Kitchen Chemistry Experiment 21
Silly Putty

Non-Newtonian Fluids and Colloids
Many of the materials we use every day, like starch, are made up of molecules called POLYMERS. POLY means many and MER means unit. Because the units in chains are so long, they interfere with the ability of the solution to flow. Viscosity is a physical property of liquids that descibes how they flow. Honey and corn syrup are described as having high viscosities because they flow more slowly than water

 

 

Materials	Substitutions
2 400 mL beakers	2 jars
Elmer's Glue All
a spatula	a spoon
Borax
scissors
water
25 mL graduated cylinder	measuring spoons
food coloring

Procedure

1. Mix 30 mL (2 Tbsp) of glue with 20 mL water (4 tsp) in a beaker or jar.
2. Add 2 or 3 drops of the desired color of food coloring.
3. Take the second beaker and to it add 200 mL (3/4 cup) of water. Add 2.6 grams (1/2 tsp) of powdered Borax and stir until it dissolves.
4. Add 15 mL (1 Tbsp) of the borax solution into the beaker with glue and water.
5. Stir gently allowing it to sit momentarily to achieve the optimal "puttiness".
6. Take the putty out of the beaker and stretch it. Will it bounce? Does its consistency change? Can you break it?

 

Extensions

Try making on of the other non-Newtonian fluids in this lab manual. See GLURCH or SLIME AND OOBLECK.

Teacher's Notes

1. The silly putty is a non-Newtonian fluid --so-called because of its unusual viscosities. A non-Newtonian fluid has properties of both a solid and a liquid and reacts to stress with increased viscosity.
2. Glue can make a mess!! Be prepared for your students to have some "play" time. Towels and water should be on-hand as bits of silly putty will be on countertops.
3. If you have ziptop bags, you could allow the students to take their silly putty home with them. The putty will dry over time.
4. Do Not Eat Glue or Silly Putty.