Dielectric relaxation of poled polymer DCNP/PMMA

✍ Scribed by Wei Shi; Changshui Fang; Qiwei Pan; Xun Sun; Qintian Gu; Dong Xu; Jinzhong Yu

• Book ID: 104425816
• Publisher: Elsevier Science
• Year: 2000
• Tongue: English
• Weight: 193 KB
• Volume: 44
• Category: Article
• ISSN: 1381-5148
• DOI: 10.1016/s1381-5148(99)00093-0

✦ Synopsis

We have prepared the polymer thin films of a 3-(1,1-dicyanothenyl)-1-phenyl-4,5-dihydro-1H-pyrazole (DCNP) / 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 (958C) of the DCNP/ PMMA system was from 958C to 1258C. By using the g Adam-Gibbs model, the temperature dependence of the characteristic time t above T was fitted, and the values of the g characteristic times t below T were estimated. The lifetimes of the polymer were evaluated by the Kohlrausch-Williamsg Watts (KWW) empirical decay model.