Dissolve Styrofoam in Acetone

Dissolving Styrofoam or another polystyrene product in acetone is a spectacular demonstration of the solubility of this plastic in an organic solvent. It also illustrates just how much air is in the Styrofoam. All you need to do is to pour a bit of acetone into a bowl, and place Styrofoam beads, packing peanuts, chunks of foam, or even a Styrofoam cup in the container. The Styrofoam will dissolve in the acetone much like sugar dissolves in hot water. Since Styrofoam is mostly air, you may be surprised by how much (or, in the end, how little) foam will dissolve in the acetone. A cup of acetone is enough to dissolve an entire bean bag's worth of styrofoam beads.

How It Works

Styrofoam is made of polystyrene foam. When the polystyrene dissolves in the acetone, the air in the foam is released. This makes it look like you're dissolving a massive quantity of material into a small volume of liquid.

You can see a less-dramatic version of the same effect by dissolving other polystyrene items in acetone. Common polystyrene products include disposable razors, plastic yogurt containers, plastic mailers, and CD jewel cases. The plastic dissolves in just about any organic solvent, not just acetone. Acetone is found in some nail polish removers. If you can't find this product, you could dissolve styrofoam in gasoline just as easily. It's best to do this project outdoors because acetone, gasoline, and other organic solvents tend to be toxic when inhaled.