|
|
Department of Chemistry and Biochemistry | |
| DEMONSTRATIONS |
Faculty & Research |
| |
Academic Programs |
| |
Industrial Relations |
| |
Research Facilities |
| |
Department Administration |
Hydrogen Bonding in Slime
Procedure
- Pour 100ml of 4% polyvinyl alcohol solution into a 250ml beaker, add a couple of drops of food coloring for your favorite color.
- Pour 16ml 4% sodium tetraborate solution into the polyvinyl alcohol solution while stirring vigorously with the supplied wooden stick.
- Stir the solution as fast as you can for 30 seconds or so - until the solution begins to polymerize.
- You now have a colored polymer.
Reactions
Sodium borate hydrolyzes in water to form a boric acid-borate ion buffer with pH around 9.
B4O72 (aq) + H2O <---> HB4O72- (aq) + OH- (aq)The borate ions react with the hydroxyl groups of the poly(vinyl alcohol) [-CH2 CHOH-]n to form cross links possibly with the elimination of water. The cross links probably involve hydrogen bonds that break and reform under flow.
