Biobased Oligo- and Polyesters from Fatty Acids with Demonstrated Biodegradability or Recyclability for Industrial Applications in a Circular Economy.

This "Perspective"-article describes and discusses two recent developments in the field of biobased and biodegradable or chemically recyclable oligomers/polymers for applications in the lubricant and plastics product segments, which are accessible from unsaturated fatty acids as feedstocks. Within an industrial-academic collaboration, oleic acid was converted into hydroxymethylated stearates using the matured industrial technologies hydroformylation and hydrogenation. Subsequent solvent-free enzymatic esterification then furnished a novel generation of lubricants that are biobased, ensure rapid biodegradation and show needed performance data. Furthermore, when starting from a C18 diester being also derived from fatty acid-based sources, polyesters were designed through polycondensation with biobased diols such as C18 diol or ethylene glycol in the presence of a titanium alkoxide catalyst. The resulting polyesters showed material properties being comparable to high density polyethylene-type materials and enabled at the same time a closed-loop recycling due to their proven degradability properties. Both case studies illustrate the need to integrate various research issues "along the value chain" in such a product design, which range from biorenewable raw material selection, choice of economically attractive monomer synthesis, efficient polymerization steps and product features covering performance as well as sustainability properties such as biodegradability or (molecular) recyclability.