Phenolic-triazine network

Modified phenolics may be applied as matrix resins in composites. Cyanate esters of phenolics have the potential to replace conventional phenolics in thermo-structural applications. Thermal curing of the cyanate esters [149, 150] provide thermally stable phenolic-triazine networks, as shown at the bottom of Scheme 18. 

Nair and co-workers [203] reported polycyanate esters of an imide-modified novolac of different maleimide content. The resins underwent a two-stage independent thermal curing through trimerisation of the cyanate groups, as well as addition polymerisation of maleimide moieties. On heating, cyanate esters were transformed into an imido-phenolic-triazine network polymer. The cured resins exhibited a higher initial decomposition temperature compared with the cured maleimide novolacs. However, the thermal stability was found to be inferior to the conventional phenolic-triazine resin. 

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