Piezoelectric performance and crystallization properties of poly (vinylidene fluoride) (PVDF)/thermoplastic polyurethane elastomer (TPU) nanofiber solution blends

A series of poly(vinylidene fluoride) (PVDF)/thermoplastic polyurethane elastomer (TPU) blends was prepared with various mass ratios through electrospinning. The piezoelectric performance, along with the miscibility and crystallization behavior of the blends, was studied. The results showed that the incorporation of TPU significantly promoted β-phase formation, and the PVDF with 10 wt% TPU exhibited the highest β-phase content as confirmed by ATR-IR and Raman. XRD analysis reveals that blending PVDF with 10 wt% TPU enhances the β-phase crystallite size. Due to the maximum interactions between the crystalline structure of PVDF and 10 wt% TPU, these can include torsional and bending modes related to PVDF chain movements from alpha to beta and crystal lattice vibrations, as proved by FT-IR, Raman, and XRD. However, as the TPU content increased further than 50 wt%, FT-IR, and Raman spectra were dominated by TPU-related peaks, while the characteristic signals of PVDF were no longer evident. This absence results from TPU overlap, which diminishes PVDF spectral contribution. When TPU content reached 50 wt%, DSC showed the lowest crystallinity at 24.0%.