title: Guar gum-g-N,N'-dimethylacrylamide: synthesis, characterization and applications.
abstract: The graft copolymerization of N,N'-dimethylacrylamide onto guar gum initiated by potassium peroxymonosulphate/glycolic acid redox pair in an aqueous medium was studied gravimetrically under a nitrogen atmosphere. Grafting ratio, grafting efficiency and add on increase on increasing the concentration of potassium peroxymonosulphate (8.0 × 10(-3) to 24.0 × 10(-3) mol dm(-3)) and glycolic acid concentration (4.4 × 10(-3) to 7.6 × 10(-3) mol dm(-3)). On increasing the hydrogen ion concentration from 4 × 10(-3) to 12.0 × 10(-3) mol dm(-3), grafting ratio, efficiency, add on and conversion were increased. Maximum grafting was obtained when guar gum and N,N'-dimethylacrylamide concentration were 1.0 × 10(-2) g dm(-3) and 14.0 × 10(-2) mol dm(-3), respectively. An increase in temperature from 25 °C to 45 °C, the grafting ratio increases but conversion and homopolymer decrease. The optimum time period for graft copolymerization was 2h. The graft copolymers were characterized by IR spectroscopy and thermogravimetric analysis.
authors.affiliation: Polymer Science Research Laboratory Department of Chemistry, University of Allahabad, Allahabad 211002, India.
authors.forename: Vijay Shankar
authors.initials: VS
authors.lastname: Pandey
authors.forename: Shiv Kumar
authors.initials: SK
authors.lastname: Verma
authors.forename: Mithilesh
authors.initials: M
authors.lastname: Yadav
authors.forename: Kunj
authors.initials: K
authors.lastname: Behari
mesh_terms: D000178:Acrylamides / Q000737:chemistry*; D001672:Biocompatible Materials / Q000737:chemistry*; D005685:Galactans / Q000737:chemistry*; D006016:Glycolates / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D008351:Mannans / Q000737:chemistry*; D010084:Oxidation-Reduction; D010545:Peroxides / Q000737:chemistry*; D053149:Plant Gums / Q000737:chemistry*; D058105:Polymerization; D017550:Spectroscopy, Fourier Transform Infrared; D013696:Temperature; D013818:Thermogravimetry; D014867:Water / Q000737:chemistry
chemical_list: D000178:Acrylamides; D001672:Biocompatible Materials; D005685:Galactans; D006016:Glycolates; D008351:Mannans; D010545:Peroxides; D053149:Plant Gums; D014867:Water; C031149:glycolic acid; C038288:peroxymonosulfate; C099046:N,N-dimethylacrylamide; C007894:guar gum
keywords: Graft copolymerization; Guar gum; N,N′-dimethylacrylamide; Redox pair; Thermogravimetric analysis