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Updated: Jun 24, 2026
09:12
Functionalization of Single-walled Carbon Nanotubes with Thermo-reversible Block Copolymers and Characterization by Small-angle Neutron Scattering
Published on: June 1, 2016
Temperature-Driven Switching Between Block, Near-Statistical, and Gradient Copolymers Enabled by Multinuclear
Yoseph Kim1, So Han Kim1, Gue Seon Lee2
1Department of Chemistry, Chungbuk National University, Cheongju, Chungbuk, Republic of Korea.
Macromolecular Rapid Communications
|June 23, 2026
Summary
A novel aluminum catalyst enables precise control over copolymer microstructure in ring-opening polymerization of ε-caprolactone (CL) and lactide (LA). This platform allows tunable synthesis of block, statistical, and gradient copolymers by adjusting temperature and monomer addition.
Area of Science:
- Polymer Chemistry
- Materials Science
- Catalysis
Background:
- Ring-opening copolymerization of ε-caprolactone (CL) and lactide (LA) is crucial for biodegradable polymers.
- Controlling copolymer microstructure (sequence distribution) is challenging due to monomer reactivity differences and transesterification.
- Existing methods often lack precise control over the final polymer architecture.
Purpose of the Study:
- To develop a single catalytic platform for programmable synthesis of diverse CL/LA copolymer microstructures.
- To investigate the influence of reaction conditions on copolymer sequence distribution.
- To establish a kinetic-thermodynamic framework for sequence control in CL/LA copolymerization.
Main Methods:
- Utilized a single tetrameric multinuclear aluminum catalyst for ring-opening polymerization.
- Synthesized block copolymers via sequential monomer addition under insertion-dominated conditions.
- Investigated simultaneous copolymerization at varying temperatures to modulate microstructure.
Main Results:
- Achieved well-controlled synthesis of diblock, triblock, and multiblock CL/LA copolymers.
- Demonstrated temperature-dependent control over copolymer microstructure, yielding near-statistical at low temperatures and gradient at high temperatures.
- Observed reactivity ratios near unity and average sequence lengths of two for near-statistical copolymers.
Conclusions:
- Multinuclear aluminum catalysis offers a versatile platform for accessing diverse CL/LA copolymer architectures.
- Temperature is a key parameter to control the balance between propagation and transesterification, thus dictating copolymer microstructure.
- This work provides a unified framework for sequence control and highlights earth-abundant aluminum catalysts for advanced polymer synthesis.
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