Flubber

Make your own flubber and find out if it bounces back into shape after you stretch it out. Does it bounce on the table?

 

Equipment

  • Labcoats or protective clothing (1 per child)
  • Non-latex gloves (for children with sensitive skin)
  • Disposable plastic cups (1 per child)
  • PVA Glue (Craft Planet is best) 1 tablespoon per child
  • Coloured paint
  • 4% Borax solution (approx. 3mls per child)
  • Pipettes
  • Wooden tongue depressors (1 per child)
  • Safety glasses (1 pair per child)

 

Method

  1. Pour 1 x tablespoon (2 lines from bottom of cup) of PVA glue into a
    plastic cup/beaker
  2. Add one or two drops of paint to the glue. (It’s important to not add too much paint, or the mixture will be too runny and will not make good slime)
  3. Mix the glue and paint together using a wooden stirrer
  4. Workshop leader (and not the children) should now add 3mls of 4% borax solution (using a pipette)
  5. Using a wooden tongue depressor, carefully mix the borax into the glue-paint mixture until the mixture turns thick and jelly-like – you will have to spend a few minutes doing this.
  6. Take your flubber out of your cup. Squeeze/roll the flubber in your hands for 2 minutes. The warmth of your hands will make it more pliable
  7. See how well it stretches. If you pull it apart, does it squash back together? How well does it bounce on the table?

 

The science

The glue is a long-chained polymer (Poly Vinyl Acetate), meaning it is a set of molecules that are linked together in a long series. By adding the Borax mixture that consists of Borate ion and water molecules, these long chains of polymers (glue) can be linked together, forming a kind of matrix. The bond between these polymers in this matrix is not very strong, which explains why the flubber is bendable and stretchable.

 

Health and Safety

Powdered Borax may be a risk to pregnant women. Please check online material hazard sheets for Borax prior to its use. Borax can be an irritant in liquid form so please ensure any children with sensitive skin are wearing gloves. To protect clothing and eyes from any splashes, all children should wear lab coats and safety glasses.