Synthesis and properties of polyurethanes containing s‐triazine rings in the main chain

Eight new diisocyanate monomers containing s‐triazine ring have been prepared from the parent diacids via the Curtius rearrangement of the corresponding diacyl azides. The parent diacids were synthesised by the reaction of p‐ and m‐hydroxybenzoic acid with 6‐methoxy‐2,4‐dichloro‐s‐triazine, 6‐phenoxy‐2,4‐dichloro‐s‐triazine, 6‐phenyl‐2,4‐dichloro‐s‐triazine, and 2‐diphenylamino‐4,6‐dichloro‐s‐triazine respectively. Polyurethanes have been synthesised by solution polymerization of these diisocyanates with ethylene glycol in N,N‐dimethylacetamide (DMAC). The resulting polymers were characterized by IR spectroscopy, viscosity measurement, solubility tests, and softening points.