Alexandria Digital Research Library

The Use of Facile and Efficient Chemistries for Functional Macromolecular Systems

Author:
Kang, Taegon
Degree Grantor:
University of California, Santa Barbara. Materials
Degree Supervisor:
Craig J. Hawker
Place of Publication:
[Santa Barbara, Calif.]
Publisher:
University of California, Santa Barbara
Creation Date:
2012
Issued Date:
2012
Topics:
Engineering, Materials Science
Keywords:
Polysiloxane
Antifouling
Lubrication
Hydrogel
Catechol
Underwater adhesion
Genres:
Dissertations, Academic and Online resources
Dissertation:
Ph.D.--University of California, Santa Barbara, 2012
Description:

The field of polymer synthesis has been extensively studied and expanded over several decades to create well-defined functional materials. As more sophisticated materials become increasingly valuable, the demand for tailoring high performance polymers by facile and efficient chemistries is vital to the advancement of the field. This thesis is focused on the incorporation of facile and efficient chemistries for designing and functionalization of high performance materials within few synthetic steps.

A facile synthetic strategy has been developed for accessing internally functionalized dendrimers. The key feature of this strategy is the use of two orthogonal and efficient reactions --- `epoxy-amine' and `thiol-ene' --- for the rapid growth of dendrimer scaffolds with functionalizable hydroxyl groups positioned at each dendritic layer. This work primarily demonstrates the practicality, high efficiency, and modular nature of the epoxy-amine reaction for the synthesis of dendrimers and suggests a greater role for this reaction in the preparation of functional macromolecules. With `epoxy-amine' and `thiol-yne' chemistries, trackable multifunctional dendritic scaffolds with high internal loading capacity were designed and synthesized based on a PEG core and an accelerated AB2/CD2 approach. Orthogonal functionalization of chain ends and internal groups allowed the dendritic scaffolds to be both labeled and loaded with releasable dyes.

While most artificial adhesives lack adhesion properties under water, marine adhesives stick to nearly all surfaces under water. The presence of catecholic moieties is crucial for the behavior of these systems. Unfortunately, introducing catecholic moieties into artificial synthetic systems is challenging due to their propensity toward oxidation, yielding o-quinone. To overcome these issues, we have utilized two highly efficient and orthogonal reactions: tris(pentafluorophenyl)borane (TPFPB)-catalyzed silylation and `thiol-ene' coupling for the synthesis of new silyl-protected catecholic materials through a facile, cost effective, and simple protecting/deprotecting synthetic process. The novel catecholic moieties were used to functionalize poly(ethyleneoxide) as well as poly(siloxane) based polymers for the facile preparation of biomimetic adhesives, non-covalently cross-linked hydrogels, and anti-biofouling coatings with high lubrication.

Physical Description:
1 online resource (174 pages)
Format:
Text
Collection(s):
UCSB electronic theses and dissertations
ARK:
ark:/48907/f33x84rk
ISBN:
9781267767615
Catalog System Number:
990039147610203776
Rights:
Inc.icon only.dark In Copyright
Copyright Holder:
Taegon Kang
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