time of polymerization of DSDA is increased, a small change in the oxidation state is detected, but in DSeDA the number of imine groups decreases. When polymerization is carried out in HCl media, both polymers present a minimum percentage of chlorine unit with covalent linkage to macromolecule. Moreover, electron spin resonance (ESR) study shows the presence of nitrogen and carbon radicals in the structure, and both radicals should be associated to chlorine or sulfate ions. The two polymers present low level of conductivity related to low level of doping. The macromolecules present a granular structure, but DSeDA is more pulverulent.