Slime [poly(vinyl alcohol) with sodium borate]

Introduction:
The reaction is as follows:

Materials:
  • Large flask of 4% PVA
  • Large flask of 4% sodium borate (borax solution)
  • Small styrofoam or Dixie cups
  • Wooden stir sticks
  • Food coloring
  • Zip lock bags
Procedure:
Mix the PVA and the sodium borate solution together in a small cup (about a 4:1 ratio). First the PVA should be added to the cup. This along with a wooden stir stick can be passed out to each student. Next, the cross linker (sodium borate) can be added to each cup (remember, you only need about 1/4 as much cross linker). At this point food coloring can be added. One or two drops should be plenty. The student should begin to stir the mixture immediately. Within a few minutes of stirring the polymer should be dry enough to handle. If the student is to bring the slime home, zip lock bags should be provided.