Dielectric relaxations above room temperature in DMPU derived polyaniline film

Mallya, Ashwini N and Kumar, Yashavanth GS and Ranjan, Rajeev and Ramamurthy, Praveen C (2012) Dielectric relaxations above room temperature in DMPU derived polyaniline film. In: PHYSICA B-CONDENSED MATTER, 407 (18). pp. 3828-3832.

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Abstract

Dielectric measurements carried out on drop casted from solution of emeraldine base form of polyaniline films in the temperature range 30-300 degrees C revealed occurrence of two maxima in the loss tangent as a function of temperature. The activation energies corresponding to these two relaxation processes were found to be similar to 0.5 eV and similar to 1.5 eV. The occurrence of one relaxation peak in the dispersion curve of the imaginary part of the electric modulus suggests the absence of microphase separation in the film. Thermogravimetric analysis and infrared spectroscopic measurements showed that the films retained its integrity up to 300 degrees C. The dielectric relaxation at higher temperatures with large activation energy of 1.5 eV is attributed to increase in the barrier potential due to decrease in the polymer conjugation as a result of wide amplitude motion of the chain segments well above the glass transition temperature. (c) 2012 Elsevier B.V. All rights reserved.

Item Type:	Journal Article
Publication:	PHYSICA B-CONDENSED MATTER
Publisher:	ELSEVIER SCIENCE BV
Additional Information:	Copyright for this article belongs to Elsevier
Keywords:	Polyaniline; Microphase separation; Dielectric relaxation; Activation energy
Department/Centre:	Division of Mechanical Sciences > Materials Engineering (formerly Metallurgy)
Date Deposited:	11 Jan 2013 09:13
Last Modified:	11 Jan 2013 09:13
URI:	http://eprints.iisc.ac.in/id/eprint/45269

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