GLUE-P!

Posted by: on Oct 31, 2013 | No Comments

Plastics are all around us. There are many different kinds. Most plastics are made in factories, but here’s a version of a popular one you can make yourselves.glue

You will need:

1 teaspoon laundry borax,

1 tablespoon white glue,

Food colouring (optional),

Two cups

Spoon

Water

Instructions

In one of the cups, dissolve 1 teaspoon of laundry borax in 5 tablespoons (75 mL) of water. You will need to stir this for a while to get it to dissolve

In the other cup, combine 1 tablespoon of water and 1 tablespoon of white glue. If you wish, you may colour the mixture with a couple drops of food colouring. With a clean spoon, stir the mixture thoroughly until it is uniform.

Put 2 teaspoons of the borax solution from the first cup into the glue mixture in the second cup. Stir the mixture.

As you stir the mixture, it will stiffen into a soft lump. After the lump has formed, take it from the cup and knead it in your hand for a couple minutes.

The material you have made is called Gluep, and it is ready for you to examine.

Roll the Gluep into a ball and then let it rest. Does the ball maintain its shape?

Drop a Gluep ball onto a table top. What does the ball do?

Flatten the Gluep into a thin strip. Hold up the strip by one end. What happens to the strip?

Roll the Gluep into a cylinder and pull the ends slowly.

What happens to the cylinder? Roll the Gluep into a cylinder and pull the ends quickly. What happens to the cylinder?

What’s Happening?

The materials we call plastics are all composed of large molecules whose structure is like a chain. These molecules are composed of many small repeating units, like the links in a chain. Like a chain, the molecules of a polymer are long and narrow. The name plastic is applied to a wide variety of substances, some of them soft and others very hard. Originally, plastic referred to something shapeable or bendable. However, as new polymer materials were made that were hard and stiff, the name plastic was applied to them, too.

White glue is a mixture of water with a polymer. The polymer molecules are shaped like very tiny pieces of spaghetti. The tangled molecules make glue thick and viscous rather than thin and runny. When glue is exposed to air, the water evaporates, leaving the tangled polymer molecules. The tangled molecules stick to the surfaces on which they dried, and hold the surfaces together.

When Gluep rests, the flexible network gradually relaxes, and the Gluep flattens. When Gluep is stretched quickly, the links between molecules break, and the Gluep snaps apart into pieces. If the Gluep is left exposed to open air, the water will evaporate, and the Gluep will gradually stiffen. To preserve the Gluep, store it in an air-tight plastic bag.

Have Fun!

Thanks to and adapted from scifun.chem