Crystallization kinetics and phase transformation of poly(vinylidene fluoride) films incorporated with functionalized baTiO₃ nanoparticles

Abstract

The transformation of a to b-phase in poly(vinylidene fluoride) (PVDF) induced by the addition of tetradecylphosphonic acid (TDPA)-BaTiO 3 nanoparticles and subsequently the isothermal crystallization kinetics of pristine PVDF and its nanocomposites have been investigated. The result of infrared spectra showed that the relative crystalline fraction of b-phase was enhanced greatly after the introduction of TDPA-BaTiO 3 nanoparticles, and reached the peak of 93% when the concentration of nanofillers was 20%. The interaction between TDPA-BaTiO 3 nanoparticles and PVDF macromolecular chains induced the change of conformation from trans-gauche to all-trans crystal structure in PVDF segment. The isothermal crystallization of TDPA-BaTiO 3 /PVDF nanocomposites was carried out by the differential scanning calorimetry (DSC). The influence of TDPA-BaTiO 3 nanoparticles concentration on crystallization rate, activate energy, melting enthalpy, and peak temperature were studied. The nanocomposite film loaded 20% TDPA-BaTiO 3 nanoparticles exhibited the highest crystallization rate and activate energy, which decreased after loading more nanofillers in the host because of high volume fraction of nanoparticles leading to steric hindrance and further weakening the mobility of PVDF chains during the crystallization.

Crystalline polymorphism in poly(vinylidenefluoride) membranes

“…The interactions between the negatively charged particles and the polymer CH 2 groups, having a positive charge density, favors the nucleation of the β phase from the melt process [126]. It is interesting that the β PVDF nucleation was found to be dependent on the filler size but almost independent of the filler content [127]. It is believed that the nucleation is strongly influenced both by geometrical factors and interactions at the interface between the local electric field around the nanoparticles and the PVDF dipoles [125].…”

Effect of ionic liquid anion and cation on the physico-chemical properties of poly(vinylidene fluoride)/ionic liquid blends

“…Some studies showed that the presence of charged fillers within the PVDF matrix can acts as crystallization directors to promote the crystallization of specific polar b or c phases of the PVDF polymer from the melt [29,30]. The presence of IL in this polymer matrix could, in this way, induce the crystallization in one of the electroactive phases of PVDF.…”

Facile preparation of highly oriented poly(vinylidene fluoride) uniform films and their ferro- and piezoelectric properties

“…The desirable piezoelectric crystallization phase is b-phase, which has all-trans (TTTT) conformation is commonly achieved by biaxial stretching aphase lms, 5-7 electrical poling, 8 ultra-fast cooling, 9,10 or presence of llers. [11][12][13] The g-phase has a T 3 GT 3 G 0 conformation between that of a and b phases.…”