This project is devoted to synthesis of non-isocyanate polyurethanes (NIPU) from bio-based sources and their post-modification towards industrial application. The use of bio-based monomers for NIPU synthesis allows to overcome the dependence on fossil resources and to reduce the CO2 emissions. However there are several possible drawbacks for industry such as high prices for bio-based monomers and demand for arable land to ensure large scale production.
NIPU were introduced in 1990s as the alternative to conventional polyurethanes because they allow to avoid usage of toxic isocyanates. However, they were not industrialised due to their insufficient molecular weights limited by reaction ability of monomers and increased hydrophilicity that facilitates hydrolysis during processing.
The SPRUT project will simultaneously deal with several NIPU related issues.
At first, the effective catalyst based on Al heteroscorpionate complexes for converting bio-based bisepoxides to 5-membered cyclic bicarbonates via CO2 addition will be developed. The obtained bicarbonate bio-compounds will be used as feedstock for production of NIPU applying various approaches to increase their MW above 20000 Da: synthesis in bulk, copolymerization of two different bicarbonates and the use of ionic liquids.
In the 2nd stage of the project, the unique method for post-synthetic modification of NIPU that was never used for these polymers will be introduced to increase their mechanical properties and processability. The basic “click” reaction of bio-based aldehydes (heptaldehyde and benzaldehyde) with adjacent hydroxyl groups in the NIPU backbone enables the reduction of intermolecular hydrogen bonding leading to better processability. The resulting aldehyde modified NIPUs containing non-polar side chains are supposed to be much more hydrophobic and possess increased physico-mechanical properties compared to previously developed NIPU and even some conventional PUs.
Fields of science
- HORIZON.1.2 - Marie Skłodowska-Curie Actions (MSCA) Main Programme