This can be done by adding a few spoonfuls of baking soda (Arm & Hammer®) to the borax solution and vinegar to the glue on a 1:1 basis. As the Zen proverb says: "Only when you can be extremely pliable and soft can you be extremely hard and strong.")"Ĭonsider a second set of mixture experiments that incorporates a gas-producing reaction to reduce density of the putty. What happens if you hit a ball of putty with a heavy object, such as a hard-cover book? (Hint: Putty behaves as a "dilatant," which means it reacts differently to hard, fast pressure than it does to slow, even pressure. See how far it flows as days go by.) Does temperature affect the deformation? How does your putty deform with time? (Suggestion: Take a blob, roll it in a ball and stick it to the side of a metal cabinet or refrigerator. Does cooling improve the "bounceability"? If cooled too much, in a freezer for example, will the putty shatter when bounced? Do the experiment and analyze the results. It should last about 2 weeks before drying out.Ĥ. Store the putty in an airtight container (such as a Ziploc® bag). Add food coloring if you wish (wear rubber gloves unless you want your hands the same color!). Lift the glob from the bowl and allow the moisture to drain off. Then knead it by hand when it forms a glob that's too stiff for the spoon. Using the output from Design-Expert software for the recipe, add the borax/water (and/or the liquid starch) to the glue mixture. In another bowl combine 2.5 ml (1/2 teaspoon) of borax and 25 ml hot water. In one bowl, combine 50 milliliters (ml) of glue and 25 ml cold water. Cover your work area with newspaper or paper towels.ī. Here's a specific recipe modified from a. With the aid of Design-Expert® software, plan a mixture experiment. At the very least, establish ratings on a 1 to 9 scale, with 1 being worst :(, 9 being best :) and 5 so-so :|.ģ. Select at least two properties and decide exactly how you will measure them. (Hints: consider bounciness (percent rebound), elongation (percent stretch) and possibly surface sheen and tackiness (ability to pick up printed copy from newspaper).)Ģ. Brainstorm a list of desirable properties and how to quantify them. These instructions leave plenty of room to be creative! Plan on taking at least two hours to complete the project. See how well you can do with this home-made material in comparison to the real thing sold commercially as a toy: Silly Putty® (see note below). To make things more interesting, add laundry starch (STA-FLO® concentrated liquid) to the mixture. Mix ordinary white glue (Elmer's®) and a cross-linking agent: borax (20 MULE TEAM® brand from your local grocery store). Sheldon of Honeywell International as an exercise for learning design of experiments (DOE). This article is greatly expanded from a document contributed by Paul N.
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