CO2-based sustainable polymers: from CO2-sourced monomers to low CO2 emission foamed materials

Due to concerns about the climate change combined with the decrease of fossil resources, the use of CO2 as a C1 feedstock for producing added value chemicals and materials has become a huge challenge in academic laboratories and in industry. The coupling of CO2 with epoxide has emerged as one of the most promising way to convert CO2 into cyclic carbonates finding application as green solvents or electrolyte for batteries. Interestingly, these cyclic carbonates can also be valorised as monomers to produce new non-isocyanate polyurethanes by step-growth polymerization with amines. Polyurethane (PU) is one of the most important polymers in our everyday life with numerous applications such as thermosets, thermoplastics, elastomers, adhesives, sealants, coatings, rigid and flexible foams for wellness or acoustic and/or thermal insulation. In this talk, we will discuss the preparation of all green bio- and CO2-sourced non-isocyanate polyurethane (NIPU) microcellular foams with thermal insulation properties by using an eco-efficient process based on the supercritical carbon dioxide (scCO2) foaming technology. This talk will be divided in three sections:

The synthesis of CO2-sourced cyclic carbonates by coupling CO2 with epoxides using a new highly-efficient bicomponent homogeneous organocatalyst combining the use of an ammonium salt as the catalyst and a fluorinated hydrogen bond donor activator that allows the fast and solvent-free coupling of CO2 with (biosourced) epoxides under mild experimental conditions.

The synthesis of (bio- and) CO2-sourced isocyanates-free PUs by melt step-growth copolymerization, eliminating the toxicological issues associated to the conventional synthesis of polyurethanes from diols and isocyanates.

The foaming of NIPUs by exploiting the scCO2 foaming technology. By finely choosing the appropriate CO2 impregnation and foaming conditions, thermally insulating CO2-blown microcellular NIPUs foams were produced.