The density of polymers can be measured using a density gradient column and relevant apparatus from Techne Incorporated. The prepared density gradient columns are thermostated at 23.0 ± 0.1 °C and calibrated with glass floats allowing density measurements to four decimal places (in g/cc) with an accuracy of ± 0.0002 g/cc. Our current supply of calibrated glass floats gives us the capability of making density measurements between 0.83 g/cc – 1.35 g/cc.