pps proceeding - Abstract Preview
pps proceeding
Symposium: S07 - Smart and Multifunctional Polymers
Oral Presentation
 
 

A straightforward Melt-Processing of Electroactive PVDF-based Blends via calendering-extrusion technology

Raquez Jean-Marie (1)*, De Neef Alexandre (1), Samuel Cedric (2), Stoclet Gregory (3), Rguiti Mohamed (4), Courtois Christian (4), Soulestin Jeremie (2), Dubois Philippe (1)

(1) University of Mons - Not applicable - Belgium, (2) Ecole des Mines de Douai - Not applicable - France, (3) University of France - not applicable - France, (4) Université de Valenciennes et du Hainaut-Cambrésis - Not applicable - France

Poly(vinylidene fluoride) (PVDF) displays attractive ferroelectric/piezoelectric properties and PVDF polar β-crystals are specifically targeted for electroactive applications. However, their direct crystallization from the melt state represents a challenging task to access electroactive polymer films by melt-state processes. Here, the role of poly(methyl methacrylate) (PMMA) as a β-phase promoter for PVDF blends is investigated. PVDF/PMMA films were produced by extrusion-calendering and an tocrystaltransition at 5wt-% PMMA is clearly identified by infrared spectroscopy (FTIR) and wide-angle X-ray scattering experiments (WAXS). A significative impact of the cooling rate is highlighted using Flash DSC experiments, showing that the incorporation of PMMA into PVDF clearly favoured the development of β-crystals at lower cooling rates. Ferroelectric properties were finally established and ferroelectric behaviors were observed for PMMA content up to 10wt-% but the highest remanent polarization could be obtained with 5wt-% PMMA. Interestingly, dielectric properties of PVDF/PMMA films could be readily tuned up upon the PMMA content from a classical ferroelectric to pseudo-relaxor/anti-ferroelectric behaviors and these effects are discussed in terms of -phase content, size and nanoconfinement. We demonstrated that PMMA plays a key role in the crystallization of polar PVDF crystals from the melt state and PVDF/PMMA blends processed by extrusion-calendering represent an elegant way for the development of smart polymer materials.