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Isocyanate–epoxy reactions in bulk and solution
Author(s) -
Senger J. S.,
Yilgor I.,
McGrath J. E.,
Patsiga R. A.
Publication year - 1989
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.1989.070380218
Subject(s) - isocyanate , diglycidyl ether , polymer chemistry , epoxy , differential scanning calorimetry , ether , catalysis , bisphenol a , materials science , polymer , chemistry , polyurethane , organic chemistry , physics , thermodynamics
The reaction between diisocyanates and diepoxides can produce polyoxazolidones. However, the reaction may be accompanied by concurrent cyclization of isocyanate to produce trimeric isocyanurate. Studies were performed with pure phenyl isocyanate or diphenylmethane‐4,4′‐diisocyanate (MDI) and the diglycidyl ether of bisphenol‐A (DGEBA). Reactions were followed by FT‐IR and differential scanning calorimetry in order to determine relative rates of conversion to polyoxazolidone and isocyanurate. Various catalysts were utilized, with the most effective being 2‐ethyl‐4‐methylimidazole (EMI). Bulk reactions between MDI and DGEBA at 150°C resulted in considerable amounts of trimerization, thus giving crosslinked polymers. Solution reactions at 180–185°C in dry N ‐methylpyrrolidone using 0.1% EMI gave soluble and moldable polyoxazolidones.