Impact of graphene nanoplatelet size and hybridisation on the properties of natural rubber nanocomposites

This study explores how the size and hybridisation of graphene nanoplatelets (GNPs) affect the properties of graphene nanoplatelet-filled natural rubber (NR) nanocomposites (GNP-filled NR). Results demonstrate notable enhancements in the thermal properties and electrical conductivity of NR with the addition of GNPs. However, mechanical properties experienced partial enhancement, showing increased modulus by up to 200% and hardness by up to 50%, alongside decreased tensile strength by up to 60% and elongation by up to 70%. The comparative analysis highlights the superior mechanical and thermal properties associated with smaller GNPs. These smaller particles enhanced mechanical properties such as modulus at 100% strain and Shore A hardness, increased the glass transition temperature by up to 10%, and reduced thermal degradation rates by up to 30% due to their superior dispersion and interfacial bonding with NR. Larger GNPs exhibited a 1000% increase in electrical conductivity at 10 × 10⁶ Hz due to increased surface area and network formation due to reduced dispersion. Notably, hybrid GNPs contributed significantly to overall property enhancements compared to the single filler system, with up to 80% higher tensile strength, up to 30% higher elongation at break, up to 20% higher glass transition temperature, lower degradation rate at high temperature, attributed to improved dispersion of GNPs and interfacial adhesion with NR. This study highlights the substantial influence of GNP sizes on the performance of NR nanocomposites and the significant effects of hybridisation, providing valuable insights for optimising material properties for advanced applications.