Effects of Annealing on the Polarization Switching of Phase 1 Poly(vinylidene Fluoride)
Abstract
To obtain information about microscopic processes involved in the polarization switching in uniaxially oriented poly vinylidene fluoride film, a least squares estimation of nonlinear parameters was developed to yield parameters of an equation which describes the nucleation and domain growth process. Time domain measurements of polarization reversal revealed that switching times decreased as the annealing temperature, Ta, increased (67.0 micro s, 52.4 micro s and 41.3 micro s at -20 C under a 200 MV/m pulse field for the as-stretched samples, the samples being annealed at Ta = 120 C, and Ta = 160 C, respectively). The analysis showed that the value of the domain growth speed increased as Ta increased. This is consistent with X ray diffraction data which indicated that the annealing process brought about better chain packing and increased crystallite perfection. The analysis also showed that the nucleation probably significantly increased as Ta increased. This result was interpreted in terms of a morphological transformation, which was indicated by the decrease in elastic modulus with increasing Ta with no corresponding loss of orientation. It is suggested that the annealing process brought about an increase in the number of nucleation sites as a result of a transformation from a fibrous structure to a crystal-amorphous series structure which has increased boundary zone area.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 1988
- Accession Number
- ADA202115
Entities
People
- B. A. Newman
- J. I. Scheinbeim
- Y. Takase
Organizations
- Rutgers University–New Brunswick