Dipole potential barrier simulation model for studying polar polymers

HASHIM, A. A., EVANS-FREEMAN, J., HASSAN, A. K. and MOHAMMAD, M. T. (2007). Dipole potential barrier simulation model for studying polar polymers. Materials science and engineering b-solid state materials for advanced technology, 138 (2), 161-165. [Article]

Abstract
Thin layers of amorphous PMA, PMMA, PM alpha Cl and PVAc were prepared using a spray pyrolysis technique. The dielectric loss epsilon '' of each polymer was measured as a function of temperature in the range 20-160 degrees C, at a fixed frequency of 1 kHz using a thick layer of polymer (48-61 mu m) as a capacitor dielectric material. The maximum alpha-relaxation peak value of epsilon ''(PMA) = 0.65 was observed at T-0 = 36 degrees C, epsilon ''(PMMA) = 0.26 at T-0 = 65 degrees C, epsilon ''(PM alpha Cl) = 0.45 at T-0 = 140 degrees C and epsilon ''(PVAc) = 1.6 at T-0 = 75 degrees C. The potential energy U between the stable levels of the dipoles was calculated from the dipole relaxation time and simulated using a polynomial fitting method. The experimental result obtained indicates the energy band shape. The maximum value of U obtained was U(PMA) = 2 eV, U(PMMA) = 0.38 eV, U(PM alpha Cl) = -0.85 eV, and U(PVAc) = -1.4 eV. The positive and negative sign indicates the dipole direction with respect to electric field direction (within the field direction or in the opposite direction). A theoretical model for epsilon '' was developed for each polymer using the value of U obtained at the dielectric response regions (gamma, beta, and alpha) and compared with the experimental results. The maximum alpha-relaxation theoretical peak value of epsilon ''(PMA) was observed at T=45 degrees C, epsilon ''(PMMA) at T= 80 degrees C, epsilon ''(PM alpha Cl) at T= 150 degrees C and epsilon ''(PVAc) at T-0 = 83 degrees C, with a polynomial fitting error P = (-9 to -15 degrees C). (c) 2007 Published by Elsevier B.V.
More Information
Metrics

Altmetric Badge

Dimensions Badge

Share
Add to AnyAdd to TwitterAdd to FacebookAdd to LinkedinAdd to PinterestAdd to Email

Actions (login required)

View Item View Item