SILLY PUTTY - WSKG

WSKG
Science in the Park
SILLY PUTTY
To demonstrate the properties of polymers.
Silly Putty is a substance that behaves like both a solid and a liquid at the same
time, which is called a polymer. It is a mixture of glue, water and borax. Borax
acts like a “cross-liker” and joins the molecules of glue & water together.
Because polymers are a chain of many molecules linking together, they can be
quite long. Polymers can be pulled apart like a solid or they can ooze and take
the shape of their container like a liquid.
The history of silly putty is quite interesting. In 1943 James Wright, an engineer,
was attempting to create a synthetic rubber. He was unable to achieve the
properties he was looking for and put his creation (later to be called silly putty) on
the shelf as a failure. A few years later, a salesman for the Dow Corning
Corporation was using the putty to entertain some customers. One of his
customers became intrigued with the putty and saw that it had potential as a new
toy. In 1957, after being endorsed on the "Howdy Doody Show", silly putty
became a toy fad. Recently new uses such as a grip strengthener and as an art
medium have been developed. Silly putt even went into space on the Apollo 8
mission.
KEY WORDS:
POLYMER - a substance that has liquid and solid properties at the same time.
VISCOSITY – the measurable thickness or resistance to flow in a fluid. (Water
has a low viscosity; honey has a high viscosity.)
MATERIALS:
One box of Borax detergent, zip-lock bags, water, food coloring, Elmer’s Glue,
water, wooden stir sticks, plastic spoons, 6oz. cups, pipettes or eye droppers.
PREPARATION:
1. Create a Borax solution by mixing 2 Tablespoons of Borax to 1 cup of water
and stir. This will be your cross linker to create the polymer.
2. Add food coloring to glue.
3. This experiment can be messy. Cover tables appropriately.
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WSKG
Science in the Park
DIRECTIONS:
1. Give each student a zip-lock bag, wooden stir stick, cup and assist them
with the following steps:
2. Have students measure 2 tsp of glue and 2 tsp of water into their cups.
3. Stir glue/water mixture.
4. Add Borax solution to glue/water mixture 5 drops at a time.
5. Stir mixture. The mixture should start creating a visible polymer on the
end of the stir stick. Continue adding Borax solution in small amounts until
all liquid disappears in your cup. Do not add too much cross linker
solution or the reaction will not work.
6. Have students take the polymer out of the cup and touch it. They should
roll the mixture around in their hands, first slowly and then quickly.
7. Have students place the polymer on the table, what happens? It should
ooze like a liquid. Have students pull the polymer apart and it will break
apart like a solid.
8. Store in Ziploc bag (which is also a polymer).
RESULTS:
The polymers in silly putty have covalent bonds within the molecules, but
hydrogen bonds between the molecules. The hydrogen bonds are easily broken.
When small amounts of stress are slowly applied to the putty, only a few bonds
are broken and the putty "flows". When larger amounts of stress are applied
quickly, there are many hydrogen bonds that break, causing the putty to break or
tear. Examples of polymers are plastics, such as plastic bags, rubber, synthetic
fabrics in some shirts and pants, keyboard and computer casings, Ipods, cell
phone covers, glasses (including lenses if they are not glass)
QUESTIONS:
How can it be solid and liquid at the same time?
Is a polymer more than one molecule? (hint: name the ingredients
used for the experiment)
Why isn’t your hand wet after you let the mixture slide through your
fingers?
**Important note! Do NOT pour Silly Putty down the drain
It will
clog the pipes. Dispose of the mixture in the zipper lock bag in the
garbage!
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