Functionalized montmorillonite/epoxy resin nanocomposites with enhanced thermal and mechanical properties

Abstract

The poor interaction between the hydrophilic montmorillonite and hydrophobic epoxy resins leads to agglomeration of montmorillonite within epoxy resins, which finally results in poor macro properties of the epoxy resin nanocomposites. Although silane modification can improve the hydrophobicity of montmorillonite surface, the hydrolysis and condensation of silane lead to locking effect in the interlayer structure of functionalized montmorillonite. The effect of the functionalized montmorillonite on the properties of the epoxy resin remains unclear. Herein, we present multi technique approach to thoroughly evaluate the macro properties of the montmorillonite/epoxy resin nanocomposites, including dynamic mechanical thermal, thermo-mechanical, dielectric, water absorption and subsequently evaluate the molecular factors governing these characteristics. Importantly, the storage modulus has been enhanced by 44%, from 2416 MPa for pure epoxy resin to 2416 MPa for nanocomposites with 5.0 wt% functionalized montmorillonite. Our analysis reveals the increase of thermal stability and glass-transition temperature, as well as a reduction of the coefficient of thermal expansion with the addition of functionalized montmorillonite. Additionally, functionalized montmorillonite leads to decreased water absorption. This research aims to offer guidance for the development of high-performance montmorillonite/polymer nanocomposites, potentially opening up new applications for montmorillonite in polymer nanocomposites.