Molecular weight of polyethylene glycols by vapor pressure osmometry: An alternative data treatment

✍ Scribed by E. Sabadini; E.M. Assano; T.D.Z. Atvars

• Publisher: John Wiley and Sons
• Year: 1997
• Tongue: English
• Weight: 197 KB
• Volume: 65
• Category: Article
• ISSN: 0021-8995
• DOI: 10.1002/(sici)1097-4628(19970718)65:3<595::aid-app19>3.0.co;2-w

✦ Synopsis

In this work, we determined the number average molecular weight of some polyethylene glycols (PEGs) using vapor pressure osmometry. In general, this technique works with a plot of Dr p /c p versus c p (concentration) and the molecular weight is determined by the calibration constant obtained from the curve intercept. We demonstrated that this method induces a high dispersion of the data, which can be minimized using a plot of Dr p versus c p . Therefore, more precise values of molecular weight can be obtained and the number average molecular weight, M n , of several PEGs is directly determined from the ratio between the curve slopes obtained for a standard and the polymer sample.