Graduate Research Projects
Profs. Robin A. Hutchinson and Michael F. Cunningham
Design of Automotive Coatings Using
Living-Radical Polymerization
Background:
The research will explore the use of a new, innovative polymerization chemistry, "living radical polymerization", for the design of automotive coatings. Living radical polymerization (LRP) represents an innovation in free radical polymerization technology with the potential for major advances in manufacturing polymeric materials with controlled microstructure (e.g. narrow molecular weight distributions (MWD), control of branching, control of copolymer composition distribution). Because LRP permits a much greater degree of control over the polymer microstructure, there are opportunities for improving automotive coatings to yield a variety of advantages such as higher solids contents (and therefore lower VOC levels) and lower required levels of high-cost functional monomers. The LRP technology is compatible with existing manufacturing processes, and is also suitable for use in water-based coating systems. The project is exploratory in nature, with the potential to have a significant impact on the materials used for automotive coatings and their manufacturing processes.
(PhD project in progress, Yao Fu) The project will involve extensive experimental work supported by modeling and theoretical development. A "typical" acrylic-based coating formulation (e.g. styrene / acrylate / methacrylate terpolymer with one functional monomer) would be used. Initial work will focus on nitroxide-mediated LRP (SFRP) as we have considerable experience with SFRP. However, we are structuring the research to probe the generic question of the suitability of any form of LRP to make automotive coatings, and the general advantages of coatings with controlled microstructure. We plan to have one student begin the project as soon as possible, and a second student to start a few months later. Because the project is exploratory in nature, we wish to leave two avenues of further investigation open. Our initial progress will dictate later directions. The first possible avenue is the use of other living radical polymerization systems, such as RAFT or ATRP. The second possible avenue is the design of water-based coatings.
Experiments will be conducted in a polymerization reactor that has been commissioned for this research. The reaction mixture (monomers, initiators, solvent) will be selected based on realistic formulations used in automotive coatings. Samples will be taken frequently to enable kinetic studies and facilitate mathematical modelling, which will be used in conjunction with the experimental work to further our fundamental understanding. Samples will be subject to detailed analysis. Conversion of the individual monomers will be determined using gas chromatography and molecular weight distribution measured by gel permeation chromatography (GPC). Copolymer composition will be obtained by NMR analysis. We currently have a GPC with a DRI (differential refractive index) detector. More information about the process and the materials could be obtained if we could quantify the amount of nitroxide controlling agent on the polymer chain ends. Using recently developed methods, we plan to achieve this using a fluorescence detector on the GPC.
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