Synthesis and Biodegradation of Model Intermediates of Polyethylene Mineralization
Jessica Henzler, Tobias O. Morgen, Taylor F. Nelson, and Stefan Mecking, University of Konstanz, Germany.
Polyethylene (PE) with disperse in-chain functional groups (such as ester- or keto-groups) represent promising materials for supporting a more sustainable plastics economy. Such polymers retain the desirable properties and performance of PE while being more amenable to degradation processes with the functional groups acting as “pre-determined breaking points”. Thereby, external biotic (e.g., enzymatic) or abiotic (e.g., hydrolytic or photochemical) degradation processes can break the polymer down at these disperse in-chain functional groups, yielding lower molecular weight segments which may be more accessible for ultimate biodegradation.1,2 In order to obtain polyethylene-like properties of such polymers, the predetermined breaking points must be present in a small amount and isolated. For this reason, the degradation intermediates are expected to consist of long linear methylene chains with a small number of functional groups; the amenability of such compounds to ultimate biodegradation has not yet been clarified. To elucidate the ultimate biodegradability of these materials, model degradation intermediates of PE-like polymers are synthesized using advanced catalytic chain-growth systems to enable control over the molecular weight and distributions as well as the possibility of introducing functional groups.3,4 These polymers are subjected to biodegradation studies in laboratory incubations with natural soil samples to determine the relationship between structure and biodegradability.
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