Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1404930 | Journal of Molecular Structure | 2015 | 5 Pages |
•The THz complex dielectric constant of form II PVDF was determined by broadband THz-TDS.•Four phonon modes and a broad relaxation mode were clearly observed.•The glass transition temperature of form II PVDF was determined by THz-TDS.
The complex dielectric constant of semicrystalline form II polyvinylidene fluoride (PVDF (II)) in the frequency range from 0.2 to 6.0 THz has been determined by broadband terahertz time-domain spectroscopy (THz-TDS). The obtained dielectric constant consists of superposition of four vibration modes at 1.60, 2.36, 3.04 and 5.31 THz of crystalline part and a broad relaxation mode with center frequency of 0.68 THz which will be attributed to boson peak of amorphous fraction. In addition, the temperature dependence of the dielectric constant has also been measured, and we have determined the glass transition temperature of amorphous fraction of PVDF (II) as about 192 K by analysis of the temperature variation of peak frequency of the lattice vibration mode.
Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slide