Chemical and Radiation-Induced Grafting of p-Carboxy N-Phenyl Maleimide onto Chitosan

摘要

Chitosan was grafted with p-carboxy N-phenyl maleimide (PCPM) using a redox initiator potassium persulfate (K2S2O8) and sodium bisulfite (NaHSO3) and also by γ irradiation. The effects of monomer concentration, initiator concentration, pH value, and temperature on the extent of grafting were studied. The grafting percentage reached maximum at 1.0mol/l monomer concentration and an initiator mixture ratio of 0.004:0.004 mol/l of K2S2O8:NaHSO3 respectively. Maximum grafting percentage was achieved at 30.0 KGy using dioxane as solvent. The grafted chitosan samples were insoluble in all known solvents. The complexation of the grafted chitosan with Cd(II) ion at different pH has been investigated using atomic absorption spectrometry. The grafted samples show a higher chelation capacity than chitosan itself. Thermogravi-metric analysis of grafted chitosan showed an enhancement of the thermal stability of the graft copolymers.