Effect of Graphene Nanoplatelets and Paraffin Oil Addition on the Mechanical and Tribological Properties of Low-Density Polyethylene Nanocomposites

Polymeric nanocomposite materials have solved many problems due to their extensive applications such as aerospace, automobiles, coatings, and packaging materials. Low-density polyethylene (LDPE)/graphene nanoplatelets (GNPs) impregnated by paraffin oil (PO) were fabricated by a hot compression technique. Elastic modulus was calculated by results of compression test that conducted on the testing nanocomposites using a universal testing machine. Microhardness of LDPE and its composites was measured by Vickers microhardness testing machine. Tribological properties of LDPE and its composites were investigated by pin-on-disc tester at 20 N normal load, 1.2ms-1\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$1.2~\hbox {ms}^{-1}$$\end{document} sliding velocity, and 212 m sliding distance. The results showed that the elastic modulus and microhardness of LDPE/GNP nanocomposites are higher than that of pure LDPE and then gradually decreased by adding PO contents. Tribological properties proved that LDPE/GNP nanocomposites have lower coefficient of friction (COF) and wear rates in comparison with pure LDPE. By adding PO contents to the LDPE and its composites, COF and wear rates were gradually increased. Wear specimens’ surfaces were imaged using scanning electron microscope.