Prediction of delamination state of 2D filler materials in cyclic olefin copolymer for enhanced barrier applications

Surface energies described by Hansen solubility parameters (HSP) of a synthetic organophilic fluoromica (MAE), molybdenum disulfide (MoS2), and graphene are used to predict their delamination properties in a cyclic olefin copolymer (COC). This prediction suggests MAE as the most appropriate filler for COC, followed by MoS2 and graphene. Nanocomposites are prepared via solution process and have been investigated on their delamination state using X-ray-diffraction (XRD), Raman spectroscopy, transmission electron microscopy (TEM), and angle-resolved light scattering (ARS). Nanocomposites based on MAE shown morphologies close to complete delamination. Agglomerations are detected in the case of MoS2 and graphene. For a potential barrier application, water vapor transmission rates (WVTR) are experimentally determined. In such nanocomposites, inorganic fillers increase the diffusion length of water, known as tortuous path model, which enhances the barrier properties. Highest barrier enhancements are obtained using MAE based nanocomposites reducing the WVTR down to 40% of the initial value. The prediction of delamination based on Hansen solubility parameters is found to be a very helpful tool for selecting fillers in composites.