Fantastic Flubber

This week at science club we made flubber.

Flubber is a bouncy, rubbery substance.

The science behind it

Most liquids, like water, are made up of molecules that are not linked together. These are called monomers. These liquids flow easily and are not sticky when you touch them.

In some substances the monomers are linked together in long chains. These are called polymers. These long chains do not flow over each other easily. Liquid polymers tend to be gooey, sticky and hard to pour.

Flubber is an example of a cross-linked polymer. This means that the polymer chains are linked and this stops the molecules moving over each other.

How to make flubber

First you put 25ml of PVA glue into a beaker. Then an 2 drops of food colouring and stir to mix. While stirring slowly add 15ml of borax solution. Keep stirring vigorously until the flubber starts to form. Finally, roll the flubber in your hands. Dry hands work best. Keep rolling until it forms a rubbery, smooth ball.

Properties of Flubber

• When you feel the flubber it is all rubbery.
  
• When you pull the flubber quickly it will snap like a piece of plastic.
• When you stretch the flubber slowly it stretches more.
• Flubber balls can bounce on the table.
• We found out that flubber can be used as a rubber.
• If you put your flubber on some pencil writing the writing prints onto the flubber.

If you add too much borax to the mixture the flubber does not work and goes all sticky and gooey. The mixture was really wrinkly.


To start with lots of us had problems getting the mixture to work. But we persevered and finally it worked.

Playing with flubber is really addictive. We couldn't stop squishing, rolling and bouncing it.