Microwave assisted synthesis of Guar-g-polyacrylamide

Microwave (MW) assisted synthesis of guar-g-polyacrylamide (G-g-PAA), a co-polymer of wide applications is being reported in the present communication. Graft co-polymerization of the guar gum (GG) with acrylamide (AA) under the influence of MW in absence of any radical initiators and catalyst resulted in grafting yields comparable to redox (potassium persulphate/Ascorbic acid) initiated conventional heating graft co-polymerization in very short reaction times. The grafting efficiency up to 20% was further increased when initiators and catalyst were used with MW heating. The effect of MW power and exposure time on the grafting yields, both in presence and in absence of redox initiator and catalyst were studied. Maximum grafting efficiency achieved under MW was 66.66% in 0.22 m in in comparison to 49.12% in 90 min by the conventional method. A representative MW grafted copolymer was characterized using IR, H-1 NMR, XRD and TGA. (C) 2004 Published by Elsevier Ltd.