Cyclic Guanidines as Efficient Organocatalysts for the Synthesis of Polyurethanes

Abstract : A systematic survey of basic/nucleophilic organocatalysts for the polyaddition in bulk of polyols, PEG-600, and PTMO-650, to isophorone diisocyanate (IPDI) has been performed. Guanidines were shown to be very efficient catalysts for the urethane linkage formation. Bicyclic penta-alkylated guanidines such as MTBD led to polyurethane molecular weight and dispersity that are in the range of those observed with tin-based catalysts such as DBTDL. Tetra-alkylated guanidine such as TBD was shown to be a weaker catalyst as compared to pentaalkylated guanidines, as a result of its high reactivity toward isocyanate, resulting in the formation of a less nucleophilic urea. Although the mechanism has not yet been firmly established, these experiments suggest that a nucleophilic-catalysis mechanism, involving the attack of one of the nitrogen of the guanidine onto the unsaturated system of the isocyanate, should not be totally ruled out with such strong Bronsted base catalysts.
Document type :
Journal articles
Complete list of metadatas

https://hal.archives-ouvertes.fr/hal-00758513
Contributor : Dominique Richard <>
Submitted on : Wednesday, November 28, 2012 - 5:26:19 PM
Last modification on : Monday, March 19, 2018 - 9:40:02 PM

Identifiers

Collections

Citation

Jérôme Alsarraf, Yacine Ait Ammar, Frédéric Robert, Eric Cloutet, Henri Cramail, et al.. Cyclic Guanidines as Efficient Organocatalysts for the Synthesis of Polyurethanes. Macromolecules, American Chemical Society, 2012, 45 (5), pp.2249-2256. ⟨10.1021/ma2026258⟩. ⟨hal-00758513⟩

Share

Metrics

Record views

155