Effect of Radiation Dose and Foaming Agent Concentration Onto Synthesis and Characteristic of Superabsorbent Polyacrilamide-sodium Carboxy Methyl Celulose Copolymer Hydrogel

Effect of radiation dose and foaming agent concentration onto synthesis and characteristic of superabsorbent hydrogel based on copolymer of polyacrylamide and sodium carboxyl methyl Cellulose (PAAm-co-CMCNa ) was studied. In order to improve the swelling ratio of PAAm-co-CMCNa hydrogel sodiumbicarbonate (NaHCO3) was added, due to its capability to form pores in the polymer matrix. The concentration of acrylamide (AAm) and sodium carboxyl methyl cellulose (CMCNa) used were 7.5 % and 3 % respectively while the concentration of NaHCO3 used was 1, 2 and 3 %. Samples were irradiated at irradiation dose of 15, 20, 25 and 30 kGy with a dose rate of 10 kGy/hours. Hydrogel PAAm-co-CMCNa was examined for several items such as physical appearance, gel fraction, effects of immersion time and temperature on the swelling ratio, as well as the equilibrium degree swelling (EDS). The functional groups were characterized by using infrared spectrophotometer (FT-IR). FT-IR analysis of PAAm-co-CMCNa showed an appearance of new peaks appeared at wave numbers of 3643 and 1782 cm-1 which belong to N-H group of NH2 and C=O group respectively. Whereas the intensity of wave number 1606 cm-1 which belong to C=C group decreased, due to the occurrence of crosslinking between C=C group of AAm with CMCNa. The hydrogel characterization results also showed that the optimum irradiation dosage was 30 kGy with a concentration of NaHCO3 was 3 %. The EDS value was obtained at 240th minutes. The PAAm-co-CMCNa hydrogel had a high swelling ratio with increasing temperature from 27 °C to 50 °C