Novel nucleophilic/basic and acidic organocatalysts for reaction between poorly reactive diisocyanate and diols

Fatima-Zohra Belmokaddem (1) , Julie Dagonneau (1) , Julien Lhomme (1) , Romain Blanc (2) , Azucena Garduno-Alva (2) , Christian Maliverney , Antoine Baceiredo (2) , Eddy Maerten (2) , Etienne Fleury (1) , Françoise Méchin (1)

1 IMP - Ingénierie des Matériaux Polymères
2 LHFA - Laboratoire Hétérochimie Fondamentale et Appliquée

Original basic or acidic organic compounds derived from guanidine or phenyl phosphonic acid were specifically designed and tested as new catalysts for the bulk synthesis of polyurethane prepolymers from a precursor system with particularly low reactivity (secondary alcohol + aliphatic isocyanate at low temperature). Both families showed interesting catalytic activities at 60-80 degrees C, but must nevertheless be used in much higher amounts (1mol%, i.e. between 0.15 and 0.50wt%) than traditional metal-based catalysts. The efficiency of guanidine derivatives seems to be related to their nucleophilicity, whereas that of phosphonic acid derivatives depends on their acidity. However, the solubility of the considered species in the reactive medium also plays a major role. The water/alcohol selectivity of the catalysts, especially at room temperature, was then examined as an additional criterion. Guanidines are not selective and favor the reaction of isocyanate groups with water as much as that with alcohols. Phenyl phosphonic acid derivatives are more selective, and particularly pentafluorophenyl phosphonic acid displays a remarkable catalytic activity together with an acceptable selectivity and could represent an interesting and safer alternative to toxic tin and mercury derivatives for many industrial polyurethanes.

Mots clés: organocatalysis; prepolymers; phenylphosphonic acid; water/alcohol selectivity; Polyurethane; guanidine

Domaines: Polymères; Catalyse

Fatima-Zohra Belmokaddem, Julie Dagonneau, Julien Lhomme, Romain Blanc, Azucena Garduno-Alva, et al.. Novel nucleophilic/basic and acidic organocatalysts for reaction between poorly reactive diisocyanate and diols. Designed Monomers and Polymers, 2016, 19 (4), pp.347-360. ⟨10.1080/15685551.2016.1152545⟩. ⟨hal-01397183⟩