Development of poly(vinylidene fluoride)/thermoplastic polyurethane/carbon black‐polypyrrole composites with enhanced piezoelectric properties

Abstract

AbstractPoly(vinylidene fluoride)/thermoplastic polyurethane (PVDF/TPU) composites filled with carbon‐black polypyrrole were prepared via melt compounding followed by compression molding and fused filament fabrication. CB‐PPy was added to the blends from 0 up to 15% to possible act as nucleating filler for PVDF β phase in order to increase its piezoelectric response. The influence of blending PVDF and TPU and of the addition of CB‐PPy on the overall crystallinity, content of β phase, and piezoelectric response of composites were investigated by differential scanning calorimetry (DSC), Fourier‐transformed infrared spectroscopy (FTIR), X‐ray diffraction (XRD) and determination of the piezoelectric coefficient (d33). It was found that the addition of TPU to PVDF induced an increase of the crystallinity degree and content of β phase in PVDF. Moreover, although the degree of crystallinity of the composites decreased with the addition of CB‐PPy, the percentage of β phase in PVDF was increased. This effect is more significant in samples with filler concentration higher than 6 wt%. As expected, the d33 of the composites increased as the content of the β phase increased. Furthermore, 3D printed samples displayed lower content of β phase and reduced piezoelectric responses when compared to compression molded samples with same composition.