Unexpected Synthesis of Segmented Poly(hydroxyurea–urethane)s from Dicyclic Carbonates and Diamines by Organocatalysis - Archive ouverte HAL Accéder directement au contenu
Article Dans Une Revue Macromolecules Année : 2018

Unexpected Synthesis of Segmented Poly(hydroxyurea–urethane)s from Dicyclic Carbonates and Diamines by Organocatalysis

Résumé

A complete study of the effect of different organocatalysts on the step-growth polyaddition of a five-membered dicyclic carbonate, namely diglycerol dicarbonate, with a poly(ethylene glycol)-based diamine in bulk at 120 °C was first carried out. The reaction was found to be dramatically catalyst-dependent, higher rates being observed in the presence of strong bases, such as phosphazenes (t-Bu-P4 or P4) and 5,7-triazabicyclo[4.4.0]dec-5-ene (TBD). Unexpectedly, the as-formed urethane linkages entirely vanished with time, as evidenced by FTIR and 13C NMR spectroscopies, while signals due to urea bond formation progressively appeared. An advantage of the chemical transformation occurring from urethane to urea linkages was further taken by optimizing the polymerization conditions to access a range of poly(hydroxyurea–urethane)s (PHUUs) with precise urethane to urea ratio in a one-pot process. Characterization of the corresponding polymers by rheological measurements showed that the storage modulus reached a plateau at high temperatures and at high urea contents. The application temperature range of poly(hydroxyurea–urethane)s could thus be increased from 30 to 140 °C, as for regular polyurethanes. Furthermore, SAXS and phase-contrast microscopy images demonstrated that increasing the urea content improved the phase separation between soft and hard segments of these PHUUs. Altogether, this novel, straightforward, efficient, and environmentally friendly strategy enables the access to non-isocyanate poly(urea–urethane)s with tunable urethane-to-urea ratio from five-membered dicyclic carbonates following an organocatalytic pathway.

Domaines

Polymères
Fichier principal
Vignette du fichier
PubliHAL.pdf (5.85 Mo) Télécharger le fichier
Origine : Fichiers produits par l'(les) auteur(s)
Loading...

Dates et versions

hal-01917939 , version 1 (22-11-2019)

Identifiants

Citer

Amaury Bossion, Roberto H Aguirresarobe, Lourdes Irusta, Daniel Taton, Henri Cramail, et al.. Unexpected Synthesis of Segmented Poly(hydroxyurea–urethane)s from Dicyclic Carbonates and Diamines by Organocatalysis. Macromolecules, 2018, 51 (15), pp.5556-5566. ⟨10.1021/acs.macromol.8b00731⟩. ⟨hal-01917939⟩

Collections

CNRS INC-CNRS LCPO
60 Consultations
101 Téléchargements

Altmetric

Partager

Gmail Facebook X LinkedIn More