Effect of pressing temperature on β-phase ratio of electrospun PVDF

In this study, the morphological evolution of electrospun PVDF during hot compression for piezoelectric sensor production is investigated. The work assesses how compression alters total crystallinity, structural relaxation, and partial crystalline forms known as Form II, I, and III (α, β, and γphases), including transitions among these forms. Relaxation in amorphous and crystalline regions, together with stress-induced melting, produces changes in phase distribution. FTIR, XRD, and DSC measurements show a reduction in the absolute fraction of the beta phase. Changes in dielectric spectra confirm a decline in ordered beta and indicate a corresponding increase in amorphous fraction as compression temperature rises. The method used here enables identification of a threshold compression temperature at which electrospun PVDF samples achieve minimal porosity while preserving the high long-range order of the beta phase. These results guide optimization of conditions and support robust, device-relevant functional performance in PVDF-based piezoelectric sensors.