You can make a polymer ball using some basic ingredients including 1/2 tsp. borax, 1 tbsp. white glue, 1 tbsp. cornstarch, 2 tbsp. warm water, measuring spoons, two small containers for mixing, something to stir with, marker, ruler, stop watch or watch with a second hand, and a baggie. Food coloring is optional. Mark "borax solution" on one container and "ball mixture" on the other. Mix the borax and the warm water to make the solution. Add food coloring if you want. The ball mixture is the glue plus 1/2 tsp. of the borax solution and cornstarch. Wait about 15 seconds and then stir the mixture. When you can no longer stir it, take the mixture and mold the ball in your hands for a few moments. You can experiment with the basic recipe and see what different amounts of ingredients do to the ball. More corn starch will make it stretchy and more glue will make it slimy.
Polymers have characteristics of both a solid and a liquid. Making slime is another way to perform experiments on polymers. For this you will need borax powder, white glue, two disposable cups, food coloring, water, a tablespoon, and something to stir with. Fill one cup mostly with water and add one spoonful of borax. Let it sit for a while and fill the other cup with one inch of glue. Add three tbsp. of water and stir. Add one tbsp. of the borax solution you made and stir. When it is formed, wait for about 30 seconds, pull it off the spoon and play with it. Be careful not to get it on clothes or hair. Experiment with the slime to discover its properties, like testing to see if it bounces or how far it will stretch. Vary the amount of ingredients to see the effect on the final product. The reason glue is used with borax is that glue has polyvinyl acetate, or PVA, which is a polymer and reacts to the borax.
Hydrogel, also called slush powder or water gel, is very absorbent and can absorb 1,000 times its weight in water. This is used in baby diapers for that reason. Some polymers are very efficient at absorbing oil and can be used to clean up oil spills. This experiment will demonstrate these properties. Materials include hydrogel, motor oil, water, small and large spoons and a clear plastic cup. Fill the cup halfway with water and add motor oil until there is a film of it on top of the water. Sprinkle some hydrogel on top of the oil with a spoon and wait for a few minutes to see what happens. After it congeals from a liquid to a soft solid, take a large spoon and scoop it out.
Polymers are found in hair gel. This experiment shows how it can be broken down with salt. Put about a tablespoon of hair gel into a petri dish. With a small spoon, sprinkle some salt on the gel. Observe the salt react with the gel, causing it to shrink rapidly. After a few minutes, only a liquid will be left in the dish.