Co-polycondensation of 4-(4-Phthalimidophenyl)-1,2,4-triazolidin-3,5-dion and 4-(4-Nitrophenyl)-1,2,4-triazolidin-3,5-dionwith DiisocyanatesAuthor(s): H.Nasr-Isfahani1, S.Soldoozi1, Z.Kalantar1, H.Mighani
4-(4-Nitrophenyl)urazole(4) was reacted with two equivalents of hexamethylene diisocyanate (HMDI)(5), isophorone diisocyanate (IPDI)(6) and tolylene-2,4-diisocyanate (TDI)(7), in DMF as a solvent to forming the related diisocyanates. The reaction of 4-(4-aminophenyl)urazole(1) with phthalic anhydride(2) in a mixture of pyridine and acetic acid (2:3) as a solvent led to the related amic acid. The amic acid was heated in the same solvent mixture to give 4-(4-phthalimidophenyl)-1,2,4-triazolidine-3,5- dione(3). Solution polyconden-sation reactions of the new diisocyanates, with 4-(4-phthalimidophenyl)-1,2,4-triazolidine-3,5-dione(3)were performed in DMF in the presence of pyridine as a catalyst and lead to the formation of novel aliphatic and aromatic co-polyureas(8, 9, 10). These novel co-polyureas have inherent viscosities in a range of 0.11-0.23 dLg-1 inDMF at 25oC. Some structural characterization and physical properties of these novel co-polymers are reported.