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Multiple Relaxations in Poly (p-hydroxybenzoic acid-CO-ethylene terephthalate) Liquid Crystal Polymer: TSD Current Investigations

Published online by Cambridge University Press:  01 February 2011

Jitendra Kumar Quamara ,
Sridharbabu Yarramaneni  and
Geetika Goyal
Jitendra Kumar Quamara
Affiliation:
jkquamara@yahoo.com, National Institute of Technology, Deptt. of Applied Physics, NIT Kurukshetra, Kurukshetra, N/A, India, 91 1744 238470, 91 1744 238050
Sridharbabu Yarramaneni
Affiliation:
sridharsridharsridhar@yahoo.com, National Institute of Technology, Department of Applied Physics, Kurukshetra, N/A, India
Geetika Goyal
Affiliation:
smart_geetu@yahoo.com, National Institute of Technology, Department of Applied Physics, Kurukshetra, N/A, India
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Abstract

The PET/x.PHB samples were polarized at different temperatures (30-250°C) under various biasing fields ranging from 40 to 200 kV/ cm. The TSD currents were obtained at a heating rate of 2 °C/min in the temperature range (15-250)°C. The TSD current spectra in general comprise of three maxima namely β, α and δ in ascending order of temperature. However number of peaks actually appearing in these spectra, their location, height and sharpness are governed by polarization/depolarization parameters as well as the value of ‘x’ in a particular sample. The β peak appearing around (110-140°C) has been recognized as a dipolar relaxation process and is due to PET rich phase. The α- peak (160-180°C) recognized as space charge process is due to PHB rich phase and cold crystallization of PET rich phase. The δ peak (190-210°C) is a melting process due to the movement of large segments leading to Smectic-E like phase. In addition PET/x.PHB also exhibit a weak low temperature dipolar relaxation process β′ peak around (30-40)°C. In the vicinity of α-relaxation a rigid amorphous phase dipolar relaxation process γ relaxation is also observed.

Keywords

dielectric propertiesthermally stimulated currentpolymer
Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 949: Symposium C – Smart Dielectric Polymer Properties, Characterization and Their Devices , 2006 , 0949-C03-20
Copyright
Copyright © Materials Research Society 2007

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References

REFERENCES

1. Reinitzer, F., Monatsh. Chem., 9 (1888) 421.Google Scholar
2. Brostow, Witold, Polymer, 31 (1990) 979.Google Scholar
3. Quamara, J. K. and Kaushik, B. K., Indian Journal of Pure and Applied Physics, 34 (1996) 553.Google Scholar
4. Sessler, G. M., Electrets, New York (Springer-Verlag), Berlin, Heidelberg, 33 (1980).Google Scholar
5. Brostow, W., Kaushik, B. K., Mal, S. B. and Talwar, I. M., Polymer, 33 (1992) 4687.Google Scholar
6. Maneesha, G., Kumar, S., Quamara, J. K., Indian J. of Pure and Appl. Phys., 39 (2001) 259.Google Scholar
7. Lenz, R. W., Faraday Disc, 79 (1985) 21.Google Scholar
8. Huo, P., Cebe, P., Macromolecules, 25 (2) (1992) 902.Google Scholar
9. Brostow, W., Samatowicz, D., Polym. Engg. Sci., 1 (1992) 87.Google Scholar
10. Quamara, J. K., Mahna, S. K. and Kaushik, B. K., Indian J. of Pure and Appl. Phys., 36 (1998) 374.Google Scholar