4A30.80 - Thermal Properties of Rubber

Code Number:
4A30.80
Demo Title:
Thermal Properties of Rubber
Condition:
Excellent
Principle:
Expansion/Contraction
Area of Study:
Heat & Fluids

Disclaimer

Equipment:
Thermal Properties Demo, Infrared Heat Lamps (2), Heat Gun (Optional), and Large Rubber Bands.
Procedure:

See also 1R30.21 in Mechanics.

Set the Thermal Properties Demo Unit up as shown.  The lightweight mass goes with the spring and the heavier mass with the rubber band.  The rubber band will have to be stretched several times before hanging or until the pointers are about opposite each other.  A small difference can be overcome by moving the rods the spring and/or the rubber band hang from. Move the scale up or down to the desired setting.  Turn on the heat lamps.  The spring will stretch about 1 cm and the rubber band will shrink up to 2 cm.  It is important that the heat lamps are closest to the spring.  The heat gun may be used in place of the heat lamps but the air movement may make the pointers move violently if you are not careful.

Hang a 50 gram mass from the rubber band in front of a uniform background and focus the IR camera for a clear image.  DO NOT touch the rubber band with your fingers as the camera will pick that up very clearly.  Grab hold of the mass and stretch the rubber band down to table top level.  You will observe the rubber band heat significantly due to the stretching.

 

References:
  • Mark I. Liff, "Another Demo of the Unusual Thermal Properties of Rubber", TPT, Vol. 48, #7, Oct. 2010, p. 444.
  • Mark I. liff, "Polymer Physics in an Introductory General Physics Course", TPT, Vol. 42, #9, Dec. 2004, p. 536. 
  • Bruce Denardo and Richard Masada, "Rubber Hysteresis Experiment", TPT, Vol. 28, #7, Oct. 1990, p. 489.
  • D. Easton, "Hooke's Law and Deformation", TPT, Vol. 25, #8, Nov. 1987, p. 494.
  • David Roundy and Michael Rogers, "Exploring the Thermodynamics of a Rubber Band", AJP, Vol. 81, #1, Jan. 2013, p. 20.
  • G. Savarino and M. R. Fisch, "A General Physics Laboratory Investigation of the Thermodynamics of a Rubber Band", AJP, Vol. 69, #2, Feb. 1991, p. 141.
  • J. H. Weiner, "Entropic Versus Kinetic Viewpoints in Rubber Elasticity", AJP, Vol. 55, #8, Aug. 1987, p. 746.
  • H. B. Carroll, M. Eisner, and R. M. Henson, "Rubber Band Experiment in Thermodynamics", AJP, Vol. 31, #10, Oct. 1963, p. 808.
  • J. B. Brown, "Thermodynamics of a Rubber Band", AJP, Vol. 31, #5, May 1963, p. 397.
  • C. L. Stong, "The Amateur Scientist: Concerning Experiments with Rubber and How to Re-Create a Classical Electrostatic Generator", Scientific American, Vol. 202, #6, June 1960, p. 175.
  • "M-438. Rubber Band & Bungee Cord", DICK and RAE Physics Demo Notebook.
  • "H-054. Rubber Band", DICK and RAE Physics Demo Notebook.
  • G. D. Freier and F. J. Anderson, "Hm-5", A Demonstration Handbook for Physics.
  • G. D. Freier and F. J. Anderson, "Hm-4", A Demonstration Handbook for Physics.
  • Martin Gardner, "The Mysterious Arrow", Entertaining Science Experiments with Everyday Objects, p. 119.
  • Walpole, "Shrinking Rubber", 175 Science Experiments, p. 119.
  • Neil A. Downie, "Electronic Elastic", Ink Sandwiches, Electric Worms and 37 Other Experiments for Saturday Science, p. 198.
  • Bobby Mercer, "Balloon Secret", Junk Drawer Chemistry, 2016, p. 79 - 83.
  • Tik L. Liem, "The Cooling Rubber Band", Invitations to Science Inquiry - Supplement to 1st and 2nd Ed. p. 35.
  • Julius Sumner Miller, Q56 & A56, Millergrams I – Some Enchanting Questions for Enquiring Minds, p. 39 & 96.

Disclaimer: These demonstrations are provided only for illustrative use by persons affiliated with The University of Iowa and only under the direction of a trained instructor or physicist.  The University of Iowa is not responsible for demonstrations performed by those using their own equipment or who choose to use this reference material for their own purpose.  The demonstrations included here are within the public domain and can be found in materials contained in libraries, bookstores, and through electronic sources.  Performing all or any portion of any of these demonstrations, with or without revisions not depicted here entails inherent risks.  These risks include, without limitation, bodily injury (and possibly death), including risks to health that may be temporary or permanent and that may exacerbate a pre-existing medical condition; and property loss or damage.  Anyone performing any part of these demonstrations, even with revisions, knowingly and voluntarily assumes all risks associated with them.