Deformation and tearing of graphene-reinforced elastomer nanocomposites

TL;DR

This study demonstrates that incorporating graphene nanoplatelets into elastomers significantly enhances tear resistance, primarily through interfacial debonding mechanisms, with a threefold increase at maximum GNP content.

Contribution

It provides a quantitative analysis of toughening mechanisms in graphene-reinforced elastomers, highlighting the dominant role of interfacial debonding over pull-out.

Findings

Tearing energy increases linearly with GNP volume fraction.

Maximum GNP content triples the tear resistance.

Interfacial debonding is the primary toughening mechanism.

Abstract

The resistance to failure through tearing is a crucial mechanical property for the application of different elastomers. In this work, graphene nanoplatelets (GNPs) were introduced into a fluoroelastomer (FKM) matrix with the aim of improving its tear resistance. The fracture energy through tearing was evaluated using the pure shear test. It was found that the tearing energy increased linearly with the volume fraction of the GNPs. At the maximum GNP content, the tearing resistance was 3 times higher, suggesting efficient toughening from the GNPs. Theoretical analysis of the micromechanics was conducted by considering debonding and pull-out of the nanoplatelets as possible toughening mechanisms. It was determined quantitatively that the main toughening mechanism was debonding of the interface rather than pull-out. The formation of cavities at flake ends during the deformation, as confirmed by scanning electron microscopy, was found to contribute to the remarkably high interfacial debonding energy (~1 kJ/m2).