Lise Maisonneuve

Isocyanate-Free Routes to Polyurethanes and Poly(hydroxy Urethane)s

Greener routes to polyurethanes are required and arouse a growing interest in the academic and industrial communities. To this purpose, the depletion of fossil resources exacerbates the need of renewable materials. This review details two main routes to phosgene-free and isocyanate-free pathways to polyurethanes: the transurethanization and the cyclic carbonate/amine routes. A focus is also made on bio-based synthons toward non-phosgene and non-isocyanate PUs.

Novel green fatty acid-based bis-cyclic carbonates for the synthesis of isocyanate-free poly(hydroxyurethane amide)s

Fatty acid-based bis-cyclic 5-membered carbonates containing amide linkages were prepared from methyl 10-undecenoate. The reaction in bulk of these bio-based carbonates with a series of di-amines led to poly(hydroxyurethane amide)s with molar masses up to 31 000 g mol−1. As expected, the so-formed bio-based thermoplastic poly(hydroxyurethane)s exhibit amorphous to semi-crystalline features with respect to the chemical structure of the monomers used.

Fatty acid-based (bis) 6-membered cyclic carbonates as efficient isocyanate free poly(hydroxyurethane) precursors

(Bis) 6-membered cyclic carbonates were prepared from methyl 10-undecenoate, which is produced from ricinoleic acid, a main constituent of castor oil. Kinetic studies on these new fatty acid-based 6-membered cyclic carbonates revealed that they are much more reactive than their homologs, 5-membered ones (30 times). Poly(hydroxyurethane)s (PHUs) were then synthesized from these bis 6-membered cyclic carbonates at a temperature as low as room temperature and in the solvent or bulk. Unexpectedly, chemical gels were obtained. The latter were the consequence of side reactions of carbonate ring-opening with the hydroxyl groups of the formed poly(hydroxyurethane)s. Quenching with a large excess of hexylamine enabled the breaking-up of the gel with the formation of urea linkages.

Solubility in CO2 and swelling studies by in situ IR spectroscopy of vegetable-based epoxidized oils as polyurethane precursors

The phase behaviour of carbon dioxide/vegetable based epoxidized oil (VBEO) mixtures has been investigated at three different temperatures (40, 70 and 100 degrees C) and pressures ranging between 0.1 and 20 MPa. The measurements have been performed using an efficient in situ FTIR method that allowed us to determine the variation of the concentration of each component in the two phases (CO2 rich phase and VBEO rich phase) as a function of temperature and pressure. Several epoxidized mono-, di- and triglyceride derivatives have been tested. The solubility of these epoxidized oils in the CO2 rich phase and the swelling of the VBEO rich phase resulting from the CO2 sorption have been investigated. From these concentration measurements, we could establish the pressure-composition phase diagrams of these VBEO/CO2 binary mixtures. The three studied monoglyceride derivatives were found to be more soluble in CO2 and more easily swelled by CO2 in comparison to the di- and tri-glyceride derivatives. Nevertheless, it was found that a significant amount of CO2 was incorporated in all these VBEO at relatively moderate pressures. Thus, we expect these VBEO to be good candidates for performing carbonation reaction to generate in good yields vegetable-based cyclic carbonates as polyurethane precursors.

Methyl 10-undecenoate as a raw material for the synthesis of renewable semi-crystalline polyesters and poly(ester-amide)s

Castor oil was efficiently used as a raw material for the synthesis of polyesters and poly(ester-amide)s. Aliphatic diols containing monoester, diester, ester-amide, monoamide and diamide linkages were synthesized from methyl 10-undecenoate through transesterification, amidation and thiol–ene reactions. These diols were then reacted with a bio-based methyl diester in the presence of TBD as a transesterification catalyst, yielding polyesters or poly(ester-amide)s with relatively high molar masses. These polyesters were characterized by FTIR, SEC and 1H-NMR spectroscopy and showed good accordance in terms of chemical structure with the theoretical compositions. Most of the polyesters displayed good thermal stability with temperature at 5% weight loss in the range 330–350 °C. Due to the fully aliphatic nature, the glass transition temperature of these materials was well below room temperature. However the incorporation of amide functions in the polyester backbone resulted in semi-crystalline materials with melting points ranging from 22 °C to 127 °C and complex melting behaviors due to polymorphism and melting–crystallization processes. Tensile properties of these polyesters were also investigated revealing a large increase of Youngs modulus from 83 to 363 MPa with increasing ratios of amide functions.