Characterization of poly(naphthalenesulfonate) salts by ion-pair chromatography and ultrafiltration

• Published in: Journal of Chromatography A 1995-06, Vol.704 (2), p.377-385
• Main Authors: Piotte, M., Bossányi, F., Perreault, F., Jolicoeur, C.
• Format: Article
• Language: English
• ISSN: 0021-9673
• DOI: 10.1016/0021-9673(95)00226-D

The molecular mass distribution of naphthalenesulfonate condensation products (PNS) was investigated using ion-pair reversed-phase chromatography and ultrafiltration. The chromatograms obtained under an optimized solvent elution program yielded nearly 20 well resolved peaks corresponding to low and intermediate molecular mass species. A distinct broad peak was also resolved and attributed to polymeric species with relative molecular mass in excess of 5000. Under isocratic elution conditions, a linear relationship was obtained between the peak number and the log of the retention time for the first 17 peaks, thus indicating a homologous series of linear oligomers. The fractionation of the PNS mixtures by ultrafiltration enabled further resolution of the high molecular mass species; the latter also exhibited a broad distribution of molecular mass. Significant differences were also found amongst different commercial PNS products with similar average chemical composition.