Investigation of the dielectric, mechanical, and thermal properties of noncovalent functionalized MWCNTs/polyvinylidene fluoride (PVDF) composites

To improve the dispersion of multi-walled walled carbon nanotubes (MWCNTs) and investigate the effect of dispersant for MWCNTs functionalization on the dielectric, mechanical, and thermal properties of Polyvinylidene fluoride (PVDF) composites, two different dispersants (Chitosan and TritonX-100) with different dispersion capability and dielectric properties were used to noncovalently functionalize MWCNTs and prepare PVDF composites via solution blending. Fourier transform infrared, X-Ray diffraction, and Raman spectroscopy indicated that TritonX-100 and Chitosan were noncovalent functionalized successfully on the surface of MWCNTs. With the functionalization of Chitosan and TritonX-100, the dispersion of MWCNTs changed in different extent, which was investigated by dynamic light scattering and confocal laser scan microscopy. The dielectric, mechanical, and thermal properties of PVDF composites were also improved. Meanwhile, it was also found that the dielectric properties of PVDF composites are closely related to the dielectric properties of dispersant. High dielectric constant of dispersant contributes to the grant dielectric constant of PVDF composites. The mechanical and thermal properties of MWCNTs/PVDF composites largely depend on the dispersion of MWCNTs in PVDF, interfacial interactions and the residual solvent. Copyright © 2016 John Wiley & Sons, Ltd.