High dielectric constant epoxy nanocomposites based on metal organic frameworks decorated multi-walled carbon nanotubes

The interfacial region between nanofillers and polymer matrix plays a crucial role in determining the dielectric and mechanical properties of dielectric nanocomposites. A new strategy using metal-organic-framework (MOF) as a modifier to decorate multi-walled carbon nanotubes (MWCNTs) to achieve high-k polymer nanocomposites is introduced. The MOF-decorated MWCNTs serve both as a curing agent and as a nano-filler to enhance dielectric, thermal and mechanical properties of epoxy. The organic component in the MOF can trigger the crosslinking of epoxy resins, leading to good dispersion of MWCNTs and strong covalent bonding between MWCNT-MOF and the epoxy matrix. It is found that covalent bonding between MOF-epoxy significantly reduces both dielectric loss and coefficient of thermal expansion (CTE), while increasing the elastic modulus of epoxy. Two types of MWCNT-MOF hybrids with distinctly different morphologies were prepared to determine their influences on dielectric and mechanical properties. The usefulness of the present approach for the preparation of multi-functional polymer nanocomposites is discussed.