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Updated: Jun 20, 2026

Designed for Molecular Recycling: A Lignin-Derived Semi-aromatic Biobased Polymer
Published on: November 30, 2020
Consequences of polylactide stereochemistry on the properties of polylactide-polymenthide-polylactide thermoplastic
Carolyn L Wanamaker1, Michael J Bluemle, Louis M Pitet
1Department of Chemistry, University of Minnesota, Minneapolis, Minnesota 55455-0431, USA.
Abstract:
A series of polylactide-polymenthide-polylactide triblock copolymers containing either amorphous poly(D,L-lactide) or semicrystalline, enantiopure poly(L-lactide) or poly(D-lactide) end segments were synthesized. Small-angle X-ray scattering and differential scanning calorimetry data were consistent with microphase separation of these materials. The Young's moduli and ultimate tensile strengths of the semicrystalline triblock copolymers were 2- and 3-fold greater, respectively, than their amorphous analogs. Symmetric (50:50) and asymmetric (95:5) blends of the triblock copolymers containing two different enantomeric forms of the polylactide segments formed stereocomplex crystallites, as revealed by wide-angle X-ray scattering and differential scanning calorimetry. Compared to the enantiopure analogs, these blends exhibited similar ultimate elongations and tensile strengths, but significantly increased Young's moduli. Collectively, these results demonstrate that the properties of these new biorenewable thermoplastic elastomers can be systematically modulated by changing the stereochemistry of the polylactide end blocks.
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