On the Error of Relative Molecular Mass of Polyacrylic Acid Determined by GPC Using Polyethylene Glycol as Reference Standard

A study on the error of relative molecular mass of polyelectrolyte polyacrylic acid (PAA) determined by gel permeation chromatography (GPC) using the nonelectrolyte polyethylene glycol (PEG) as reference standard was made as compared with the use of selfprepared PAA as reference standard.It was found that more accurate relative molecular mass of PAA was obtained by using the self-prepared PAA as reference standard.No significant systematic error was found as compared with the results obtained by the viscosimetry,with values of random error less than 10%.When PEG was used as reference standard,unsatisfactory results of relative molecular mass of samples of PAA were obtained by either the direct calibration or the universal calibration,giving deviations over 40%,and values of distribution coefficient of relative molecular mass less than the theoratical value.Hence,the non-electrolyte PEG was not feasible to be used as reference standard in the determination of relative molecular mass of PAA by GPC.