Polymeric Nanocomposites Enabled by Controlled Architecture Materials

Clay nanocomposites have been shown to improve barrier properties, increase modulus, increase heat distortion temperature, and improve flame retardancy. To fully utilize these benefits, the clay platelets must be exfoliated and dispersed within the polymer. It is well known that clay will readily exfoliate in some polymeric resins, e.g. nylon. For hydrophobic resins, such as polyolefins, the exfoliation process is much more difficult. 3M is currently developing a portfolio of Controlled Architecture Materials (CAMs) as specialty additives for a variety of applications, including clay nanocomposites. In this paper we demonstrate the ability of CAMs to exfoliate both organically modified and unmodified natural clays in polystyrene (PS) and polypropylene (PP) resins. Complementary characterization techniques of Transmission Electron Microscopy (TEM), x-ray diffraction (XRD), and rheology are used to identify exfoliation. In addition we demonstrate the efficiency of CAMs to exfoliate clay at low additive levels.