Reversing-pulse electric birefringence of poly(γ-benzyl-L-glutamate). III. The temperature dependence of the transient and steady-state behavior in cyclohexanone

✍ Scribed by Kiwamu Yamaoka; Shinobu Yamamoto; Kazuyoshi Ueda

• Publisher: Wiley (John Wiley & Sons)
• Year: 1987
• Tongue: English
• Weight: 921 KB
• Volume: 26
• Category: Article
• ISSN: 0006-3525
• DOI: 10.1002/bip.360260509

✦ Synopsis

Higashisenda-machi, N h -k u , Hiroshima 730, Japan synopma

The reversing-pulee electric bkfringence (WEB) technique was applied to the study of the temperature d e c t on the electrooptical and hydrodynamic properties of a fractionated [Glu(OBzl)], aample, which is molecularly dissolved in cyclohexanone. The aim was to develop a standard analytical method for thermal denaturation and temperaturc+induced confonnational traaeitiona The field-on revand steady-state signal, and the field-off decay signal, were measured at 536 nm and at a constant low field strength (a. 3 kV/m) over a wide temperature range (6-90°C). The steady-state birefringence and the relaxation time in the decay proceas were also measured at two constant temperatures (5 and 70°C) over a wide field strength range (E 5 20 kV/m). By the combination of these two differeat sets of RPEB measurements, the unwanted effect of the high pulee field on polymer confonnation at elevated temperaturea could beminimized . Together with the doneity and vhcogity of cyclohexanone measured between 5 and 96°C. the following quantitiea could be evaluated: the weight-average permanent dipole moment and polarizability anisotrOpy, the reduced optical anisotropy factor (Ag/n), the weight-average length, and the degree of polydispersity. AU t h e quantities, except for Ag/n, were found to be almoet independent of temperature (5-90°C) and concentration (1.54-427 mM).