A spectroscopic study has been conducted for the analysis of electric field induced microstructural changes in a uniaxially drawn 75/25 vinylidene fluoride/trifluoroethylene copolymer. Based on the relative intensities of the infra-red active bands measured, changes in the average orientation of the CH2 dipoles after poling could be determined. Upon applying an electric field of 1.0 MV cm-1 to the sample, the mean-squared value of cos ct for the CH2 dipoles in the crystalline domain with respect to the film plane was found to change irreversibly from 0.46 to 0.34. Additionally, an increase in the degree of crystallinity of approximately 8% was observed after poling. Factor analysis was utilized in our spectroscopic analysis. Infra-red spectra for both the crystalline and amorphous regions have been constructed. These spectra are identical to those previously measured for isotropic samples. The conformational distribution for samples after poling contains a larger fraction of trans segments than unpoled samples
Посилання на статтю:
infra-red spectroscopic study of structural reorganization of a uniaxially drawn VDF/TrFE copolymer in an electric field / Kap Jin Kim* and Shaw Ling Hsu // Polymer. – 1994. – Vol 35. – P. 3612-3618.