K2S2O8/ascorbic acid initiated grafting of methylmethacrylate on to guar (Cyanaposis tetragonolobus) seed galactomannan has been studied gravimetrically at 35 +/- 0.2 degrees C in presence of atmospheric oxygen and the conditions were optimized. Grafted guar gum was characterized using FTIR, XRD, H-1 NMR and TGA analysis. Under optimal grafting conditions for the guar gum, five other wildly sourced seed galactomannans from Cassia abbreviata, Cassia javanica, Cassia reticulata, Ipomoea palmata and Ipomoea hedracea were grafted with methylmethacrylate in order to study the effect of structural diversity in the galactomannans on grafting and also for the possible commercial exploitation of these non-conventional galactomannans from Cassia and Ipomoea seeds. Results for all the galactomannans are compared and discussed. (c) 2006 Elsevier B.V. All rights reserved.