RELATIONSHIPS BETWEEN POLYMERIZATION ACTIVATING SYSTEMS AND VISCOELASTIC PROPERTIES OF THE SUBSEQUENT POLYURETHANE POLY(TERT-BUTYL ACRYLATE) INTERPENETRATING POLYMER NETWORKS/

To date, most interpenetrating polymer networks (IPNs) are developed f or slow processes such as casting or coating. For industrial manufactu ring, fast-reactive polymer processing is often required. Simply incre asing the amount of catalyst and/or free-radical initiator shows some limitations. Also, increasing too much temperature may cause degradati on or side reactions. For polyurethane/polyacrylate IPNs, more or less simultaneous formation of the two networks, with over 97% conversion was obtained after 4 to 6 min at 110 degrees C, using appropriate cata lyst/initiator combinations. Depending on the relative kinetics of net work formation, either one, two, or multiple transitions were found fo r a given composition. Kinetics of formation and phase behavior have b een investigated by Fourier transform infrared spectroscopy and dynami c mechanical analysis. (C) 1997 John Wiley & Sons, Inc.