Craig, Sarah
(2024)
Synthetic Routes Approaching Functional Micro-Block Copolymers of γ-Substituted ε-Caprolactones.
Master's Thesis, University of Pittsburgh.
(Unpublished)
Abstract
Described herein is a generalizable process towards the synthesis micro-block copolymers of γ-substituted ε-caprolactone moieties with reliable block alternation based on thermodynamic preferences in olefin metathesis. These micro-block copolymeric materials, containing oligomeric segments of multiple repeat unit types, inhabit a unique property space and can be used to probe the interface between alternating-like and block-like copolymer bulk behavior when synthesized at scale. The limitations of functional pendant groups are explored, demonstrating that the strategy is limited by both the solubility of the pendant group and its tolerance towards the anionic ring opening strategy employed for chain growth. Based on findings that pendant ester groups are most reactive towards anionic ring opening methods, the major product— chains terminated by an annulation event that occurs via intramolecular transesterification— is thus characterized and the mechanism used to inform alternate potential catalytic approaches. The product distribution of an aluminum salen catalyst with more sterically precluded coordination sites is found to slightly favor the linear product as opposed to its annulated counterpart, more so than is evidenced in the traditional aluminum alkoxide catalyzed oligomerization of the same γ-ester substituted ε-caprolactone monomer. While this change in preference is modest, such an improvement is indicative of potential options for attainable further improvements in the selectivity and tolerance in anionic ring-opening polymerizations of lactides, potentially providing a plethora of options for bespoke functionalized biocompatible polymer materials.
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Details
| Item Type: |
University of Pittsburgh ETD
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| Status: |
Unpublished |
| Creators/Authors: |
|
| ETD Committee: |
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| Date: |
27 August 2024 |
| Date Type: |
Publication |
| Defense Date: |
12 December 2023 |
| Approval Date: |
27 August 2024 |
| Submission Date: |
25 July 2024 |
| Access Restriction: |
No restriction; Release the ETD for access worldwide immediately. |
| Number of Pages: |
107 |
| Institution: |
University of Pittsburgh |
| Schools and Programs: |
Dietrich School of Arts and Sciences > Chemistry |
| Degree: |
MS - Master of Science |
| Thesis Type: |
Master's Thesis |
| Refereed: |
Yes |
| Uncontrolled Keywords: |
micro-block copolymer, caprolactone, synthesis |
| Date Deposited: |
27 Aug 2024 13:28 |
| Last Modified: |
27 Aug 2024 13:28 |
| URI: |
http://d-scholarship.pitt.edu/id/eprint/46752 |
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