Effect of copper nanoparticles incorporation on the polar beta-phase development in polyvinylidene fluoride

The effect of the addition of copper nanoparticles on the transformation from α to β phase found in PVDF by stretching and thermal treatments was studied in this paper. These PVDF crystalline changes were in situ observed, evaluating simultaneously the uniaxial deformation process and the structural evolvement by 2D X-ray diffraction with synchrotron radiation. The results showed that the presence of copper nanoparticles facilitated the development of the β-phase instead of the α-polymorph in PVDF. Thus, less deformation is needed in the nanocomposite compared with that required in the pristine PVDF to achieve the same amount of that β polymorph, and a higher proportion of this β phase is obtained at the same level of deformation. This increase in the content of the β phase was also corroborated by FTIR spectroscopy. - Graphical abstract: Display Omitted - Highlights: • The α-β transition starts after necking formation in PVDF and its nanocomposite. • Cu nanoparticles promote obtainment by stretching of higher β content in the hybrid. • β form is efficiently obtained from the melt by fast quench into ice-water. • Orientation rises up to 0.87 at a strain of 31% in the initial stretching stage. • Further PVDF alignment continues increasing smoothly along the strain hardening