Benefit of the Reactive Extrusion in the Course of Polyhydroxyurethanes Synthesis by Aminolysis of Cyclic Carbonates

Abstract

Replacing toxic isocyanates and petro-based reactants currently employed for polyurethanes (PUs) synthesis is nowadays a major concern. Among all the possible routes to isocyanate-free PUs, aminolysis of cyclic carbonates, leading to polyhydroxyurethanes (PHUs) seems to be one of the most promising pathways. Herein, we discuss the added value brought by the reactive extrusion process on PHU synthesis. In order to evaluate the benefit and the versatility of the process, three different bis-cyclic carbonates exhibiting different reactivity (Diglycerol Dicarbonate, Seb-bCC-ester and one bisCC containing amide function, Und-6DA-bisCC), were tested in the course of polymerization with different diamines. The PHUs synthesized through reactive extrusion were then compared with the ones obtained through classical bulk polymerizations in terms of kinetics, PHU molar masses and side reactions, clearly demonstrating the benefit of the extrusion process.

Enantioselective Crystallization of Diglycerol Dicarbonate: Impact of the Microstructure on Polyhydroxyurethane Properties

“…DGDC was synthesized according to the previously reported synthesis. [ 6 ] DGDC was prepared from diglycerol with a 40% yield through a one‐step procedure. In a round‐bottom flask, 76 g (1 eq.)…”

“…[ 5 ] Following this DGDC synthetic procedure, our group described the benefit brought by the reactive extrusion process, on DGDC‐based PHUs synthesis. [ 6 ]…”

“…We recently reported the synthesis of DGDC‐based PHUs through reactive extrusion. [ 6,7 ] In this work, DGDC monomer was synthesized in one step from diglycerol and recovered as a white powder, characterized by a melting temperature of 62–69 °C ( Figure , pathway 1). The application of the recrystallization procedure, recently described by Schimpf et al., to DGDC reaction crude led to the following observation: two different crystalline structures were clearly visible in the flask after 48 h at −20 °C and readily separable (Figure 1, pathway 2).…”

Solubility-governed architectural design of polyhydroxyurethane-graft-poly(ε-caprolactone) copolymers

“…1 The most common synthesis route to create PHUs is step-growth polymerization between diamines and cyclic dicarbonates, a highly attractive method from a sustainability point of view. It is atom-economical, it can be performed under bulk conditions and can be combined with extrusion techniques 2,3 to shorten the polymerization time needed and improve the final characteristics of the PHUs.…”

Hybrid polyhydroxyurethanes: How to overcome limitations and reach cutting edge properties?

“…Furthermore, to avoid the use of organic solvents, current trends propose to work in bulk (without solvent), [79] in water [80][81][82][83] or under reactive extrusion or blending. [84][85][86][87] Besides, new routes have also emerged to avoid side-reactions, low conversions, low molar masses and the need of high temperature. For this purpose but also to obtain better properties, the use of different reactive sites is required.…”