Physical Properties of PVA:PVP blend reinforced by MWCNT

Abstract

The polyvinyl alcohol (PVA), Polyvinylpyrrolidone (PVP), PVA-PVP blend, and reinforced-sample with multi-walled carbon nanotubes (MWCNTs) were prepared in different proportions by casting technique. X-ray diffraction testing denotes a blending of copolymers and the added CNTs. The FE-SEM images illustrate rubber-like entangled of pure PVA-PVP blend. The MWCNTs of 1% ratio completely imbedded within the polymer and the blend appeared higher compact. The stress-strain curves for PVA-PVP blend sample and samples reinforced with CNTs show that the sample stiffness increased, where the elongation reduced when the carbon nanotube added increased to 1.5 wt% due to the contribution of binding to the added MWCNTs which limits the flexibility of the sample. The sample delivery behaviour greatly affected the charge carriers hopping over the barriers between neighbouring localized states. Increasing the MWCNT contents leads to an increase in the AC conductivity due to the creation of more localized states or by reducing the potential barriers. The dielectric constant (ε1) of the PVA-PVP blend samples decreased with increasing frequency until it reached quasi-constant at higher frequencies. The dielectric constant also decreased with the increase of the carbon nanotube contents. The dielectric loss (ε2) also decreases with frequency. These results demonstrated that the conductivity and dielectric parameters of the copolymer samples strongly depend on frequency and are significantly affected by the proportion of the added MWCNTs.