Acetone has no ingredients per se. Asking about the ingredients in acetone is like asking what the ingredients in water (H2O) are. If you take any atoms away from the molecule of acetone, it's no longer acetone. The chemical formula for acetone, however, is: (CH3)2 CO.
The mixture of Polystyrene and Acetone results in the creation of a sticky residue as the Polystyrene beads dissolve into the Acetone. You can use Nail polish remover with Acetone. However, the chemical reaction occurs at a much more rapid pace with pure Acetone.