Solvent Replacement: What is an Azeotrope?

Q: How do I know if the solvent blend I’m using is an azeotrope?

A: If you have analytical equipment, you can run a GC over time. Let it sit out or boil it in a distillation apparatus or a vapor degreaser. Or you can ask your supplier for that information.

Q: What are the risks of using solvent blends that are not azeotropes?

A: If they’re labeled as non-flammable, they can become flammable over time, as a result, their cleaning performance and solvency properties can change.

Q: Why are the boiling points of some azeotropes lower than the individual components?

A: This is due to a molecular finding of two materials that causes the heat of vaporization to be lower, which lowers the boiling point. So you don’t need to put as much heat into it to get it to boil.

Q: How easy or difficult is it to “break” an azeotrope?

A: It’s pretty difficult. You need a high temperature. Sometimes, pressure can break the Azeotrope, but it would have to be a very unusual circumstance. That does not happen very easily.