Modification of guar gum through grafting of 4‐vinyl pyridine using potassium peroxymonosulphate/ascorbic acid redox pair |
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Authors: | Abhishek Srivastava Jasaswini Tripathy Madan Mohan Mishra Kunj Behari |
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Affiliation: | Polymer Science Research Laboratory, Department of Chemistry, University of Allahabad, Allahabad 211002, India |
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Abstract: | In the present article, the graft copolymerization of 4‐vinyl pyridine onto guar gum initiated by potassium peroxymonosulphate/ascorbic acid redox pair in an aqueous medium was studied gravimetrically under a nitrogen atmosphere. Grafting ratio, grafting efficiency, and add on increased on increasing the concentration of potassium peroxymonosulphate from 5.0 × 10?4 to 10 × 10?4 mol/L and ascorbic acid concentration from 0.4 × 10?3 to 2.0 × 10?3 mol/L. On increasing the hydrogen ion concentration from 2.5 × 10?3 to 10.0 × 10?3 mol/L, grafting ratio, efficiency, add on and conversion were increased. Maximum grafting was obtained when guar gum and monomer concentration were 1.0 g/L and 20.0 × 10?2 mol/L, respectively. An increase in temperature from 30 to 35°C increased the grafting ratio, but conversion and homopolymer decreased. The graft copolymers were characterized by IR spectroscopy and thermogravimetric analysis. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007 |
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Keywords: | graft copolymerization 4‐vinyl pyridine guar gum redox pair |
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