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A novel and green method for polycondensation reaction of 4‐substituted phenylurazoles with different diisocyanates under solvent‐free conditions
Author(s) -
Mallakpour Shadpour,
Dinari Mohammad
Publication year - 2008
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/app.27851
Subject(s) - isophorone diisocyanate , polymerization , polymer chemistry , condensation polymer , thermogravimetric analysis , solvent , step growth polymerization , solution polymerization , dimethylformamide , chemistry , monomer , materials science , polymer , dimethylacetamide , organic chemistry , polyurethane
Abstract In this investigation, a new method for step‐growth polymerization reactions of 4‐phenylurazole ( PHU ) and 4‐(4‐methoxyphenyl)urazole ( MPU ) with various diisocyanates were developed under solvent‐free conditions. The reaction of these monomers with hexamethylene diisocyanate ( HMDI ), isophorone diisocyanate ( IPDI ), and tolulyene‐2,4‐diisocyanate ( TDI ) were performed in the presence or absence of dibutyltin dilaurate ( DBTDL ) as a catalyst. The results of polymerization revealed that DBTDL did not have considerable effect on the polymerization process. The resulting polyureas showed good yields and moderate inherent viscosities ranging of 0.17–0.30 dL/g in N,N ‐dimethylformamide (DMF) at 25°C. They are soluble in most polar organic solvents. All of the above polymers were characterized by 1 H‐NMR, FTIR spectroscopy, and thermogravimetric analysis (TGA). This method was compared with the polymerization reaction in N,N ‐dimethylacetamide as a solvent via solution polymerization. Under solvent‐free conditions, higher yields and inherent viscosities were obtained. In addition, in this method we do not need to use any solvents and the polymerization reaction can be classified as a green and environmentally friendly method. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008