Investigation of the electrical, thermal and mechanical properties of graphene reinforced low density polyethylene nanocomposite

Abstract

Low-density polyethylene (LDPE), the synthetic polymer is widely used material due to its excellent properties and applications such as, in the automobile industry, the insulator of electric wire, laboratory equipment, etc. In spite of a large number of applications, the LDPE has some limitations in electrical, mechanical and thermal applications, thus to overcome these limitations it needs to be incorporated with other filler materials. Several materials are used as fillers, among them graphene, the derivative of carbon is widely used filler owing to its redundant performance in modern technology. The newly invented 2D wonder material graphene has auspicious presentation because of its lightweight, very strong and high mobility for charge carriers. The graphene is synthesized from natural graphite powder by chemical reduction method. Having synthesized the graphene is added to the LDPE matrix. Many composite fabrication techniques are available, among them, the extrusion molding method is best to avoid the problematic functionalization of graphene. The machine used for this techniques is called the extrusion molding machine (EMM). In this machine, the composites are fabricated by the simultaneous operation of heater and extruder. The EMM is locally fabricated where the necessary components are collected from a local market at a very low cost. Then the graphene reinforced LDPE nanocomposites are prepared by using this machine. The fabricated nanocomposites are studied by field emission scanning electron microscopy (FESEM) analysis to obtain surface morphology. This result reveals that the filler contents are properly dispersed in the matrix. Structural analysis is investigated by x-ray diffraction (XRD). The chemical structure is studied by Fourier transform infrared (FTIR) spectroscopy. Thermal stability is investigated by thermogravimetric analysis (TGA), which is very consistent with the theoretical value. Mechanical strength is observed by the calculation of ultimate tensile strength (UTS) and Young modulus. Current density, electrical conductivity, and dielectric constant are investigated to obtain the electrical properties of the as-synthesized nanocomposites. The current density is increased with increasing temperature, which is very consistent with the semiconducting nature of material.