Recipes

Bouncing ball recipe

This is, in fact the same materials as slime, however the method and quantities are a little different.
By experimenting you can make lots of different types of ball/slime

Polymer balls can be quite beautiful.

From an original recipe by Anne Helmenstine

Introduction

Balls have been toys practically forever, but the bouncing ball is a more recent innovation. Bouncing balls were originally made of natural rubber, though now bouncing balls can be made of plastics and other polymers or even treated leather. You can use chemistry to make your own bouncing ball. Once you understand the basic technique, you can alter the recipe for the ball to see how the chemical composition affects the bounciness of the ball, as well as other characteristics.

The bouncing ball in this activity is made from a polymer. Polymers are molecules made up of repeating chemical units. Glue contains the polymer polyvinyl acetate (PVA), which cross-links to itself when reacted with borax.

Bouncing Polymer Ball Materials

Here’s a list of materials you need to gather to make bouncing polymer balls:

  • borax (found in the laundry section of the store)
  • cornstarch (found in the baking section of the store)
  • white glue
  • warm water
  • food coloring (optional)
  • measuring spoons
  • spoon or craft stick to stir the mixture
  • 2 small plastic cups or other containers for mixing
  • marking pen
  • watch with a second hand
  • metric ruler
  • zip-lock plastic baggie

 

Make a Bouncing Polymer Ball – Procedure

Procedure

  1. Label one cup ‘Borax Solution’ and the other cup ‘Ball Mixture’.
  2. Pour 2 tablespoons warm water and 1/2 teaspoon borax powder into the cup labeled ‘Borax Solution’. Stir the mixture to dissolve the borax. Add food coloring, if desired.
  3. Pour 1 tablespoon of glue into the cup labeled ‘Ball Mixture’. Add 1/2 teaspoon of the borax solution you just made and 1 tablespoon of cornstarch. Do not stir. Allow the ingredients to interact on their own for 10-15 seconds and then stir them together to fully mix. Once the mixture becomes impossible to stir, take it out of the cup and start molding the ball with your hands.
  4. The ball will start out sticky and messy, but will solidify as you knead it.
  5. Once the ball is less sticky, go ahead and bounce it!
  6. You can store your plastic ball in a sealed ziploc bag when you are finished playing with it.
  7. Don’t eat the materials used to make the ball or the ball itself. Wash your work area, utensils, and hands when you have completed this activity.