AMORPHOUS PHENOLPHTHALEIN-BASED POLY(ARYLENE ETHER)-MODIFIED CYANATE ESTER NETWORKS - MICROWAVE PROCESSING

Toughenability of cyanate ester networks with reactive hydroxyl-functi onalized phenolphthalein-based amorphous poly(arylene ether sulfone) t hermoplastics, via conventional thermal curing, without a sacrifice in either the T-g or the moderately high modulus of the unmodified cyana te ester networks was already demonstrated. The present article invest igated the rapid processing of unmodified and thermoplastic-modified c yanate ester networks utilizing microwave radiation. Controlled morpho logies were generated by variations in both the rates of conversion an d the thermoplastic compositions. Improved toughness can be achieved w hich can be coupled with significantly reduced curing times. The use o f nonreactive modifiers resulted in macrophase separation in contrast to the well-defined morphologies of the reactive thermoplastic-modifie d networks. (C) 1997 John Wiley & Sons, Inc.