Reactive & Functional Polymers, Vol.44, No.2, 177-182, 2000
Dielectric relaxation of poled polymer DCNP/PMMA
We have prepared the polymer thin films of a 3-(1,1-dicyanothenyl)-1-phenyl-4,5-dihydro-1H-pyrazole (DChTP)/poly (methyl methacrylate) (PMMA) guest-host system by spin coating. In order to investigate their temporal and temperature stability, we have measured their dielectric relaxation spectra including the frequency dependence of the real and imaginary parts of dielectric constants. The investigated frequency ranged from 50 Hz to 10 MHz. The measured temperature range above the glass transition temperature T-g (95 degrees C) of the DCNP/PMMA system was from 95 degrees C to 1250C. By using the Adam-Gibbs model, the temperature dependence of the characteristic time tau above T-g was fitted, and the values of the characteristic times tau below T-g were estimated. The lifetimes of the polymer were evaluated by the Kohlrausch-Williams Watts (KWW) empirical decay model. (C) 2000 Elsevier Science B.V. All rights reserved.
Keywords:TEMPERATURE-DEPENDENCE