Orientation of PVDF [alpha] and [gamma] crystals in nanolayered films

• Published in: Colloid and polymer science Vol. 293; no. 4; p. 1289
• Main Authors: Jurczuk, Kinga, Galeski, Andrzej, Mackey, Matthew, Hiltner, Anne, Baer, Eric
• Format: Journal Article
• Language: English
• Published: Heidelberg Springer Nature B.V 01.04.2015
• ISSN: 0303-402X; 1435-1536
• DOI: 10.1007/s00396-015-3542-7

Wide-angle X-ray scattering in conjunction with pole figure technique was used to study the texture of poly(vinylidene fluoride) (PVDF) [alpha] and γ phase crystals in nanolayered polysulfone/poly(vinylidene fluoride) films (PSF/PVDF) produced by layer-multiplying coextrusion. In all as-extruded PSF/PVDF films, the PVDF nanolayers crystallized into the [alpha] phase crystals. A large fraction of those crystals was oriented with macromolecular chains perpendicular to the PSF/PVDF interface as evidenced from the (021) pole figures. Further refinement of the texture occurs during isothermal recrystallization at 170 °C in conjunction with transformation of [alpha] to γ crystals. The γ crystals orientation was probed with the (004) pole figures showing the c-axis of PVDF γ crystals perpendicular to the PSF/PVDF interface. The thinner the PVDF layers the stronger the orientation of γ crystals. It was proven that the X-ray reflections from the (021) planes of [alpha] crystals and from the (004) planes of γ crystals are not overlapped with other reflections and can be effectively used for the texture determination of PVDF nanolayers in multilayered PSF/PVDF films.