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NMR investigations of polymer electrets
Author(s) -
Geschke Dieter,
Holstein Peter
Publication year - 1990
Publication title -
makromolekulare chemie. macromolecular symposia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.257
H-Index - 76
eISSN - 1521-3900
pISSN - 0258-0322
DOI - 10.1002/masy.19900340113
Subject(s) - poling , legendre polynomials , dipole , materials science , electret , polyamide , polymer , polar , electric field , field (mathematics) , orientation (vector space) , polymer chemistry , composite material , physics , chemistry , optoelectronics , dielectric , mathematics , geometry , pure mathematics , mathematical analysis , organic chemistry , ferroelectricity , quantum mechanics , astronomy
1H NMR investigations were performed on thin films of poly(vinylidene fluoride) (PVDF) and polyamide 11 (PA 11). The variation of the angle between the static magnetic B o ‐field and preferred directions given by drawing and poling leads to characteristic dependences of T 20ff , which can be discussed in terms of Legendre polynomials of the orientational distribution functions of crystallographic c‐ and b‐axis. A good c‐axis alignment can be realized by uniaxial drawing. The tendency for b‐axis to orient towards the direction of the applied electric field via the orientation of the electric dipoles is evident. The b‐axis alignment can be “switched” periodically.