A comparison of shear‐mixing and solvent‐induced on phase behavior, thermal and dielectric properties of PVDF‐HFP/MOF composites

Abstract

The effects of processing techniques significantly alter on the electroactive β-phase, thermal, and dielectric behavior of polymer composites. The metalorganic framework filler (C 3 N 2 H 5 )(Mg(HCOO) 3 ), HImMg is prepared and introduced into poly(vinylidenefluoride-co-hexafluoropropylene) (PVDF-HFP) matrix using two distinguished methods: melt-mixing and solution-casting methods. The processing conditions are important in determining the dominant phase in PVDF-HFP. As a result of solvent-induced crystallization, the β-phase content of solution-cast composites containing 10% HImMg is 22% higher than that of melt-mixed composites. In both methods, the nucleating effect of HImMg particles increases the overall crystallinity of the polymer matrix and enhances the dielectric constant in composite films by improving the interfacial and dipolar polarization. Furthermore, the melt-mixed composites with 7 wt% HImMg demonstrate the highest dielectric constant of 17.8 at 1 kHz, showing an enhancement of 59% compared with that of pristine PVDF-HFP. Meanwhile, the dielectric loss is suppressed at 0.083. These findings suggest the possibility of enhancing composites' electroactive phase and dielectric properties without mechanical stretching or a large electrical field.

Poly(vinylidene fluoride) ultrafiltration membranes tailored with zirconium‐based MOF‐801 for water treatment applications

“…The peak at 1225 cm −1 in the spectrum of PVDF‐2 is assigned to the acidic group which arises from fumaric acid. Overall data indicate that the introduction of MOF‐801 has a slight effect on changes in phase behavior of the PVDF matrix 30 …”

“…Overall data indicate that the introduction of MOF-801 has a slight effect on changes in phase behavior of the PVDF matrix. 30 FESEM/EDX and AFM Figure 4 displays the top surface and cross-section FESEM images as well as the EDX spectra of bare PVDF and PVDF/MOF-801 membranes. From Fig.…”