Grafting of polyacrylamide on to guar gum using K₂S₂O₈ ascorbic acid redox system

Abstract

SynopsisThe grafting of polyacrylamide on to guar gum in aqueous medium initiated by the potassium persulfate/ascorbic acid redox system has been studied gravimetrically at the temperature 35 0.2"C in the presence of atmospheric oxygen and Ag+ ions. The rate of grafting was found to increase with temperature, concentration of redox components, acrylamide, and guar gum. But a t higher concentration of guar gum, the rate of grafting was found to decrease. A mechanism for grafting and suitable rate expression have been suggested.

Modification and Properties of Polyolefin with Maleic Anhydride as a Functional Monomer

“…15 There has been significant research in techniques of graft polymerization of different monomers on backbone polymers. 16 Surface modification techniques including chemical, 17,18 plasma 19,20 treatments, flame, 21 ultraviolet (UV) irradiation and corona discharge 22,23 which improve interfacial adhesion by changing surface energy to increase wettability have been ex- Ⅱ. Experimental PE used was low density PE(Daehan Petrochemicals, E-308, d = 0.956, MI = 0.8 g/10min).…”

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

“…This redox system has been exploited for polymerization of vinyl monomers by several workers 21,22 and has been shown to initiate vinyl copolymerization with guar gum. 5,7 The reaction between persulfate and ascorbic acid involves a chain mechanism 21 due to the formation of sulfate ion radicals, which are wellknown ion chain carriers. The mechanism may be written as shown in Scheme 1.…”

“…The viscosity of the gum solutions is reported to stablize 6 after vinyl monomer grafting. GG has been favorably modified by grafting various vinyl monomers using various redox systems 5,7 and microwave irradiation. 8,9 Singh and coworkers 10 have…”

A Facile Method for Grafting Polymerisation of Acrylonitrile onto LDPE Film with High Grafting Efficiency

“…The grafting polymerisation can also be chemically initiated using initiators such as benzoyl peroxide, [11,12] hydrogen peroxide, [13] ceric ion [14] and redox system. [15] Generally speaking, grafting polymerisation initiated by chemical initiators has often resulted in the production of significant amounts of homopolymers because the initiators are usually more prone to initiate homopolymerisation than grafting polymerisation. The undesired homopolymers not only waste expensive starting materials but also make postprocessing more laborious.…”