Structural, mechanical, and dielectric properties of polyvinylchloride/graphene nano platelets composites

Abstract

Composites of polyvinylchloride (PVC) embedded with different ratios of graphene nano-platelets (GnP) were prepared by the casting method. Some techniques as X-ray diffraction technique (XRD), Fourier transform infrared (FT-IR), optical microscopy, and scanning electron microscopy (SEM) were investigated. The crystalline structure of GnP dominated by increasing its ratio to 2.5 wt.% in the hosting matrix compared to the amorphous structure of the pristine PVC. Microstructural analysis showed uniform distribution of GnP in PVC with some aggregates. Also, the article represents a study of the impact of GnP loading on PVC dielectric parameters such as dielectric loss, electric modulus, ac conductivity, and their dependencies on frequency and temperature. The permittivity ε' displayed an increase in its values with increasing GnP content due to the creation of a strengthened interfacial polarization phenomenon. The values of the activation energy of the polymer were decreased with increasing the content of GnP due to the growing number of conductive networks in the composites. Therefore, GnP enhanced considerably the conductivity of the polymer composites. The mechanical strength of PVC improved with increasing GnP content in which the tensile strength increased up to ∼100%. However, Young’s modulus of PVC enhanced remarkably to be about 109%. In contrast, the elongation at break of PVC decreased by GnP reinforcement from 139.5 to 28.4% by incorporate 0.25% GnP.