Fundamentals of an ATRP Reaction
- Early Emulsion Systems
- A "true" Emulsion system
- Inverse Miniemulsion
ATRP is a particularly successful CRP that has attracted commercial interest(1) because of its easy experimental setup, use of readily accessible and inexpensive catalyst components, usually copper complexes formed with commercially available aliphatic amines, imines, or pyridine based ligands, and simple commercially available or easily prepared initiators or macroinitiators (often alkyl halides).
ATRP is probably the most robust and efficient CRP, and well-defined polymers with controlled topology, composition and preselected site specific functionality can be prepared over a range of temperatures without the formation of side products. Historically, the primary objection to commercial introduction of materials prepared by ATRP was the presence of a significant amount of the transition metal catalyst complex in the final product. This barrier to commercialization is continuing to be addressed within the Matyjaszewski group(2) and within several industrial entities.(3-4) Commercially viable ATRP systems with reduced concentration of the transition metal complex, in the low ppm levels, have been developed, simplifying purification of the final product.(5-8)
As noted on the introductory page, one of the primary objectives of the research conducted in the Matyjaszewski group is development of an understanding of the mechanistic features, or parameters, influencing transition metal catalyzed living/controlled radical polymerization. ATRP, and numerous improvements to the basic ATRP process, remains the subject of an extensive, active patent portfolio at Carnegie Mellon University.
This portfolio was the first to disclose and protect controlled polymerization processes using components claimed by others to operate through a different mechanism, e.g. systems based on addition or formation of Cu(0)/Cu(II) based catalyst complexes. The patent portfolio also covers the composition of many materials prepared for the first time by ATRP. Indeed, because ATRP was the first robust CRP process, and RAFT polymerization processes and second generation NMP mediators were not developed until later than 1995, many materials disclosed in the initial CMU patents are materials that were prepared for the first time by any CRP process. The patents cover polymerizations conducted with the four fundamental components of an ATRP reaction, listed below, and ATRP conducted in biphasic media, including a full spectrum of heterogeneous aqueous media,(9) and grafting from initiators tethered to solid surfaces.(10-11)
(1) Matyjaszewski, K.; Spanswick, J. Materials Today 2005, 8, 26-33.
(2) Matyjaszewski, K.; Pintauer, T.; Gaynor, S. Macromolecules 2000, 33, 1476-1478.
(3) Kitano, K.; Nakagawa, Y. In Jpn. Kokai Tokkyo Koho; (Kanegafuchi Chemical Industry Co., Ltd., Japan). JP2001323012, 2001; p 23 pp.
(4) Yamahiro, M.; Fujita, M.; Oikawa, T.; Okuma, Y.; Watanabe, K.; Ono, K.; Tsujii, T.; Fukuda, T. In Jpn. Kokai Tokkyo Koho; (Chisso Corp., Japan). Jp, 2005; p 75 pp.
(5) Matyjaszewski, K.; Bombalski, L.; Jakubowski, W.; Min, K.; Spanswick, J.; Tsarevsky, N. In PCT Int. Appl.; (Carnegie Mellon University, USA). WO 2005087819, 2005; p 96 pp.
(6) Matyjaszewski, K.; Jakubowski, W.; Spanswick, J. In PCT Int. Appl.; (Carnegie Mellon University, USA). WO2007025310, 2007; p 95pp.
(7) Pintauer, T.; Matyjaszewski, K. Chem. Soc. Rev. 2008, 37, 1087-1097.
(8) Magenau, A. J. D.; Kwak, Y.; Schroder, K.; Matyjaszewski, K. ACS Macro Lett. 2012, 1, 508-512.
(9) Min, K. In Chemistry of Synthetic High Polymers; Carnegie-Mellon Univ: Pittsburgh, 2008; p 238 pp.
(10) Pyun, J.; Jia, S.; Kowalewski, T.; Patterson, G. D.; Matyjaszewski, K. Macromolecules 2003, 36, 5094-5104.
(11) Matyjaszewski, K.; Dong, H.; Jakubowski, W.; Pietrasik, J.; Kusumo, A. Langmuir 2007, 23, 4528-4531.