Microwave-assisted rapid polycondensation reaction of 4-(4′-acetamidophenyl)-1,2,4-triazolidine-3,5-dione with diisocyanates

Authors

  • Shadpour Mallakpour,

    Corresponding author
    1. Organic Polymer Chemistry Research Laboratory, College of Chemistry, Isfahan University of Technology, Isfahan 84156, Iran
    • Organic Polymer Chemistry Research Laboratory, College of Chemistry, Isfahan University of Technology, Isfahan 84156, Iran
    Search for more papers by this author
  • Zahra Rafiee

    1. Organic Polymer Chemistry Research Laboratory, College of Chemistry, Isfahan University of Technology, Isfahan 84156, Iran
    Search for more papers by this author

Abstract

4-(4′-Aminophenyl)-1,2,4-triazolidine-3,5-dione was reacted with 1 mol of acetyl chloride in dry N,N-dimethylacetamide (DMAc) at −15°C and 4-(4′-acetamidophenyl)-1,2,4-triazolidine-3,5-dione [4-(4′-acetanilido)-1,2,4-triazolidine-3,5-dione] (APTD) was obtained in high yield. The reaction of the APTD monomer with excess n-isopropylisocyanate was performed at room temperature in DMAc solution. The resulting bis-urea derivative was obtained in high yield and was finally used as a model for the polymerization reaction. The step-growth polymerization reactions of monomer APTD with hexamethylene diisocyanate, isophorone diisocyanate, and tolylene-2,4-diisocyanate were performed under microwave irradiation and solution polymerization in the presence of pyridine, triethylamine, or dibutyltin dilaurate as a catalyst. Polycondensation proceeded rapidly, compared with conventional solution polycondensation; it was almost completed within 8 min. The resulting novel polyureas had an inherent viscosity in the range of 0.07–0.17 dL/g in dimethylformamide or sulfuric acid at 25°C. These polyureas were characterized by IR, 1H-NMR, elemental analysis, and thermogravimetric analysis. The physical properties and structural characterization of these novel polyureas are reported. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 2103–2113, 2004

Ancillary