Nitroxide-mediated radical polymerization and functional group-containing block copolymers

Abstract Nitroxide-mediated radical polymerization (NMRP) is a living radical polymerization technique that allows the use of free radical chemistry in the synthesis of block copolymers. This allows the incorporation into polymers of functional groups that are not compatible with other polymerization chemistries, and the ability to form block-random copolymers with compositional control over the blocks. This dissertation investigates the incorporation of functional groups with interesting properties into block copolymers and block-random copolymers which allow control over self-assembled microphase structure and the concentration of functional groups.;One functional group investigated is the hole-transporting carbazole ring. Two different synthetic approaches for the polymerization of N-vinylcarbazole into block copolymers were found to be ineffective. This monomer is unsuitable for polymerization by NMRP even with second-generation nitroxides, as oligomers are formed rather than high molecular weight polymer. Poly(N-vinylcarbazole) can be synthesized with alkoxyamine endgroups for the initiation of a second monomer by NMRP, but the attempt to chain extend with styrene results in coupling together of initiator chains rather than the formation of block copolymer.;N-ethyl-2-vinylcarbazole, another carbazole monomer, was more suitable for NMRP, as it proceeds in a living fashion with control over molecular weight. Chain extension of these polymers with styrene results in block copolymer formation by a fraction of the chains. This result shows the promise to be an effective route to the synthesis of block copolymers containing carbazole groups.;Another functional group studied is the hydrogen-bonding phenol group. Hydroxystyrene can be introduced into a polymer by the polymerization of 4-acetoxystyrene followed by cleavage of the acetoxy group to form the phenol. Block copolymers and block-random copolymers of styrene and acetoxystyrene were synthesized, and their phase behavior follows the trends expected from random mixing of polymer chains. When phenol groups are introduced, the specific hydrogen-bonding interactions result in deviations from the predictions of random mixing. This result shows that specific interactions must be accounted for in the entropic mixing terms of block copolymer models in order to describe the phase behavior for systems containing specific interactions.