The study of the ferroelectricity of odd, even, odd-even, and even-even nylons

奇数、偶数ナイロンおよび奇数-偶数、偶数-偶数ナイロンの強誘電性に関する研究

2020-09-24

2020-09-24

Nylons are one of the useful engineering plastics possessing high melting point, high heat resistance, and high crystallinity with intermolecular hydrogen bond between amide groups. Polar amide groups in the molecular chain in odd-numbered and odd-odd-numbered nylons in which the number of carbon atoms are odd have parallel packing with intermolecular hydrogen bond, and thus non-zero net polarization in odd-numbered nylons and odd-odd-numbered nylons are switched by the external alternative electric field, so-called ferroelectric switching. On the other hand, anti-parallel packing of the polar amide groups in the molecular chain of even-numbered, even-even-numbered, or odd-even-numbered nylons leads the zero net polarization and thus non-ferroelectric properties. These discussions are very simple model and the practical net polarization and it’s switching in nylons are significantly related to the each crystal forms. Thus to investigate the ferroelectric nature of nylons is challenging and thus I focused on the ferroelectric nature of even-numbered and odd-numbered nylons and even-even-numbered and even-odd-numbered nylons in this thesis. In this thesis, not only polarization ? applied electric field (P ? E ) hysteresis curve, in which the spontaneous polarization Ps can be reversed by applying external electric field E to a ferroelectrics, but also I ? E hysteresis curve of the bipolar current I against the sinusoidal applied electric field E, in which the details of the polarization reversal history of ferroelectrics are presented, are used to investigate the ferroelectric properties of even-numbered and odd-numbered nylons and even-even-numbered and even-odd-numbered nylons in detail. Furthermore, a nylon thin film is fabricated using a spin coating method in which no molecular orientation is occurred, and thus ferroelectric nature of nylons can be investigated. The purpose of this study is to elucidate the mechanism of polarization reversal of spontaneous polarization in even-numbered and odd-numbered nylons and even-even-numbered and even-odd-numbered nylons and the characteristics of ferroelectricity of even-numbered and odd-numbered nylons and even-even-numbered and even-odd-numbered nylons. Furthermore, to clarify the origin of the ferroelectricity and the antiferroelectricity of even-numbered and odd-numbered nylons and even-even-numbered and even-odd-numbered nylons, the ferroelectricity of various nylons are investigated, and the possible application to the energy harvest or the energy storage materials is also discussed.

博士(工学)

京都工芸繊維大学

14303甲第971号

http://hdl.handle.net/10212/2600

eng

ETD

Thesis or Dissertation

Thesis