Transcript Kansas State Fair Demonstration Explanation

Kansas State Fair Demonstration
Explanation & Recipes
Presented by:
NU Chemistry Club
Chemistry of Elmer’s Glue
Active ingredients
• Polyvinyl acetate
• Polyvinyl alcohol
Chemistry of 20 Mule Team Borax
• The main active ingredient is called sodium
tetraborate decahydrate
Tetraborate Complex Ion
[B4O5 (OH)4]2-
Chemical Reaction
• Cross-linking Polymerization
– The borate ion forms hydrogen bonds with
available hydroxyl groups of the polyvinyl alcohol
and those that are created due to the reaction of
the acetate groups of the polyvinyl acetate with
water
• Similar to forming the rungs of a ladder
Final Results
A Bouncy Ball
Recipe for One Bouncy Ball
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½ - ¾ tsp. 40 Mule Team Borax
2 T. Water & coloring (optional)
1 T. Elmer’s Glue
To “color” your ball; add color to water, then
stir in borax, then glue. Mix with a stirring
stick until a ball forms; roll the ball between
your palms until smooth and Bouncy!
“Classroom” Size Recipe
• Pre-mix borax and water in a 4:1 ratio
• i.e. 4 cups water, 1 cup borax (yields 32 balls)
6 cups water, 1 ½ cups borax (48 balls)
• Shake or stir well; this will be a supersaturated
solution. Allow sediment to settle.
• Put 1 oz (33 cc) of liquid mixture in a small paper
cup; add 1 generous Tablespoon Elmer’s glue to
solution to make one ball.
• 4 oz. bottle Elmer’s glue yields approx. 6 T. glue (1 T.
per ball) and this size bottle is usually the cheapest!