I tried it and couldn't get it to ignite, in spite of holding a flame on it for over three minutes. I also tried stretching it into thin threads to see if they would catch fire easier. They didn't. All I got for my trouble was a few brief and tiny flickers of flame that went out in a second or so. Exposed to flame, my Silly Putty bubbled a little and broke down into a whitish mass. Caution: I don't know what harmful chemicals might be given off by burning or attempting to burn Silly Putty. I did it outside where a draft carried any fumes away from me.
I don't recommend anyone repeating this experiment. Dow Corning sells the base material for Silly Putty in pound lots under the name Dilatant Compound.
Smaller bulk quantities can be purchased on-line from several sources. All the Silly Putty in the world is made from the Dow Corning product. The only differences are in the additives and colorants incorporated into it. For example, Binney and Smith add some type of filler to make it a little stiffer. Ja-Ru doesn't, or at least doesn't add as much, and as a consequence tends to be softer and sag thinner, as the following picture shows:.
Both were formed into spheres and allowed to sag for the same period of time. Immediately after mixing, Silly Putty is clear or slightly yellow. After a week of aging it turns white.
Colors are added later. Silly Putty has a shelf life of 24 months. But no source I researched could tell me what happens after this time. Psychiatrists have found that moulding Silly Putty in one hand as you work or relax is an effective method of reducing stress. I've tried it and it works.
Although I'm not a psychiatrist, I theorize that the reason is that it quickly becomes an unconscious activity that occupies some of your subconscious thought processes. If the subconscious is busy with a simple, non-threatening activity it can't work itself into a frenzy trying to resolve a more troubling problem haunting some darker corner of your mind.
Actually, I've found that the softer, homemade Silly Putty works better for this. Most retail Silly Puttys comes in 7 main colors: coral a fleshy-pink , blue, magenta, yellow, orange, gold actually translucent with fine gold-colored glitter , greenish-yellow glow-in-the-dark, and a color-changing putty that alters its color depending on its temperature. Below are some of the most commonly available shades:.
The six on the top are original Silly Putty by Binney and Smith. The two on the bottom are by Ja-Ru and are slightly different shades: the coral is pinker and the magenta is brighter. They offer four different glow-in-the-dark colors alone!
The following picture is of their amber glowing putty:. It's a testament to the sensitivity of the human eye that the glow from this putty appears quite bright, yet to capture this image of it I had to make a second exposure at ISO Even more interesting about this glow putty is that it is faintly triboluminescent, meaning that when it's discharged you can see a flash of light when it it is quickly stretched or torn in half. This phenomenon is similar to the flash seen when a wintergreen lifesaver is crushed.
The flash given off by glow-in-the-dark Thinking putty is extremely faint, requiring an ISO of and two stacked percent contrast enhancements to make it even faintly visible in a photograph. Such as it is, here it is:. The faint, oblong grayish blob extending from the lower left to upper right corner is the open, freshly torn face of Thinking Putty that was clamped between two boards before ripping in half. In comparison, the flash from a wintergreen lifesaver is ten times as bright. As hard as it was to capture this flash, it is easily seen in person.
Silly Putty is sold in 0. Off-brand companies also offer 2-pacts at cut-rate prices but usually the quantity of putty per egg is reduced to 0. While Silly Putty can still be used to pick up black newsprint and black-line images off newspapers, the colored inks used in the comics section have changed and you can no longer lift such images and stretch them into funny faces. However, faces printed in black still transfer nicely:. And you can still pull the faces into odd shapes:.
The reason this works is that while the color images use true inks that are absorbed by the paper and adhere to it, print and black-line images are printed with a mixture of oil and lamp black finely powdered carbon black. The result is that the black powder that creates the letters and pictures is only mechanically connected to the surface of the paper.
When blotted with Silly Putty it comes off. If warmed in a microwave it turns thinner and sticky, then returns to normal as it cools. Most references report that when bounced it bounces back to percent of the height it was dropped. This is halfway between a standard rubber ball and a superball.
My tests only average percent, but then I may not have made perfectly round spheres. I have read two reports of people dropping a large ball of Silly Putty from a tall building and that after bouncing up from the first impact, it shattered when it hit on the second. Perhaps the first impact was enough to create a myriad of small fractures, but not quite enough to shatter it. These cracks didn't have time to heal before the second impact, which was enough to finish the job. Because there is no water in Silly Putty it will never dry out, unlike homemade formulations.
In spite of its stretchability, Silly Putty can be easily torn. The putty should tear cleanly in half. Silly Putty is classed as a visco-elastic material, something half way between a liquid and a solid. While many sources state that Silly Putty can be shattered by hitting it with a hammer, it's not as easy as it sounds. Even chilled in a freezer it takes a good, hard whack to get it to break.
Placing it on a very hard and solid surface, like a concrete slab, also helps. The displacement of the material increases over time until equilibrium is reached. Common examples are plastics and rubbers.
Revisit Predictions: After completing Part 1, have students revisit their earlier predictions and look ahead to the material that will be covered in the associated lesson.
Discuss as a class or assign students to write down their own answers. Ask the students:. Data Reflection: After completing Part 2, have students reflect on the data they collected and answer the following questions. Data Analysis: Assign students to complete the Creepy Silly Putty Data Analysis Worksheet , in which they create bar plots in Excel, calculate the standard deviation of creep time for their data, and answer questions to probe their results for meaning and conclusions.
Review their answers to gauge their mastery of the material. Part 2 works best when specific team jobs are assigned to students at the beginning of the activity and not varied throughout the activity. Part 2 of this activity is very sensitive to human variability and error. The force driving the creep behavior is the weight of the silly putty. If the silly putty is not formed into a uniform cross section cylinder and held in the same way for every trial, the results will have a lot of variability and error.
If students obtain questionable results, run more trials and throw out bad data. Refer to the Everyday Polymers lesson and its Let's Make Silly Putty activity in which students make two different formulations of silly putty to explore the chemical identities of polymeric materials and learn how chemical composition and cross-linking affect their physical properties.
However, these contents do not necessarily represent the policies of the National Science Foundation, and you should not assume endorsement by the federal government. Why Teach Engineering in K? Find more at TeachEngineering. Group Size: 3 Activity Dependency: Viscoelasticity. Quick Look. Associated Sprinkle indicates that an abbreviated version of this activity is available.
Print this activity. Suggest an edit. Discuss this activity. Understanding silly putty provides useful clues as to how all those other materials behave. You can see what is happening more clearly when the heavy ball is dropped.
The light steel ball 28 grams bounces off quickly, in about 0. Silly putty is definitely elastic on that short time scale. The heavy steel ball 2. The impact takes 0. Restitution is not complete, so the collision is one with a low coefficient of restitution.
However, when the putty is pulled with suitable force, the crosslinks do not have time to break and reform, so elastic behaviour is seen. With suitable force exerted, the putty can even be shattered. That smoking causes cancer is a well known and scientifically proven fact. What Makes Shampoo Foam? Everyday Compounds: Sodium Lauryl Sulfate.
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