Sustainable Process Design for Catalytic Polymerization to In-Chain Functionalized Polyethylenes – SUPRCAT

Polyethylene is the largest produced plastic material, used in many key technology areas. Its production efficiency is superior to most other plastics in terms of environmental impact. The linear hydrocarbon chains of polyethylene (HDPE) enable crystalline packing and provide excellent mechanical properties. However, their chemically inert nature results in persistence for many decades when released to the environment. We have found that polyethylene materials with in-chain keto groups can be generated by non-alternating copolymerization of ethylene with carbon monoxide. These endow the material with a desirable photodegradability, while not compromising the processing and materials properties (Science 2021, 374, 604). Gas phase polymerization can be considered the most advanced process for the generation of semicrystalline polymers as it is solvent-free and enables a direct control of the resulting polymers' morphology. For the copolymerization of ethylene with polar monomers in general, gas phase polymerization has been neglected essentially, however. This project will study the gas phase copolymerization of ethylene with carbon monoxide, which is a highly relevant reaction and also a particularly suited probe for copolymerizations of polar monomers. Supporting methods for novel CO-compatible (cocatalyst-free) molecular polymerization catalysts by means of non-covalent binding to porous support materials will be explored (UKon). These catalysts will be explored in gas phase copolymerizations to keto-polyethylenes, addressing amongst others support fragmentation and morphology evolution, and effect of support and gas phase conditions on the catalysts' fundamental copolymerization behaviour (CP2M). Improved (photo)degradability and recyclability properties are expected for these keto-polyethylenes while retaining mechanical and processibility properties. This synergistic collaboration is enabled by the unique expertise of CP2M in gas phase polymerization process, and of the Konstanz group in functional group tolerant polymerization catalysts.