Ring-opening polymerization (ROP) is a promising approach to accessing well-defined polyesters with superior (bio)degradability and recyclability. However, the living/controlled polymerization of glycolide (GL), a well-known sustainable monomer derived from carbon mono/di-oxide, has never been reported due to the extremely low solubility of its polymer in common solvents. Herein, we report the first living/controlled anionic ROP of GL in strong protic fluoroalcohols (FAs), which are conventionally considered incompatible with anionic polymerization. Well-defined polyglycolide (PGA, Ð < 1.15, Mn up to 55.4 kg mol-1) and various PGA-based macromolecules are obtained at room temperature for the first time. NMR titration and computational studies revealed that FAs simultaneously activate the chain-end and monomer without being involved in initiation. Low boiling point FAs and PGA can be recycled through simple distillation and sublimation at 220 oC in vacuo, respectively, providing a promising sustainable alternative for tackling plastic pollution problems.
Well-defined multicrystalline multiblock polymers are essential model polymers for advancing crystallization physics, phase separation, self-assembly, and improving the mechanical properties of materials. However, due to the different chain properties and incompatible synthetic methodology, multicrystalline multiblock polymers with more than two crystallites are rarely reported. Herein, by combining polyhomologation, ring-opening polymerization, and “catalyst switch” strategy, we synthesized the first pentacrystalline pentablock quintopolymer, polyethylene-b-poly(ethylene oxide)-b-poly(e-caprolactone)-b-poly(L-lactide)-b-polyglycolide (PE-b-PEO-b-PCL-b-PLLA-b-PGA). The novel “fluoroalcohol-assisted catalyst switch” enables the first successful incorporation of a high melting point polyglycolide into the complex multiblock polymer. Solid-state NMR spectroscopy, X-ray diffraction, and differential scanning calorimetry revealed the existence of five different crystalline phases.
| Identifer | oai:union.ndltd.org:kaust.edu.sa/oai:repository.kaust.edu.sa:10754/692509 |
| Date | 05 1900 |
| Creators | Zhang, Pengfei |
| Contributors | Hadjichristidis, Nikos, Physical Science and Engineering (PSE) Division, Yavuz, Cafer T., Schwingenschlögl, Udo |
| Source Sets | King Abdullah University of Science and Technology |
| Language | English |
| Detected Language | English |
| Type | Thesis |
| Rights | 2024-06-08, At the time of archiving, the student author of this thesis opted to temporarily restrict access to it. The full text of this thesis will become available to the public after the expiration of the embargo on 2024-06-08. |
| Relation | N/A |
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