Story content courtesy of Malvern, UK
A novel gel permeation chromatography (GPC) method for characterizing Nylon, developed by researchers at Malvern Instruments, significantly reduces the cost of analysis while simultaneously improving safety, when compared with conventional techniques. The new method uses formic acid as a solvent for Nylon, in place of the traditional choice of hexafluoroisopropanol (HFIPA), a relatively expensive, aggressively corrosive solvent with poor health and safety characteristics. The breakthrough is expected to generate significant industrial interest.
GPC is routinely used to determine the molecular weight and molecular weight distribution of Nylon, and indeed many other polymers. It relies on complete dissolution of the polymer in a suitable solvent and this can be a challenge with sparingly soluble polymers. For Nylon, HFIPA is conventionally chosen as a solvent because of its effectiveness, despite the deterrents of toxicity, cost and corrosivity.
The new method, developed by Drs Wei Sen Wong and Kyle Williams at Malvern’s research facility in Houston, Texas, achieves complete dissolution using formic acid, a solvent that is typically around 1% of the cost of HFIPA. In addition, formic acid has a more favourable health and safety profile. The new technique can also handle residual water from the polymerization process and does not require the addition of corrosive salts (such as potassium trifluoroacetate KTFA), reducing wear and tear on the chromatography system. These benefits add up to a considerable advance for Nylon characterization, an improvement in health and safety coupled with significant potential for cost reduction.