The Science Behind Homemade Silly Putty 2
| To make homemade silly putty you need Elmer's Glue which is just poly vinyl alcohol with water. Then you add Borax solution which through some chemical reactions becomes borate ions. | |
PVA and WATER (normal Elmer's Glue) |
PVA without WATER (dried up Elmer's Glue) |
Elmer's Glue is a mixture of long PVA molecules and water. All of the molecules attract to each other with hydrogen bonds (dipole-dipole attractions). The water helps lubricate the PVA molecules and keeps them sliding around by each other. |
When the water evaporates, the glue hardens because many hydrogen bonds (dipole-dipole attractions) can form directly between PVA molecules. |
PVA with WATER and BORATE (homemade silly putty) |
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The borate ions form hydrogen bonds (dipole-dipole attractions) directly between two PVA molecules, weakly cross-linking them and causing the mixture to become putty-like. The borate cross-links make it harder for the PVA molecules to slide by each other, but not so difficult that it completely hardens. |
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<-- see the charges on the surface of these moleucles