Modification of dextran through the grafting of N-vinyl-2-pyrrolidone and studies of physicochemical phenomena in terms of metal-ion uptake, swelling capacity, and flocculation
✍ Scribed by Dinesh Kumar Mishra; Jasaswini Tripathy; Madan Mohan Mishra; Kunj Behari
- Publisher
- John Wiley and Sons
- Year
- 2008
- Tongue
- English
- Weight
- 201 KB
- Volume
- 110
- Category
- Article
- ISSN
- 0021-8995
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✦ Synopsis
Abstract
The optimum conditions for grafting N‐vinyl‐2‐pyrrolidone onto dextran initiated by a peroxydiphosphate/thiourea redox system were determined through the variation of the concentrations of N‐vinyl‐2‐pyrrolidone, hydrogen ion, potassium peroxydiphosphate, thiourea, and dextran along with the time and temperature. The grafting ratio increased as the concentration of N‐vinyl‐2‐pyrrolidone increased and reached the maximum value at 24 × 10^−2^ mol/dm^3^. Similarly, when the concentration of hydrogen ion increased, the grafting parameters increased from 3 × 10^−3^ to 5 × 10^−3^ mol/dm^3^ and attained the maximum value at 5 × 10^−3^ mol/dm^3^. The grafting ratio, add‐on, and efficiency increased continuously with the concentration of peroxydiphosphate increasing from 0.8 × 10^−2^ to 2.4 × 10^−2^ mol/dm^3^. When the concentration of thiourea increased from 0.4 × 10^−2^ to 2.0 × 10^−2^ mol/dm^3^, the grafting ratio attained the maximum value at 1.2 × 10^−2^ mol/dm^3^. The grafting parameters decreased continuously as the concentration of dextran increased from 0.6 to 1.4 g/dm^3^. An attempt was made to study some physicochemical properties in terms of metal‐ion sorption, swelling, and flocculation. Dextran‐g‐N‐vinyl‐2‐pyrrolidone was characterized with infrared spectroscopy and thermogravimetric analysis. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008