Modification of guar gum through grafting of 4-vinyl pyridine using potassium peroxymonosulphate/ascorbic acid redox pair

• Published in: Journal of applied polymer science 2007-10, Vol.106 (2), p.1353-1358
• Main Authors: Srivastava, Abhishek, Tripathy, Jasaswini, Mishra, Madan Mohan, Behari, Kunj
• Format: Article
• Language: English
• Subjects: 4-vinyl pyridine; Applied sciences; Exact sciences and technology; graft copolymerization; guar gum; Natural polymers; Physicochemistry of polymers; redox pair; Starch and polysaccharides
• ISSN: 0021-8995; 1097-4628
• DOI: 10.1002/app.26575

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