Poling Effects in Melt-Spun PVDF Bicomponent Fibres

Kurzfassung

This research shows the successful functionalisation of bicomponent fibres, consisting of a conductive polypropylene (PP) core, doped with carbon nano tubes (CNT) and a piezoelectric sheath (polyvinylidene fluoride, PVDF) by draw winding and poling. These steps lead to the usability of the PVDF’s piezoelectric capabilities. The PP/CNT constitutes the fibre core that is conductive due to a percolation CNT network. The PVDF sheath’s piezoelectric effect is based on the formation of β phase crystals (all-trans conformation), caused by draw-winding of the fibres. This β phase eventually has to be poled for the uniform alignment of polymer chains. The material’s behaviour in high electric field is analysed recording the poling voltage during the poling process. The outcome is hysteresis curves for different β phase contents, which verify a successful material poling.