Master of Chaos and Order: Opposite Microstructures of PCL‐<i>co</i>‐PGA‐<i>co</i>‐PLA Accessible by a Single Catalyst**
Ruth D. Rittinghaus, Johannes Zenner, Andrij Pich, Moshe Kol, Sonja Herres‐Pawlis
Abstract
Abstract One catalyst, two reaction set‐ups, three monomers and unlimited macromolecular microstructural designs: The iron guanidine complex [FeCl 2 (TMG5NMe 2 asme)] ( 1 ) polymerizes lactide faster than the industrially used Sn(Oct) 2 and shows high activity towards glycolide and ϵ‐caprolactone. Its distinguished features enable the synthesis of both block and random‐like copolymers in the melt by a simple change of the polymerization set‐up. Sequential addition of monomers yields highly ordered block copolymers including the symmetrical PLA‐ b ‐PGA‐ b ‐PCL‐ b ‐PGA‐ b ‐PLA pentablock copolymers, while polymerizations of monomer mixtures feature enhanced transesterifications and pave the way to di‐ and terpolymers with highly dispersed repeating unit distributions. A robust catalyst active under industrially applicable conditions and producing copolymers with desired microstructures is a major step towards biocompatible polymers with tailor‐made properties as alternatives for traditional plastics on the way towards a sustainable, circular material flow.