Experimental and modelling studies on the properties of natural rubber reinforced with conductive hybrid filler systems

Abstract

Conductive elastomers have significant technological promise in the current world. The work focuses on the fabrication of high-performance conductive rubber composites by integrating natural rubber with a combination of carbon-based conductive fillers and ionic liquid-modified fillers. Unlike traditional metallic conductors, these elastomers offer advantages such as easy processability, flexibility, and cost-effectiveness. The primary objective of this work is to enhance the electrical properties of natural rubber, focusing on improving interfacial interaction and dispersion of hybrid fillers within the rubber matrix. This is achieved through the incorporation of ionic liquid modification and the utilisation of two distinct processing techniques. The chosen carbon-based fillers include conductive carbon black, carbon nanotubes, and reduced graphene oxide. The comprehensive investigation includes experimental and theoretical analysis, exploring dielectric, electrical and mechanical properties. The study probes into the reinforcement mechanisms of fillers in the rubber matrix, examining physical and chemical interactions. Viscoelastic properties and solvent transport characteristics are thoroughly examined, and the EMI shielding efficiency of the composites is measured. Thermal stability is evaluated via thermogravimetric analysis, with experimental findings compared to kinetic models to unveil underlying mechanisms. Additionally, this research involves the synthesis and characterisation of laboratory- synthesised thermally reduced graphene oxide. A comparative analysis is conducted on the properties of the natural rubber hybrid filler system, with carbon nanotubes and conductive carbon black, alongside both laboratory-synthesised and purchased reduced graphene oxide. In essence, this work contributes to the advancement of conductive elastomers, shedding light on their potential applications as electromagnetic interference shielding devices. The findings offer a glimpse into the future of flexible, efficient, cost-effective conductors.