Polycarbonate-based polyurethane nanocomposite films

Abstract This study presents the preparation of polyurethane (PU) nanocomposite films based on polycarbonate diols, 1,6-diisocyanatohexane, and nanofillers (colloidal silica and clay). The effort is focused on nanocomposites prepared either in bulk or from waterborne polyurethane dispersions (WPUDs). The nanocomposite preparation from WPUD is very simple and environmentally friendly: the nanofiller is dispersed either in water and mixed with a WPUD or mixed directly in a WPUD. The preparation process is finalized by slow water evaporation. PU nanocomposites prepared in bulk feature excellent mechanical properties and can be used as strong and durable films/coatings. On the other hand, PU nanocomposites prepared from WPUDs are more susceptible to biodegradation compared to PU nanocomposites with a very similar composition prepared in bulk. The extent of degradability can thus be set in a certain range only by the preparation method of the PU nanocomposites.