Structural investigations of Surlyn ionomer/titanate nanocomposites formed by ionomer-in situ sol-gel processes

摘要

The Mauritz Research Group demonstrated that novel nanostructured poly[ethylene-co-methacrylic acid (and Zn~(2+) ionomer forms)]/silicate hybrids are achievable via polymer-in situ sol-gel reactions for tetraethylorthosilicate. The copolymer utilized as the sol-gel polymerization matrix was commercial Surlyn in the form of melt-pressed films. Later, [acid form Surlyn]/titanate nanocomposites were achieved by means of polymer-in situ sol-gel reactions for titanium butoxide monomer. In these studies, AFM images revealed arrays of distinct titania nanoparticles having diameters on the order of 10-30 nm. FTIR spectroscopy verified the presence of an internally-polymerized titanate phase (i.e., formation of Ti-O-Ti bonds) that also contained unhydrolyzed TiOBu groups. COmpared with the silicate-filled systems, the primary, high temperature melting endotherm appears on the first scan for [acid form Surlyn]/titanate hybrids, but the lower temperature transition of the twin melting endotherm region is not present or weak. Primary crystallinity persists despite titanate phase incorporation.