Preparation and Properties of Epoxy/Phenol Formaldehyde Novolac/Hexakis(methoxymethyl)melamine Hybrid Resins from In Situ Polymerization

Based on the self-condensation of hexakis (methoxymethyl)melamine (HMMM), the condensation between HMMM and phenol formaldehyde novolac resin (n-PF), and the addition reaction of diglycidyl ether of biphenyl A (DGEBA) and n-PF, a homogeneous, transparent hybrid thermoset was prepared via in situ polymerization of DGEBA, n-PF, and HMMM. No phase separations were observed even for the DGEBA/n-PF/HMMM hybrid thermoset containing 40 wt% HMMM. These hybrid thermosets had high glass-transition temperatures (98-127 degrees C from differential scanning calorimetry and 111-138 degrees C from dynamic mechanical analysis), excellent thermal stability with high 5 wt% decomposition temperatures (>322 degrees C, high char yields (>24 wt%), and improved flame retardancy with high limited oxygen indices (>28.5). The excellent overall properties of these hybrid resins may lead to their applications in high-performance "green" electronic products. (C) 2008 Wiley Periodicals, Inc. J Appl Polym Sci 110: 4084-4092, 2008