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Speciality polyurethane soft segments. II. Mixing studies in micro‐RIM using polyether diamine oligomers containing backbone urea moieties
Author(s) -
Harris Robert F.,
Anderson Robert M.,
Shan David M.
Publication year - 1992
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.1992.070460905
Subject(s) - urea , diamine , polyurethane , polymer chemistry , polymer , materials science , mixing (physics) , solvent , molecule , dynamic mechanical analysis , chemical engineering , chemistry , organic chemistry , composite material , physics , quantum mechanics , engineering
Polyether polyamines containing preformed urea moieties in their backbone, prepared by the reaction of aminated polyglycols with urea, were used to fabricate high modulus urea polymers by reaction injection molding (RIM) on micro‐RIM equipment. A formulation was studied based on a 2000 g/mol molecular weight polyether diamine containing about 4 internal urea moieties/molecule as the soft segment and Isonate 143L and diethyltoluenediamine (DETDA) as the hard segment (60 vol %). Mixing was measured by the temperature rise produced by injection of the components into an adiabatic cup as a function of the B‐side Reynolds number at the mixhead. B‐Side Reynolds numbers of about 300 or above were required for adequate mixing in this system. Plaques were made and compared to the corresponding polyether diamine without urea moieties. The formulation containing preformed urea moieties in the soft segment produced urea polymers with superior properties such as higher modulus, greater strength, increased hardness, superior organic solvent resistance, and improved green strength at demold. Impact properties were reduced. © 1992 John Wiley & Sons, Inc.