Polymer Recipe

  1. Measure 20 ml water into cup.
  2. Add 25 ml Elmer’s-type glue. Mix with stirrer.
  3. Add 1 level teaspoon talcum powder. Stir 2 minutes until compound is made—or ingredients are thoroughly mixed together.
  4. May add up to 5 drops of food coloring—AND NO MORE! Decisions about mixing two or more colors should be made before the five-drop limit is reached. More coloring makes too big a mess on hands, clothing, and surroundings.
  5. Add 5-8 ml or 1 teaspoon of saturated borax-and-water solution. [Be careful! The borax solution can burn your eyes a little, so take care not to splash it. Also, don’t rub your eyes until you have washed your hands. Younger children should have the borax solution measured out for them.] Stir 2 minutes.
  6. Remove polymer from cup. Pull off extra material from stirrer. Form a glob.
  7. Dispose of cup. When done playing with polymer, store in plastic bag. If you plan to keep it awhile, store in the refrigerator.

Extension Ideas to Try at Home

  1. Do experiments to measure the elasticity of your polymer ball. You could try dropping it from different heights and measuring how high it bounces. Will it bounce farther from a short height or a long one? Such results could be charted to make interpretation of data easier.
  2. See how elasticity changes with temperature. When warmed by handling, your polymer will stretch a certain amount before breaking apart. What happens if it is chilled in the refrigerator first? What happens if it is frozen? (Hint: the shattering of a frozen ball will prove that this is a thermoplastic polymer.
  3. Demonstrate dehydration. Leave some of the material we made outside of the plastic bag for a period of time. Observe and feel how it gets harder and less flexible. Why? Dehydration is happening—water molecules are evaporating. See if you can rehydrate the material by adding some water to it in the plastic bag.
  4. Observe the strength of polymers by filling a plastic sandwich bag 2/3 full with water. Twist-tie the top. Take a freshly sharpened pencil and stick it through the bag into the water. See how polymer flexibility allows the material of the baggie to mold around the pencil and keep water from pouring out. Is this process reversible? See that it is NOT by holding the bag of water with pencil through it over a sink or bucket. Slowly pull pencil out; water flows out. Polymer is not capable of sealing back together, re-joining molecules that were severed and torn apart.
  5. Can polymers shrink? Try shrinking globs of the material. Do experiments to promote evaporation of water. Recall from original recipe that it is more than half water. Ideas are to just play with and handle the material. See the water on your hands and how your glob shrinks in size/mass. Place a glob on a piece of material which absorbs water, like a paper towel. See the decrease in size over time and the water/moisture on the towel material. Leave glob out on a sunny shelf. Observe and record what happens to it over time.
  6. Observe saturation by looking at how the borax and water mixture was made. Try stirring more and more borax into a gallon container of water until no more will dissolve and particles can be seen at the bottom of the jug. See that, after a point, the water simply can’t absorb more borax. Then try making a polymer with this super-saturated solution (one that has more borax in it than will dissolve). You will feel the difference: the material is not soft but has lumps and a gritty feel. Try stirring other powders into water to the point of saturation. You could chart experiments to see how many cups of sugar, salt, and borax a gallon of water can hold before it becomes saturated. Or try mixing coffee, instant tea, and cocoa mixes with water and/or milk.

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