Let's Make Silly Putty
Students make two different formulations of imitation Silly Putty with varying degrees of cross-linking. They witness how changes in the degree of cross-linking influence the putty properties.
Students experiment with putty.Copyright Jason Koski, University Photography http://news.cornell.edu
Materials engineers and more specifically, plastics engineers combine their knowledge of chemistry and material science to design, develop and manufacture new materials that have special properties to meet new applications. For example, to make aircraft, cars and electronic parts lighter and from recycled materials to reduce waste challenges engineers to make "smart polymers" that change their properties according to their environment. Such materials can be sensitive to many factors, such as temperature, humidity, pH, light intensity or electrical and magnetic fields, and can respond in various ways, such as altering color or transparency, becoming conductive or permeable to water or changing shape (shape memory polymers).
After this activity, students should be able to:
- Describe the role of cross-linkers in changing the physical properties of polymers.
- Design an experimental procedure for a design challenge.