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Abstract
Two novel macromolecular engineering protocols termed enhanced spin
capturing polymerization (ESCP) and nitrone-mediated radical coupling (NMRC)
reactions were developed in the current thesis to provide new and interesting
alternatives in synthesizing complex polymeric architectures. The synthesis of such
materials via ESCP and NMRC were achieved using a well known class of radical
spin traps, nitrones. Owing to the ability of the nitrones to efficiently enforce
combination reactions between two identical radical centers (hence leading to the
formation of homotelechelic compounds with centered-alkoxyamine functionalities)
while simultaneously acting as 'carriers' of secondary functional groups (e.g. alkynes),
both ESCP and NMRC therefore allow for the construction of a variety of welldefined
polymer structures. The versatility of this nitrone radical chemistry were
evidenced by the successful formation of linear and star copolymers, dendrimers and
step growth polymers as well as its robustness in controlling radical polymerizations
in different reaction conditions. These few examples – though proved adequate in
realizing the synthetic potential of nitrones as a facile tool via radical pathways –
however, merely constitute a fraction of chemistry that it can potentially be applied to.
Due to the efficiency of the nitrones in the spin capturing of radicals, many options
for the design of new synthesis avenues open up. It is with the hope that the
technology developed herein serves as a stimulus to other researchers to explore the
use of nitrones in their own synthetic endeavours.