Characterization of poly (N‐vinyl formamide) by size exclusion chromatography–multiangle light scattering and asymmetric‐flow field‐flow fractionation–multiangle light scattering

Abstract

The molar mass and the radius of gyration of three poly N-vinyl formamide (polyNVF) synthesized in aqueous solution polymerization were characterized using two different fractionation techniques: size exclusion chromatography (SEC) and asymmetric-flow field-flow fractionation (AF4) coupled with a multiangle light scattering (MALS) and a refractive index (RI) detector. For the sake of comparison, the polymers were also characterized by MALS using the Zimm plot approach (no fractionation). The dn dc 21 of the poly (N-vinyl formamide) was measured (0.1564 mL g 21 ) and it was found to be insensitive to the molar mass (in the range 150-450 kDa) and also to the eluents used (DDI water or mixed eluent DDI water/acetonitrile (80 : 20) at pH 5 5.5). Interestingly, the concentrations of the samples injected in the SEC and AF4 should be different because concentrations in the range of 20-40 mg mL 21 used for the AF4 caused overloading and anomalous elution in the SEC and hence misleading molar masses. At adequate concentrations in each fractionation equipment, the molar masses were in reasonable good agreement although AF4/MALS provided larger values than the other two techniques likely because samples were not filtered before injection. V C 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42434.