Polyurethane Nanocomposites of Layered Silicates

Abstract

This chapter describes the effect of layered silicate on polyurethane in terms of morphology and other properties. Depending upon the compatibility of the layered silicate with the polymer along with the processing technique dictates the degree of intercalation and/or exfoliation of nanoclay. Morphology and the properties of polyurethane are highly influenced by the layered silicates at low concentration. Enhancements in the thermal properties are observed with the incorporation of nanoclay in polymer matrix. Improvement in mechanical responses of the nanocomposites with respect to pure polymer is due to stress transfer from polymer to filler as well as orientation of the clay platelets towards the applied force. Foaming behavior and the properties of polyurethane are highly influenced by the nature of nanoclay and the constituents of polyurethane (polyol and diisocyanate). Significant improvement in fire-retardant behavior is reported for nanocomposites as compared to neat PU, especially phosphonium ions modified clay. Enhancement of the gas barrier properties is observed for nanocomposites due to high aspect ratio of the layered silicates which increase the tortuous path of the gas. Polyurethane nanocomposites show good biocompatibility with most cell lines. Tuned and sustained drug delivery is achieved using nanocomposite of layered silicates. In brief, polyurethane nanocomposites have the potential for a wide range of applications. © 2017 Elsevier Inc. All rights reserved.