As director of the National Science Foundation Materials Research Science and Engineering Center (MRSEC) and Industry/University Cooperative Research Center in Coatings at the University of Southern Mississippi (Hattiesburg), Dr. Marek Urban led a research team that developed a novel self-healing clear coat material. An article about the material appeared in a recent issue of the journal Science, but we caught up with Urban to ask a few questions of our own.
What are your research areas?
MU: My research is in the areas of both polymers and coatings. The material we developed and reported on is based on polyurethane chemistry, but the same idea can be applied to other types of polymeric materials as well. That research is a work in progress.
How is the material your team developed different from other self-healing materials?
MU: A big difference is, it is relatively easy to produce. It is made using organic compounds called oxetanes combined with chitosan. Chitosan is a derivative of chitin, a naturally occurring material produced in the shells of crustaceans such as shrimp, lobster and crabs. It’s also user-friendly. It doesn’t require major redesign of products, processes or equipment to use.
Is the material ultraviolet cured, or is it exposure to UV that causes the material to self-heal?
MU: It is not a UV-cured material. Instead, exposure to UV causes it to self-heal in about an hour. It can be either sunlight or an artificial UV source. The polyurethane material cures at ambient temperature, and the self-healing process works at ambient temperature.
How is the material applied?
MU: The paint can be applied just like any conventional coating material—by spraying, dipping, brushing. It depends on the type of application the user desires. Like any coating, there are different application techniques for different materials, but the fact that it has self-healing properties really doesn’t affect application characteristics.
How large a scratch can the material self-heal?
MU: We tested it using scratches 20–30 μm deep, which is about the thickness of a typical clear coat. In terms of how wide a scratch it can repair, the issue in testing is creating a scratch with a controllable width. We haven’t done as much work in that area.
What is the plan to move this material from the laboratory to commercial use?
MU: We are trying to work with major companies to develop and commercialize the material as soon as we can. I really can’t say anything more than that at the moment, but many people are anxious to see this product.
What is in the pipeline in terms of your research?
MU: We started working on stimulus-responsive polymers several years ago, and this material is one of the products of that research. We are continuing with different approaches in that general line of research, and you will be hearing more about self-healing materials in the not-too-distant future. We have several things in the pipeline.