Silly Putty

DESCRIPTION:
This is a hands on activity that demonstrates how chemical reactions change the properties of a substance. In this case, borax (sodium borate) changes the sticky properties of Elmer’s glue, to make a fun to play with putty. Elmer’s glue is polyvinyl acetate, and when sodium borate is added to it, a cross-linked polymer is created giving the glue very different properties that make for a fun activity for students!

 

TOPICS COVERED:
chemical change
polymers

MATERIALS NEEDED:
– Elmer’s glue
– plastic cup
– water
– 10-mL graduated cylinder
– food coloring
– popsicle stick
– 4% borax solution
– sandwich bag

PROCEDURE:
1. Add ~ 25 mL of glue to the plastic cup (fill to the bottommost line on the cup)
2. Add 10 mL of water
3. Add a few drops of food coloring and stir
4. Add 2-3 pipetfulls of borax and stir
5. the mixture should become very very viscous, remove and “smush” with hands until the texture becomes putty-like. If needed add another squirt of borax
6. Place in plastic bag to keep.

ADDITIONAL COMMENTS:
Food coloring can stain the hands when “smushing”. This is usually done as a hands on activity, not as a demo.

SAFETY:
The putty should not be eaten.

REFERENCES:
“Gluep Production Lab.” Chem Fax! Flinn Scientific, Inc. 2007.

STORY:
Borax is usually referred to as the magic ingredient with younger students.

Handout