SYNTHESIS OF NOVEL ION-CONDUCTING POLYMERS VIA REVERSIBLE ADDITION-FRAGMENTATION CHAIN TRANSFER POLYMERIZATION

Open Access
Author:
Bryson, Kyle Clarence
Area of Honors:
Materials Science and Engineering
Degree:
Bachelor of Science
Document Type:
Thesis
Thesis Supervisors:
  • Michael Anthony Hickner, Thesis Supervisor
  • Paul C Painter, Honors Advisor
Keywords:
  • chain polymerization
  • radical addition-fragmentation chain transfer poly
  • polymers
  • fuel cells
  • alternative energy
  • chemistry
  • materials science
  • controlled radical polymerization
  • triblock copolymers
  • transport properties
  • Nafion
Abstract:
Recent work in the Hickner research group has focused on creating novel, welldefined ion-containing block copolymers for studies relating macromolecular chemistry, architecture, and resulting microphase-separated morphology to the transport properties of bulk films, such as ion-conductivity and water uptake, for application in polymer membranes for water salinity management and Polymer Electrolyte Membrane Fuel Cells (PEMFCs). Reversible addition fragmentation chain transfer (RAFT) polymerization, a controlled free radical polymerization technique, was used to synthesize homopolymers and block copolymers of styrene and vinylbenzyl chloride (VBC), a versatile vinylic monomer that serves as a precursor to a wide array of ionic moieties. Synthesis of both a monofunctional (grown from one end) and a difunctional (grown from two ends) RAFT chain transfer agent was successful. Many attempts at difunctional, monofunctional, and chain extension RAFT polymerization of styrene and VBC yielded experimental conditions most conducive to molecular weight control. Difunctional RAFT polymerization poses particular obstacles related to the unwanted creation of monofunctionalized polymer chains. Styrene polymerizations proceeded with more control than VBC polymerizations.