Determination of the degree of sulphonation of sulphonated poly(aryl ether sulphone)

Abstract

A Raman spectroscopic method has been developed that allows the precise and rapid determination of the degree of sulphonation (DS) of sulphonated poly(aryl ether sulphone). The calibration samples were characterized extensively by several independent reference techniques. It was possible to identify a baseline-separated band being characteristic for the sulphonic acid substituent. The assignment of this band was confirmed by the investigation of corresponding alkali metal salts. The advantages of the proposed method over conventional approaches to DS determinations are discussed. © 1997 John Wiley & Sons, Ltd.