Silly Semi-Solids
Student teams make polymers using ordinary household supplies (glue, borax, water). They experiment with the semi-solid material when warm and cold to see and feel its elastic and viscous properties. Students will begin to understand how the electrical forces between particles change as temperature or the force applied to the substance changes. Is it a solid, a liquid, or something in between? How might it be used?
The molecules of a polymer.Copyright Lawrence Berkeley National Laboratory http://www.lbl.gov/Science-Articles/Archive/sabl/2005/February/water-solid.html
Viscoelastic materials have a wide variety of applications. Many prosthetic implants require materials that have these properties. Biomedical and biomechanical engineers investigate and design these materials to get the best possible combination of elastic and viscous properties in one material to support the functioning of the prostheses that they create.It is also important for engineers to understand why various materials display different viscoelastic properties. It is typically the role of a chemical engineer to understand the forces at the molecular level so conclusions can be made as to why certain materials display different properties.
After the activity students should be able to:
- Understand the properties of polymers and determine whether they are solids, liquids or something in between.
- Understand how molecular forces change the viscoelastic properties of materials
- Discuss real-world applications of polymers.