WEB EXCLUSIVE: Malvern Instruments, Westborough, Mass., has a novel gel permeation chromatography (GPC) method for characterizing nylon that is said to significantly reduce the cost of analysis while simultaneously improving safety, compared with existing methods. GPC is routinely used to determine the molecular weight and MW distribution of nylon and many other polymers and relies on the complete dissolution of the polymer in a solvent.
The new method is said to achieve complete dissolution using formic acid as a the solvent, which is typically around 1% of the cost of hexafluoroisopropanol (HFIPA), the solvent used with conventional techniques. In addition to its high cost, HFIPA is an aggressively corrosive solvent with poor health and safety characteristics. Malvern’s new technique can also handle residual water from the polymerization process and does not require addition of corrosive salts, such as potassium trifluoroacetate (KFTA), reducing wear and tear on the chromatography system.