03 Dec, 2011
PRESENTATION: Some materials tend to return to their original shape when exposed to certain conditions. This ‘shape memory’ can be found in heat-shrink materials such as Polyethylene (PE) or Polystyrene (PS). When heat is applied using a blow-torch or a lighter flame to a piece of PE, noticeable shrinking is observed and there is a reduction in its diameter. Or if a PS yoghourt container is put into an oven, it can be seen to return to its original flat shape. It can also be seen when a PET bottle is heated to temperatures over 90ºC.
- Another Demo of the Unusual Thermal Properties of Rubber, Mark I. Liff, Phys. Teach. 48, 444 (2010)
- Polymer Physics in an Introductory General Physics Course, Mark I. Liff, Phys. Teach. 42, 536 (2004)