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Updated: Jun 2, 2026
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Fabricating Reactive Surfaces with Brush-like and Crosslinked Films of Azlactone-Functionalized Block Co-Polymers
Published on: June 30, 2018
Interfacial Dynamics Accelerate Aging Yet Sustain Toughness in Poly(l‑lactide) Block Polymer Plastics
Daniel M Krajovic1, Benjamin D Chayet1, Marc A Hillmyer2
1Department of Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, Minnesota 55455, United States.
ACS Central Science
|June 1, 2026
Summary
Block copolymers with poly-(γ-methyl-ε-caprolactone) (PγMCL) and poly-(l-lactide) (PLLA) offer enhanced mechanical durability. Star-shaped architectures (n≥2) provide persistent toughness, enabling PLLA as a sustainable plastic alternative.
Area of Science:
- Polymer Science
- Materials Science
- Sustainable Plastics
Background:
- Poly-(lactide) (PLA) homopolymers embrittle rapidly after melt processing due to physical aging.
- This aging limits PLA's use as a sustainable alternative to conventional plastics.
- Block copolymers with rubbery segments show potential for improved mechanical longevity.
Purpose of the Study:
- To investigate the relationship between block copolymer architecture and mechanical aging resistance.
- To synthesize and characterize novel PLA-based block copolymers.
- To identify key structural features for enhanced material durability.
Main Methods:
- A two-step synthesis was employed to create n-arm block copolymers (n=1-4).
- Poly-(γ-methyl-ε-caprolactone) (PγMCL) formed the rubbery core, and poly-(l-lactide) (PLLA) constituted the outer block (80 wt% PLLA).
- Mechanical properties, crystallinity, and physical aging were assessed using tensile testing and calorimetry.
Main Results:
- Triblock and star-block copolymers (n≥2) demonstrated sustained tensile toughness over extended aging periods.
- Mechanical longevity was enhanced by crystallinity and architectural purity.
- Faster physical aging in the most durable samples (M PLLA < 35 kg mol⁻¹) was linked to block dynamics at domain interfaces.
Conclusions:
- Block copolymer architecture, particularly star-shaped structures, significantly improves poly-(l-lactide) mechanical longevity.
- These findings expand the range of accessible block polymer designs for durable and sustainable PLLA applications.
- The results facilitate the development of scalable and melt-processable PLLA-based materials.
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