Studies on K2S2O8/ascorbic acid initiated synthesis of Ipomoea dasysperma seed gum-g-poly(acrylonitrile): A potential industrial gum



Seed gum from Ipomoea dasysperma was grafted with polyacrylonitrile using potassium persulfate/ascorbic acid redox initiator in the presence of molecular oxygen, where the maximum percentage grafting and percentage efficiency observed were 360 and 97.2%, respectively. Optimal grafting conditions were established for the gum and a representative polyacrylonitrile grafted gum was characterized using FTIR, NMR, X-ray diffraction, and TGA studies. Grafted gums with %G up to 185% showed water solubility; thereafter, the solubility in water was observed to decrease with the increase in %G. After the saponification of the nitrile groups to amide and carboxylic acid groups, the water retention of the grafted gum increased significantly and this increase was dependent on the extent of grafting. Various properties like viscosity, gel/film forming ability, shelf life of the grafted gum solutions (with samples where %G were not >185%) along with the water, and saline retention capacity were studied and compared with that of the parent gum to evaluate it for industrial applications. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 1652–1662, 2005