Development and applications of new catalysts in atom transfer radical polymerization

Transition metal mediated atom transfer radical polymerization (ATRP) is one of the most versatile methodologies developed for “living”/controlled radical polymerization. Continuing research in ATRP is directed towards the search for more efficient catalysts and the preparation of new polymeric materials with well-defined and complex compositions, functionalities, and architectures. Effort and work in both directions are covered in this thesis.; The majority of the research presented here is on the development of new catalytic systems in copper-mediated ATRP. First, a general approach for homogeneous ATRP is reported. This allows for the detailed kinetic studies of styrene polymerization, which helps to shed more insight into the mechanism of ATRP. In addition, reverse ATRP, where conventional radical initiators are used, have been successfully carried out under homogeneous conditions, and the dramatic differences of reverse ATRP using azobisisobutyronitrile and benzoyl peroxide as the initiator are addressed. Second, significant catalyst development is made by discovering that multidentate amines can be successfully employed as ligands in copper-mediated ATRP. The ready availability, low cost, fast rate, and high efficiency of some of the multidentate amines make the industrial applications of ATRP closer to reality. Last, a series of ligands based on picolyl amine structure are synthesized and successfully applied in ATRP. The picolyl amine ligands are easily made in high yields and can allow for facile further modifications and tuning of the catalyst.; The second part of the thesis presents a few applications of the newly developed catalytic systems and the synthesis of new polymeric materials. Specifically, controlled polymerization of 4-vinylpyridine, which used to be a great challenge for copper-mediated ATRP, has been successfully carried out. In addition, ATRP can now proceed in supercritical carbon dioxide in the absence of any organic solvent with the use of a fluoro-substituted bpy ligand. Finally, the synthesis of end-functional star polymers and attempted controlled polymerization of vinyl acetate have been carried out.