Objective: The objective of the present research is to formulate acrylamide grafted Karaya gum by using microwave-assisted grafting method and optimisation is performed by using Box behnken design. Methods: The extracted mucilage of gum Karaya was modified into grafted gum Karaya by using a microwave-assisted method. Acrylamide was used as monomer and ceric ammonium nitrate (CAN) is used as redox initiator. The experimental design for optimisation include three independent variables gum concentration (X1), ceric ammonium nitrate (CAN) amount (X2) and irradiation time (X3) while the dependent variables were % yield (Y1), % grafting (Y2) and % grafting efficiency (Y3). The optimised formulation was characterized by fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), x-ray diffraction (XRD) and scanning electron microscopy (SEM) analysis. Results: After optimisation the formulation with acrylamide amount 5 g, ceric ammonium nitrate amount 200 mg and irradiation time of 2 min was selected as optimized formulation. The optimised formulation has percentage grafting of 853.5%, with grafting efficiency of 77.59%. Conclusion: The application of box behnken design for optimisation was performed successfully in microwave assisted grafting of acrylamide on karaya gum.

In the present investigation, an attempt has been made for grafting of acrylamide on the backbone of Colocasia esculenta by using microwave-assisted grafting method, which is a convenient and versatile route for the development of polysaccharide-based materials. The dried mucilage of colocasia was prepared from fresh rhizomes. The optimization was performed by using Box Behnken matrix design (BBD) and response surface methodology (RSM) using design expert software. A series of graft polymers, varying in the amount of acrylamide, ammonium persulphate and microwave irradiation was prepared. The effect of Microwave time, gum concentration and power on percentage yield, percentage grafting and percentage grafting efficiency has been optimized and evaluated by 3D surface response graphs. It has been observed that power and irradiation time has a significant synergistic effect on % yield, % grafting and % grafting efficiency however gum concentration produce slight increment up to a limit after that the effect becomes almost constant. The selected optimized formulation is F8  with a percentage yield of 99.57%, percentage grafting of 634.33% and percentage grafting efficiency of 87.49%. Optimized formulation was subjected to Fourier transform infrared spectroscopy, Differential scanning calorimetry, X-ray diffraction and Scanning electron microscopy for characterization which committed the grafting of acrylamide on Colocasia esculenta.