| Autor: |
Kazuhiro Tanimoto, Hisayoshi Nishizaki, Teruyuki Tada, Yuki Shiomi, Nariaki Ito, Kouki Shibata, Hidemine Furuya, Akihiro Abe, Kenji Imoto, Munehiro Date, Eiichi Fukada, Yoshiro Tajitsu |
| Zdroj: |
Japanese Journal of Applied Physics; Sep2014, Vol. 53 Issue 9S, p1-1, 1p |
| Abstrakt: |
It has been reported that poly(β-phenethyl l-aspartate) (PPLA) exhibits irreversible inversion from right-handed to left-handed helixes in a solid state at 130–140 °C from the results of circular dichroism measurement and X-ray diffraction. On the other hand, it is well known that semicrystalline chiral polymers show shear piezoelectricity due to their asymmetric crystal structure. The results of macroscopic shear piezoelectric measurement include information on macroscopic and microscopic properties due to the helix structure of the chain molecules. However, in general, no direct correspondence has been reported between the macroscopic piezoelectric properties and crystal characteristics because of the existence of a unique complex high-order structure in polymer films. We measured the temperature dependence of the piezoelectricity of a PPLA film in order to obtain more information concerning the helix inversion process. As a result, the sign inversion of the piezoelectric constant was observed at the temperature at which the helix inversion took place. It was also shown that the macroscopic orientation of the crystalline structure was maintained in the PPLA film after the sign inversion, even though molecular motion such as the segmental motion and side-chain motion of PPLA molecules was activated. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
|
