Kick-Starting Oxetane Photopolymerizations

In the presence of small amounts of 2,2-dialkyl-, 2,2,3-trialkyl-, or 2,2,3,3-tetraalkyl substituted epoxides such as isobutylene oxide, 1,2-limonene oxide, and 2,2,3,3,-tetramethyl oxirane, the photoinitiated cationic ring-opening polymerizations of 3,3-disubstituted oxetanes are dramatically accelerated. The acceleration affect was attributed to an increase in the rate of the initiation step of these latter monomers. Both mono-and disubstituted oxetane monomers are similarly accelerated by the above-mentioned epoxides to give crosslinked network polymers. The potential for the use of such kick-started systems in applications such as coatings, adhesives, printing inks, dental composites and in three-dimensional imaging is discussed. (C) 2014 Wiley Periodicals, Inc.