Microstructure, crystallization and dynamic mechanical behaviour of poly(vinylidene fluoride) composites containing poly(methyl methacrylate)-grafted multiwalled carbon nanotubes

Composites of poly(vinylidene fluoride) (PVDF) and poly(methyl methacrylate) (PMMA)-grafted MWNTs were prepared by melt mixing. The miscibility between PVDF and PMMA helps improve the dispersion of PMMA-grafted MWNTs in the PVDF matrix and also the load transfer from the PVDF matrix to the nanotubes. MWNTs act as nucleation agents to increase the crystallization and melting temperatures of PVDF, but the nucleation effect is suppressed when PMMA is grafted onto the nanotubes. X-ray diffraction and infrared spectroscopic studies showed that MWNTs induce the formation of β-form PVDF crystallites. The storage modulus of PVDF is increased by nearly 150% at 20 °C upon the incorporation of PMMA-grafted MWNTs with MWNT content of 1.93 wt%. PMMA-grafted MWNTs are more effective than organoclay in increasing the storage modulus of PVDF.