I am trying to soundproof a second floor condo. Has there been any tests on this product for using as underlayment for a free-floating laminate floor?

Our 1/4" Tough Rubber Rolls can be used as underlayment, but they are not tested for that purpose. We do offer 1/4" thick underlayment that has been tested. Feel free to take a look at that product and others on our underlayments page.