No. Grafting % IEC (meq/g.) Sulfonation and phosphoration % Equivalent Area 1- 10 0.66 0.46 1515 2- 18 0.72 0.49 1388 3- 26 0.84 0.52 1190 4- 31 0.92 0.54 1086 5- 35 1.1 0.55 909

Table 3: Relationship among grafting %, Ion exchange capacity, sulfonation % and equivalent area.