Overlap concentration of an aqueous poly(N-vinylcaprolactam) solution in the dynamic and static states

✍ Scribed by Masoumeh Foroutan; Sepideh Khoee; Mona Zarrabi

• Publisher: John Wiley and Sons
• Year: 2008
• Tongue: English
• Weight: 111 KB
• Volume: 109
• Category: Article
• ISSN: 0021-8995
• DOI: 10.1002/app.27935

✦ Synopsis

Abstract

The overlap concentration of poly(N‐vinylcaprolactam)s (PVCLs) of low molecular weights was studied with dynamic and static methods (with viscosity and refractive‐index measurements) at three temperatures (25, 30, and 35°C). This concentration, determined by viscometry, was lower than the overlap concentration determined by refractometry. Also, the influence of the temperature and molecular weight on the viscosity and refractive index was investigated, and the opposite effect of the temperature on the viscosity and refractive index of PVCL solutions was observed. The experimental overlap concentration values were compared with those calculated with the Rao, Huggins, and Fuoss equations. The results showed that the Huggins equation is the best equation to describe the dilute solution properties of this polymer. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008