Biopolymers and Bioplastics

Biography

Biography: Etienne Grau

Abstract

Thermoplastic poly(hydroxyurethane)s (PHUs) raised industrial and academic research curiosity, since their synthesis is achieved via the ring-opening of bis-cyclic carbonates with diamines, enabling the replacement of phosgene and isocyanates employed in the classical polyurethane (PU) manufacture. Due to fossil fuel depletion and environmental concerns, the use of building-blocks from renewable resources is highly investigated. Combining PHUs synthesis and bio-based compounds, a large platform of fatty acid-based cyclic carbonates as poly(hydroxyurethane) precursors was synthesized by epoxidation/carbonation routes. However, such monomers exhibited a slow polymerization rate towards amines, due to the electron-releasing alkyl chains, which deactivate the cyclic carbonates. rnAn alternative route consists in inserting a heteroatom nearby the cyclic carbonate to improve/activate its reactivity. Herein, the synthesis of new activated lipidic cyclic carbonates from glycerol carbonate and epichlorohydrin has been achieved, leading respectively to an ester or an ether linkage in β position of the carbonate. After kinetic investigations of the cyclic carbonate aminolysis on model compounds, the corresponding activated bis-cyclic carbonates were polymerized with two diamines and exhibited enhanced reactivities. A specific focus on the side reactions that could occur in both model reaction and polymerization is also discussed. rnOn the other hand, a new route to access bio-based diamines using mild and green conditions has been set up through an optimization of aliphatic alcohol oxidation into the corresponding nitriles, followed by an hydrogenation. The resulting diamines were subsequently polymerized with activated cyclic carbonates in order to obtain fully bio-based poly(hydroxy urethane)s.