title: Electric-Field-Induced Dynamics of Polymer Chains in a Ferroelectric Melt-Quenched Cold-Drawn Film of Nylon-11 Using Infrared Spectroscopy.
abstract: The changes in intensity of the infrared bands of a ferroelectric melt-quenched, cold-drawn film of nylon-11 were measured as a function of a cyclic external electric field of 1.4 MV/cm. The infrared bands assigned to the NH stretching, amide I, NH-vicinal, and CO-vicinal CH2 scissoring modes showed butterfly-shaped hysteresis loops that are characteristic of ferroelectrics; however, the intensity changes of the infrared bands assigned to the CH2 antisymmetric and symmetric stretching modes are small and showed no butterfly-shaped hysteresis loops. These results indicate that the amide groups are inverted, while the methylene groups are not inverted under the external electric field. We propose a new molecular mechanism that explains the ferroelectric properties of nylon-11. Only the amide groups in the antiparallel β-sheet structure are inverted by the external electric field to form new hydrogen bonds; these two states form a nearly double-minimum potential.
authors.affiliation: Department of Chemistry and Biochemistry, Graduate School of Advanced Science and Engineering, Waseda University , Okubo 3-4-1, Shinjuku-ku, Tokyo 169-8555, Japan.
authors.forename: Hayato
authors.initials: H
authors.lastname: Isoda
authors.affiliation: Department of Chemistry and Biochemistry, Graduate School of Advanced Science and Engineering, Waseda University , Okubo 3-4-1, Shinjuku-ku, Tokyo 169-8555, Japan.
authors.forename: Yukio
authors.initials: Y
authors.lastname: Furukawa