Dielectric properties of natural rubber/polyethylene oxide block copolymer complexed with transition metal ions

Transition metal ion complexes of natural rubber/polyethylene oxide block copolymer (NR/PEO block copolymer, BC) are prepared by the process of adsorption in aqueous solutions and subjected to electrical analysis and XRD studies. AC conductance, impedance, dielectric relaxation and modulus have been measured as a function of frequency. The conductivity shows a linear relation with frequency. Among the complexes studied, BC–Co(II) shows the highest conductivity, while BC–Cu(II) shows the lowest value which may be due to different coordination pattern adopted. The Nyquist plot of impedance shows that except BC and BC–Cu(II), other samples give single skewed semicircles, while the former two yield arc bending towards the abscissa. The relaxation studies indicate electrode polarisation effect at lower frequencies and ion migration at higher frequencies. Argand plot indicates the presence of viscoelastic relaxation, and a distribution of relaxation time occurs in all the samples. XRD results support the electrical properties observed for the BC and the complexes.