Functional Polymer Materials: From Iptycenes to Ring-Opening Polymerizations

In Chapter 1, we incorporate functional groups in triptycene-containing poly aryl ethers to serve a variety of applications. Amine-functionalized polymers are used in graphene oxide composite membranes towards aqueous filtration. Guanidinium-functionalized polymers are explored for impedance-based g...

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Bibliographic Details
Main Author: Wu, You-Chi
Other Authors: Swager, Timothy M.
Format: Thesis
Published: Massachusetts Institute of Technology 2022
Online Access:https://hdl.handle.net/1721.1/138955
http://orcid.org/0000-0002-6585-7908
Description
Summary:In Chapter 1, we incorporate functional groups in triptycene-containing poly aryl ethers to serve a variety of applications. Amine-functionalized polymers are used in graphene oxide composite membranes towards aqueous filtration. Guanidinium-functionalized polymers are explored for impedance-based gas sensing. Pyrazolium-functionalized polymers are fabricated into anion-exchange membranes. In Chapter 2, we design a set of two- and three-component polyurethanes to elucidate the influence of molecular composition on thermal transition characteristics, crystallinity, segmental dynamics of PTMO, as well as high-strain-rate impact response. In Chapter 3, we describe the living cationic ring-opening polymerization of a 2-alkylthio-2-oxazoline as a general platform for postpolymerization modification. Mild substitution conditions provide broad functional group tolerance, constituting a versatile postpolymerization modification platform with access to a diversity of polyureas and polythiocarbamates. In Chapter 4, we seek to synthesize a dibenzobarrelene-elaborated polyacetylene, whereby the dibenzobarrelene groups can provide stability by steric shielding, as well as a site for attaching solubilizing and functional groups. Routes based on dehydrogenation, bromination–elimination, sulfoxide elimination, and reductive defluorination are discussed. In Chapter 5, we study a family of bottlebrush polymers that consist of a flexible backbone with rigid, porogenic side chains. Tuning of side-chain length and dispersity, as well as incorporation of new functional groups, are performed to elucidate structure–property relationships and to enable improvements in selectivity.