Dielectric properties of natural rubber/polyethylene oxide block copolymer complexed with transition metal ions
- PDF / 1,720,477 Bytes
- 20 Pages / 439.37 x 666.142 pts Page_size
- 16 Downloads / 200 Views
Dielectric properties of natural rubber/polyethylene oxide block copolymer complexed with transition metal ions M. S. Mrudula1 · M. R. Gopinathan Nair1 Received: 12 July 2019 / Revised: 17 October 2019 / Accepted: 25 November 2019 © Springer-Verlag GmbH Germany, part of Springer Nature 2019
Abstract 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. Keywords NR/PEO block copolymer · Polymer–metal ion complexes · Dielectric properties · XRD
Introduction Polymers loaded with metal ions have been studied extensively which find application in various fields of engineering. A notable class of such materials includes solid polymer electrolytes (SPE) among which polyethylene oxide (PEO) gained much attention due to its specific structural features and related characteristics such as complexation and solvating ability. It has the ability to form complexes through oxygen donor present as ether linkages in high density. Easy solubility in various solvents and relatively easy way of chemical modification are added * M. R. Gopinathan Nair [email protected] 1
School of Chemical Sciences, Mahatma Gandhi University, Kottayam, Kerala 686560, India
13
Vol.:(0123456789)
Polymer Bulletin
advantages for the PEO. The macromolecular flexibility of the backbone ensures sufficient ionic dynamics. Suitably modified PEO is widely used in rechargeable batteries, photo-electrochemical cells, fuel cells, electrochromic displays and sensors. Achieving high ionic conductivity at ambient temperature is a crucial criterion for finding application in these technologies [1–6]. This criterion which is highly dependent on the type of polymer, morphology, degree of crystallinity, etc., is met successfully by PEO and its modifications [7, 8]. The modification mainly includes metal ion doping which significantly improves the electrical conductivity. Alkali metal ion doping, particularly lithium ion, has been widely studied and reported [9–11]. Ramesh et al. [12] analysed the electrical properties of polyethylene oxide complexed
Data Loading...
