Making "Slime"
Purpose:
Slime is fun to play around with and demonstrates the properties of a polymer. The polyvinyl alcohol polymer has a repeating vinyl alcohol unit of -CH2-CHOH-.
Materials and Procedure:
- Place about 20 ml of 4% polyvinyl alcohol solution in a paper cup.
- Optional: add a few drops of food coloring.
- Add 3 ml of 4% sodium borate (tetra)solution. This solution is made by putting 4 grams of sodium borate into 96 ml of water.
- Stir vigorously.
- When slime is formed, put it between paper towels to remove the excess liquid.
Discussion:
- Stretch it, roll it into a ball, leave it alone and see what happens. Slime is a polymer with cross-links of sodium borate.
- "When the two solutions of polyvinyl alcohol and sodium borate are mixed, the borate ions (B4O7-2) react with the hydroxly (OH-1) groups of the polyvinyl alcohol. Weak crosslinking within the polymer occurs to produce the viscoelastic (viscous and elastic) gel. The high solubility in water suggests that extensive hydrogen bonding exists." * from Chem Fax, 1990 by Flinn Scientific, Inc.; PO Box 219; Batavia, IL 60510
- Slime is considered non-toxic, but it is recommended to wash your hands after use. Do not eat it or get it into the eyes.
- Slime will mold so it should be refrigerated between uses.
- Slime can remove paint and will stick to carpet.
You can purchase the chemicals from many supply houses, but I like Flinn Scientific because you can get small volumes which reduces disposal problems.
To measure in "ml" you can purchase graduated cylinders from a chemical supply house like Flinn or get syringes from a vet or animal supply house. Cow syringes are nice for larger volumes. Do not get needles to go with the syringes. Beakers do not measure volumes.
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Slime is fun to play around with and demonstrates the properties of a polymer. The polyvinyl alcohol polymer has a repeating vinyl alcohol unit of -CH2-CHOH-.
- Place about 20 ml of 4% polyvinyl alcohol solution in a paper cup.
- Optional: add a few drops of food coloring.
- Add 3 ml of 4% sodium borate (tetra)solution. This solution is made by putting 4 grams of sodium borate into 96 ml of water.
- Stir vigorously.
- When slime is formed, put it between paper towels to remove the excess liquid.
Discussion:
- Stretch it, roll it into a ball, leave it alone and see what happens. Slime is a polymer with cross-links of sodium borate.
- "When the two solutions of polyvinyl alcohol and sodium borate are mixed, the borate ions (B4O7-2) react with the hydroxly (OH-1) groups of the polyvinyl alcohol. Weak crosslinking within the polymer occurs to produce the viscoelastic (viscous and elastic) gel. The high solubility in water suggests that extensive hydrogen bonding exists." * from Chem Fax, 1990 by Flinn Scientific, Inc.; PO Box 219; Batavia, IL 60510
- Slime is considered non-toxic, but it is recommended to wash your hands after use. Do not eat it or get it into the eyes.
- Slime will mold so it should be refrigerated between uses.
- Slime can remove paint and will stick to carpet.