Fabrication and characterization of intercalated/exfoliated polydiene polymers-clay nanocomposites

摘要

A novel technique to create exfoliated polydiene polymer-clay nanocomposites is explored, in which the polymer chains penetrate into the layer spacing of the clay by solution or melt blending. The structures and viscoelastic properties of exfoliated or intercalated polymer/clay nanocomposites have been studied as a function of the clay volume fraction with two different molecular weights of polydiene polymers using small-angle X-ray scattering (SAXS), transmission electron microscopy (TEM), and oscillatory shear rheology. The results presented here indicate that the molecular weight of polyisoprene (PI) or polybutadiene (PB) homopolymer affects the dispersion of nanoclay sheets as well as the viscoelastic properties of the exfoliated or intercalated Pi/clay and PB/clay nanocomposits. Additionally, we report that the nanoclay sheets dispersed in the low molecular weight PI matrix form elastic physical network above the elastic percolation threshold, φEP, at which the elastic modulus of the PIanoclay nanocomposite exhibits solid-like behaviors, where φ is the volume fraction of nanoclay.