Christoph Gürtler

Carbon dioxide (CO2) as sustainable feedstock for polyurethane production

A dream comes true: tailor-made polyethercarbonate polyols are synthesised from propylene oxide and CO2. Molecular weight and functionality of these polyethercarbonate polyols are controlled by the use of an appropriate alcohol starter enabling innovative applications as a polymer building block. Interestingly, the properties of the polyethercarbonate polyols can be adjusted in a wide range by tuning CO2 content and architecture. The feasibility of using such tailored polyethercarbonate polyols in the production of polyurethanes is demonstrated as a prime example for a novel CO2 utilization with industrial potential.

Light-mediated curing of CO2-based unsaturated polyethercarbonates via thiol–ene click chemistry

Facile cross-linking of CO2-based unsaturated polyethercarbonates with polymercaptanes via thiol–ene click chemistry makes them highly interesting sustainable pre-polymers for material applications as elastomers and sealants. CO2-Based unsaturated polyethercarbonates, characterised by a glass transition temperature well below room temperature, were obtained by convenient one-pot synthesis. Terpolymerization of CO2 with propylene oxide and allylglycidylether provided the polyethercarbonates with a defined number of pendant unsaturated bonds along the backbone of the polymer chain. The time-dependent viscoelastic behaviour during cross-linking with pentaerythritol tetrakis(3-mercaptopropionate) revealed faster curing with increasing content of double bonds in the pre-polymer. In parallel, the higher cross-linking density provided access to more rigid elastic materials.

Electrochemical Functionalization of 1,3‐Diisopropylbenzene

The anodic oxidation of 1,3-diisopropylbenzene in methanol gave exclusively the desired dimethoxy-functionalized product in excellent yield when potassium bromate was utilized as supporting electrolyte. Similar electrochemical conversions in other alcoholic solvents were not successful based on the low conductivity of the mixture. The introduction of other alcohols could then be realized when the dimethoxy derivative was converted under S(N)1 conditions in alcohols used as solvent. Thereby, higher alcohols could be introduced in moderate yields and acceptable selectivities.