Novel thermal curing reaction of oxetane resins with polyfunctional phenols

The thermal curing reaction of polyfunctional oxetanes (oxetane resins) such as tris[4-(3-ethyloxetane-3-yl)methoxyphenyl]methane (TEOMP) and 1,3,5-tris(3-ethyl-3-oxetanylmethoxy)benzene with certain polyfunctional phenols was performed in bulk with quaternary onium salts as catalysts. The reaction proceeded smoothly at 180–220 °C and produced insoluble gel products, and the rate of gel production increased with the reaction temperature. The rate of the addition reaction of TEOMP with 3,3′,5,5′-tetrachlorobisphenol A was also measured by IR spectroscopy, and the rate of reaction was proportional to the product of the oxetane concentration and the catalyst concentration in the film state. Furthermore, the glass-transition temperatures and 5 and 10 wt % weight-loss temperatures of the resulting gel products were confirmed with differential scanning calorimetry and thermogravimetric analysis, and the glass-transition temperatures and 5 wt % weight-loss temperatures were 127–162 °C and 323–351 °C, respectively. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 2028–2037, 2005