Graft Copolymerization of Acrylamide onto Rayon by Chemical and Radiation Methods

The inherent properties of rayon fibre have been changed with additional properties through graft copolymerization of acrylamide, AAm, by chemical method using eerie ammonium nitrate/nitric acid, (CAN/HNO3), as a redox initiator and gamma-radiation induced mutual method. Reaction conditions such as monomer and initiator concentration, liquor ratio, temperature and time of reaction, amount of radiation dose have been optimized with respect to percentage of grafting. Maximum percentage of grafting (Pg), (40 %) using CAN/HNO3 was obtained at [CAN]=31.92x10(-3) moles/l, [HNO3]=79.36x10(-2) moles/l, [AAm]=14.07x10(2) moles/l in 20 ml of H2O at 45 degrees C within 120 min while in case of radiation induced method, maximum Pg (30 %) was obtained at higher monomer concentration (28.14x10(-2) moles/l) and time (180 min) in 10 ml of H2O at room temperature with total dose exposure of 11.178 kGy. The graft copolymers were characterized by FTIR, thermogravimetric and scanning electron micrographic analysis. Swelling behaviour in water, methanol, ethanol, acetone and DMF and dyeing and flame retarding properties of rayon fibre and grafted rayon fibre were investigated. Percent dye uptake (71.8 %) was found to be higher than that observed for the pristine fibre (57.4 %) and the grafted fibre after post phosphorylation reaction showed excellent flame retarding properties.