DOI: https://doi.org/10.55373/mjchem.v27i6.120

Keywords: Thermoplastics; graphene; elastomer; compatibilizer; conductivity

Abstract

Linear low-density polyethylene (LLDPE) is a polyolefin with attractive properties such as low density, ease of processing, and recyclability. However, its low stiffness and high oxygen permeability restricts its use in durable packaging and necessitates modification of its mechanical and barrier properties. Adding fillers to the polymer matrix is one strategy to enhance product performance. In this study, natural rubber (NR, 5–25 wt%) was blended with LLDPE/graphene nanoplatelet (GNP) nanocomposites to produce thermoplastic elastomer films as potential packaging materials. Liquid natural rubber (LNR, 2–12 wt%) was added as a compatibilizing agent. The LLDPE:GNP:NR:LNR ratio of 66:4:20:10 provided optimal characteristics, such as improved mechanical strength and a 90.6 % increase in thermal conductivity (0.61 W/mK) compared to LLDPE alone (0.32 W/mK). This enhancement is attributed to better GNP dispersion and interfacial adhesion from NR and LNR, which improved stress transfer and heat conduction. In contrast, electrical conductivity decreased although the product remained a semiconductor (~10^-8), likely due to the insulating effect of rubber disrupting the GNP network. Thermal conductivity declined sharply beyond 60 °C, likely due to phonon scattering and restricted filler mobility at higher temperatures, which hinder heat transfer. This novel LLDPE/GNP/NR/LNR nanocomposite shows potential as a durable packaging material with semiconductive electrical properties and high thermal resistance.