Ultra‐high performance size‐exclusion chromatography of synthetic polymers

Ultra‐high performance size‐exclusion chromatography (UHP SEC) is a newly developed disruptive technology that allows the high‐resolution separation of synthetic polymers in as little as 2 min. The capability of UHP SEC for the characterization of synthetic polymers in organic solvents has been demonstrated. Using the Waters ACQUITY UPLC®¹ H‐Class system and ethylene‐bridged hybrid size‐exclusion chromatography (SEC) columns packed with 1.7 to 2.5‐μm particles with pore sizes ranging from 45 to 900 Å, size‐based separations of polystyrene and poly(methyl methacrylate) standards in tetrahydrofuran and poly(ethylene oxide) standards in 20 mM ammonium acetate in methanol are achieved within 2–4 min. The speed of analysis is about ten times faster than conventional SEC separations, and greater resolution is achieved. Average molecular weights of selected commercial polymers have been determined using ultra‐high performance and conventional SEC. Average M data of analyzed samples are in good agreement using the two approaches. An inherent limitation of SEC in UHP mode is the characterization of very high M polymers (above ca. 2 million Da) due to the deformation and/or mechanical shearing of large molecules at high flow rates.