Influence of Spray Drying Parameters on the Formation of β‐Phase Poly(vinylidene fluoride)

Abstract

This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.A simple one-step spraying method to produce poly(vinylidene fluoride) (PVDF) in the desired conformation is presented. The content of the piezoelectric b-phase is measured at different spray drying conditions and during electrospray. The influence of a strong electrical field and charges on the droplet are investigated separately from the electrospray setup with a pneumatic atomizer. For this purpose, the electric field is integrated into a pneumatic atomization process by a plate capacitor and the charge of the droplets by corona discharge. To investigate the drying properties, the drying temperature and the flow rate of dry air are examined. The presented process offers the possibility to deposit PVDF films or to produce PVDF powders, in their piezoelectric band g-phases or in the nonpolar a-phase.

Fluoride recovery in degradable fluorinated polyesters

“…Furthermore, a sharp singlet at À122 ppm is formed, which can be assigned to sodium fluoride (NaF). This can be rationalised considering a defluorination pathway via nucleophilic aromatic substitution in which an alkoxide or hydroxide anion attacks an arylic sp 2 -carbon centre forming a tetrahedral sp 3 -carbon that thereafter eliminates inorganic fluoride. 43 To investigate whether full defluorination of the aromatic backbone can be achieved, the F PA derived polymer films were subjected to a 5 wt% sodium methoxide solution in methanol and left to stir at 110 1C for 8 h (see Fig.…”

“…Fluorinated polymers are not only popular materials in a wide range of consumer applications but are currently irreplaceable in many industries. 1,2 The low polarizability of the fluorine groups for example renders these polymers more hydrophobic and less adhesive than their non-fluorinated counterparts making them useful as, for example, water repellent and low-friction surface coatings. 3–5 Such polymers can be classified as per- and polyfluoroalkyl substances (PFAS) which have come under much scrutiny for being “forever chemicals”, meaning they do not show appreciable degradation in the environment with respect to their time in use.…”