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Complex polymer architectures via group transfer polymerisation

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Title: Complex polymer architectures via group transfer polymerisation
Authors: Carroll, Dean Robert
Item Type: Thesis or dissertation
Abstract: This thesis reports the synthesis of complex architectures via group transfer polymerisation (GTP), specifically well-defined multiblock and gradient copolymers. As a living polymerisation method, GTP has been demonstrated at industrial scale for block copolymer synthesis by sequential addition of monomers. The aim of this thesis was to demonstrate that GTP can be used to fabricate copolymers with complex architectures. The first study is on multiblock copolymers, which are block copolymers with more than three distinct blocks. Sequential polymerisation was used to demonstrate scalable synthesis of four pentadecablock (15-block) copolymers AB7A bipolymers and (ABCDE)3 quintopolymers) and polymerisation of a heneicosablock (24-block) bipolymer. The following chapters study the synthesis of gradient polymers. Gradient copolymers have a progressive change in monomer composition which may prove beneficial for modifying the properties of thermoresponsive gels. For the first time, gradient copolymers have been produced with a stepwise (or many-shot) polymerisation protocol with GTP. A-gradient-B and A-gradient-B-gradient-A copolymers were prepared with GTP. Comparable block and statistical copolymers were also prepared to investigate structure-property relationships. Polymer series were synthesised with thermoresponsive monomers 2-(dimethylamino)ethyl methacrylate (DMAEMA) and di(ethylene glycol) methyl ether methacrylate (DEGMA). The cloud point temperatures were lower than the comparable di/triblock copolymer, and micelle diameters were determined to be larger due to the diffuse core-corona transition. \par The polymerisation control provided by GTP resulted in low dispersity values (Đ < 1.3) for all copolymers in this thesis, despite the complex architectures produced. The Mn closely matched the Mth and polymer composition was confirmed by NMR. Due to high conversion rates and fast polymerisation rates, all polymers were prepared in less than 6 hours per polymerisation. The number of commercially available methacrylate monomers and the tolerance for many functional groups indicate that GTP can readily prepare copolymers with complex architectures suitable for many applications.
Content Version: Open Access
Issue Date: Jun-2020
Date Awarded: Feb-2021
URI: http://hdl.handle.net/10044/1/99139
DOI: https://doi.org/10.25560/99139
Copyright Statement: Creative Commons Attribution NonCommercial Licence
Supervisor: Georgiou, Theonitsa
Stingelin, Natalie
Sponsor/Funder: Engineering and Physical Sciences Research Council (EPSRC)
Department: Materials
Publisher: Imperial College London
Qualification Level: Doctoral
Qualification Name: Doctor of Philosophy (PhD)
Appears in Collections:Materials PhD theses

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