Effect of multi-walled carbon nanotubes on crystallization, thermal, and mechanical properties of poly(vinylidene fluoride)

Composites were prepared by solution blending poly(vinylidene fluoride) (PVDF) and multi-walled carbon nanotubes (MWNTs). Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) results showed that the crystalline structure of PVDF was changed by the addition of MWNTs and a MWNTs-induced crystal transformation from α-phase to β-phase of PVDF was confirmed. With differential scanning calorimeter (DSC) and dynamic mechanic thermal analysis (DMA) techniques, thermal and mechanical properties of the composite films were examined. As the DSC results showed, addition of MWNTs would lead to the increased cooling crystallization temperature (Tc), implying that MWNTs nanoparticles could act as nucleating agents, which is further proved with the help of polarized optical microphotographs. On the other hand, the decreasing of Dd (degree of crystallinity) implied that the MWNTs networks can confine the crystallization of PVDF. Through the curve analysis of the dynamic mechanical measurements, it was found that the storage modulus (E′) is significantly enhanced, revealing that a strong interaction should exist between PVDF and MWNTs. POLYM. COMPOS., 2010. © 2009 Society of Plastics Engineers