Branching out with CCTP : the synthesis of branched functional polymers

• Main Author: McEwan, Kayleigh A.
• Published: University of Warwick 2012
• Subjects: 540; QD Chemistry
• Online Access: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.582248

Initially the aims of this thesis were to settle conflicting literature that arose based on the consistency of results obtained from the synthesis of branched polymers, using divinyl monomer ethylene glycol dimethacrylate (EGDMA), by catalytic chain transfer polymerisation (CCTP). By polymerisation of EGDMA using a range of catalyst concentrations, and introduction of comonomers, a range of branched polymers were obtained, all of which retained high levels of vinyl functionality in the resulting products. With the increasing popularity of click chemistry, the natural progression of this work lent towards the functionalisation of these branched vinyl containing polymers by thiol- Michael addition, using a range of commercial thiols, in the creation of branched highly functional polymers, which display enhanced solution properties compared to their linear counterparts, from a small commercial monomer set. The desire to synthesise highly functional polymers led to investigation of epoxide containing monomer, glycidyl methacrylate (GMA), which has proven to be versatile to a range of functionalities. The synthesis of linear GMA homopolymers via CCTP resulted in polymers with the potential for dual functionalisation, at both epoxide and ω- unsaturated groups; to which, thiol-Michael addition and self-catalysed epoxide ringopening with amines was investigated in the synthesis of a range of functional polymers, from a single polymer precursor. Finally the copolymerisation of EGDMA and GMA via CCTP was investigated in the synthesis of branched functional polymers, whereby the level of vinyl groups retained and epoxide functionality can be tuned through monomer ratios. Site selective functionalisation of the high level of epoxide and vinyl groups was conducted using both thiol-Michael addition and self-catalysed ring-opening of epoxides with functional amines. By site selective functionalisation with both hydrophobic and hydrophilic groups, amphiphilic branched copolymers are obtained, with the potential for the synthesis of branched polymers capable of self-assembly.