Premium
Moisture curing kinetics of isocyanate ended urethane quasi‐prepolymers monitored by IR spectroscopy and DSC
Author(s) -
DanieldaSilva Ana Luísa,
Bordado João Carlos Moura,
MartínMartínez José Miguel
Publication year - 2007
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.26453
Subject(s) - isocyanate , curing (chemistry) , prepolymer , differential scanning calorimetry , kinetics , polyurethane , polymer chemistry , materials science , activation energy , order of reaction , infrared spectroscopy , chemical engineering , isothermal process , polyol , chemistry , composite material , organic chemistry , thermodynamics , reaction rate constant , physics , quantum mechanics , engineering
The study of the kinetics of the curing of isocyanate quasi‐prepolymers with water was performed by infrared spectroscopy and differential scanning calorimetry. The influence of the free isocyanate content, polyol functionality, and of the addition of an amine catalyst (2,2′‐dimorpholinediethylether) in the reaction kinetics and morphology of the final poly(urethane urea) was analyzed. A second‐order autocatalyzed model was successfully applied to reproduce the curing process under isothermal curing conditions, until gelation occurred. A kinetic model‐free approach was used to find the dependence of the effective activation energy ( E a ) with the extent of cure, when the reaction was performed under nonisothermal conditions. The dependence of E a with the reaction progress was different depending on the initial composition of the quasi‐prepolymer, which reveals the complexity of the curing process. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2008