High-performance fluoroelastomer-graphene nanocomposites for advanced sealing applications

TL;DR

This study develops fluoroelastomer-graphene nanocomposites with enhanced mechanical and barrier properties, demonstrating their potential for high-pressure sealing applications by incorporating graphene nanoplatelets into the elastomer matrix.

Contribution

It introduces a novel FKM/graphene nanocomposite with improved properties and analyzes its reinforcement mechanism and swelling behavior for sealing uses.

Findings

GNPs are homogeneously dispersed and aligned within the matrix.

Mechanical and barrier properties are significantly improved at low GNP loadings.

Modified Nielsen's theory effectively analyzes CO2 permeability in the nanocomposites.

Abstract

High-performance sealing materials that can guard key components against high pressure gases and liquid chemicals while withstanding mechanical deformation are of utmost importance in a number of industries. In this present work, graphene nanoplatelets (GNPs) were introduced into a fluoroelastomer (FKM) matrix to improve its mechanical and barrier properties and test its suitability for sealing applications. Nanocomposites filled with different loadings of GNPs were prepared and compared with their counterparts loaded with carbon black (CB). GNPs were dispersed homogeneously with a high degree of in-plane alignment. The tensile and barrier properties of the FKM were improved significantly by the addition of GNPs. Micromechanical modelling based on the shear-lag/rule-of-mixtures theory was used to analyse the reinforcing efficiency of the GNPs. Upon the addition of the GNPs, the elastomer was able to swell anisotropically in liquids, a fact that can be used to tune the swelling properties for sealing applications. In terms of gas permeability, a modification of the well-established Nielsen's theory was introduced to analyse the CO2 permeability for the bulk composite samples. The significantly improved mechanical, thermal and barrier properties at relatively low filler loadings, reveal that the FKM/GNP nanocomposites produced are very promising for use in advanced sealing applications.